v0.8.10

If no free registry id found, we call protect_lua! macro while keeping mutex guard to the unref list.
Protected calls can trigger garbage collection and if RegistryKey is placed in userdata being collected, this can lead to deadlock.
The solution is drop mutex guard as soon as possible.
Also this commit includes optimization in creating reference in Lua registry.

.github/workflows/coverage.yml

@@ -14,7 +14,7 @@ jobs:
 
       - name: Generate coverage report
         run: |
-          cargo tarpaulin --out xml --tests --exclude-files benches/* --exclude-files mlua-sys/src/*/*
+          cargo tarpaulin --out xml --tests --exclude-files benches/* --exclude-files src/ffi/*/*
 
       - name: Upload report to codecov.io
         uses: codecov/codecov-action@v3

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
@@ -18,7 +18,7 @@ jobs:
           - os: windows-latest
             target: x86_64-pc-windows-msvc
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rust }}
@@ -27,7 +27,7 @@ jobs:
       - name: Build ${{ matrix.lua }} vendored
         run: |
           cargo build --features "${{ matrix.lua }},vendored"
-          cargo build --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+          cargo build --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
         shell: bash
       - name: Build ${{ matrix.lua }} pkg-config
         if: ${{ matrix.os == 'ubuntu-22.04' }}
@@ -44,13 +44,13 @@ jobs:
       matrix:
         lua: [lua54, lua53, lua52, lua51, luajit]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
           target: aarch64-apple-darwin
       - name: Cross-compile
-        run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
 
   build_aarch64_cross_ubuntu:
     name: Cross-compile to aarch64-unknown-linux-gnu
@@ -60,7 +60,7 @@ jobs:
       matrix:
         lua: [lua54, lua53, lua52, lua51, luajit]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
@@ -71,7 +71,7 @@ jobs:
           sudo apt-get install -y --no-install-recommends gcc-aarch64-linux-gnu libc6-dev-arm64-cross
         shell: bash
       - name: Cross-compile
-        run: cargo build --target aarch64-unknown-linux-gnu --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        run: cargo build --target aarch64-unknown-linux-gnu --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
         shell: bash
 
   build_armv7_cross_ubuntu:
@@ -82,7 +82,7 @@ jobs:
       matrix:
         lua: [lua54, lua53, lua52, lua51]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
@@ -93,7 +93,7 @@ jobs:
           sudo apt-get install -y --no-install-recommends gcc-arm-linux-gnueabihf libc-dev-armhf-cross
         shell: bash
       - name: Cross-compile
-        run: cargo build --target armv7-unknown-linux-gnueabihf --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        run: cargo build --target armv7-unknown-linux-gnueabihf --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
         shell: bash
 
   test:
@@ -104,7 +104,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable, nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit, luajit52, luau, luau-jit, luau-vector4]
+        lua: [lua54, lua53, lua52, lua51, luajit, luajit52, luau]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
@@ -113,23 +113,22 @@ jobs:
           - os: windows-latest
             target: x86_64-pc-windows-msvc
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
-      - uses: Swatinem/rust-cache@v2
+      - uses: Swatinem/rust-cache@v1
       - name: Run ${{ matrix.lua }} tests
         run: |
           cargo test --features "${{ matrix.lua }},vendored"
           cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
-          cargo test --features "${{ matrix.lua }},vendored,async,serialize,macros,parking_lot,unstable"
         shell: bash
       - name: Run compile tests (macos lua54)
         if: ${{ matrix.os == 'macos-latest' && matrix.lua == 'lua54' }}
         run: |
           TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored" -- --ignored
-          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable" -- --ignored
+          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot" -- --ignored
         shell: bash
 
   test_with_sanitizer:
@@ -140,23 +139,22 @@ jobs:
       matrix:
         os: [ubuntu-22.04]
         rust: [nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
-      - uses: Swatinem/rust-cache@v2
+      - uses: Swatinem/rust-cache@v1
       - name: Run ${{ matrix.lua }} tests with address sanitizer
         run: |
-            cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
+          RUSTFLAGS="-Z sanitizer=address" \
+            cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
         shell: bash
-        env:
-          RUSTFLAGS: -Z sanitizer=address
 
   test_modules:
     name: Test modules
@@ -166,19 +164,19 @@ jobs:
       matrix:
         os: [ubuntu-22.04, macos-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau]
+        lua: [lua54, lua53, lua52, lua51, luajit]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
           - os: macos-latest
             target: x86_64-apple-darwin
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
-      - uses: Swatinem/rust-cache@v2
+      - uses: Swatinem/rust-cache@v1
       - name: Run ${{ matrix.lua }} module tests
         run: |
           (cd tests/module && cargo build --release --features "${{ matrix.lua }}")
@@ -197,7 +195,7 @@ jobs:
         shell: msys2 {0}
     steps:
       - uses: msys2/setup-msys2@v2
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Install Rust & Lua
         run: |
           pacman -S --noconfirm mingw-w64-x86_64-rust mingw-w64-x86_64-lua mingw-w64-x86_64-luajit mingw-w64-x86_64-pkg-config
@@ -206,34 +204,11 @@ jobs:
           (cd tests/module && cargo build --release --features "${{ matrix.lua }}")
           (cd tests/module/loader && cargo test --release --features "${{ matrix.lua }}")
 
-  test_wasm32_emscripten:
-    name: Test on wasm32-unknown-emscripten
-    runs-on: ubuntu-22.04
-    needs: build
-    strategy:
-      matrix:
-        lua: [lua54, lua53, lua52, lua51, luau]
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          toolchain: stable
-          target: wasm32-unknown-emscripten
-      - name: Install Emscripten
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y --no-install-recommends emscripten
-      - name: Run ${{ matrix.lua }} tests
-        run: |
-          cargo test --tests --features "${{ matrix.lua }},vendored"
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,serialize,macros,parking_lot,unstable"
-
   rustfmt:
     name: Rustfmt
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
@@ -241,18 +216,18 @@ jobs:
       - run: cargo fmt -- --check
 
   clippy:
-    name: Clippy
+    name: Clippy check
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: nightly
           components: clippy
-      - uses: giraffate/clippy-action@v1
+      - uses: actions-rs/clippy-check@v1
         with:
-          reporter: 'github-pr-review'
-          clippy_flags: --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"

.gitignore

@@ -4,4 +4,3 @@ Cargo.lock
 
 .vscode/
 .DS_Store
-.stignore

CHANGELOG.md

@@ -1,169 +1,3 @@
-## v0.9.9
-
-- Minimal Luau updated to 0.629
-- Fixed bug when attempting to reset or resume already running coroutines (#416).
-- Added `RegistryKey::id()` method to get the underlying Lua registry key id.
-
-## v0.9.8
-
-- Fixed serializing same table multiple times (#408)
-- Use `mlua-sys` v0.6 (to support Luau 0.624+)
-- Fixed cross compilation of windows dlls from unix (#394)
-
-## v0.9.7
-
-- Implemented `IntoLua` for `RegistryKey`
-- Mark `__idiv` metamethod as available for luau
-- Added `Function::deep_clone()` method (Luau)
-- Added `SerializeOptions::detect_serde_json_arbitrary_precision` option
-- Added `Lua::create_buffer()` method (Luau)
-- Support serializing buffer type as a byte slice (Luau)
-- Perf: Implemented `push_into_stack`/`from_stack` for `Option<T>`
-- Added `Lua::create_ser_any_userdata()` method
-
-## v0.9.6
-
-- Added `to_pointer` function to `Function`/`Table`/`Thread`
-- Implemented `IntoLua` for `&Value`
-- Implemented `FromLua` for `RegistryKey`
-- Faster (~5%) table array traversal during serialization
-- Some performance improvements for bool/int types
-
-## v0.9.5
-
-- Minimal Luau updated to 0.609
-- Luau max stack size increased to 1M (from 100K)
-- Implemented `IntoLua` for refs to `String`/`Table`/`Function`/`AnyUserData`/`Thread` + `RegistryKey`
-- Implemented `IntoLua` and `FromLua` for `OwnedThread`/`OwnedString`
-- Fixed `FromLua` derive proc macro to cover more cases
-
-## v0.9.4
-
-- Fixed loading all-in-one modules under mixed states (eg. main state and coroutines)
-
-## v0.9.3
-
-- WebAssembly support (`wasm32-unknown-emscripten` target)
-- Performance improvements (faster Lua function calls for lua51/jit/luau)
-
-## v0.9.2
-
-- Added binary modules support to Luau
-- Added Luau package module (uses `StdLib::PACKAGE`) with loaders (follows lua5.1 interface)
-- Added support of Luau 0.601+ buffer type (represented as userdata in Rust)
-- LuaJIT `cdata` type is also represented as userdata in Rust (instead of panic)
-- Vendored LuaJIT switched to rolling vanilla (from openresty)
-- Added `Table::for_each` method for fast table pairs traversal (faster than `pairs`)
-- Performance improvements around table traversal (and faster serialization)
-- Bug fixes and improvements
-
-## v0.9.1
-
-- impl Default for Lua
-- impl IntoLuaMulti for `std::result::Result<(), E>`
-- Fix using wrong userdata index after processing Variadic args (#311)
-
-## v0.9.0
-
-Changes since v0.9.0-rc.3
-
-- Improved non-static (scoped) userdata support
-- Added `Scope::create_any_userdata()` method
-- Added `Lua::set_vector_metatable()` method (`unstable` feature flag)
-- Added `OwnedThread` type (`unstable` feature flag)
-- Minimal Luau updated to 0.590
-- Added new option `sort_keys` to `DeserializeOptions` (`Lua::from_value()` method)
-- Changed `Table::raw_len()` output type to `usize`
-- Helper functions for `Value` (eg: `Value::as_number()`/`Value::as_string`/etc)
-- Performance improvements
-
-## v0.9.0-rc.3
-
-- Minimal Luau updated to 0.588
-
-## v0.9.0-rc.2
-
-- Added `#[derive(FromLua)]` macro to opt-in into `FromLua<T> where T: 'static + Clone` (userdata type).
-- Support vendored module mode for windows (raw-dylib linking, Rust 1.71+)
-- `module` and `vendored` features are now mutually exclusive
-- Use `C-unwind` ABI (Rust 1.71+)
-- Changed `AsChunk` trait to support capturing wrapped Lua types
-
-## v0.9.0-rc.1
-
-- `UserDataMethods::add_async_method()` takes `&T` instead of cloning `T`
-- Implemented `PartialEq<[T]>` for tables
-- Added Luau 4-dimensional vectors support (`luau-vector4` feature)
-- `Table::sequence_values()` iterator no longer uses any metamethods (`Table::raw_sequence_values()` is deprecated)
-- Added `Table:is_empty()` function that checks both hash and array parts
-- Refactored Debug interface
-- Re-exported `ffi` (`mlua-sys`) crate for easier writing of unsafe code
-- Refactored Lua 5.4 warnings interface
-- Take `&str` as function name in `TableExt` and `AnyUserDataExt` traits
-- Added module attribule `skip_memory_check` to improve performance
-- Added `AnyUserData::wrap()` to provide more easy way of creating _any_ userdata in Lua
-
-## v0.9.0-beta.3
-
-- Added `OwnedAnyUserData::take()`
-- Switch to `DeserializeOwned`
-- Overwrite error context when called multiple times
-- New feature flag `luau-jit` to enable (experimental) Luau codegen backend
-- Set `__name` field in userdata metatable
-- Added `Value::to_string()` method similar to `luaL_tolstring`
-- Lua 5.4.6
-- Application data container now allows to mutably and immutably borrow different types at the same time
-- Performance optimizations
-- Support getting and setting environment for Lua functions.
-- Added `UserDataFields::add_field()` method to add static fields to UserData
-
-Breaking changes:
-- Require environment to be a `Table` instead of `Value` in Chunks.
-- `AsChunk::env()` renamed to `AsChunk::environment()`
-
-## v0.9.0-beta.2
-
-New features:
-- Added `Thread::set_hook()` function to set hook on threads
-- Added pretty print to the Debug formatting to Lua `Value` and `Table`
-- ffi layer moved to `mlua-sys` crate
-- Added OwnedString (unstable)
-
-Breaking changes:
-- Refactor `HookTriggers` (make it const)
-
-## v0.9.0-beta.1
-
-New features:
-- Owned Lua types (unstable feature flag)
-- New functions `Function::wrap`/`Function::wrap_mut`/`Function::wrap_async`
-- `Lua::register_userdata_type()` to register a custom userdata types (without requiring `UserData` trait)
-- `Lua::create_any_userdata()`
-- Added `create_userdata_ref`/`create_userdata_ref_mut` for scopes
-- Added `AnyUserDataExt` trait with auxiliary functions for `AnyUserData`
-- Added `UserDataRef` and `UserDataRefMut` type wrapped that implement `FromLua`
-- Improved error handling:
-  * Improved error reporting when calling Rust functions from Lua.
-  * Added `Error::BadArgument` to help identify bad argument position or name
-  * Added `ErrorContext` extension trait to attach additional context to `Error`
-
-Breaking changes:
-- Refactored `AsChunk` trait
-- `ToLua`/`ToLuaMulti` renamed to `IntoLua`/`IntoLuaMulti`
-- Renamed `to_lua_err` to `into_lua_err`
-- Removed `FromLua` impl for `T: UserData+Clone`
-- Removed `Lua::async_scope`
-- Added `&Lua` arg to Luau interrupt callback
-
-Other:
-- Better Debug for String
-- Allow deserializing values from serializable UserData using `Lua::from_value()` method
-- Added `Table::clear()` method
-- Added `Error::downcast_ref()` method
-- Support setting memory limit for Lua 5.1/JIT/Luau
-- Support setting module name in `#[lua_module(name = "...")]` macro
-- Minor fixes and improvements
-
 ## v0.8.10
 
 - Update to Luau 0.590 (luau0-src to 0.7.x)

Cargo.toml

@@ -1,8 +1,7 @@
 [package]
 name = "mlua"
-version = "0.9.9" # remember to update mlua_derive
-authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@kyju.org>"]
-rust-version = "1.71"
+version = "0.8.10" # remember to update mlua_derive
+authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@chucklefish.org>"]
 edition = "2021"
 repository = "https://github.com/khvzak/mlua"
 documentation = "https://docs.rs/mlua"
@@ -10,88 +9,76 @@ readme = "README.md"
 keywords = ["lua", "luajit", "luau", "async", "scripting"]
 categories = ["api-bindings", "asynchronous"]
 license = "MIT"
+links = "lua"
+build = "build/main.rs"
 description = """
 High level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau
 with async/await features and support of writing native Lua modules in Rust.
 """
 
 [package.metadata.docs.rs]
-features = ["lua54", "vendored", "async", "send", "serialize", "macros", "parking_lot", "unstable"]
+features = ["lua54", "vendored", "async", "send", "serialize", "macros", "parking_lot"]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [workspace]
 members = [
     "mlua_derive",
-    "mlua-sys",
 ]
 
 [features]
-lua54 = ["ffi/lua54"]
-lua53 = ["ffi/lua53"]
-lua52 = ["ffi/lua52"]
-lua51 = ["ffi/lua51"]
-luajit = ["ffi/luajit"]
-luajit52 = ["luajit", "ffi/luajit52"]
-luau = ["ffi/luau", "dep:libloading"]
-luau-jit = ["luau", "ffi/luau-codegen"]
-luau-vector4 = ["luau", "ffi/luau-vector4"]
-vendored = ["ffi/vendored"]
-module = ["dep:mlua_derive", "ffi/module"]
-async = ["dep:futures-util"]
+lua54 = []
+lua53 = []
+lua52 = []
+lua51 = []
+luajit = []
+luajit52 = ["luajit"]
+luau = ["luau0-src"]
+vendored = ["lua-src", "luajit-src"]
+module = ["mlua_derive"]
+async = ["futures-core", "futures-task", "futures-util"]
 send = []
-serialize = ["dep:serde", "dep:erased-serde", "dep:serde-value"]
+serialize = ["serde", "erased-serde"]
 macros = ["mlua_derive/macros"]
-unstable = []
 
 [dependencies]
-mlua_derive = { version = "=0.9.3", optional = true, path = "mlua_derive" }
-bstr = { version = "1.0", features = ["std"], default-features = false }
+mlua_derive = { version = "=0.8.0", optional = true, path = "mlua_derive" }
+bstr = { version = "0.2", features = ["std"], default_features = false }
 once_cell = { version = "1.0" }
 num-traits = { version = "0.2.14" }
-rustc-hash = "2.0"
-futures-util = { version = "0.3", optional = true, default-features = false, features = ["std"] }
+rustc-hash = "1.0"
+futures-core = { version = "0.3.5", optional = true }
+futures-task = { version = "0.3.5", optional = true }
+futures-util = { version = "0.3.5", optional = true }
 serde = { version = "1.0", optional = true }
-erased-serde = { version = "0.4", optional = true }
-serde-value = { version = "0.7", optional = true }
+erased-serde = { version = "0.3", optional = true }
 parking_lot = { version = "0.12", optional = true }
 
-ffi = { package = "mlua-sys", version = "0.6.1", path = "mlua-sys" }
-
-[target.'cfg(unix)'.dependencies]
-libloading = { version = "0.8", optional = true }
+[build-dependencies]
+cc = { version = "1.0" }
+pkg-config = { version = "0.3.17" }
+lua-src = { version = ">= 546.0.0, < 546.1.0", optional = true }
+luajit-src = { version = ">= 210.4.0, < 210.5.0", optional = true }
+luau0-src = { version = "0.7.0", optional = true }
 
 [dev-dependencies]
+rustyline = "10.0"
+criterion = { version = "0.3.4", features = ["html_reports", "async_tokio"] }
 trybuild = "1.0"
 futures = "0.3.5"
-hyper = { version = "1.2", features = ["full"] }
-hyper-util = { version = "0.1.3", features = ["full"] }
-http-body-util = "0.1.1"
-reqwest = { version = "0.12", features = ["json"] }
-tokio = { version = "1.0", features = ["macros", "rt", "time"] }
+hyper = { version = "0.14", features = ["client", "server"] }
+reqwest = { version = "0.11", features = ["json"] }
+tokio = { version = "1.0", features = ["full"] }
+futures-timer = "3.0"
 serde = { version = "1.0", features = ["derive"] }
-serde_json = { version = "1.0", features = ["arbitrary_precision"] }
+serde_json = "1.0"
 maplit = "1.0"
 tempfile = "3"
-static_assertions = "1.0"
-
-[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
-criterion = { version = "0.5", features = ["async_tokio"] }
-rustyline = "14.0"
-tokio = { version = "1.0", features = ["full"] }
-
-[lints.rust]
-unexpected_cfgs = { level = "allow", check-cfg = ['cfg(tarpaulin_include)'] }
 
 [[bench]]
 name = "benchmark"
 harness = false
 required-features = ["async"]
 
-[[bench]]
-name = "serde"
-harness = false
-required-features = ["serialize"]
-
 [[example]]
 name = "async_http_client"
 required-features = ["async", "macros"]

README.md

@@ -7,9 +7,9 @@
 [crates.io]: https://crates.io/crates/mlua
 [API Documentation]: https://docs.rs/mlua/badge.svg
 [docs.rs]: https://docs.rs/mlua
-[Coverage Status]: https://codecov.io/gh/mlua-rs/mlua/branch/main/graph/badge.svg?token=99339FS1CG
-[codecov.io]: https://codecov.io/gh/mlua-rs/mlua
-[MSRV]: https://img.shields.io/badge/rust-1.71+-brightgreen.svg?&logo=rust
+[Coverage Status]: https://codecov.io/gh/khvzak/mlua/branch/v0.8/graph/badge.svg?token=99339FS1CG
+[codecov.io]: https://codecov.io/gh/khvzak/mlua
+[MSRV]: https://img.shields.io/badge/rust-1.56+-brightgreen.svg?&logo=rust
 
 [Guided Tour] | [Benchmarks] | [FAQ]
 
@@ -17,10 +17,6 @@
 [Benchmarks]: https://github.com/khvzak/script-bench-rs
 [FAQ]: FAQ.md
 
-> **Note**
->
-> See v0.9 [release notes](https://github.com/khvzak/mlua/blob/main/docs/release_notes/v0.9.md).
-
 `mlua` is bindings to [Lua](https://www.lua.org) programming language for Rust with a goal to provide
 _safe_ (as far as it's possible), high level, easy to use, practical and flexible API.
 
@@ -28,8 +24,6 @@ Started as `rlua` fork, `mlua` supports Lua 5.4, 5.3, 5.2, 5.1 (including LuaJIT
 
 `mlua` tested on Windows/macOS/Linux including module mode in [GitHub Actions] on `x86_64` platform and cross-compilation to `aarch64` (other targets are also supported).
 
-WebAssembly (WASM) is supported through `wasm32-unknown-emscripten` target for all Lua versions excluding JIT.
-
 [GitHub Actions]: https://github.com/khvzak/mlua/actions
 [Roblox Luau]: https://luau-lang.org
 
@@ -47,8 +41,6 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 * `luajit`: activate [LuaJIT] support
 * `luajit52`: activate [LuaJIT] support with partial compatibility with Lua 5.2
 * `luau`: activate [Luau] support (auto vendored mode)
-* `luau-jit`: activate [Luau] support with JIT backend.
-* `luau-vector4`: activate [Luau] support with 4-dimensional vector.
 * `vendored`: build static Lua(JIT) library from sources during `mlua` compilation using [lua-src] or [luajit-src] crates
 * `module`: enable module mode (building loadable `cdylib` library for Lua)
 * `async`: enable async/await support (any executor can be used, eg. [tokio] or [async-std])
@@ -56,7 +48,6 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 * `serialize`: add serialization and deserialization support to `mlua` types using [serde] framework
 * `macros`: enable procedural macros (such as `chunk!`)
 * `parking_lot`: support UserData types wrapped in [parking_lot]'s primitives (`Arc<Mutex>` and `Arc<RwLock>`)
-* `unstable`: enable **unstable** features. The public API of these features may break between releases.
 
 [5.4]: https://www.lua.org/manual/5.4/manual.html
 [5.3]: https://www.lua.org/manual/5.3/manual.html
@@ -84,20 +75,6 @@ This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6
 - [HTTP Server](examples/async_http_server.rs)
 - [TCP Server](examples/async_tcp_server.rs)
 
-
-**shell command examples**:
-```shell
-# async http client (hyper)
-cargo run --example async_http_client --features=lua54,async,macros
-
-# async http client (reqwest)
-cargo run --example async_http_reqwest --features=lua54,async,macros,serialize
-
-# async http server
-cargo run --example async_http_server --features=lua54,async,macros
-curl -v http://localhost:3000
-```
-
 ### Serialization (serde) support
 
 With `serialize` feature flag enabled, `mlua` allows you to serialize/deserialize any type that implements [`serde::Serialize`] and [`serde::Deserialize`] into/from [`mlua::Value`]. In addition `mlua` provides [`serde::Serialize`] trait implementation for it (including `UserData` support).
@@ -114,12 +91,12 @@ You have to enable one of the features: `lua54`, `lua53`, `lua52`, `lua51`, `lua
 
 By default `mlua` uses `pkg-config` tool to find lua includes and libraries for the chosen Lua version.
 In most cases it works as desired, although sometimes could be more preferable to use a custom lua library.
-To achieve this, mlua supports `LUA_LIB`, `LUA_LIB_NAME` and `LUA_LINK` environment variables.
+To achieve this, mlua supports `LUA_INC`, `LUA_LIB`, `LUA_LIB_NAME` and `LUA_LINK` environment variables.
 `LUA_LINK` is optional and may be `dylib` (a dynamic library) or `static` (a static library, `.a` archive).
 
 An example how to use them:
 ``` sh
-my_project $ LUA_LIB=$HOME/tmp/lua-5.2.4/src LUA_LIB_NAME=lua LUA_LINK=static cargo build
+my_project $ LUA_INC=$HOME/tmp/lua-5.2.4/src LUA_LIB=$HOME/tmp/lua-5.2.4/src LUA_LIB_NAME=lua LUA_LINK=static cargo build
 ```
 
 `mlua` also supports vendored lua/luajit using the auxiliary crates [lua-src](https://crates.io/crates/lua-src) and
@@ -133,7 +110,7 @@ Add to `Cargo.toml` :
 
 ``` toml
 [dependencies]
-mlua = { version = "0.9.9", features = ["lua54", "vendored"] }
+mlua = { version = "0.8", features = ["lua54", "vendored"] }
 ```
 
 `main.rs`
@@ -168,7 +145,7 @@ Add to `Cargo.toml` :
 crate-type = ["cdylib"]
 
 [dependencies]
-mlua = { version = "0.9.9", features = ["lua54", "module"] }
+mlua = { version = "0.8", features = ["lua54", "vendored", "module"] }
 ```
 
 `lib.rs` :
@@ -213,22 +190,20 @@ rustflags = [
 ]
 ```
 On Linux you can build modules normally with `cargo build --release`.
+Vendored and non-vendored builds are supported for these OS.
 
-On Windows the target module will be linked with `lua5x.dll` library (depending on your feature flags).
-Your main application should provide this library.
+On Windows `vendored` mode for modules is not supported since you need to link to a Lua dll.
+Easiest way is to use either MinGW64 (as part of [MSYS2](https://github.com/msys2/msys2) package) with `pkg-config` or
+MSVC with `LUA_INC` / `LUA_LIB` / `LUA_LIB_NAME` environment variables.
 
-Module builds don't require Lua lib or headers to be installed on the system.
+More details about compiling and linking Lua modules can be found on the [Building Modules](http://lua-users.org/wiki/BuildingModules) page.
 
 ### Publishing to luarocks.org
 
 There is a LuaRocks build backend for mlua modules [`luarocks-build-rust-mlua`].
 
 Modules written in Rust and published to luarocks:
-- [`decasify`](https://github.com/alerque/decasify)
 - [`lua-ryaml`](https://github.com/khvzak/lua-ryaml)
-- [`tiktoken_core`](https://github.com/gptlang/lua-tiktoken)
-- [`toml-edit`](https://github.com/vhyrro/toml-edit.lua)
-- [`typst-lua`](https://github.com/rousbound/typst-lua)
 
 [`luarocks-build-rust-mlua`]: https://luarocks.org/modules/khvzak/luarocks-build-rust-mlua
 

benches/benchmark.rs

@@ -1,7 +1,5 @@
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::time::Duration;
-
 use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
+use std::time::Duration;
 use tokio::runtime::Runtime;
 use tokio::task;
 
@@ -12,10 +10,10 @@ fn collect_gc_twice(lua: &Lua) {
     lua.gc_collect().unwrap();
 }
 
-fn table_create_empty(c: &mut Criterion) {
+fn create_table(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("table [create empty]", |b| {
+    c.bench_function("create [table empty]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
@@ -26,55 +24,71 @@ fn table_create_empty(c: &mut Criterion) {
     });
 }
 
-fn table_create_array(c: &mut Criterion) {
+fn create_array(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("table [create array]", |b| {
+    c.bench_function("create [array] 10", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                lua.create_sequence_from(1..=10).unwrap();
+                let table = lua.create_table().unwrap();
+                for i in 1..=10 {
+                    table.set(i, i).unwrap();
+                }
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn table_create_hash(c: &mut Criterion) {
+fn create_string_table(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("table [create hash]", |b| {
+    c.bench_function("create [table string] 10", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                lua.create_table_from(
-                    ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"]
-                        .into_iter()
-                        .map(|s| (s, s)),
-                )
-                .unwrap();
+                let table = lua.create_table().unwrap();
+                for &s in &["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"] {
+                    let s = lua.create_string(s).unwrap();
+                    table.set(s.clone(), s).unwrap();
+                }
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn table_get_set(c: &mut Criterion) {
+fn create_function(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("table [get and set]", |b| {
+    c.bench_function("create [function] 10", |b| {
         b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                for i in 0..10 {
+                    lua.create_function(move |_, ()| Ok(i)).unwrap();
+                }
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn call_lua_function(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    c.bench_function("call Lua function [sum] 3 10", |b| {
+        b.iter_batched_ref(
             || {
                 collect_gc_twice(&lua);
-                lua.create_table().unwrap()
+                lua.load("function(a, b, c) return a + b + c end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
             },
-            |table| {
-                for (i, s) in ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]
-                    .into_iter()
-                    .enumerate()
-                {
-                    table.raw_set(s, i).unwrap();
-                    assert_eq!(table.raw_get::<_, usize>(s).unwrap(), i);
+            |function| {
+                for i in 0..10 {
+                    let _result: i64 = function.call((i, i + 1, i + 2)).unwrap();
                 }
             },
             BatchSize::SmallInput,
@@ -82,318 +96,197 @@ fn table_get_set(c: &mut Criterion) {
     });
 }
 
-fn table_traversal_pairs(c: &mut Criterion) {
+fn call_sum_callback(c: &mut Criterion) {
     let lua = Lua::new();
-
-    c.bench_function("table [traversal pairs]", |b| {
-        b.iter_batched(
-            || lua.globals(),
-            |globals| {
-                for kv in globals.pairs::<String, LuaValue>() {
-                    let (_k, _v) = kv.unwrap();
-                }
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn table_traversal_for_each(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    c.bench_function("table [traversal for_each]", |b| {
-        b.iter_batched(
-            || lua.globals(),
-            |globals| globals.for_each::<String, LuaValue>(|_k, _v| Ok(())),
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn table_traversal_sequence(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    let table = lua.create_sequence_from(1..1000).unwrap();
-
-    c.bench_function("table [traversal sequence]", |b| {
-        b.iter_batched(
-            || table.clone(),
-            |table| {
-                for v in table.sequence_values::<i32>() {
-                    let _i = v.unwrap();
-                }
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn function_create(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    c.bench_function("function [create Rust]", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                lua.create_function(|_, ()| Ok(123)).unwrap();
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn function_call_sum(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    let sum = lua
-        .create_function(|_, (a, b, c): (i64, i64, i64)| Ok(a + b - c))
+    let callback = lua
+        .create_function(|_, (a, b, c): (i64, i64, i64)| Ok(a + b + c))
         .unwrap();
+    lua.globals().set("callback", callback).unwrap();
 
-    c.bench_function("function [call Rust sum]", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                assert_eq!(sum.call::<_, i64>((10, 20, 30)).unwrap(), 0);
+    c.bench_function("call Rust callback [sum] 3 10", |b| {
+        b.iter_batched_ref(
+            || {
+                collect_gc_twice(&lua);
+                lua.load("function() for i = 1,10 do callback(i, i+1, i+2) end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
+            },
+            |function| {
+                function.call::<_, ()>(()).unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn function_call_lua_sum(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    let sum = lua
-        .load("function(a, b, c) return a + b - c end")
-        .eval::<LuaFunction>()
+fn call_async_sum_callback(c: &mut Criterion) {
+    let options = LuaOptions::new().thread_cache_size(1024);
+    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
+    let callback = lua
+        .create_async_function(|_, (a, b, c): (i64, i64, i64)| async move {
+            task::yield_now().await;
+            Ok(a + b + c)
+        })
         .unwrap();
+    lua.globals().set("callback", callback).unwrap();
 
-    c.bench_function("function [call Lua sum]", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                assert_eq!(sum.call::<_, i64>((10, 20, 30)).unwrap(), 0);
+    c.bench_function("call async Rust callback [sum] 3 10", |b| {
+        let rt = Runtime::new().unwrap();
+        b.to_async(rt).iter_batched(
+            || {
+                collect_gc_twice(&lua);
+                lua.load("function() for i = 1,10 do callback(i, i+1, i+2) end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
+            },
+            |function| async move {
+                function.call_async::<_, ()>(()).await.unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn function_call_concat(c: &mut Criterion) {
+fn call_concat_callback(c: &mut Criterion) {
     let lua = Lua::new();
-
-    let concat = lua
+    let callback = lua
         .create_function(|_, (a, b): (LuaString, LuaString)| {
             Ok(format!("{}{}", a.to_str()?, b.to_str()?))
         })
         .unwrap();
-    let i = AtomicUsize::new(0);
+    lua.globals().set("callback", callback).unwrap();
 
-    c.bench_function("function [call Rust concat string]", |b| {
-        b.iter_batched(
+    c.bench_function("call Rust callback [concat string] 10", |b| {
+        b.iter_batched_ref(
             || {
                 collect_gc_twice(&lua);
-                i.fetch_add(1, Ordering::Relaxed)
+                lua.load("function() for i = 1,10 do callback('a', tostring(i)) end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
             },
-            |i| {
-                assert_eq!(
-                    concat.call::<_, LuaString>(("num:", i)).unwrap(),
-                    format!("num:{i}")
-                );
+            |function| {
+                function.call::<_, ()>(()).unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn function_call_lua_concat(c: &mut Criterion) {
+fn create_registry_values(c: &mut Criterion) {
     let lua = Lua::new();
 
-    let concat = lua
-        .load("function(a, b) return a..b end")
-        .eval::<LuaFunction>()
-        .unwrap();
-    let i = AtomicUsize::new(0);
-
-    c.bench_function("function [call Lua concat string]", |b| {
-        b.iter_batched(
-            || {
-                collect_gc_twice(&lua);
-                i.fetch_add(1, Ordering::Relaxed)
-            },
-            |i| {
-                assert_eq!(
-                    concat.call::<_, LuaString>(("num:", i)).unwrap(),
-                    format!("num:{i}")
-                );
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn function_async_call_sum(c: &mut Criterion) {
-    let options = LuaOptions::new().thread_pool_size(1024);
-    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
-
-    let sum = lua
-        .create_async_function(|_, (a, b, c): (i64, i64, i64)| async move {
-            task::yield_now().await;
-            Ok(a + b - c)
-        })
-        .unwrap();
-
-    c.bench_function("function [async call Rust sum]", |b| {
-        let rt = Runtime::new().unwrap();
-        b.to_async(rt).iter_batched(
-            || collect_gc_twice(&lua),
-            |_| async {
-                assert_eq!(sum.call_async::<_, i64>((10, 20, 30)).await.unwrap(), 0);
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn registry_value_create(c: &mut Criterion) {
-    let lua = Lua::new();
-    lua.gc_stop();
-
-    c.bench_function("registry value [create]", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| lua.create_registry_value("hello").unwrap(),
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn registry_value_get(c: &mut Criterion) {
-    let lua = Lua::new();
-    lua.gc_stop();
-
-    let value = lua.create_registry_value("hello").unwrap();
-
-    c.bench_function("registry value [get]", |b| {
+    c.bench_function("create [registry value] 10", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                assert_eq!(lua.registry_value::<LuaString>(&value).unwrap(), "hello");
+                for _ in 0..10 {
+                    lua.create_registry_value(lua.pack(true).unwrap()).unwrap();
+                }
+                lua.expire_registry_values();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn userdata_create(c: &mut Criterion) {
-    struct UserData(#[allow(unused)] i64);
+fn create_userdata(c: &mut Criterion) {
+    struct UserData(i64);
     impl LuaUserData for UserData {}
 
     let lua = Lua::new();
 
-    c.bench_function("userdata [create]", |b| {
+    c.bench_function("create [table userdata] 10", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                lua.create_userdata(UserData(123)).unwrap();
+                let table: LuaTable = lua.create_table().unwrap();
+                for i in 1..11 {
+                    table.set(i, UserData(i)).unwrap();
+                }
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn userdata_call_index(c: &mut Criterion) {
-    struct UserData(#[allow(unused)] i64);
-    impl LuaUserData for UserData {
-        fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_meta_method(LuaMetaMethod::Index, move |_, _, key: LuaString| Ok(key));
-        }
-    }
-
-    let lua = Lua::new();
-    let ud = lua.create_userdata(UserData(123)).unwrap();
-    let index = lua
-        .load("function(ud) return ud.test end")
-        .eval::<LuaFunction>()
-        .unwrap();
-
-    c.bench_function("userdata [call index]", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                assert_eq!(index.call::<_, LuaString>(&ud).unwrap(), "test");
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn userdata_call_method(c: &mut Criterion) {
+fn call_userdata_index(c: &mut Criterion) {
     struct UserData(i64);
     impl LuaUserData for UserData {
         fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_method("add", |_, this, i: i64| Ok(this.0 + i));
+            methods.add_meta_method(LuaMetaMethod::Index, move |_, _, index: String| Ok(index));
         }
     }
 
     let lua = Lua::new();
-    let ud = lua.create_userdata(UserData(123)).unwrap();
-    let method = lua
-        .load("function(ud, i) return ud:add(i) end")
-        .eval::<LuaFunction>()
-        .unwrap();
-    let i = AtomicUsize::new(0);
+    lua.globals().set("userdata", UserData(10)).unwrap();
 
-    c.bench_function("userdata [call method]", |b| {
-        b.iter_batched(
+    c.bench_function("call [userdata index] 10", |b| {
+        b.iter_batched_ref(
             || {
                 collect_gc_twice(&lua);
-                i.fetch_add(1, Ordering::Relaxed)
+                lua.load("function() for i = 1,10 do local v = userdata.test end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
             },
-            |i| {
-                assert_eq!(method.call::<_, usize>((&ud, i)).unwrap(), 123 + i);
+            |function| {
+                function.call::<_, ()>(()).unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn userdata_async_call_method(c: &mut Criterion) {
+fn call_userdata_method(c: &mut Criterion) {
     struct UserData(i64);
     impl LuaUserData for UserData {
         fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_async_method("add", |_, this, i: i64| async move {
-                task::yield_now().await;
-                Ok(this.0 + i)
-            });
+            methods.add_method("method", |_, this, ()| Ok(this.0));
         }
     }
 
-    let options = LuaOptions::new().thread_pool_size(1024);
-    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
-    let ud = lua.create_userdata(UserData(123)).unwrap();
-    let method = lua
-        .load("function(ud, i) return ud:add(i) end")
-        .eval::<LuaFunction>()
-        .unwrap();
-    let i = AtomicUsize::new(0);
+    let lua = Lua::new();
+    lua.globals().set("userdata", UserData(10)).unwrap();
 
-    c.bench_function("userdata [async call method] 10", |b| {
+    c.bench_function("call [userdata method] 10", |b| {
+        b.iter_batched_ref(
+            || {
+                collect_gc_twice(&lua);
+                lua.load("function() for i = 1,10 do userdata:method() end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
+            },
+            |function| {
+                function.call::<_, ()>(()).unwrap();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn call_async_userdata_method(c: &mut Criterion) {
+    #[derive(Clone, Copy)]
+    struct UserData(i64);
+    impl LuaUserData for UserData {
+        fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
+            methods.add_async_method("method", |_, this, ()| async move { Ok(this.0) });
+        }
+    }
+
+    let options = LuaOptions::new().thread_cache_size(1024);
+    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
+    lua.globals().set("userdata", UserData(10)).unwrap();
+
+    c.bench_function("call async [userdata method] 10", |b| {
         let rt = Runtime::new().unwrap();
         b.to_async(rt).iter_batched(
             || {
                 collect_gc_twice(&lua);
-                (
-                    method.clone(),
-                    ud.clone(),
-                    i.fetch_add(1, Ordering::Relaxed),
-                )
+                lua.load("function() for i = 1,10 do userdata:method() end end")
+                    .eval::<LuaFunction>()
+                    .unwrap()
             },
-            |(method, ud, i)| async move {
-                assert_eq!(
-                    method.call_async::<_, usize>((ud, i)).await.unwrap(),
-                    123 + i
-                );
+            |function| async move {
+                function.call_async::<_, ()>(()).await.unwrap();
             },
             BatchSize::SmallInput,
         );
@@ -403,32 +296,23 @@ fn userdata_async_call_method(c: &mut Criterion) {
 criterion_group! {
     name = benches;
     config = Criterion::default()
-        .sample_size(500)
+        .sample_size(300)
         .measurement_time(Duration::from_secs(10))
         .noise_threshold(0.02);
     targets =
-        table_create_empty,
-        table_create_array,
-        table_create_hash,
-        table_get_set,
-        table_traversal_pairs,
-        table_traversal_for_each,
-        table_traversal_sequence,
-
-        function_create,
-        function_call_sum,
-        function_call_lua_sum,
-        function_call_concat,
-        function_call_lua_concat,
-        function_async_call_sum,
-
-        registry_value_create,
-        registry_value_get,
-
-        userdata_create,
-        userdata_call_index,
-        userdata_call_method,
-        userdata_async_call_method,
+        create_table,
+        create_array,
+        create_string_table,
+        create_function,
+        call_lua_function,
+        call_sum_callback,
+        call_async_sum_callback,
+        call_concat_callback,
+        create_registry_values,
+        create_userdata,
+        call_userdata_index,
+        call_userdata_method,
+        call_async_userdata_method,
 }
 
 criterion_main!(benches);

benches/serde.rs

@@ -1,90 +0,0 @@
-use std::time::Duration;
-
-use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
-
-use mlua::prelude::*;
-
-fn collect_gc_twice(lua: &Lua) {
-    lua.gc_collect().unwrap();
-    lua.gc_collect().unwrap();
-}
-
-fn encode_json(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    let encode = lua
-        .create_function(|_, t: LuaValue| Ok(serde_json::to_string(&t).unwrap()))
-        .unwrap();
-    let table = lua
-        .load(
-            r#"{
-        name = "Clark Kent",
-        address = {
-            city = "Smallville",
-            state = "Kansas",
-            country = "USA",
-        },
-        age = 22,
-        parents = {"Jonathan Kent", "Martha Kent"},
-        superman = true,
-        interests = {"flying", "saving the world", "kryptonite"},
-    }"#,
-        )
-        .eval::<LuaTable>()
-        .unwrap();
-
-    c.bench_function("serialize json", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                encode.call::<_, LuaString>(&table).unwrap();
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn decode_json(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    let decode = lua
-        .create_function(|lua, s: String| {
-            lua.to_value(&serde_json::from_str::<serde_json::Value>(&s).unwrap())
-        })
-        .unwrap();
-    let json = r#"{
-        "name": "Clark Kent",
-        "address": {
-            "city": "Smallville",
-            "state": "Kansas",
-            "country": "USA"
-        },
-        "age": 22,
-        "parents": ["Jonathan Kent", "Martha Kent"],
-        "superman": true,
-        "interests": ["flying", "saving the world", "kryptonite"]
-    }"#;
-
-    c.bench_function("deserialize json", |b| {
-        b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                decode.call::<_, LuaTable>(json).unwrap();
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-criterion_group! {
-    name = benches;
-    config = Criterion::default()
-        .sample_size(500)
-        .measurement_time(Duration::from_secs(10))
-        .noise_threshold(0.02);
-    targets =
-        encode_json,
-        decode_json,
-}
-
-criterion_main!(benches);

build/find_dummy.rs

@@ -0,0 +1,5 @@
+use std::path::PathBuf;
+
+pub fn probe_lua() -> Option<PathBuf> {
+    None
+}

build/find_normal.rs

@@ -0,0 +1,93 @@
+#![allow(dead_code)]
+
+use std::env;
+use std::ops::Bound;
+use std::path::PathBuf;
+
+fn get_env_var(name: &str) -> String {
+    match env::var(name) {
+        Ok(val) => val,
+        Err(env::VarError::NotPresent) => String::new(),
+        Err(err) => panic!("cannot get {}: {}", name, err),
+    }
+}
+
+pub fn probe_lua() -> Option<PathBuf> {
+    let include_dir = get_env_var("LUA_INC");
+    let lib_dir = get_env_var("LUA_LIB");
+    let lua_lib = get_env_var("LUA_LIB_NAME");
+
+    println!("cargo:rerun-if-env-changed=LUA_INC");
+    println!("cargo:rerun-if-env-changed=LUA_LIB");
+    println!("cargo:rerun-if-env-changed=LUA_LIB_NAME");
+    println!("cargo:rerun-if-env-changed=LUA_LINK");
+
+    let need_lua_lib = cfg!(any(not(feature = "module"), target_os = "windows"));
+
+    if !include_dir.is_empty() {
+        if need_lua_lib {
+            if lib_dir.is_empty() {
+                panic!("LUA_LIB is not set");
+            }
+            if lua_lib.is_empty() {
+                panic!("LUA_LIB_NAME is not set");
+            }
+
+            let mut link_lib = "";
+            if get_env_var("LUA_LINK") == "static" {
+                link_lib = "static=";
+            };
+            println!("cargo:rustc-link-search=native={}", lib_dir);
+            println!("cargo:rustc-link-lib={}{}", link_lib, lua_lib);
+        }
+        return Some(PathBuf::from(include_dir));
+    }
+
+    // Find using `pkg-config`
+
+    #[cfg(feature = "lua54")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.4", "5.5", "lua5.4", "5.4");
+    #[cfg(feature = "lua53")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.3", "5.4", "lua5.3", "5.3");
+    #[cfg(feature = "lua52")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.2", "5.3", "lua5.2", "5.2");
+    #[cfg(feature = "lua51")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.1", "5.2", "lua5.1", "5.1");
+
+    #[cfg(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "lua51"
+    ))]
+    {
+        let mut lua = pkg_config::Config::new()
+            .range_version((Bound::Included(incl_bound), Bound::Excluded(excl_bound)))
+            .cargo_metadata(need_lua_lib)
+            .probe("lua");
+
+        if lua.is_err() {
+            lua = pkg_config::Config::new()
+                .cargo_metadata(need_lua_lib)
+                .probe(alt_probe);
+        }
+
+        lua.unwrap_or_else(|_| panic!("cannot find Lua {} using `pkg-config`", ver))
+            .include_paths
+            .get(0)
+            .cloned()
+    }
+
+    #[cfg(feature = "luajit")]
+    {
+        let lua = pkg_config::Config::new()
+            .range_version((Bound::Included("2.0.4"), Bound::Unbounded))
+            .cargo_metadata(need_lua_lib)
+            .probe("luajit");
+
+        lua.expect("cannot find LuaJIT using `pkg-config`")
+            .include_paths
+            .get(0)
+            .cloned()
+    }
+}

build/find_vendored.rs

@@ -1,29 +1,28 @@
 #![allow(dead_code)]
 
-pub fn probe_lua() {
+use std::path::PathBuf;
+
+pub fn probe_lua() -> Option<PathBuf> {
     #[cfg(feature = "lua54")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua54);
-
     #[cfg(feature = "lua53")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua53);
-
     #[cfg(feature = "lua52")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua52);
-
     #[cfg(feature = "lua51")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua51);
-
     #[cfg(feature = "luajit")]
-    let artifacts = luajit_src::Build::new()
-        .lua52compat(cfg!(feature = "luajit52"))
-        .build();
-
+    let artifacts = {
+        let mut builder = luajit_src::Build::new();
+        if cfg!(feature = "luajit52") {
+            builder.lua52compat(true);
+        }
+        builder.build()
+    };
     #[cfg(feature = "luau")]
-    let artifacts = luau0_src::Build::new()
-        .enable_codegen(cfg!(feature = "luau-codegen"))
-        .set_max_cstack_size(1000000)
-        .set_vector_size(if cfg!(feature = "luau-vector4") { 4 } else { 3 })
-        .build();
+    let artifacts = luau0_src::Build::new().build();
 
     artifacts.print_cargo_metadata();
+
+    Some(artifacts.include_dir().to_owned())
 }

build/main.rs

@@ -0,0 +1,115 @@
+#[cfg_attr(
+    any(
+        feature = "luau",
+        all(
+            feature = "vendored",
+            any(
+                feature = "lua54",
+                feature = "lua53",
+                feature = "lua52",
+                feature = "lua51",
+                feature = "luajit"
+            )
+        )
+    ),
+    path = "find_vendored.rs"
+)]
+#[cfg_attr(
+    all(
+        not(feature = "vendored"),
+        any(
+            feature = "lua54",
+            feature = "lua53",
+            feature = "lua52",
+            feature = "lua51",
+            feature = "luajit"
+        )
+    ),
+    path = "find_normal.rs"
+)]
+#[cfg_attr(
+    not(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "lua51",
+        feature = "luajit",
+        feature = "luau"
+    )),
+    path = "find_dummy.rs"
+)]
+mod find;
+
+fn main() {
+    #[cfg(not(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "lua51",
+        feature = "luajit",
+        feature = "luau"
+    )))]
+    compile_error!(
+        "You must enable one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    #[cfg(all(
+        feature = "lua54",
+        any(
+            feature = "lua53",
+            feature = "lua52",
+            feature = "lua51",
+            feature = "luajit",
+            feature = "luau"
+        )
+    ))]
+    compile_error!(
+        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    #[cfg(all(
+        feature = "lua53",
+        any(
+            feature = "lua52",
+            feature = "lua51",
+            feature = "luajit",
+            feature = "luau"
+        )
+    ))]
+    compile_error!(
+        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    #[cfg(all(
+        feature = "lua52",
+        any(feature = "lua51", feature = "luajit", feature = "luau")
+    ))]
+    compile_error!(
+        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    #[cfg(all(feature = "lua51", any(feature = "luajit", feature = "luau")))]
+    compile_error!(
+        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    #[cfg(all(feature = "luajit", feature = "luau"))]
+    compile_error!(
+        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau"
+    );
+
+    // We don't support "vendored module" mode on windows
+    #[cfg(all(feature = "vendored", feature = "module", target_os = "windows"))]
+    compile_error!(
+        "Vendored (static) builds are not supported for modules on Windows.\n"
+            + "Please, use `pkg-config` or custom mode to link to a Lua dll."
+    );
+
+    #[cfg(all(feature = "luau", feature = "module"))]
+    compile_error!("Luau does not support module mode");
+
+    #[cfg(any(not(feature = "module"), target_os = "windows"))]
+    find::probe_lua();
+
+    println!("cargo:rerun-if-changed=build");
+}

docs/release_notes/v0.9.md

@@ -1,361 +0,0 @@
-## mlua v0.9 release notes
-
-The v0.9 version of mlua is a major release that includes a number of API changes and improvements. This release is a stepping stone towards the v1.0.
-This document highlights the most important changes. For a full list of changes, see the [CHANGELOG].
-
-[CHANGELOG]: https://github.com/khvzak/mlua/blob/main/CHANGELOG.md
-
-### New features
-
-#### 1. New Any UserData API
-
-This is a long awaited feature that allows to register in Lua foreign types that cannot implement `UserData` trait because of the Rust orphan rules.
-
-Now you can register any type that implements [`Any`] trait as a userdata type.
-
-Consider the following example:
-
-```rust
-lua.register_userdata_type::<std::string::String>(|reg| {
-    reg.add_method("len", |_, this, ()| Ok(this.len()));
-
-    reg.add_method_mut("push", |_, this, s: String| {
-        this.push_str(&s);
-        Ok(())
-    });
-
-    reg.add_meta_method(MetaMethod::ToString, |lua, this, ()| lua.create_string(this));
-})?;
-
-let s = lua.create_any_userdata("hello".to_string())?;
-lua.load(chunk! {
-    print("s:len() is " .. $s:len())
-    $s:push(" world")
-    // Prints: hello, world
-    print($s)
-})
-.exec()?;
-```
-
-In this example we registered [`std::string::String`] as a userdata type with a set of methods and then created an instance of this type in Lua.
-
-It's _not_ required to register a type before using the `Lua::create_any_userdata()` method, instead an empty metatable will be created for you.
-You can also register the same type multiple times with different methods. Any previously created instances will share the old metatable, while new instances will have the new one.
-
-The new set of API is called `any_userdata` because it allows to register types that implements [`Any`] trait.
-
-[`std::string::String`]: https://doc.rust-lang.org/stable/std/string/struct.String.html
-[`Any`]: https://doc.rust-lang.org/stable/std/any/trait.Any.html
-
-#### 2. Scope support for the new any userdata types
-
-When you need to create non-static userdata instances in Lua, the usual way is use `Lua::scope()` helper to make them scoped. When out of scope, any scoped objects will be automatically
-dropped. The only downside of this approach is that every new instance will have a new metatable. This is not very fast if you need to create a lot of instances.
-
-With the new Any UserData API, you can place non-static references `&T` where `T: 'static` into a scope and they will share a single static metatable.
-
-```rust
-lua.register_userdata_type::<std::string::String>(|reg| {
-    reg.add_method_mut("replace", |_, this, (pat, to): (String, String)| {
-        *this = this.replace(&pat, &to);
-        Ok(())
-    });
-
-    reg.add_meta_method(MetaMethod::ToString, |lua, this, ()| lua.create_string(this));
-})?;
-
-let mut s = "hello, world".to_string();
-
-lua.scope(|scope| {
-    // This userdata instance holds only a mutable reference to our string
-    let ud = scope.create_any_userdata_ref_mut(&mut s)?;
-    lua.load(chunk! {
-        $ud:replace("world", "user")
-    })
-    .exec()
-})?;
-
-// Prints: hello, user!
-println!("{s}!");
-```
-
-#### 3. Owned types (`unstable`)
-
-One of the common questions was how to embed a Lua type into Rust struct to use it later. It was non-trivial to do because of the `'lua` lifetime attached to every Lua value.
-
-In v0.9 mlua introduces "owned" types `OwnedTable`/`OwnedFunction`/`OwnedString`/`OwnedAnyUserData`/ `OwnedThread`that are `'static` (no lifetime attached).
-
-```rust
-let lua = Lua::new();
-
-struct MyStruct {
-    table: OwnedTable,
-    func: OwnedFunction,
-}
-
-let my_struct = MyStruct {
-    table: lua.globals().into_owned(),
-    func: lua
-        .create_function(|_, t: Table| Ok(format!("{t:#?}")))?
-        .into_owned(),
-};
-
-// It's safe to drop Lua!
-drop(lua);
-
-let result = my_struct.func.call::<_, String>(my_struct.table)?;
-println!("{result}");
-```
-
-Prior to v0.9, it was possible to do by creating a reference to the Lua value in registry using `Lua::create_registry_value()`
-and retrieving value later using `Lua::registry_value()` method.
-
-All owned handles hold a *strong* reference to the current Lua instance.
-Be warned, if you place them into a Lua type (eg. `UserData` or a Rust callback), it is *very easy*
-to accidentally cause reference cycles that would prevent destroying Lua instance.
-
-Please note this functionality is available under the `unstable` feature flag and not available when the `send` feature is enabled.
-
-#### New ffi module
-
-In v0.9 release the internal `ffi` module has been moved into the new [`mlua-sys`] crate and became available for public use.
-This crate provides unified Lua FFI API (targeting Lua 5.4) using a (limited) compatibility layer for older versions.
-
-mlua re-exports the `ffi` module aliasing the `mlua-sys` crate and provides (unsafe) functionality to work with raw Lua state:
-
-```rust
-unsafe {
-    unsafe extern "C-unwind" fn lua_add(state: *mut mlua::lua_State) -> i32 {
-        let a = mlua::ffi::luaL_checkinteger(state, 1);
-        let b = mlua::ffi::luaL_checkinteger(state, 2);
-        mlua::ffi::lua_pushinteger(state, a + b);
-        1
-    }
-
-    let add = lua.create_c_function(lua_add)?;
-    assert_eq!(add.call::<_, i32>((2, 3))?, 5);
-}
-```
-
-[`mlua-sys`]: https://crates.io/crates/mlua-sys
-
-#### Luau JIT support
-
-mlua brings support for the new [Luau] JIT backend under the `luau-jit` feature flag.
-
-It will automatically trigger JIT compilation for new Lua chunks. To disable it, just call `lua.enable_jit(false)` before loading Lua code
-(but any previously compiled chunks will remain JIT-compiled).
-
-[Luau]: https://luau-lang.org
-
-### Improvements
-
-#### 1. Better error reporting
-
-When calling a Rust function from Lua and passing wrong arguments, previous mlua versions reported a error message without any context or reference to the particular argument.
-
-In v0.9 it reports a error message with the argument index and expected type:
-
-```rust
-let func = lua.create_function(|_, _a: i32| Ok(()))?;
-lua.load(chunk! {
-    local ok, err = pcall($func, "not a number")
-    // Prints: bad argument #1: error converting Lua string to i32 (expected number or string coercible to number)
-    print(err)
-})
-.exec()?;
-```
-
-Similar changes have been made for userdata functions and methods:
-
-```rust
-lua.register_userdata_type::<&'static str>(|reg| {
-    reg.add_method("len", |_, this, ()| Ok(this.len()));
-})?;
-
-let s = lua.create_any_userdata("hello")?;
-lua.load(chunk! {
-    local ok, err = pcall($s.len, 123)
-    // Prints: bad argument `self` to `&str.len`: error converting Lua integer to userdata
-    print(err)
-})
-.exec()?;
-```
-
-#### 2. Error context
-
-Similar to the [`anyhow`] Error type, now it's possible to attach context to Lua errors:
-
-```rust
-let read = lua.create_function(|lua, path: String| {
-    let bytes = std::fs::read(&path)
-        .into_lua_err()
-        .context(format!("Failed to open `{path}`"))?;
-    Ok(lua.create_string(bytes))
-})?;
-
-lua.load(chunk! {
-    local ok, err = pcall($read, "/nonexistent")
-    /// Prints:
-    /// Failed to open /nonexistent
-    /// No such file or directory (os error 2)
-    /// stack traceback:
-    /// ...
-    print(err)
-})
-.exec()?;
-```
-
-[`anyhow`]: https://crates.io/crates/anyhow
-
-#### 4. New methods `Function::wrap`/`AnyUserData::wrap`
-
-Sometimes it's useful to have `IntoLua` trait implementation for a Rust function or type `T: Any` without needing to call `Lua::create_function()`/`Lua::create_any_userdata()` methods.
-Since v0.9 you can call the new methods `Function::wrap()`/`AnyUserData::wrap()` that allows to do this. They return an abstract type that `impl IntoLua`:
-
-```rust
-lua.globals().set("print_rust", Function::wrap(|_, s: String| Ok(println!("{}", s))))?;
-lua.globals().set("rust_ud", AnyUserData::wrap("hello"))?;
-```
-
-In addition there are also `Function::wrap_mut()`/`Function::wrap_async()` methods that allow to wrap mutable and async functions respectively.
-
-For a `T: 'UserData + 'static` the `IntoLua` trait is still always implemented.
-
-#### `UserDataRef` and `UserDataRefMut` type wrappers
-
-The new wrappers `UserDataRef` and `UserDataRefMut` are receivers for userdata type `T` and borrow underlying instance for the lifetime of the wrapper.
-
-```rust
-lua.globals()
-    .set("ud", AnyUserData::wrap("hello".to_string()))?;
-
-let mut ud_mut: UserDataRefMut<String> = lua.globals().get("ud")?;
-ud_mut.push_str(", Rust");
-drop(ud_mut);
-
-let ud_ref: UserDataRef<String> = lua.globals().get("ud")?;
-// Prints: hello, Rust
-println!("{}", *ud_ref);
-```
-
-In the previous mlua versions the same functionality can be achieved by receiving `AnyUserData` and calling `AnyUserData::borrow()`/`AnyUserData::borrow_mut()` methods.
-
-The new wrappers are identical to Rust [`Ref`]/[`RefMut`] types.
-
-[`Ref`]: https://doc.rust-lang.org/std/cell/struct.Ref.html
-[`RefMut`]: https://doc.rust-lang.org/std/cell/struct.RefMut.html
-
-#### New `AnyUserDataExt` trait
-
-Similar to the `TableExt` trait, the `AnyUserDataExt` provides a set of extra methods for the `AnyUserData` type.
-
-1) `AnyUserDataExt::get()/set()` to get/set a value by key from the userdata, assuming it has `__index` metamethod.
-
-2) `AnyUserDataExt::call()` to call the userdata as a function assuming it has `__call` metamethod.
-
-3) `AnyUserData::call_method(name, ...)` to call the userdata method, assuming it has `__index` metamethod and the associated function.
-
-#### Pretty formatting Lua values
-
-`mlua::Value` implements a new format `:#?` that allows to (recursively) pretty print Lua values:
-
-```rust
-println!("{:#?}", lua.globals());
-```
-
-Prints:
-```
-{
-  ["_G"] = table: 0x7fa2d0706260,
-  ["_VERSION"] = "Lua 5.4",
-  ["assert"] = function: 0x10451d11d,
-  ["collectgarbage"] = function: 0x10451d198,
-  ["coroutine"] = {
-    ["close"] = function: 0x10451e28f,
-    ...
-  },
-  ["dofile"] = function: 0x10451d37c,
-  ...
-}
-```
-
-In addition a new method `Value::to_string()` has been added to convert `Value` to a string (using `__tostring` metamethod if available).
-
-#### Environment for Lua functions
-
-Any Lua functions have an associated environment table that is used to resolve global variables. By default it sets to a Lua globals table.
-
-In the new release it's possible to get or update a function environment using `Function::environment()` or `Function::set_environment()` methods respectively.
-
-```rust
-let f = lua.load("return a").into_function()?;
-
-assert_eq!(f.environment(), Some(lua.globals()));
-
-lua.globals().set("a", 1)?;
-assert_eq!(f.call::<_, i32>(())?, 1);
-
-f.set_environment(lua.create_table_from([("a", "hello")])?)?;
-assert_eq!(f.call::<_, mlua::String>(())?, "hello");
-```
-
-#### Performance optimizations
-
-The new mlua version has a number of performance improvements. Please check the [benchmarks results] to see how mlua compares to rlua and rhai.
-
-[benchmarks results]: https://github.com/khvzak/script-bench-rs
-
-### Changes in `module` mode
-
-#### New attributes
-
-The `lua_module` macro now support the following attributes:
-
-- `name=...` - sets name of the module (defaults to the name of the function).
-
-Eg.:
-
-```rust
-#[mlua::lua_module(name = "alt_module")]
-fn my_module(lua: &Lua) -> LuaResult<LuaTable> {
-    lua.create_table()
-}
-```
-
-Under the hood a new function `luaopen_alt_module` will be created for the Lua module loader.
-
-- `skip_memory_check` - skip memory allocation checks for some operations.
-
-In module mode, mlua runs in unknown environment and cannot say are there any memory limits or not. As result, some operations that require memory allocation runs in
-protected mode. Setting this attribute will improve performance of such operations with risk of having uncaught exceptions and memory leaks.
-
-#### Improved Windows target
-
-In previous mlua versions, building a Lua module for Windows requires having Lua development libraries installed on the system.
-In contrast, on Linux and macOS, modules can be built without any external dependencies using the `-undefined=dynamic_lookup` linker flag.
-
-With Rust 1.71+ it's now possible to lift this restriction for Windows as well. You can build modules normally and they will be linked with
-`lua54.dll`/`lua53.dll`/`lua52.dll`/`lua51.dll` depending on the enabled Lua version.
-
-You still need to have the dll although, linked to application where the module will be loaded.
-
-### Breaking changes
-
-1) `ToLua`/`ToLuaMulti` traits have been renamed to `IntoLua`/`IntoLuaMulti` respectively (with the methods called `into_lua`/`into_lua_multi`).
-
-The main reason for this change is following the Rust self [convention](https://rust-lang.github.io/rust-clippy/master/index.html#/wrong_self_convention).
-
-2) Removed `FromLua` implementation for `T: UserData + Clone`.
-
-During the usage of mlua, it was found that this implementation is not very useful and prevents custom `FromLua` implementations for `T: UserData`.
-It should be a developer decision to opt-in `FromLua` for their `T` if needed rather than having enabled it unconditionally.
-
-To opt-in `FromLua` for `T: Clone` you can use a simple `#[derive(FromLua)]` macro (requires `feature = "macros"`):
-
-```rust
-#[derive(Clone, Copy, mlua::FromLua)]
-struct MyUserData(i32);
-```
-
-`T` is not required to implement `UserData` because of the new relaxed restrictions on userdata types.

examples/async_http_client.rs

@@ -1,36 +1,33 @@
 use std::collections::HashMap;
 
-use http_body_util::BodyExt as _;
-use hyper::body::Incoming;
-use hyper_util::client::legacy::Client as HyperClient;
-use hyper_util::rt::TokioExecutor;
+use hyper::body::{Body as HyperBody, HttpBody as _};
+use hyper::Client as HyperClient;
 
-use mlua::{chunk, ExternalResult, Lua, Result, UserData, UserDataMethods};
+use mlua::{chunk, AnyUserData, ExternalResult, Lua, Result, UserData, UserDataMethods};
 
-struct BodyReader(Incoming);
+struct BodyReader(HyperBody);
 
 impl UserData for BodyReader {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        // Every call returns a next chunk
-        methods.add_async_method_mut("read", |lua, reader, ()| async move {
-            if let Some(bytes) = reader.0.frame().await {
-                if let Some(bytes) = bytes.into_lua_err()?.data_ref() {
-                    return Some(lua.create_string(&bytes)).transpose();
-                }
+        methods.add_async_function("read", |lua, reader: AnyUserData| async move {
+            let mut reader = reader.borrow_mut::<Self>()?;
+            if let Some(bytes) = reader.0.data().await {
+                let bytes = bytes.to_lua_err()?;
+                return Some(lua.create_string(&bytes)).transpose();
             }
             Ok(None)
         });
     }
 }
 
-#[tokio::main(flavor = "current_thread")]
+#[tokio::main]
 async fn main() -> Result<()> {
     let lua = Lua::new();
 
     let fetch_url = lua.create_async_function(|lua, uri: String| async move {
-        let client = HyperClient::builder(TokioExecutor::new()).build_http::<String>();
-        let uri = uri.parse().into_lua_err()?;
-        let resp = client.get(uri).await.into_lua_err()?;
+        let client = HyperClient::new();
+        let uri = uri.parse().to_lua_err()?;
+        let resp = client.get(uri).await.to_lua_err()?;
 
         let lua_resp = lua.create_table()?;
         lua_resp.set("status", resp.status().as_u16())?;
@@ -40,7 +37,7 @@ async fn main() -> Result<()> {
             headers
                 .entry(key.as_str())
                 .or_insert(Vec::new())
-                .push(value.to_str().into_lua_err()?);
+                .push(value.to_str().to_lua_err()?);
         }
 
         lua_resp.set("headers", headers)?;
@@ -59,11 +56,11 @@ async fn main() -> Result<()> {
                 end
             end
             repeat
-                local chunk = res.body:read()
-                if chunk then
-                    print(chunk)
+                local body = res.body:read()
+                if body then
+                    print(body)
                 end
-            until not chunk
+            until not body
         })
         .into_function()?;
 

examples/async_http_reqwest.rs

@@ -1,27 +1,33 @@
-use mlua::{chunk, ExternalResult, Lua, LuaSerdeExt, Result, Value};
+use mlua::{chunk, ExternalResult, Lua, LuaSerdeExt, Result};
 
-#[tokio::main(flavor = "current_thread")]
+#[tokio::main]
 async fn main() -> Result<()> {
     let lua = Lua::new();
 
+    let null = lua.null();
+
     let fetch_json = lua.create_async_function(|lua, uri: String| async move {
         let resp = reqwest::get(&uri)
             .await
             .and_then(|resp| resp.error_for_status())
-            .into_lua_err()?;
-        let json = resp.json::<serde_json::Value>().await.into_lua_err()?;
+            .to_lua_err()?;
+        let json = resp.json::<serde_json::Value>().await.to_lua_err()?;
         lua.to_value(&json)
     })?;
 
-    let dbg = lua.create_function(|_, value: Value| {
-        println!("{value:#?}");
-        Ok(())
-    })?;
-
     let f = lua
         .load(chunk! {
+            function print_r(t, indent)
+                local indent = indent or ""
+                for k, v in pairs(t) do
+                    io.write(indent, tostring(k))
+                    if type(v) == "table" then io.write(":\n") print_r(v, indent.."  ")
+                    else io.write(": ", v == $null and "null" or tostring(v), "\n") end
+                end
+            end
+
             local res = $fetch_json(...)
-            $dbg(res)
+            print_r(res)
         })
         .into_function()?;
 

examples/async_http_server.rs

@@ -1,63 +1,43 @@
-use std::convert::Infallible;
 use std::future::Future;
 use std::net::SocketAddr;
+use std::pin::Pin;
 use std::rc::Rc;
+use std::task::{Context, Poll};
 
-use futures::future::LocalBoxFuture;
-use http_body_util::{combinators::BoxBody, BodyExt as _, Empty, Full};
-use hyper::body::{Bytes, Incoming};
-use hyper::{Request, Response};
-use hyper_util::rt::TokioIo;
-use hyper_util::server::conn::auto::Builder as ServerConnBuilder;
-use tokio::net::TcpListener;
-use tokio::task::LocalSet;
+use hyper::server::conn::AddrStream;
+use hyper::service::Service;
+use hyper::{Body, Request, Response, Server};
 
 use mlua::{
-    chunk, Error as LuaError, Function, Lua, RegistryKey, String as LuaString, Table, UserData,
-    UserDataMethods,
+    chunk, Error as LuaError, Function, Lua, String as LuaString, Table, UserData, UserDataMethods,
 };
 
-/// Wrapper around incoming request that implements UserData
-struct LuaRequest(SocketAddr, Request<Incoming>);
+struct LuaRequest(SocketAddr, Request<Body>);
 
 impl UserData for LuaRequest {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        methods.add_method("remote_addr", |_, req, ()| Ok((req.0).to_string()));
-        methods.add_method("method", |_, req, ()| Ok((req.1).method().to_string()));
-        methods.add_method("path", |_, req, ()| Ok(req.1.uri().path().to_string()));
+        methods.add_method("remote_addr", |_lua, req, ()| Ok((req.0).to_string()));
+        methods.add_method("method", |_lua, req, ()| Ok((req.1).method().to_string()));
     }
 }
 
-/// Service that handles incoming requests
-#[derive(Clone)]
-pub struct Svc {
-    lua: Rc<Lua>,
-    handler: Rc<RegistryKey>,
-    peer_addr: SocketAddr,
-}
+pub struct Svc(Rc<Lua>, SocketAddr);
 
-impl Svc {
-    pub fn new(lua: Rc<Lua>, handler: Rc<RegistryKey>, peer_addr: SocketAddr) -> Self {
-        Self {
-            lua,
-            handler,
-            peer_addr,
-        }
-    }
-}
-
-impl hyper::service::Service<Request<Incoming>> for Svc {
-    type Response = Response<BoxBody<Bytes, Infallible>>;
+impl Service<Request<Body>> for Svc {
+    type Response = Response<Body>;
     type Error = LuaError;
-    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
 
-    fn call(&self, req: Request<Incoming>) -> Self::Future {
+    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn call(&mut self, req: Request<Body>) -> Self::Future {
         // If handler returns an error then generate 5xx response
-        let lua = self.lua.clone();
-        let handler_key = self.handler.clone();
-        let lua_req = LuaRequest(self.peer_addr, req);
+        let lua = self.0.clone();
+        let lua_req = LuaRequest(self.1, req);
         Box::pin(async move {
-            let handler: Function = lua.registry_value(&handler_key)?;
+            let handler: Function = lua.named_registry_value("http_handler")?;
             match handler.call_async::<_, Table>(lua_req).await {
                 Ok(lua_resp) => {
                     let status = lua_resp.get::<_, Option<u16>>("status")?.unwrap_or(200);
@@ -71,11 +51,10 @@ impl hyper::service::Service<Request<Incoming>> for Svc {
                         }
                     }
 
-                    // Set body
                     let body = lua_resp
                         .get::<_, Option<LuaString>>("body")?
-                        .map(|b| Full::new(Bytes::copy_from_slice(b.as_bytes())).boxed())
-                        .unwrap_or_else(|| Empty::<Bytes>::new().boxed());
+                        .map(|b| Body::from(b.as_bytes().to_vec()))
+                        .unwrap_or_else(Body::empty);
 
                     Ok(resp.body(body).unwrap())
                 }
@@ -83,7 +62,7 @@ impl hyper::service::Service<Request<Incoming>> for Svc {
                     eprintln!("{}", err);
                     Ok(Response::builder()
                         .status(500)
-                        .body(Full::new(Bytes::from("Internal Server Error")).boxed())
+                        .body(Body::from("Internal Server Error"))
                         .unwrap())
                 }
             }
@@ -96,14 +75,13 @@ async fn main() {
     let lua = Rc::new(Lua::new());
 
     // Create Lua handler function
-    let handler: RegistryKey = lua
+    let handler: Function = lua
         .load(chunk! {
             function(req)
                 return {
                     status = 200,
                     headers = {
                         ["X-Req-Method"] = req:method(),
-                        ["X-Req-Path"] = req:path(),
                         ["X-Remote-Addr"] = req:remote_addr(),
                     },
                     body = "Hello from Lua!\n"
@@ -111,35 +89,37 @@ async fn main() {
             end
         })
         .eval()
-        .expect("Failed to create Lua handler");
-    let handler = Rc::new(handler);
+        .expect("cannot create Lua handler");
 
-    let listen_addr = "127.0.0.1:3000";
-    let listener = TcpListener::bind(listen_addr).await.unwrap();
-    println!("Listening on http://{listen_addr}");
+    // Store it in the Registry
+    lua.set_named_registry_value("http_handler", handler)
+        .expect("cannot store Lua handler");
 
-    let local = LocalSet::new();
-    loop {
-        let (stream, peer_addr) = match listener.accept().await {
-            Ok(x) => x,
-            Err(err) => {
-                eprintln!("Failed to accept connection: {err}");
-                continue;
-            }
-        };
+    let addr = ([127, 0, 0, 1], 3000).into();
+    let server = Server::bind(&addr).executor(LocalExec).serve(MakeSvc(lua));
 
-        let svc = Svc::new(lua.clone(), handler.clone(), peer_addr);
-        local
-            .run_until(async move {
-                let result = ServerConnBuilder::new(LocalExec)
-                    .http1()
-                    .serve_connection(TokioIo::new(stream), svc)
-                    .await;
-                if let Err(err) = result {
-                    eprintln!("Error serving connection: {err:?}");
-                }
-            })
-            .await;
+    println!("Listening on http://{}", addr);
+
+    // Create `LocalSet` to spawn !Send futures
+    let local = tokio::task::LocalSet::new();
+    local.run_until(server).await.expect("cannot run server")
+}
+
+struct MakeSvc(Rc<Lua>);
+
+impl Service<&AddrStream> for MakeSvc {
+    type Response = Svc;
+    type Error = hyper::Error;
+    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
+
+    fn poll_ready(&mut self, _: &mut Context) -> Poll<Result<(), Self::Error>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn call(&mut self, stream: &AddrStream) -> Self::Future {
+        let lua = self.0.clone();
+        let remote_addr = stream.remote_addr();
+        Box::pin(async move { Ok(Svc(lua, remote_addr)) })
     }
 }
 
@@ -148,7 +128,7 @@ struct LocalExec;
 
 impl<F> hyper::rt::Executor<F> for LocalExec
 where
-    F: Future + 'static, // not requiring `Send`
+    F: std::future::Future + 'static, // not requiring `Send`
 {
     fn execute(&self, fut: F) {
         tokio::task::spawn_local(fut);

examples/async_tcp_server.rs

@@ -6,7 +6,9 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::{TcpListener, TcpStream};
 use tokio::task;
 
-use mlua::{chunk, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods};
+use mlua::{
+    chunk, AnyUserData, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods,
+};
 
 struct LuaTcpStream(TcpStream);
 
@@ -16,19 +18,28 @@ impl UserData for LuaTcpStream {
             Ok(this.0.peer_addr()?.to_string())
         });
 
-        methods.add_async_method_mut("read", |lua, this, size| async move {
-            let mut buf = vec![0; size];
-            let n = this.0.read(&mut buf).await?;
-            buf.truncate(n);
-            lua.create_string(&buf)
-        });
+        methods.add_async_function(
+            "read",
+            |lua, (this, size): (AnyUserData, usize)| async move {
+                let mut this = this.borrow_mut::<Self>()?;
+                let mut buf = vec![0; size];
+                let n = this.0.read(&mut buf).await?;
+                buf.truncate(n);
+                lua.create_string(&buf)
+            },
+        );
 
-        methods.add_async_method_mut("write", |_, this, data: LuaString| async move {
-            let n = this.0.write(&data.as_bytes()).await?;
-            Ok(n)
-        });
+        methods.add_async_function(
+            "write",
+            |_, (this, data): (AnyUserData, LuaString)| async move {
+                let mut this = this.borrow_mut::<Self>()?;
+                let n = this.0.write(&data.as_bytes()).await?;
+                Ok(n)
+            },
+        );
 
-        methods.add_async_method_mut("close", |_, this, ()| async move {
+        methods.add_async_function("close", |_, this: AnyUserData| async move {
+            let mut this = this.borrow_mut::<Self>()?;
             this.0.shutdown().await?;
             Ok(())
         });

examples/guided_tour.rs

@@ -1,9 +1,7 @@
 use std::f32;
 use std::iter::FromIterator;
 
-use mlua::{
-    chunk, FromLua, Function, Lua, MetaMethod, Result, UserData, UserDataMethods, Value, Variadic,
-};
+use mlua::{chunk, Function, Lua, MetaMethod, Result, UserData, UserDataMethods, Variadic};
 
 fn main() -> Result<()> {
     // You can create a new Lua state with `Lua::new()`. This loads the default Lua std library
@@ -24,7 +22,7 @@ fn main() -> Result<()> {
 
     // You can load and evaluate Lua code. The returned type of `Lua::load` is a builder
     // that allows you to change settings before running Lua code. Here, we are using it to set
-    // the name of the loaded chunk to "example code", which will be used when Lua error
+    // the name of the laoded chunk to "example code", which will be used when Lua error
     // messages are printed.
 
     lua.load(
@@ -32,7 +30,7 @@ fn main() -> Result<()> {
             global = 'foo'..'bar'
         "#,
     )
-    .set_name("example code")
+    .set_name("example code")?
     .exec()?;
     assert_eq!(globals.get::<_, String>("global")?, "foobar");
 
@@ -89,7 +87,7 @@ fn main() -> Result<()> {
     let print: Function = globals.get("print")?;
     print.call::<_, ()>("hello from rust")?;
 
-    // This API generally handles variadic using tuples. This is one way to call a function with
+    // This API generally handles variadics using tuples. This is one way to call a function with
     // multiple parameters:
 
     print.call::<_, ()>(("hello", "again", "from", "rust"))?;
@@ -100,7 +98,7 @@ fn main() -> Result<()> {
         ["hello", "yet", "again", "from", "rust"].iter().cloned(),
     ))?;
 
-    // You can bind rust functions to Lua as well. Callbacks receive the Lua state itself as their
+    // You can bind rust functions to Lua as well. Callbacks receive the Lua state inself as their
     // first parameter, and the arguments given to the function as the second parameter. The type
     // of the arguments can be anything that is convertible from the parameters given by Lua, in
     // this case, the function expects two string sequences.
@@ -153,16 +151,6 @@ fn main() -> Result<()> {
     #[derive(Copy, Clone)]
     struct Vec2(f32, f32);
 
-    // We can implement `FromLua` trait for our `Vec2` to return a copy
-    impl<'lua> FromLua<'lua> for Vec2 {
-        fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
-            match value {
-                Value::UserData(ud) => Ok(*ud.borrow::<Self>()?),
-                _ => unreachable!(),
-            }
-        }
-    }
-
     impl UserData for Vec2 {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
             methods.add_method("magnitude", |_, vec, ()| {

examples/module/Cargo.toml

@@ -2,7 +2,7 @@
 name = "rust_module"
 version = "0.0.0"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
-edition = "2021"
+edition = "2018"
 
 [lib]
 crate-type = ["cdylib"]

examples/repl.rs

@@ -1,11 +1,11 @@
 //! This example shows a simple read-evaluate-print-loop (REPL).
 
 use mlua::{Error, Lua, MultiValue};
-use rustyline::DefaultEditor;
+use rustyline::Editor;
 
 fn main() {
     let lua = Lua::new();
-    let mut editor = DefaultEditor::new().expect("Failed to create editor");
+    let mut editor = Editor::<()>::new().expect("Failed to make rustyline editor");
 
     loop {
         let mut prompt = "> ";
@@ -19,12 +19,12 @@ fn main() {
 
             match lua.load(&line).eval::<MultiValue>() {
                 Ok(values) => {
-                    editor.add_history_entry(line).unwrap();
+                    editor.add_history_entry(line);
                     println!(
                         "{}",
                         values
                             .iter()
-                            .map(|value| format!("{:#?}", value))
+                            .map(|value| format!("{:?}", value))
                             .collect::<Vec<_>>()
                             .join("\t")
                     );

mlua-sys/Cargo.toml

@@ -1,46 +0,0 @@
-[package]
-name = "mlua-sys"
-version = "0.6.2"
-authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
-rust-version = "1.71"
-edition = "2021"
-repository = "https://github.com/khvzak/mlua"
-documentation = "https://docs.rs/mlua-sys"
-readme = "README.md"
-categories = ["external-ffi-bindings"]
-license = "MIT"
-links = "lua"
-build = "build/main.rs"
-description = """
-Low level (FFI) bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau
-"""
-
-[package.metadata.docs.rs]
-features = ["lua54", "vendored"]
-rustdoc-args = ["--cfg", "docsrs"]
-
-[features]
-lua54 = []
-lua53 = []
-lua52 = []
-lua51 = []
-luajit = []
-luajit52 = ["luajit"]
-luau = ["luau0-src"]
-luau-codegen = ["luau"]
-luau-vector4 = ["luau"]
-vendored = ["lua-src", "luajit-src"]
-module = []
-
-[dependencies]
-
-[build-dependencies]
-cc = "1.0"
-cfg-if = "1.0"
-pkg-config = "0.3.17"
-lua-src = { version = ">= 547.0.0, < 547.1.0", optional = true }
-luajit-src = { version = ">= 210.5.0, < 210.6.0", optional = true }
-luau0-src = { version = "0.10.0", optional = true }
-
-[lints.rust]
-unexpected_cfgs = { level = "allow", check-cfg = ['cfg(raw_dylib)'] }

mlua-sys/README.md

@@ -1,8 +0,0 @@
-# mlua-sys
-
-Low level (FFI) bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox [Luau].
-
-Intended to be consumed by the [mlua] crate.
-
-[Luau]: https://github.com/Roblox/luau
-[mlua]: https://crates.io/crates/mlua

mlua-sys/build/find_normal.rs

@@ -1,58 +0,0 @@
-#![allow(dead_code)]
-
-use std::env;
-use std::ops::Bound;
-
-pub fn probe_lua() {
-    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
-
-    if target_arch == "wasm32" && cfg!(not(feature = "vendored")) {
-        panic!("Please enable `vendored` feature to build for wasm32");
-    }
-
-    let lib_dir = env::var("LUA_LIB").unwrap_or_default();
-    let lua_lib = env::var("LUA_LIB_NAME").unwrap_or_default();
-
-    println!("cargo:rerun-if-env-changed=LUA_LIB");
-    println!("cargo:rerun-if-env-changed=LUA_LIB_NAME");
-    println!("cargo:rerun-if-env-changed=LUA_LINK");
-
-    if !lua_lib.is_empty() {
-        if !lib_dir.is_empty() {
-            println!("cargo:rustc-link-search=native={lib_dir}");
-        }
-        let mut link_lib = "";
-        if env::var("LUA_LINK").as_deref() == Ok("static") {
-            link_lib = "static=";
-        };
-        println!("cargo:rustc-link-lib={link_lib}{lua_lib}");
-        return;
-    }
-
-    // Find using `pkg-config`
-
-    #[cfg(feature = "lua54")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.4", "5.5", Some("lua5.4"), "5.4");
-    #[cfg(feature = "lua53")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.3", "5.4", Some("lua5.3"), "5.3");
-    #[cfg(feature = "lua52")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.2", "5.3", Some("lua5.2"), "5.2");
-    #[cfg(feature = "lua51")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.1", "5.2", Some("lua5.1"), "5.1");
-    #[cfg(feature = "luajit")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("2.0.4", "2.2", None, "JIT");
-
-    #[rustfmt::skip]
-    let mut lua = pkg_config::Config::new()
-        .range_version((Bound::Included(incl_bound), Bound::Excluded(excl_bound)))
-        .cargo_metadata(true)
-        .probe(if cfg!(feature = "luajit") { "luajit" } else { "lua" });
-
-    if lua.is_err() && alt_probe.is_some() {
-        lua = pkg_config::Config::new()
-            .cargo_metadata(true)
-            .probe(alt_probe.unwrap());
-    }
-
-    lua.unwrap_or_else(|err| panic!("cannot find Lua{ver} using `pkg-config`: {err}"));
-}

mlua-sys/build/main.rs

@@ -1,19 +0,0 @@
-cfg_if::cfg_if! {
-    if #[cfg(all(feature = "lua54", not(any(feature = "lua53", feature = "lua52", feature = "lua51", feature = "luajit", feature = "luau"))))] {
-        include!("main_inner.rs");
-    } else if #[cfg(all(feature = "lua53", not(any(feature = "lua54", feature = "lua52", feature = "lua51", feature = "luajit", feature = "luau"))))] {
-        include!("main_inner.rs");
-    } else if #[cfg(all(feature = "lua52", not(any(feature = "lua54", feature = "lua53", feature = "lua51", feature = "luajit", feature = "luau"))))] {
-        include!("main_inner.rs");
-    } else if #[cfg(all(feature = "lua51", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luajit", feature = "luau"))))] {
-        include!("main_inner.rs");
-    } else if #[cfg(all(feature = "luajit", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "lua51", feature = "luau"))))] {
-        include!("main_inner.rs");
-    } else if #[cfg(all(feature = "luau", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "lua51", feature = "luajit"))))] {
-        include!("main_inner.rs");
-    } else {
-        fn main() {
-            compile_error!("You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau");
-        }
-    }
-}

mlua-sys/build/main_inner.rs

@@ -1,35 +0,0 @@
-use std::env;
-
-cfg_if::cfg_if! {
-    if #[cfg(any(feature = "luau", feature = "vendored"))] {
-        #[path = "find_vendored.rs"]
-        mod find;
-    } else {
-        #[path = "find_normal.rs"]
-        mod find;
-    }
-}
-
-fn main() {
-    #[cfg(all(feature = "luau", feature = "module", windows))]
-    compile_error!("Luau does not support `module` mode on Windows");
-
-    #[cfg(all(feature = "module", feature = "vendored"))]
-    compile_error!("`vendored` and `module` features are mutually exclusive");
-
-    println!("cargo:rerun-if-changed=build");
-
-    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
-    if target_os == "windows" && cfg!(feature = "module") {
-        if !std::env::var("LUA_LIB_NAME").unwrap_or_default().is_empty() {
-            // Don't use raw-dylib linking
-            find::probe_lua();
-            return;
-        }
-
-        println!("cargo:rustc-cfg=raw_dylib");
-    }
-
-    #[cfg(not(feature = "module"))]
-    find::probe_lua();
-}

mlua-sys/src/lib.rs

@@ -1,108 +0,0 @@
-//! Low level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau.
-
-#![allow(non_camel_case_types, non_snake_case, dead_code)]
-#![allow(clippy::missing_safety_doc)]
-#![doc(test(attr(deny(warnings))))]
-#![cfg_attr(docsrs, feature(doc_cfg))]
-
-use std::os::raw::c_int;
-
-#[cfg(any(feature = "lua54", doc))]
-pub use lua54::*;
-
-#[cfg(any(feature = "lua53", doc))]
-pub use lua53::*;
-
-#[cfg(any(feature = "lua52", doc))]
-pub use lua52::*;
-
-#[cfg(any(feature = "lua51", feature = "luajit", doc))]
-pub use lua51::*;
-
-#[cfg(any(feature = "luau", doc))]
-pub use luau::*;
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[doc(hidden)]
-pub const LUA_MAX_UPVALUES: c_int = 255;
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[doc(hidden)]
-pub const LUA_MAX_UPVALUES: c_int = 60;
-
-#[cfg(feature = "luau")]
-#[doc(hidden)]
-pub const LUA_MAX_UPVALUES: c_int = 200;
-
-// I believe `luaL_traceback` < 5.4 requires this much free stack to not error.
-// 5.4 uses `luaL_Buffer`
-#[doc(hidden)]
-pub const LUA_TRACEBACK_STACK: c_int = 11;
-
-// Copied from https://github.com/rust-lang/rust/blob/master/library/std/src/sys/pal/common/alloc.rs
-// The minimum alignment guaranteed by the architecture. This value is used to
-// add fast paths for low alignment values.
-#[cfg(any(
-    target_arch = "x86",
-    target_arch = "arm",
-    target_arch = "m68k",
-    target_arch = "csky",
-    target_arch = "mips",
-    target_arch = "mips32r6",
-    target_arch = "powerpc",
-    target_arch = "powerpc64",
-    target_arch = "sparc",
-    target_arch = "wasm32",
-    target_arch = "hexagon",
-    all(
-        target_arch = "riscv32",
-        not(any(target_os = "espidf", target_os = "zkvm"))
-    ),
-    all(target_arch = "xtensa", not(target_os = "espidf")),
-))]
-#[doc(hidden)]
-pub const SYS_MIN_ALIGN: usize = 8;
-#[cfg(any(
-    target_arch = "x86_64",
-    target_arch = "aarch64",
-    target_arch = "arm64ec",
-    target_arch = "loongarch64",
-    target_arch = "mips64",
-    target_arch = "mips64r6",
-    target_arch = "s390x",
-    target_arch = "sparc64",
-    target_arch = "riscv64",
-    target_arch = "wasm64",
-))]
-#[doc(hidden)]
-pub const SYS_MIN_ALIGN: usize = 16;
-// The allocator on the esp-idf and zkvm platforms guarantee 4 byte alignment.
-#[cfg(any(
-    all(target_arch = "riscv32", any(target_os = "espidf", target_os = "zkvm")),
-    all(target_arch = "xtensa", target_os = "espidf"),
-))]
-#[doc(hidden)]
-pub const SYS_MIN_ALIGN: usize = 4;
-
-#[macro_use]
-mod macros;
-
-#[cfg(any(feature = "lua54", doc))]
-#[cfg_attr(docsrs, doc(cfg(feature = "lua54")))]
-pub mod lua54;
-
-#[cfg(any(feature = "lua53", doc))]
-#[cfg_attr(docsrs, doc(cfg(feature = "lua53")))]
-pub mod lua53;
-
-#[cfg(any(feature = "lua52", doc))]
-#[cfg_attr(docsrs, doc(cfg(feature = "lua52")))]
-pub mod lua52;
-
-#[cfg(any(feature = "lua51", feature = "luajit", doc))]
-#[cfg_attr(docsrs, doc(cfg(any(feature = "lua51", feature = "luajit"))))]
-pub mod lua51;
-
-#[cfg(any(feature = "luau", doc))]
-#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-pub mod luau;

mlua-sys/src/luau/luacodegen.rs

@@ -1,11 +0,0 @@
-//! Contains definitions from `luacodegen.h`.
-
-use std::os::raw::c_int;
-
-use super::lua::lua_State;
-
-extern "C-unwind" {
-    pub fn luau_codegen_supported() -> c_int;
-    pub fn luau_codegen_create(state: *mut lua_State);
-    pub fn luau_codegen_compile(state: *mut lua_State, idx: c_int);
-}

mlua-sys/src/macros.rs

@@ -1,7 +0,0 @@
-#[allow(unused_macros)]
-macro_rules! cstr {
-    ($s:expr) => {
-        concat!($s, "\0") as *const str as *const [::std::os::raw::c_char]
-            as *const ::std::os::raw::c_char
-    };
-}

mlua_derive/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "mlua_derive"
-version = "0.9.3"
+version = "0.8.0"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
-edition = "2021"
+edition = "2018"
 description = "Procedural macros for the mlua crate."
 repository = "https://github.com/khvzak/mlua"
 keywords = ["lua", "mlua"]
@@ -18,7 +18,7 @@ macros = ["proc-macro-error", "itertools", "regex", "once_cell"]
 quote = "1.0"
 proc-macro2 = { version = "1.0", features = ["span-locations"] }
 proc-macro-error = { version = "1.0", optional = true }
-syn = { version = "2.0", features = ["full"] }
-itertools = { version = "0.12", optional = true }
+syn = { version = "1.0", features = ["full"] }
+itertools = { version = "0.10", optional = true }
 regex = { version = "1.4", optional = true }
 once_cell = { version = "1.0", optional = true }

mlua_derive/src/from_lua.rs

@@ -1,33 +0,0 @@
-use proc_macro::TokenStream;
-use quote::quote;
-use syn::{parse_macro_input, DeriveInput};
-
-pub fn from_lua(input: TokenStream) -> TokenStream {
-    let DeriveInput {
-        ident, generics, ..
-    } = parse_macro_input!(input as DeriveInput);
-
-    let ident_str = ident.to_string();
-    let (impl_generics, ty_generics, _) = generics.split_for_impl();
-    let where_clause = match &generics.where_clause {
-        Some(where_clause) => quote! { #where_clause, Self: 'static + Clone },
-        None => quote! { where Self: 'static + Clone },
-    };
-
-    quote! {
-      impl #impl_generics ::mlua::FromLua<'_> for #ident #ty_generics #where_clause {
-        #[inline]
-        fn from_lua(value: ::mlua::Value<'_>, _: &'_ ::mlua::Lua) -> ::mlua::Result<Self> {
-          match value {
-            ::mlua::Value::UserData(ud) => Ok(ud.borrow::<Self>()?.clone()),
-            _ => Err(::mlua::Error::FromLuaConversionError {
-                from: value.type_name(),
-                to: #ident_str,
-                message: None,
-            }),
-          }
-        }
-      }
-    }
-    .into()
-}

mlua_derive/src/lib.rs

@@ -1,8 +1,7 @@
 use proc_macro::TokenStream;
 use proc_macro2::{Ident, Span};
 use quote::quote;
-use syn::meta::ParseNestedMeta;
-use syn::{parse_macro_input, ItemFn, LitStr, Result};
+use syn::{parse_macro_input, AttributeArgs, Error, ItemFn};
 
 #[cfg(feature = "macros")]
 use {
@@ -10,63 +9,30 @@ use {
     proc_macro_error::proc_macro_error,
 };
 
-#[derive(Default)]
-struct ModuleAttributes {
-    name: Option<Ident>,
-    skip_memory_check: bool,
-}
-
-impl ModuleAttributes {
-    fn parse(&mut self, meta: ParseNestedMeta) -> Result<()> {
-        if meta.path.is_ident("name") {
-            match meta.value() {
-                Ok(value) => {
-                    self.name = Some(value.parse::<LitStr>()?.parse()?);
-                }
-                Err(_) => {
-                    return Err(meta.error("`name` attribute must have a value"));
-                }
-            }
-        } else if meta.path.is_ident("skip_memory_check") {
-            if meta.value().is_ok() {
-                return Err(meta.error("`skip_memory_check` attribute have no values"));
-            }
-            self.skip_memory_check = true;
-        } else {
-            return Err(meta.error("unsupported module attribute"));
-        }
-        Ok(())
-    }
-}
-
 #[proc_macro_attribute]
 pub fn lua_module(attr: TokenStream, item: TokenStream) -> TokenStream {
-    let mut args = ModuleAttributes::default();
-    if !attr.is_empty() {
-        let args_parser = syn::meta::parser(|meta| args.parse(meta));
-        parse_macro_input!(attr with args_parser);
+    let args = parse_macro_input!(attr as AttributeArgs);
+    let func = parse_macro_input!(item as ItemFn);
+
+    if !args.is_empty() {
+        let err = Error::new(Span::call_site(), "the macro does not support arguments")
+            .to_compile_error();
+        return err.into();
     }
 
-    let func = parse_macro_input!(item as ItemFn);
-    let func_name = &func.sig.ident;
-    let module_name = args.name.unwrap_or_else(|| func_name.clone());
-    let ext_entrypoint_name = Ident::new(&format!("luaopen_{module_name}"), Span::call_site());
-    let skip_memory_check = if args.skip_memory_check {
-        quote! { lua.skip_memory_check(true); }
-    } else {
-        quote! {}
-    };
+    let func_name = func.sig.ident.clone();
+    let ext_entrypoint_name = Ident::new(&format!("luaopen_{}", func_name), Span::call_site());
 
     let wrapped = quote! {
-        mlua::require_module_feature!();
+        ::mlua::require_module_feature!();
 
         #func
 
         #[no_mangle]
-        unsafe extern "C-unwind" fn #ext_entrypoint_name(state: *mut mlua::lua_State) -> ::std::os::raw::c_int {
-            let lua = mlua::Lua::init_from_ptr(state);
-            #skip_memory_check
-            lua.entrypoint1(state, #func_name)
+        unsafe extern "C" fn #ext_entrypoint_name(state: *mut ::mlua::lua_State) -> ::std::os::raw::c_int {
+            ::mlua::Lua::init_from_ptr(state)
+                .entrypoint1(#func_name)
+                .expect("cannot initialize module")
         }
     };
 
@@ -95,22 +61,30 @@ pub fn chunk(input: TokenStream) -> TokenStream {
     });
 
     let wrapped_code = quote! {{
-        use mlua::{AsChunk, ChunkMode, Lua, Result, Table};
+        use ::mlua::{AsChunk, ChunkMode, Lua, Result, Value};
         use ::std::borrow::Cow;
-        use ::std::cell::Cell;
         use ::std::io::Result as IoResult;
         use ::std::marker::PhantomData;
+        use ::std::sync::Mutex;
 
-        struct InnerChunk<'lua, F: FnOnce(&'lua Lua) -> Result<Table<'lua>>>(Cell<Option<F>>, PhantomData<&'lua ()>);
+        fn annotate<'a, F: FnOnce(&'a Lua) -> Result<Value<'a>>>(f: F) -> F { f }
 
-        impl<'lua, F> AsChunk<'lua, 'static> for InnerChunk<'lua, F>
+        struct InnerChunk<'a, F: FnOnce(&'a Lua) -> Result<Value<'a>>>(Mutex<Option<F>>, PhantomData<&'a ()>);
+
+        impl<'lua, F> AsChunk<'lua> for InnerChunk<'lua, F>
         where
-            F: FnOnce(&'lua Lua) -> Result<Table<'lua>>,
+            F: FnOnce(&'lua Lua) -> Result<Value<'lua>>,
         {
-            fn environment(&self, lua: &'lua Lua) -> Result<Option<Table<'lua>>> {
+            fn source(&self) -> IoResult<Cow<[u8]>> {
+                Ok(Cow::Borrowed((#source).as_bytes()))
+            }
+
+            fn env(&self, lua: &'lua Lua) -> Result<Option<Value<'lua>>> {
                 if #caps_len > 0 {
-                    if let Some(make_env) = self.0.take() {
-                        return make_env(lua).map(Some);
+                    if let Ok(mut make_env) = self.0.lock() {
+                        if let Some(make_env) = make_env.take() {
+                            return make_env(lua).map(Some);
+                        }
                     }
                 }
                 Ok(None)
@@ -119,15 +93,9 @@ pub fn chunk(input: TokenStream) -> TokenStream {
             fn mode(&self) -> Option<ChunkMode> {
                 Some(ChunkMode::Text)
             }
-
-            fn source(self) -> IoResult<Cow<'static, [u8]>> {
-                Ok(Cow::Borrowed((#source).as_bytes()))
-            }
         }
 
-        fn annotate<'a, F: FnOnce(&'a Lua) -> Result<Table<'a>>>(f: F) -> F { f }
-
-        let make_env = annotate(move |lua: &Lua| -> Result<Table> {
+        let make_env = annotate(move |lua: &Lua| -> Result<Value> {
             let globals = lua.globals();
             let env = lua.create_table()?;
             let meta = lua.create_table()?;
@@ -138,24 +106,16 @@ pub fn chunk(input: TokenStream) -> TokenStream {
             #(#caps)*
 
             env.set_metatable(Some(meta));
-            Ok(env)
+            Ok(Value::Table(env))
         });
 
-        InnerChunk(Cell::new(Some(make_env)), PhantomData)
+        &InnerChunk(Mutex::new(Some(make_env)), PhantomData)
     }};
 
     wrapped_code.into()
 }
 
-#[cfg(feature = "macros")]
-#[proc_macro_derive(FromLua)]
-pub fn from_lua(input: TokenStream) -> TokenStream {
-    from_lua::from_lua(input)
-}
-
 #[cfg(feature = "macros")]
 mod chunk;
 #[cfg(feature = "macros")]
-mod from_lua;
-#[cfg(feature = "macros")]
 mod token;

mlua_derive/src/token.rs

@@ -1,6 +1,7 @@
 use std::{
     cmp::{Eq, PartialEq},
     fmt::{self, Display, Formatter},
+    iter::IntoIterator,
     vec::IntoIter,
 };
 
@@ -58,7 +59,7 @@ fn parse_pos(span: &Span) -> Option<(usize, usize)> {
 
     static RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"bytes\(([0-9]+)\.\.([0-9]+)\)").unwrap());
 
-    match RE.captures(&format!("{span:?}")) {
+    match RE.captures(&format!("{:?}", span)) {
         Some(caps) => match (caps.get(1), caps.get(2)) {
             (Some(start), Some(end)) => Some((
                 match start.as_str().parse() {

src/chunk.rs

@@ -5,17 +5,23 @@ use std::io::Result as IoResult;
 use std::path::{Path, PathBuf};
 use std::string::String as StdString;
 
-use crate::error::{Error, ErrorContext, Result};
+use crate::error::{Error, Result};
+use crate::ffi;
 use crate::function::Function;
 use crate::lua::Lua;
-use crate::table::Table;
-use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
+use crate::value::{FromLuaMulti, ToLua, ToLuaMulti, Value};
+
+#[cfg(feature = "async")]
+use {futures_core::future::LocalBoxFuture, futures_util::future};
 
 /// Trait for types [loadable by Lua] and convertible to a [`Chunk`]
 ///
 /// [loadable by Lua]: https://www.lua.org/manual/5.4/manual.html#3.3.2
 /// [`Chunk`]: crate::Chunk
-pub trait AsChunk<'lua, 'a> {
+pub trait AsChunk<'lua> {
+    /// Returns chunk data (can be text or binary)
+    fn source(&self) -> IoResult<Cow<[u8]>>;
+
     /// Returns optional chunk name
     fn name(&self) -> Option<StdString> {
         None
@@ -24,8 +30,7 @@ pub trait AsChunk<'lua, 'a> {
     /// Returns optional chunk [environment]
     ///
     /// [environment]: https://www.lua.org/manual/5.4/manual.html#2.2
-    fn environment(&self, lua: &'lua Lua) -> Result<Option<Table<'lua>>> {
-        let _lua = lua; // suppress warning
+    fn env(&self, _lua: &'lua Lua) -> Result<Option<Value<'lua>>> {
         Ok(None)
     }
 
@@ -33,64 +38,49 @@ pub trait AsChunk<'lua, 'a> {
     fn mode(&self) -> Option<ChunkMode> {
         None
     }
-
-    /// Returns chunk data (can be text or binary)
-    fn source(self) -> IoResult<Cow<'a, [u8]>>;
 }
 
-impl<'a> AsChunk<'_, 'a> for &'a str {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+impl<'lua> AsChunk<'lua> for str {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
         Ok(Cow::Borrowed(self.as_ref()))
     }
 }
 
-impl AsChunk<'_, 'static> for StdString {
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
-        Ok(Cow::Owned(self.into_bytes()))
+impl<'lua> AsChunk<'lua> for StdString {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
+        Ok(Cow::Borrowed(self.as_ref()))
     }
 }
 
-impl<'a> AsChunk<'_, 'a> for &'a StdString {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
-        Ok(Cow::Borrowed(self.as_bytes()))
-    }
-}
-
-impl<'a> AsChunk<'_, 'a> for &'a [u8] {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+impl<'lua> AsChunk<'lua> for [u8] {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
         Ok(Cow::Borrowed(self))
     }
 }
 
-impl AsChunk<'_, 'static> for Vec<u8> {
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
-        Ok(Cow::Owned(self))
+impl<'lua> AsChunk<'lua> for Vec<u8> {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
+        Ok(Cow::Borrowed(self))
     }
 }
 
-impl<'a> AsChunk<'_, 'a> for &'a Vec<u8> {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
-        Ok(Cow::Borrowed(self.as_ref()))
+impl<'lua> AsChunk<'lua> for Path {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
+        std::fs::read(self).map(Cow::Owned)
     }
-}
 
-impl AsChunk<'_, 'static> for &Path {
     fn name(&self) -> Option<StdString> {
         Some(format!("@{}", self.display()))
     }
-
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
-        std::fs::read(self).map(Cow::Owned)
-    }
 }
 
-impl AsChunk<'_, 'static> for PathBuf {
-    fn name(&self) -> Option<StdString> {
-        Some(format!("@{}", self.display()))
+impl<'lua> AsChunk<'lua> for PathBuf {
+    fn source(&self) -> IoResult<Cow<[u8]>> {
+        std::fs::read(self).map(Cow::Owned)
     }
 
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
-        std::fs::read(self).map(Cow::Owned)
+    fn name(&self) -> Option<StdString> {
+        Some(format!("@{}", self.display()))
     }
 }
 
@@ -100,10 +90,10 @@ impl AsChunk<'_, 'static> for PathBuf {
 #[must_use = "`Chunk`s do nothing unless one of `exec`, `eval`, `call`, or `into_function` are called on them"]
 pub struct Chunk<'lua, 'a> {
     pub(crate) lua: &'lua Lua,
-    pub(crate) name: StdString,
-    pub(crate) env: Result<Option<Table<'lua>>>,
-    pub(crate) mode: Option<ChunkMode>,
     pub(crate) source: IoResult<Cow<'a, [u8]>>,
+    pub(crate) name: Option<StdString>,
+    pub(crate) env: Result<Option<Value<'lua>>>,
+    pub(crate) mode: Option<ChunkMode>,
     #[cfg(feature = "luau")]
     pub(crate) compiler: Option<Compiler>,
 }
@@ -122,38 +112,32 @@ pub enum ChunkMode {
 pub struct Compiler {
     optimization_level: u8,
     debug_level: u8,
-    type_info_level: u8,
     coverage_level: u8,
     vector_lib: Option<String>,
     vector_ctor: Option<String>,
-    vector_type: Option<String>,
     mutable_globals: Vec<String>,
-    userdata_types: Vec<String>,
 }
 
 #[cfg(any(feature = "luau", doc))]
 impl Default for Compiler {
     fn default() -> Self {
-        Self::new()
+        // Defaults are taken from luacode.h
+        Compiler {
+            optimization_level: 1,
+            debug_level: 1,
+            coverage_level: 0,
+            vector_lib: None,
+            vector_ctor: None,
+            mutable_globals: Vec::new(),
+        }
     }
 }
 
 #[cfg(any(feature = "luau", doc))]
 impl Compiler {
     /// Creates Luau compiler instance with default options
-    pub const fn new() -> Self {
-        // Defaults are taken from luacode.h
-        Compiler {
-            optimization_level: 1,
-            debug_level: 1,
-            type_info_level: 0,
-            coverage_level: 0,
-            vector_lib: None,
-            vector_ctor: None,
-            vector_type: None,
-            mutable_globals: Vec::new(),
-            userdata_types: Vec::new(),
-        }
+    pub fn new() -> Self {
+        Compiler::default()
     }
 
     /// Sets Luau compiler optimization level.
@@ -162,8 +146,7 @@ impl Compiler {
     /// * 0 - no optimization
     /// * 1 - baseline optimization level that doesn't prevent debuggability (default)
     /// * 2 - includes optimizations that harm debuggability such as inlining
-    #[must_use]
-    pub const fn set_optimization_level(mut self, level: u8) -> Self {
+    pub fn set_optimization_level(mut self, level: u8) -> Self {
         self.optimization_level = level;
         self
     }
@@ -174,71 +157,42 @@ impl Compiler {
     /// * 0 - no debugging support
     /// * 1 - line info & function names only; sufficient for backtraces (default)
     /// * 2 - full debug info with local & upvalue names; necessary for debugger
-    #[must_use]
-    pub const fn set_debug_level(mut self, level: u8) -> Self {
+    pub fn set_debug_level(mut self, level: u8) -> Self {
         self.debug_level = level;
         self
     }
 
-    /// Sets Luau type information level used to guide native code generation decisions.
-    ///
-    /// Possible values:
-    /// * 0 - generate for native modules (default)
-    /// * 1 - generate for all modules
-    pub const fn set_type_info_level(mut self, level: u8) -> Self {
-        self.type_info_level = level;
-        self
-    }
-
     /// Sets Luau compiler code coverage level.
     ///
     /// Possible values:
     /// * 0 - no code coverage support (default)
     /// * 1 - statement coverage
     /// * 2 - statement and expression coverage (verbose)
-    #[must_use]
-    pub const fn set_coverage_level(mut self, level: u8) -> Self {
+    pub fn set_coverage_level(mut self, level: u8) -> Self {
         self.coverage_level = level;
         self
     }
 
     #[doc(hidden)]
-    #[must_use]
-    pub fn set_vector_lib(mut self, lib: impl Into<String>) -> Self {
-        self.vector_lib = Some(lib.into());
+    pub fn set_vector_lib(mut self, lib: Option<String>) -> Self {
+        self.vector_lib = lib;
         self
     }
 
     #[doc(hidden)]
-    #[must_use]
-    pub fn set_vector_ctor(mut self, ctor: impl Into<String>) -> Self {
-        self.vector_ctor = Some(ctor.into());
-        self
-    }
-
-    #[doc(hidden)]
-    #[must_use]
-    pub fn set_vector_type(mut self, r#type: impl Into<String>) -> Self {
-        self.vector_type = Some(r#type.into());
+    pub fn set_vector_ctor(mut self, ctor: Option<String>) -> Self {
+        self.vector_ctor = ctor;
         self
     }
 
     /// Sets a list of globals that are mutable.
     ///
     /// It disables the import optimization for fields accessed through these.
-    #[must_use]
     pub fn set_mutable_globals(mut self, globals: Vec<String>) -> Self {
         self.mutable_globals = globals;
         self
     }
 
-    /// Sets a list of userdata types that will be included in the type information.
-    #[must_use]
-    pub fn set_userdata_types(mut self, types: Vec<String>) -> Self {
-        self.userdata_types = types;
-        self
-    }
-
     /// Compiles the `source` into bytecode.
     pub fn compile(&self, source: impl AsRef<[u8]>) -> Vec<u8> {
         use std::os::raw::c_int;
@@ -250,41 +204,33 @@ impl Compiler {
         let vector_ctor = self.vector_ctor.clone();
         let vector_ctor = vector_ctor.and_then(|ctor| CString::new(ctor).ok());
         let vector_ctor = vector_ctor.as_ref();
-        let vector_type = self.vector_type.clone();
-        let vector_type = vector_type.and_then(|t| CString::new(t).ok());
-        let vector_type = vector_type.as_ref();
 
-        macro_rules! vec2cstring_ptr {
-            ($name:ident, $name_ptr:ident) => {
-                let $name = self
-                    .$name
-                    .iter()
-                    .map(|name| CString::new(name.clone()).ok())
-                    .collect::<Option<Vec<_>>>()
-                    .unwrap_or_default();
-                let mut $name = $name.iter().map(|s| s.as_ptr()).collect::<Vec<_>>();
-                let mut $name_ptr = ptr::null();
-                if !$name.is_empty() {
-                    $name.push(ptr::null());
-                    $name_ptr = $name.as_ptr();
-                }
-            };
+        let mutable_globals = self
+            .mutable_globals
+            .iter()
+            .map(|name| CString::new(name.clone()).ok())
+            .collect::<Option<Vec<_>>>()
+            .unwrap_or_default();
+        let mut mutable_globals = mutable_globals
+            .iter()
+            .map(|s| s.as_ptr())
+            .collect::<Vec<_>>();
+        let mut mutable_globals_ptr = ptr::null_mut();
+        if !mutable_globals.is_empty() {
+            mutable_globals.push(ptr::null());
+            mutable_globals_ptr = mutable_globals.as_mut_ptr();
         }
 
-        vec2cstring_ptr!(mutable_globals, mutable_globals_ptr);
-        vec2cstring_ptr!(userdata_types, userdata_types_ptr);
-
         unsafe {
-            let mut options = ffi::lua_CompileOptions::default();
-            options.optimizationLevel = self.optimization_level as c_int;
-            options.debugLevel = self.debug_level as c_int;
-            options.typeInfoLevel = self.type_info_level as c_int;
-            options.coverageLevel = self.coverage_level as c_int;
-            options.vectorLib = vector_lib.map_or(ptr::null(), |s| s.as_ptr());
-            options.vectorCtor = vector_ctor.map_or(ptr::null(), |s| s.as_ptr());
-            options.vectorType = vector_type.map_or(ptr::null(), |s| s.as_ptr());
-            options.mutableGlobals = mutable_globals_ptr;
-            options.userdataTypes = userdata_types_ptr;
+            let options = ffi::lua_CompileOptions {
+                optimizationLevel: self.optimization_level as c_int,
+                debugLevel: self.debug_level as c_int,
+                coverageLevel: self.coverage_level as c_int,
+                vectorLib: vector_lib.map_or(ptr::null(), |s| s.as_ptr()),
+                vectorCtor: vector_ctor.map_or(ptr::null(), |s| s.as_ptr()),
+                vectorType: ptr::null(),
+                mutableGlobals: mutable_globals_ptr,
+            };
             ffi::luau_compile(source.as_ref(), options)
         }
     }
@@ -292,14 +238,16 @@ impl Compiler {
 
 impl<'lua, 'a> Chunk<'lua, 'a> {
     /// Sets the name of this chunk, which results in more informative error traces.
-    pub fn set_name(mut self, name: impl Into<String>) -> Self {
-        self.name = name.into();
-        self
+    pub fn set_name(mut self, name: impl AsRef<str>) -> Result<Self> {
+        self.name = Some(name.as_ref().to_string());
+        // Do extra validation
+        let _ = self.convert_name()?;
+        Ok(self)
     }
 
-    /// Sets the environment of the loaded chunk to the given value.
+    /// Sets the first upvalue (`_ENV`) of the loaded chunk to the given value.
     ///
-    /// In Lua >=5.2 main chunks always have exactly one upvalue, and this upvalue is used as the `_ENV`
+    /// Lua main chunks always have exactly one upvalue, and this upvalue is used as the `_ENV`
     /// variable inside the chunk. By default this value is set to the global environment.
     ///
     /// Calling this method changes the `_ENV` upvalue to the value provided, and variables inside
@@ -308,12 +256,10 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// All global variables (including the standard library!) are looked up in `_ENV`, so it may be
     /// necessary to populate the environment in order for scripts using custom environments to be
     /// useful.
-    pub fn set_environment<V: IntoLua<'lua>>(mut self, env: V) -> Self {
-        self.env = env
-            .into_lua(self.lua)
-            .and_then(|val| self.lua.unpack(val))
-            .context("bad environment value");
-        self
+    pub fn set_environment<V: ToLua<'lua>>(mut self, env: V) -> Result<Self> {
+        // Prefer to propagate errors here and wrap to `Ok`
+        self.env = Ok(Some(env.to_lua(self.lua)?));
+        Ok(self)
     }
 
     /// Sets whether the chunk is text or binary (autodetected by default).
@@ -341,7 +287,7 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     ///
     /// This is equivalent to calling the chunk function with no arguments and no return values.
     pub fn exec(self) -> Result<()> {
-        self.call::<_, ()>(())?;
+        self.call(())?;
         Ok(())
     }
 
@@ -354,8 +300,11 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`exec`]: #method.exec
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub async fn exec_async(self) -> Result<()> {
-        self.call_async(()).await
+    pub fn exec_async<'fut>(self) -> LocalBoxFuture<'fut, Result<()>>
+    where
+        'lua: 'fut,
+    {
+        self.call_async(())
     }
 
     /// Evaluate the chunk as either an expression or block.
@@ -386,23 +335,24 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`eval`]: #method.eval
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub async fn eval_async<R>(self) -> Result<R>
+    pub fn eval_async<'fut, R>(self) -> LocalBoxFuture<'fut, Result<R>>
     where
-        R: FromLuaMulti<'lua> + 'lua,
+        'lua: 'fut,
+        R: FromLuaMulti<'lua> + 'fut,
     {
         if self.detect_mode() == ChunkMode::Binary {
-            self.call_async(()).await
+            self.call_async(())
         } else if let Ok(function) = self.to_expression() {
-            function.call_async(()).await
+            function.call_async(())
         } else {
-            self.call_async(()).await
+            self.call_async(())
         }
     }
 
     /// Load the chunk function and call it with the given arguments.
     ///
     /// This is equivalent to `into_function` and calling the resulting function.
-    pub fn call<A: IntoLuaMulti<'lua>, R: FromLuaMulti<'lua>>(self, args: A) -> Result<R> {
+    pub fn call<A: ToLuaMulti<'lua>, R: FromLuaMulti<'lua>>(self, args: A) -> Result<R> {
         self.into_function()?.call(args)
     }
 
@@ -415,12 +365,16 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`call`]: #method.call
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub async fn call_async<A, R>(self, args: A) -> Result<R>
+    pub fn call_async<'fut, A, R>(self, args: A) -> LocalBoxFuture<'fut, Result<R>>
     where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
+        'lua: 'fut,
+        A: ToLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'fut,
     {
-        self.into_function()?.call_async(args).await
+        match self.into_function() {
+            Ok(func) => func.call_async(args),
+            Err(e) => Box::pin(future::err(e)),
+        }
     }
 
     /// Load this chunk into a regular `Function`.
@@ -434,9 +388,9 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
             self.compile();
         }
 
-        let name = Self::convert_name(self.name)?;
+        let name = self.convert_name()?;
         self.lua
-            .load_chunk(Some(&name), self.env?, self.mode, self.source?.as_ref())
+            .load_chunk(self.source?.as_ref(), name.as_deref(), self.env?, self.mode)
     }
 
     /// Compiles the chunk and changes mode to binary.
@@ -455,7 +409,7 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
                     self.mode = Some(ChunkMode::Binary);
                 }
                 #[cfg(not(feature = "luau"))]
-                if let Ok(func) = self.lua.load_chunk(None, None, None, source.as_ref()) {
+                if let Ok(func) = self.lua.load_chunk(source.as_ref(), None, None, None) {
                     let data = func.dump(false);
                     self.source = Ok(Cow::Owned(data));
                     self.mode = Some(ChunkMode::Binary);
@@ -495,7 +449,7 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
                     } else {
                         let mut cache = ChunksCache(HashMap::new());
                         cache.0.insert(text_source, binary_source.as_ref().to_vec());
-                        let _ = self.lua.try_set_app_data(cache);
+                        self.lua.set_app_data(cache);
                     }
                 }
             }
@@ -507,7 +461,7 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     fn to_expression(&self) -> Result<Function<'lua>> {
         // We assume that mode is Text
         let source = self.source.as_ref();
-        let source = source.map_err(Error::runtime)?;
+        let source = source.map_err(|err| Error::RuntimeError(err.to_string()))?;
         let source = Self::expression_source(source);
         // We don't need to compile source if no compiler options set
         #[cfg(feature = "luau")]
@@ -517,9 +471,9 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
             .map(|c| c.compile(&source))
             .unwrap_or(source);
 
-        let name = Self::convert_name(self.name.clone())?;
+        let name = self.convert_name()?;
         self.lua
-            .load_chunk(Some(&name), self.env.clone()?, None, &source)
+            .load_chunk(&source, name.as_deref(), self.env.clone()?, None)
     }
 
     fn detect_mode(&self) -> ChunkMode {
@@ -540,8 +494,12 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
         }
     }
 
-    fn convert_name(name: String) -> Result<CString> {
-        CString::new(name).map_err(|err| Error::runtime(format!("invalid name: {err}")))
+    fn convert_name(&self) -> Result<Option<CString>> {
+        self.name
+            .clone()
+            .map(CString::new)
+            .transpose()
+            .map_err(|err| Error::RuntimeError(format!("invalid name: {err}")))
     }
 
     fn expression_source(source: &[u8]) -> Vec<u8> {

src/conversion.rs

@@ -1,10 +1,11 @@
+#![allow(clippy::wrong_self_convention)]
+
 use std::borrow::Cow;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
+use std::convert::TryInto;
 use std::ffi::{CStr, CString};
 use std::hash::{BuildHasher, Hash};
-use std::os::raw::c_int;
 use std::string::String as StdString;
-use std::{slice, str};
 
 use bstr::{BStr, BString};
 use num_traits::cast;
@@ -15,35 +16,17 @@ use crate::lua::Lua;
 use crate::string::String;
 use crate::table::Table;
 use crate::thread::Thread;
-use crate::types::{LightUserData, MaybeSend, RegistryKey};
-use crate::userdata::{AnyUserData, UserData, UserDataRef, UserDataRefMut};
-use crate::value::{FromLua, IntoLua, Nil, Value};
+use crate::types::{LightUserData, MaybeSend};
+use crate::userdata::{AnyUserData, UserData};
+use crate::value::{FromLua, Nil, ToLua, Value};
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-use crate::{
-    function::OwnedFunction, string::OwnedString, table::OwnedTable, thread::OwnedThread,
-    userdata::OwnedAnyUserData,
-};
-
-impl<'lua> IntoLua<'lua> for Value<'lua> {
+impl<'lua> ToLua<'lua> for Value<'lua> {
     #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(self)
     }
 }
 
-impl<'lua> IntoLua<'lua> for &Value<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(self.clone())
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_value_ref(self)
-    }
-}
-
 impl<'lua> FromLua<'lua> for Value<'lua> {
     #[inline]
     fn from_lua(lua_value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
@@ -51,26 +34,13 @@ impl<'lua> FromLua<'lua> for Value<'lua> {
     }
 }
 
-impl<'lua> IntoLua<'lua> for String<'lua> {
+impl<'lua> ToLua<'lua> for String<'lua> {
     #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(self))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &String<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::String(self.clone()))
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_ref(&self.0);
-        Ok(())
-    }
-}
-
 impl<'lua> FromLua<'lua> for String<'lua> {
     #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<String<'lua>> {
@@ -78,65 +48,19 @@ impl<'lua> FromLua<'lua> for String<'lua> {
         lua.coerce_string(value)?
             .ok_or_else(|| Error::FromLuaConversionError {
                 from: ty,
-                to: "string",
+                to: "String",
                 message: Some("expected string or number".to_string()),
             })
     }
 }
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for OwnedString {
+impl<'lua> ToLua<'lua> for Table<'lua> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::String(String(lua.adopt_owned_ref(self.0))))
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for &OwnedString {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        OwnedString::into_lua(self.clone(), lua)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_owned_ref(&self.0);
-        Ok(())
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> FromLua<'lua> for OwnedString {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<OwnedString> {
-        String::from_lua(value, lua).map(|s| s.into_owned())
-    }
-}
-
-impl<'lua> IntoLua<'lua> for Table<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(self))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &Table<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Table(self.clone()))
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_ref(&self.0);
-        Ok(())
-    }
-}
-
 impl<'lua> FromLua<'lua> for Table<'lua> {
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Table<'lua>> {
@@ -151,59 +75,13 @@ impl<'lua> FromLua<'lua> for Table<'lua> {
     }
 }
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for OwnedTable {
+impl<'lua> ToLua<'lua> for Function<'lua> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Table(Table(lua.adopt_owned_ref(self.0))))
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for &OwnedTable {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        OwnedTable::into_lua(self.clone(), lua)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_owned_ref(&self.0);
-        Ok(())
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> FromLua<'lua> for OwnedTable {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<OwnedTable> {
-        Table::from_lua(value, lua).map(|s| s.into_owned())
-    }
-}
-
-impl<'lua> IntoLua<'lua> for Function<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Function(self))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &Function<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Function(self.clone()))
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_ref(&self.0);
-        Ok(())
-    }
-}
-
 impl<'lua> FromLua<'lua> for Function<'lua> {
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Function<'lua>> {
@@ -218,59 +96,13 @@ impl<'lua> FromLua<'lua> for Function<'lua> {
     }
 }
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for OwnedFunction {
+impl<'lua> ToLua<'lua> for Thread<'lua> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Function(Function(lua.adopt_owned_ref(self.0))))
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for &OwnedFunction {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        OwnedFunction::into_lua(self.clone(), lua)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_owned_ref(&self.0);
-        Ok(())
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> FromLua<'lua> for OwnedFunction {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<OwnedFunction> {
-        Function::from_lua(value, lua).map(|s| s.into_owned())
-    }
-}
-
-impl<'lua> IntoLua<'lua> for Thread<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Thread(self))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &Thread<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Thread(self.clone()))
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_ref(&self.0);
-        Ok(())
-    }
-}
-
 impl<'lua> FromLua<'lua> for Thread<'lua> {
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Thread<'lua>> {
@@ -285,59 +117,13 @@ impl<'lua> FromLua<'lua> for Thread<'lua> {
     }
 }
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for OwnedThread {
+impl<'lua> ToLua<'lua> for AnyUserData<'lua> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Thread(Thread(lua.adopt_owned_ref(self.0), self.1)))
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for &OwnedThread {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        OwnedThread::into_lua(self.clone(), lua)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_owned_ref(&self.0);
-        Ok(())
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> FromLua<'lua> for OwnedThread {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<OwnedThread> {
-        Thread::from_lua(value, lua).map(|s| s.into_owned())
-    }
-}
-
-impl<'lua> IntoLua<'lua> for AnyUserData<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::UserData(self))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &AnyUserData<'lua> {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::UserData(self.clone()))
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_ref(&self.0);
-        Ok(())
-    }
-}
-
 impl<'lua> FromLua<'lua> for AnyUserData<'lua> {
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<AnyUserData<'lua>> {
@@ -352,66 +138,30 @@ impl<'lua> FromLua<'lua> for AnyUserData<'lua> {
     }
 }
 
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for OwnedAnyUserData {
+impl<'lua, T: 'static + MaybeSend + UserData> ToLua<'lua> for T {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::UserData(AnyUserData(
-            lua.adopt_owned_ref(self.0),
-            self.1,
-        )))
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> IntoLua<'lua> for &OwnedAnyUserData {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        OwnedAnyUserData::into_lua(self.clone(), lua)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_owned_ref(&self.0);
-        Ok(())
-    }
-}
-
-#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-impl<'lua> FromLua<'lua> for OwnedAnyUserData {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<OwnedAnyUserData> {
-        AnyUserData::from_lua(value, lua).map(|s| s.into_owned())
-    }
-}
-
-impl<'lua, T: UserData + MaybeSend + 'static> IntoLua<'lua> for T {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::UserData(lua.create_userdata(self)?))
     }
 }
 
-impl<'lua, T: 'static> FromLua<'lua> for UserDataRef<'lua, T> {
+impl<'lua, T: 'static + UserData + Clone> FromLua<'lua> for T {
     #[inline]
-    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
-        Self::from_value(value)
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<T> {
+        match value {
+            Value::UserData(ud) => Ok(ud.borrow::<T>()?.clone()),
+            _ => Err(Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: "userdata",
+                message: None,
+            }),
+        }
     }
 }
 
-impl<'lua, T: 'static> FromLua<'lua> for UserDataRefMut<'lua, T> {
+impl<'lua> ToLua<'lua> for Error {
     #[inline]
-    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
-        Self::from_value(value)
-    }
-}
-
-impl<'lua> IntoLua<'lua> for Error {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Error(self))
     }
 }
@@ -421,7 +171,7 @@ impl<'lua> FromLua<'lua> for Error {
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Error> {
         match value {
             Value::Error(err) => Ok(err),
-            val => Ok(Error::runtime(
+            val => Ok(Error::RuntimeError(
                 lua.coerce_string(val)?
                     .and_then(|s| Some(s.to_str().ok()?.to_owned()))
                     .unwrap_or_else(|| "<unprintable error>".to_owned()),
@@ -430,57 +180,11 @@ impl<'lua> FromLua<'lua> for Error {
     }
 }
 
-impl<'lua> IntoLua<'lua> for RegistryKey {
+impl<'lua> ToLua<'lua> for bool {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        lua.registry_value(&self)
-    }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        <&RegistryKey>::push_into_stack(&self, lua)
-    }
-}
-
-impl<'lua> IntoLua<'lua> for &RegistryKey {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        lua.registry_value(self)
-    }
-
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        if !lua.owns_registry_value(self) {
-            return Err(Error::MismatchedRegistryKey);
-        }
-
-        match self.id() {
-            ffi::LUA_REFNIL => ffi::lua_pushnil(lua.state()),
-            id => {
-                ffi::lua_rawgeti(lua.state(), ffi::LUA_REGISTRYINDEX, id as _);
-            }
-        }
-        Ok(())
-    }
-}
-
-impl<'lua> FromLua<'lua> for RegistryKey {
-    #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<RegistryKey> {
-        lua.create_registry_value(value)
-    }
-}
-
-impl<'lua> IntoLua<'lua> for bool {
-    #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Boolean(self))
     }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        ffi::lua_pushboolean(lua.state(), self as c_int);
-        Ok(())
-    }
 }
 
 impl<'lua> FromLua<'lua> for bool {
@@ -492,16 +196,11 @@ impl<'lua> FromLua<'lua> for bool {
             _ => Ok(true),
         }
     }
-
-    #[inline]
-    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
-        Ok(ffi::lua_toboolean(lua.state(), idx) != 0)
-    }
 }
 
-impl<'lua> IntoLua<'lua> for LightUserData {
+impl<'lua> ToLua<'lua> for LightUserData {
     #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::LightUserData(self))
     }
 }
@@ -520,39 +219,11 @@ impl<'lua> FromLua<'lua> for LightUserData {
     }
 }
 
-#[cfg(feature = "luau")]
-impl<'lua> IntoLua<'lua> for crate::types::Vector {
+impl<'lua> ToLua<'lua> for StdString {
     #[inline]
-    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Vector(self))
-    }
-}
-
-#[cfg(feature = "luau")]
-impl<'lua> FromLua<'lua> for crate::types::Vector {
-    #[inline]
-    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
-        match value {
-            Value::Vector(v) => Ok(v),
-            _ => Err(Error::FromLuaConversionError {
-                from: value.type_name(),
-                to: "vector",
-                message: None,
-            }),
-        }
-    }
-}
-
-impl<'lua> IntoLua<'lua> for StdString {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(&self)?))
     }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        push_bytes_into_stack(self, lua)
-    }
 }
 
 impl<'lua> FromLua<'lua> for StdString {
@@ -569,49 +240,25 @@ impl<'lua> FromLua<'lua> for StdString {
             .to_str()?
             .to_owned())
     }
-
-    #[inline]
-    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
-        let state = lua.state();
-        if ffi::lua_type(state, idx) == ffi::LUA_TSTRING {
-            let mut size = 0;
-            let data = ffi::lua_tolstring(state, idx, &mut size);
-            let bytes = slice::from_raw_parts(data as *const u8, size);
-            return str::from_utf8(bytes).map(|s| s.to_owned()).map_err(|e| {
-                Error::FromLuaConversionError {
-                    from: "string",
-                    to: "String",
-                    message: Some(e.to_string()),
-                }
-            });
-        }
-        // Fallback to default
-        Self::from_lua(lua.stack_value(idx), lua)
-    }
 }
 
-impl<'lua> IntoLua<'lua> for &str {
+impl<'lua> ToLua<'lua> for &str {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self)?))
     }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        push_bytes_into_stack(self, lua)
-    }
 }
 
-impl<'lua> IntoLua<'lua> for Cow<'_, str> {
+impl<'lua> ToLua<'lua> for Cow<'_, str> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self.as_bytes())?))
     }
 }
 
-impl<'lua> IntoLua<'lua> for Box<str> {
+impl<'lua> ToLua<'lua> for Box<str> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(&*self)?))
     }
 }
@@ -633,9 +280,9 @@ impl<'lua> FromLua<'lua> for Box<str> {
     }
 }
 
-impl<'lua> IntoLua<'lua> for CString {
+impl<'lua> ToLua<'lua> for CString {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self.as_bytes())?))
     }
 }
@@ -663,101 +310,56 @@ impl<'lua> FromLua<'lua> for CString {
     }
 }
 
-impl<'lua> IntoLua<'lua> for &CStr {
+impl<'lua> ToLua<'lua> for &CStr {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self.to_bytes())?))
     }
 }
 
-impl<'lua> IntoLua<'lua> for Cow<'_, CStr> {
+impl<'lua> ToLua<'lua> for Cow<'_, CStr> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self.to_bytes())?))
     }
 }
 
-impl<'lua> IntoLua<'lua> for BString {
+impl<'lua> ToLua<'lua> for BString {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(&self)?))
     }
 }
 
 impl<'lua> FromLua<'lua> for BString {
+    #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
         let ty = value.type_name();
-        match value {
-            Value::String(s) => Ok(s.as_bytes().into()),
-            #[cfg(feature = "luau")]
-            Value::UserData(ud) if ud.1 == crate::types::SubtypeId::Buffer => unsafe {
-                let mut size = 0usize;
-                let buf = ffi::lua_tobuffer(ud.0.lua.ref_thread(), ud.0.index, &mut size);
-                mlua_assert!(!buf.is_null(), "invalid Luau buffer");
-                Ok(slice::from_raw_parts(buf as *const u8, size).into())
-            },
-            _ => Ok(lua
-                .coerce_string(value)?
+        Ok(BString::from(
+            lua.coerce_string(value)?
                 .ok_or_else(|| Error::FromLuaConversionError {
                     from: ty,
-                    to: "BString",
+                    to: "String",
                     message: Some("expected string or number".to_string()),
                 })?
                 .as_bytes()
-                .into()),
-        }
-    }
-
-    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
-        let state = lua.state();
-        match ffi::lua_type(state, idx) {
-            ffi::LUA_TSTRING => {
-                let mut size = 0;
-                let data = ffi::lua_tolstring(state, idx, &mut size);
-                Ok(slice::from_raw_parts(data as *const u8, size).into())
-            }
-            #[cfg(feature = "luau")]
-            ffi::LUA_TBUFFER => {
-                let mut size = 0;
-                let buf = ffi::lua_tobuffer(state, idx, &mut size);
-                mlua_assert!(!buf.is_null(), "invalid Luau buffer");
-                Ok(slice::from_raw_parts(buf as *const u8, size).into())
-            }
-            _ => {
-                // Fallback to default
-                Self::from_lua(lua.stack_value(idx), lua)
-            }
-        }
+                .to_vec(),
+        ))
     }
 }
 
-impl<'lua> IntoLua<'lua> for &BStr {
+impl<'lua> ToLua<'lua> for &BStr {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::String(lua.create_string(self)?))
     }
 }
 
-#[inline]
-unsafe fn push_bytes_into_stack<'lua, T>(this: T, lua: &'lua Lua) -> Result<()>
-where
-    T: IntoLua<'lua> + AsRef<[u8]>,
-{
-    let bytes = this.as_ref();
-    if lua.unlikely_memory_error() && bytes.len() < (1 << 30) {
-        // Fast path: push directly into the Lua stack.
-        ffi::lua_pushlstring(lua.state(), bytes.as_ptr() as *const _, bytes.len());
-        return Ok(());
-    }
-    // Fallback to default
-    lua.push_value(T::into_lua(this, lua)?)
-}
-
 macro_rules! lua_convert_int {
     ($x:ty) => {
-        impl<'lua> IntoLua<'lua> for $x {
+        impl<'lua> ToLua<'lua> for $x {
             #[inline]
-            fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+            fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
                 cast(self)
                     .map(Value::Integer)
                     .or_else(|| cast(self).map(Value::Number))
@@ -768,15 +370,6 @@ macro_rules! lua_convert_int {
                         message: Some("out of range".to_owned()),
                     })
             }
-
-            #[inline]
-            unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-                match cast(self) {
-                    Some(i) => ffi::lua_pushinteger(lua.state(), i),
-                    None => ffi::lua_pushnumber(lua.state(), self as ffi::lua_Number),
-                }
-                Ok(())
-            }
         }
 
         impl<'lua> FromLua<'lua> for $x {
@@ -827,9 +420,9 @@ lua_convert_int!(usize);
 
 macro_rules! lua_convert_float {
     ($x:ty) => {
-        impl<'lua> IntoLua<'lua> for $x {
+        impl<'lua> ToLua<'lua> for $x {
             #[inline]
-            fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+            fn to_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
                 cast(self)
                     .ok_or_else(|| Error::ToLuaConversionError {
                         from: stringify!($x),
@@ -865,24 +458,24 @@ macro_rules! lua_convert_float {
 lua_convert_float!(f32);
 lua_convert_float!(f64);
 
-impl<'lua, T> IntoLua<'lua> for &[T]
+impl<'lua, T> ToLua<'lua> for &[T]
 where
-    T: IntoLua<'lua> + Clone,
+    T: Clone + ToLua<'lua>,
 {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(
             lua.create_sequence_from(self.iter().cloned())?,
         ))
     }
 }
 
-impl<'lua, T, const N: usize> IntoLua<'lua> for [T; N]
+impl<'lua, T, const N: usize> ToLua<'lua> for [T; N]
 where
-    T: IntoLua<'lua>,
+    T: ToLua<'lua>,
 {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_sequence_from(self)?))
     }
 }
@@ -895,22 +488,21 @@ where
     fn from_lua(value: Value<'lua>, _lua: &'lua Lua) -> Result<Self> {
         match value {
             #[cfg(feature = "luau")]
-            #[rustfmt::skip]
-            Value::Vector(v) if N == crate::types::Vector::SIZE => unsafe {
-                use std::{mem, ptr};
-                let mut arr: [mem::MaybeUninit<T>; N] = mem::MaybeUninit::uninit().assume_init();
-                ptr::write(arr[0].as_mut_ptr() , T::from_lua(Value::Number(v.x() as _), _lua)?);
-                ptr::write(arr[1].as_mut_ptr(), T::from_lua(Value::Number(v.y() as _), _lua)?);
-                ptr::write(arr[2].as_mut_ptr(), T::from_lua(Value::Number(v.z() as _), _lua)?);
-                #[cfg(feature = "luau-vector4")]
-                ptr::write(arr[3].as_mut_ptr(), T::from_lua(Value::Number(v.w() as _), _lua)?);
-                Ok(mem::transmute_copy(&arr))
-            },
+            Value::Vector(x, y, z) if N == 3 => Ok(mlua_expect!(
+                vec![
+                    T::from_lua(Value::Number(x as _), _lua)?,
+                    T::from_lua(Value::Number(y as _), _lua)?,
+                    T::from_lua(Value::Number(z as _), _lua)?,
+                ]
+                .try_into()
+                .map_err(|_| ()),
+                "cannot convert vector to array"
+            )),
             Value::Table(table) => {
                 let vec = table.sequence_values().collect::<Result<Vec<_>>>()?;
                 vec.try_into()
                     .map_err(|vec: Vec<T>| Error::FromLuaConversionError {
-                        from: "table",
+                        from: "Table",
                         to: "Array",
                         message: Some(format!("expected table of length {}, got {}", N, vec.len())),
                     })
@@ -924,9 +516,9 @@ where
     }
 }
 
-impl<'lua, T: IntoLua<'lua>> IntoLua<'lua> for Box<[T]> {
+impl<'lua, T: ToLua<'lua>> ToLua<'lua> for Box<[T]> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_sequence_from(self.into_vec())?))
     }
 }
@@ -938,9 +530,9 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Box<[T]> {
     }
 }
 
-impl<'lua, T: IntoLua<'lua>> IntoLua<'lua> for Vec<T> {
+impl<'lua, T: ToLua<'lua>> ToLua<'lua> for Vec<T> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_sequence_from(self)?))
     }
 }
@@ -949,6 +541,12 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Vec<T> {
     #[inline]
     fn from_lua(value: Value<'lua>, _lua: &'lua Lua) -> Result<Self> {
         match value {
+            #[cfg(feature = "luau")]
+            Value::Vector(x, y, z) => Ok(vec![
+                T::from_lua(Value::Number(x as _), _lua)?,
+                T::from_lua(Value::Number(y as _), _lua)?,
+                T::from_lua(Value::Number(z as _), _lua)?,
+            ]),
             Value::Table(table) => table.sequence_values().collect(),
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
@@ -959,11 +557,11 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Vec<T> {
     }
 }
 
-impl<'lua, K: Eq + Hash + IntoLua<'lua>, V: IntoLua<'lua>, S: BuildHasher> IntoLua<'lua>
+impl<'lua, K: Eq + Hash + ToLua<'lua>, V: ToLua<'lua>, S: BuildHasher> ToLua<'lua>
     for HashMap<K, V, S>
 {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_table_from(self)?))
     }
 }
@@ -985,9 +583,9 @@ impl<'lua, K: Eq + Hash + FromLua<'lua>, V: FromLua<'lua>, S: BuildHasher + Defa
     }
 }
 
-impl<'lua, K: Ord + IntoLua<'lua>, V: IntoLua<'lua>> IntoLua<'lua> for BTreeMap<K, V> {
+impl<'lua, K: Ord + ToLua<'lua>, V: ToLua<'lua>> ToLua<'lua> for BTreeMap<K, V> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_table_from(self)?))
     }
 }
@@ -1007,9 +605,9 @@ impl<'lua, K: Ord + FromLua<'lua>, V: FromLua<'lua>> FromLua<'lua> for BTreeMap<
     }
 }
 
-impl<'lua, T: Eq + Hash + IntoLua<'lua>, S: BuildHasher> IntoLua<'lua> for HashSet<T, S> {
+impl<'lua, T: Eq + Hash + ToLua<'lua>, S: BuildHasher> ToLua<'lua> for HashSet<T, S> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_table_from(
             self.into_iter().map(|val| (val, true)),
         )?))
@@ -1020,7 +618,7 @@ impl<'lua, T: Eq + Hash + FromLua<'lua>, S: BuildHasher + Default> FromLua<'lua>
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
         match value {
-            Value::Table(table) if table.raw_len() > 0 => table.sequence_values().collect(),
+            Value::Table(table) if table.len()? > 0 => table.sequence_values().collect(),
             Value::Table(table) => table
                 .pairs::<T, Value<'lua>>()
                 .map(|res| res.map(|(k, _)| k))
@@ -1034,9 +632,9 @@ impl<'lua, T: Eq + Hash + FromLua<'lua>, S: BuildHasher + Default> FromLua<'lua>
     }
 }
 
-impl<'lua, T: Ord + IntoLua<'lua>> IntoLua<'lua> for BTreeSet<T> {
+impl<'lua, T: Ord + ToLua<'lua>> ToLua<'lua> for BTreeSet<T> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         Ok(Value::Table(lua.create_table_from(
             self.into_iter().map(|val| (val, true)),
         )?))
@@ -1047,7 +645,7 @@ impl<'lua, T: Ord + FromLua<'lua>> FromLua<'lua> for BTreeSet<T> {
     #[inline]
     fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
         match value {
-            Value::Table(table) if table.raw_len() > 0 => table.sequence_values().collect(),
+            Value::Table(table) if table.len()? > 0 => table.sequence_values().collect(),
             Value::Table(table) => table
                 .pairs::<T, Value<'lua>>()
                 .map(|res| res.map(|(k, _)| k))
@@ -1061,23 +659,14 @@ impl<'lua, T: Ord + FromLua<'lua>> FromLua<'lua> for BTreeSet<T> {
     }
 }
 
-impl<'lua, T: IntoLua<'lua>> IntoLua<'lua> for Option<T> {
+impl<'lua, T: ToLua<'lua>> ToLua<'lua> for Option<T> {
     #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
         match self {
-            Some(val) => val.into_lua(lua),
+            Some(val) => val.to_lua(lua),
             None => Ok(Nil),
         }
     }
-
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        match self {
-            Some(val) => val.push_into_stack(lua)?,
-            None => ffi::lua_pushnil(lua.state()),
-        }
-        Ok(())
-    }
 }
 
 impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Option<T> {
@@ -1088,13 +677,4 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Option<T> {
             value => Ok(Some(T::from_lua(value, lua)?)),
         }
     }
-
-    #[inline]
-    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
-        if ffi::lua_isnil(lua.state(), idx) != 0 {
-            Ok(None)
-        } else {
-            Ok(Some(T::from_stack(idx, lua)?))
-        }
-    }
 }

src/error.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::wrong_self_convention)]
+
 use std::error::Error as StdError;
 use std::fmt;
 use std::io::Error as IoError;
@@ -7,8 +9,6 @@ use std::str::Utf8Error;
 use std::string::String as StdString;
 use std::sync::Arc;
 
-use crate::private::Sealed;
-
 /// Error type returned by `mlua` methods.
 #[derive(Debug, Clone)]
 #[non_exhaustive]
@@ -47,6 +47,11 @@ pub enum Error {
     /// This error can only happen when Lua state was not created by us and does not have the
     /// custom allocator attached.
     MemoryLimitNotAvailable,
+    /// Main thread is not available.
+    ///
+    /// This error can only happen in Lua5.1/LuaJIT module mode, when module loaded within a coroutine.
+    /// These Lua versions does not have `LUA_RIDX_MAINTHREAD` registry key.
+    MainThreadNotAvailable,
     /// A mutable callback has triggered Lua code that has called the same mutable callback again.
     ///
     /// This is an error because a mutable callback can only be borrowed mutably once.
@@ -64,22 +69,8 @@ pub enum Error {
     /// called with a huge number of arguments, or a rust callback returns a huge number of return
     /// values.
     StackError,
-    /// Too many arguments to `Function::bind`.
+    /// Too many arguments to `Function::bind`
     BindError,
-    /// Bad argument received from Lua (usually when calling a function).
-    ///
-    /// This error can help to identify the argument that caused the error
-    /// (which is stored in the corresponding field).
-    BadArgument {
-        /// Function that was called.
-        to: Option<StdString>,
-        /// Argument position (usually starts from 1).
-        pos: usize,
-        /// Argument name.
-        name: Option<StdString>,
-        /// Underlying error returned when converting argument to a Lua value.
-        cause: Arc<Error>,
-    },
     /// A Rust value could not be converted to a Lua value.
     ToLuaConversionError {
         /// Name of the Rust type that could not be converted.
@@ -101,7 +92,7 @@ pub enum Error {
     /// [`Thread::resume`] was called on an inactive coroutine.
     ///
     /// A coroutine is inactive if its main function has returned or if an error has occurred inside
-    /// the coroutine. Already running coroutines are also marked as inactive (unresumable).
+    /// the coroutine.
     ///
     /// [`Thread::status`] can be used to check if the coroutine can be resumed without causing this
     /// error.
@@ -125,7 +116,7 @@ pub enum Error {
     ///
     /// [`AnyUserData`]: crate::AnyUserData
     UserDataDestructed,
-    /// An [`AnyUserData`] immutable borrow failed.
+    /// An [`AnyUserData`] immutable borrow failed because it is already borrowed mutably.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -134,7 +125,7 @@ pub enum Error {
     /// [`AnyUserData`]: crate::AnyUserData
     /// [`UserData`]: crate::UserData
     UserDataBorrowError,
-    /// An [`AnyUserData`] mutable borrow failed.
+    /// An [`AnyUserData`] mutable borrow failed because it is already borrowed.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -151,11 +142,8 @@ pub enum Error {
     ///
     /// [`MetaMethod`]: crate::MetaMethod
     MetaMethodTypeError {
-        /// Name of the metamethod.
         method: StdString,
-        /// Passed value type.
         type_name: &'static str,
-        /// A string containing more detailed error information.
         message: Option<StdString>,
     },
     /// A [`RegistryKey`] produced from a different Lua state was used.
@@ -190,13 +178,6 @@ pub enum Error {
     /// error. The Rust code that originally invoked the Lua code then receives a `CallbackError`,
     /// from which the original error (and a stack traceback) can be recovered.
     ExternalError(Arc<dyn StdError + Send + Sync>),
-    /// An error with additional context.
-    WithContext {
-        /// A string containing additional context.
-        context: StdString,
-        /// Underlying error.
-        cause: Arc<Error>,
-    },
 }
 
 /// A specialized `Result` type used by `mlua`'s API.
@@ -206,21 +187,24 @@ pub type Result<T> = StdResult<T, Error>;
 impl fmt::Display for Error {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Error::SyntaxError { ref message, .. } => write!(fmt, "syntax error: {message}"),
-            Error::RuntimeError(ref msg) => write!(fmt, "runtime error: {msg}"),
+            Error::SyntaxError { ref message, .. } => write!(fmt, "syntax error: {}", message),
+            Error::RuntimeError(ref msg) => write!(fmt, "runtime error: {}", msg),
             Error::MemoryError(ref msg) => {
-                write!(fmt, "memory error: {msg}")
+                write!(fmt, "memory error: {}", msg)
             }
             #[cfg(any(feature = "lua53", feature = "lua52"))]
             Error::GarbageCollectorError(ref msg) => {
-                write!(fmt, "garbage collector error: {msg}")
+                write!(fmt, "garbage collector error: {}", msg)
             }
             Error::SafetyError(ref msg) => {
-                write!(fmt, "safety error: {msg}")
+                write!(fmt, "safety error: {}", msg)
             },
             Error::MemoryLimitNotAvailable => {
                 write!(fmt, "setting memory limit is not available")
             }
+            Error::MainThreadNotAvailable => {
+                write!(fmt, "main thread is not available in Lua 5.1")
+            }
             Error::RecursiveMutCallback => write!(fmt, "mutable callback called recursively"),
             Error::CallbackDestructed => write!(
                 fmt,
@@ -234,55 +218,44 @@ impl fmt::Display for Error {
                 fmt,
                 "too many arguments to Function::bind"
             ),
-            Error::BadArgument { ref to, pos, ref name, ref cause } => {
-                if let Some(name) = name {
-                    write!(fmt, "bad argument `{name}`")?;
-                } else {
-                    write!(fmt, "bad argument #{pos}")?;
-                }
-                if let Some(to) = to {
-                    write!(fmt, " to `{to}`")?;
-                }
-                write!(fmt, ": {cause}")
-            },
             Error::ToLuaConversionError { from, to, ref message } => {
-                write!(fmt, "error converting {from} to Lua {to}")?;
+                write!(fmt, "error converting {} to Lua {}", from, to)?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({message})"),
+                    Some(ref message) => write!(fmt, " ({})", message),
                 }
             }
             Error::FromLuaConversionError { from, to, ref message } => {
-                write!(fmt, "error converting Lua {from} to {to}")?;
+                write!(fmt, "error converting Lua {} to {}", from, to)?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({message})"),
+                    Some(ref message) => write!(fmt, " ({})", message),
                 }
             }
             Error::CoroutineInactive => write!(fmt, "cannot resume inactive coroutine"),
             Error::UserDataTypeMismatch => write!(fmt, "userdata is not expected type"),
             Error::UserDataDestructed => write!(fmt, "userdata has been destructed"),
-            Error::UserDataBorrowError => write!(fmt, "error borrowing userdata"),
-            Error::UserDataBorrowMutError => write!(fmt, "error mutably borrowing userdata"),
-            Error::MetaMethodRestricted(ref method) => write!(fmt, "metamethod {method} is restricted"),
+            Error::UserDataBorrowError => write!(fmt, "userdata already mutably borrowed"),
+            Error::UserDataBorrowMutError => write!(fmt, "userdata already borrowed"),
+            Error::MetaMethodRestricted(ref method) => write!(fmt, "metamethod {} is restricted", method),
             Error::MetaMethodTypeError { ref method, type_name, ref message } => {
-                write!(fmt, "metamethod {method} has unsupported type {type_name}")?;
+                write!(fmt, "metamethod {} has unsupported type {}", method, type_name)?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({message})"),
+                    Some(ref message) => write!(fmt, " ({})", message),
                 }
             }
             Error::MismatchedRegistryKey => {
                 write!(fmt, "RegistryKey used from different Lua state")
             }
             Error::CallbackError { ref cause, ref traceback } => {
+                writeln!(fmt, "callback error")?;
                 // Trace errors down to the root
                 let (mut cause, mut full_traceback) = (cause, None);
                 while let Error::CallbackError { cause: ref cause2, traceback: ref traceback2 } = **cause {
                     cause = cause2;
                     full_traceback = Some(traceback2);
                 }
-                writeln!(fmt, "{cause}")?;
                 if let Some(full_traceback) = full_traceback {
                     let traceback = traceback.trim_start_matches("stack traceback:");
                     let traceback = traceback.trim_start().trim_end();
@@ -296,24 +269,20 @@ impl fmt::Display for Error {
                 } else {
                     writeln!(fmt, "{}", traceback.trim_end())?;
                 }
-                Ok(())
+                write!(fmt, "caused by: {}", cause)
             }
             Error::PreviouslyResumedPanic => {
                 write!(fmt, "previously resumed panic returned again")
             }
             #[cfg(feature = "serialize")]
             Error::SerializeError(ref err) => {
-                write!(fmt, "serialize error: {err}")
+                write!(fmt, "serialize error: {}", err)
             },
             #[cfg(feature = "serialize")]
             Error::DeserializeError(ref err) => {
-                write!(fmt, "deserialize error: {err}")
+                write!(fmt, "deserialize error: {}", err)
             },
-            Error::ExternalError(ref err) => write!(fmt, "{err}"),
-            Error::WithContext { ref context, ref cause } => {
-                writeln!(fmt, "{context}")?;
-                write!(fmt, "{cause}")
-            }
+            Error::ExternalError(ref err) => write!(fmt, "{}", err),
         }
     }
 }
@@ -327,147 +296,53 @@ impl StdError for Error {
             // Given that we include source to fmt::Display implementation for `CallbackError`, this call returns nothing.
             Error::CallbackError { .. } => None,
             Error::ExternalError(ref err) => err.source(),
-            Error::WithContext { ref cause, .. } => match cause.as_ref() {
-                Error::ExternalError(err) => err.source(),
-                _ => None,
-            },
             _ => None,
         }
     }
 }
 
 impl Error {
-    /// Creates a new `RuntimeError` with the given message.
-    #[inline]
-    pub fn runtime<S: fmt::Display>(message: S) -> Self {
-        Error::RuntimeError(message.to_string())
-    }
-
-    /// Wraps an external error object.
-    #[inline]
-    pub fn external<T: Into<Box<dyn StdError + Send + Sync>>>(err: T) -> Self {
+    pub fn external<T: Into<Box<dyn StdError + Send + Sync>>>(err: T) -> Error {
         Error::ExternalError(err.into().into())
     }
-
-    /// Attempts to downcast the external error object to a concrete type by reference.
-    pub fn downcast_ref<T>(&self) -> Option<&T>
-    where
-        T: StdError + 'static,
-    {
-        match self {
-            Error::ExternalError(err) => err.downcast_ref(),
-            Error::WithContext { cause, .. } => match cause.as_ref() {
-                Error::ExternalError(err) => err.downcast_ref(),
-                _ => None,
-            },
-            _ => None,
-        }
-    }
-
-    pub(crate) fn bad_self_argument(to: &str, cause: Error) -> Self {
-        Error::BadArgument {
-            to: Some(to.to_string()),
-            pos: 1,
-            name: Some("self".to_string()),
-            cause: Arc::new(cause),
-        }
-    }
-
-    pub(crate) fn from_lua_conversion<'a>(
-        from: &'static str,
-        to: &'static str,
-        message: impl Into<Option<&'a str>>,
-    ) -> Self {
-        Error::FromLuaConversionError {
-            from,
-            to,
-            message: message.into().map(|s| s.into()),
-        }
-    }
 }
 
-/// Trait for converting [`std::error::Error`] into Lua [`Error`].
 pub trait ExternalError {
-    fn into_lua_err(self) -> Error;
+    fn to_lua_err(self) -> Error;
 }
 
 impl<E: Into<Box<dyn StdError + Send + Sync>>> ExternalError for E {
-    fn into_lua_err(self) -> Error {
+    fn to_lua_err(self) -> Error {
         Error::external(self)
     }
 }
 
-/// Trait for converting [`std::result::Result`] into Lua [`Result`].
 pub trait ExternalResult<T> {
-    fn into_lua_err(self) -> Result<T>;
+    fn to_lua_err(self) -> Result<T>;
 }
 
 impl<T, E> ExternalResult<T> for StdResult<T, E>
 where
     E: ExternalError,
 {
-    fn into_lua_err(self) -> Result<T> {
-        self.map_err(|e| e.into_lua_err())
+    fn to_lua_err(self) -> Result<T> {
+        self.map_err(|e| e.to_lua_err())
     }
 }
 
-/// Provides the `context` method for [`Error`] and `Result<T, Error>`.
-pub trait ErrorContext: Sealed {
-    /// Wraps the error value with additional context.
-    fn context<C: fmt::Display>(self, context: C) -> Self;
-
-    /// Wrap the error value with additional context that is evaluated lazily
-    /// only once an error does occur.
-    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self;
-}
-
-impl ErrorContext for Error {
-    fn context<C: fmt::Display>(self, context: C) -> Self {
-        let context = context.to_string();
-        match self {
-            Error::WithContext { cause, .. } => Error::WithContext { context, cause },
-            _ => Error::WithContext {
-                context,
-                cause: Arc::new(self),
-            },
-        }
-    }
-
-    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self {
-        let context = f(&self).to_string();
-        match self {
-            Error::WithContext { cause, .. } => Error::WithContext { context, cause },
-            _ => Error::WithContext {
-                context,
-                cause: Arc::new(self),
-            },
-        }
-    }
-}
-
-impl<T> ErrorContext for StdResult<T, Error> {
-    fn context<C: fmt::Display>(self, context: C) -> Self {
-        self.map_err(|err| err.context(context))
-    }
-
-    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self {
-        self.map_err(|err| err.with_context(f))
-    }
-}
-
-impl From<AddrParseError> for Error {
+impl std::convert::From<AddrParseError> for Error {
     fn from(err: AddrParseError) -> Self {
         Error::external(err)
     }
 }
 
-impl From<IoError> for Error {
+impl std::convert::From<IoError> for Error {
     fn from(err: IoError) -> Self {
         Error::external(err)
     }
 }
 
-impl From<Utf8Error> for Error {
+impl std::convert::From<Utf8Error> for Error {
     fn from(err: Utf8Error) -> Self {
         Error::external(err)
     }

src/ffi/lua51/compat.rs

@@ -2,6 +2,7 @@
 //!
 //! Based on github.com/keplerproject/lua-compat-5.3
 
+use std::convert::TryInto;
 use std::mem;
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr;
@@ -485,10 +486,10 @@ pub unsafe fn luaL_traceback(
     lua_concat(L, lua_gettop(L) - top);
 }
 
-pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
-    idx = lua_absindex(L, idx);
+pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
-        match lua_type(L, idx) {
+        let t = lua_type(L, idx);
+        match t {
             LUA_TNIL => {
                 lua_pushliteral(L, "nil");
             }
@@ -502,7 +503,7 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                     lua_pushliteral(L, "true");
                 }
             }
-            t => {
+            _ => {
                 let tt = luaL_getmetafield(L, idx, cstr!("__name"));
                 let name = if tt == LUA_TSTRING {
                     lua_tostring(L, -1)
@@ -511,7 +512,7 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                 };
                 lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
                 if tt != LUA_TNIL {
-                    lua_replace(L, -2); // remove '__name'
+                    lua_replace(L, -2);
                 }
             }
         };

src/ffi/lua51/lauxlib.rs

@@ -14,8 +14,7 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_register(L: *mut lua_State, libname: *const c_char, l: *const luaL_Reg);
     #[link_name = "luaL_getmetafield"]
     pub fn luaL_getmetafield_(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
@@ -43,7 +42,7 @@ extern "C-unwind" {
     pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
 
     pub fn luaL_where(L: *mut lua_State, lvl: c_int);
-    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
 
     pub fn luaL_checkoption(
         L: *mut lua_State,
@@ -57,8 +56,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -2;
 pub const LUA_REFNIL: c_int = -1;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
     pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
 

src/ffi/lua51/lua.rs

@@ -73,23 +73,23 @@ pub type lua_Integer = i32;
 pub type lua_Integer = i64;
 
 /// Type for native C functions that can be passed to Lua.
-pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
 
 // Type for functions that read/write blocks when loading/dumping Lua chunks
-#[rustfmt::skip]
 pub type lua_Reader =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
-#[rustfmt::skip]
+    unsafe extern "C" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
 pub type lua_Writer =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
 
 /// Type for memory-allocation functions
-#[rustfmt::skip]
-pub type lua_Alloc =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+pub type lua_Alloc = unsafe extern "C" fn(
+    ud: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // State manipulation
     //
@@ -97,6 +97,9 @@ extern "C-unwind" {
     pub fn lua_close(L: *mut lua_State);
     pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
 
+    #[cfg(all(feature = "luajit", feature = "vendored"))]
+    pub fn lua_resetthread(L: *mut lua_State, th: *mut lua_State);
+
     pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
 
     //
@@ -218,33 +221,21 @@ pub const LUA_GCSTEP: c_int = 5;
 pub const LUA_GCSETPAUSE: c_int = 6;
 pub const LUA_GCSETSTEPMUL: c_int = 7;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
 //
 // Miscellaneous functions
 //
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
-    #[link_name = "lua_error"]
-    fn lua_error_(L: *mut lua_State) -> c_int;
+extern "C" {
+    pub fn lua_error(L: *mut lua_State) -> !;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_concat(L: *mut lua_State, n: c_int);
     pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
     pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
 }
 
-// lua_error does not return but is declared to return int, and Rust translates
-// ! to void which can cause link-time errors if the platform linker is aware
-// of return types and requires they match (for example: wasm does this).
-#[inline(always)]
-pub unsafe fn lua_error(L: *mut lua_State) -> ! {
-    lua_error_(L);
-    unreachable!();
-}
-
 //
 // Some useful macros (implemented as Rust functions)
 //
@@ -328,14 +319,6 @@ pub unsafe fn lua_getglobal_(L: *mut lua_State, var: *const c_char) {
     lua_getfield_(L, LUA_GLOBALSINDEX, var)
 }
 
-#[inline(always)]
-pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
-    if lua_islightuserdata(L, idx) != 0 {
-        return lua_touserdata(L, idx);
-    }
-    ptr::null_mut()
-}
-
 #[inline(always)]
 pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
     lua_tolstring(L, i, ptr::null_mut())
@@ -368,10 +351,9 @@ pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
 pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 
 /// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;

src/ffi/lua51/lualib.rs

@@ -20,8 +20,7 @@ pub const LUA_JITLIBNAME: &str = "jit";
 #[cfg(feature = "luajit")]
 pub const LUA_FFILIBNAME: &str = "ffi";
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaopen_base(L: *mut lua_State) -> c_int;
     pub fn luaopen_table(L: *mut lua_State) -> c_int;
     pub fn luaopen_io(L: *mut lua_State) -> c_int;

src/ffi/lua52/compat.rs

@@ -2,6 +2,7 @@
 //!
 //! Based on github.com/keplerproject/lua-compat-5.3
 
+use std::convert::TryInto;
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr;
 
@@ -204,10 +205,10 @@ pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_in
     }
 }
 
-pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
-    idx = lua_absindex(L, idx);
+pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
-        match lua_type(L, idx) {
+        let t = lua_type(L, idx);
+        match t {
             LUA_TNIL => {
                 lua_pushliteral(L, "nil");
             }
@@ -221,7 +222,7 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                     lua_pushliteral(L, "true");
                 }
             }
-            t => {
+            _ => {
                 let tt = luaL_getmetafield(L, idx, cstr!("__name"));
                 let name = if tt == LUA_TSTRING {
                     lua_tostring(L, -1)
@@ -230,7 +231,7 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                 };
                 lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
                 if tt != LUA_TNIL {
-                    lua_replace(L, -2); // remove '__name'
+                    lua_replace(L, -2);
                 }
             }
         };

src/ffi/lua52/lauxlib.rs

@@ -14,8 +14,7 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number);
 
     #[link_name = "luaL_getmetafield"]
@@ -49,7 +48,7 @@ extern "C-unwind" {
     pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
 
     pub fn luaL_where(L: *mut lua_State, lvl: c_int);
-    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
 
     pub fn luaL_checkoption(
         L: *mut lua_State,
@@ -66,8 +65,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -2;
 pub const LUA_REFNIL: c_int = -1;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
     pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
 
@@ -80,8 +78,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
     luaL_loadfilex(L, f, ptr::null())
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,

src/ffi/lua52/lua.rs

@@ -78,23 +78,23 @@ pub type lua_Integer = i64;
 pub type lua_Unsigned = c_uint;
 
 /// Type for native C functions that can be passed to Lua
-pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
 
 // Type for functions that read/write blocks when loading/dumping Lua chunks
-#[rustfmt::skip]
 pub type lua_Reader =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
-#[rustfmt::skip]
+    unsafe extern "C" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
 pub type lua_Writer =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
 
 /// Type for memory-allocation functions
-#[rustfmt::skip]
-pub type lua_Alloc =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+pub type lua_Alloc = unsafe extern "C" fn(
+    ud: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // State manipulation
     //
@@ -155,19 +155,20 @@ pub const LUA_OPMOD: c_int = 4;
 pub const LUA_OPPOW: c_int = 5;
 pub const LUA_OPUNM: c_int = 6;
 
+extern "C" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+}
+
 pub const LUA_OPEQ: c_int = 0;
 pub const LUA_OPLT: c_int = 1;
 pub const LUA_OPLE: c_int = 2;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
-    pub fn lua_arith(L: *mut lua_State, op: c_int);
+extern "C" {
     pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
     pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Push functions (C -> stack)
     //
@@ -261,8 +262,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
     lua_pcallk(L, n, r, f, 0, None)
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Coroutine functions
     //
@@ -298,18 +298,15 @@ pub const LUA_GCISRUNNING: c_int = 9;
 pub const LUA_GCGEN: c_int = 10;
 pub const LUA_GCINC: c_int = 11;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Miscellaneous functions
     //
-    #[link_name = "lua_error"]
-    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_error(L: *mut lua_State) -> !;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_concat(L: *mut lua_State, n: c_int);
     pub fn lua_len(L: *mut lua_State, idx: c_int);
@@ -317,15 +314,6 @@ extern "C-unwind" {
     pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
 }
 
-// lua_error does not return but is declared to return int, and Rust translates
-// ! to void which can cause link-time errors if the platform linker is aware
-// of return types and requires they match (for example: wasm does this).
-#[inline(always)]
-pub unsafe fn lua_error(L: *mut lua_State) -> ! {
-    lua_error_(L);
-    unreachable!();
-}
-
 //
 // Some useful macros (implemented as Rust functions)
 //
@@ -417,14 +405,6 @@ pub unsafe fn lua_pushglobaltable(L: *mut lua_State) {
     lua_rawgeti_(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS as _)
 }
 
-#[inline(always)]
-pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
-    if lua_islightuserdata(L, idx) != 0 {
-        return lua_touserdata(L, idx);
-    }
-    ptr::null_mut()
-}
-
 #[inline(always)]
 pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
     lua_tolstring(L, i, ptr::null_mut())
@@ -457,10 +437,9 @@ pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
 pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 
 /// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
@@ -471,12 +450,7 @@ extern "C-unwind" {
     pub fn lua_upvalueid(L: *mut lua_State, fidx: c_int, n: c_int) -> *mut c_void;
     pub fn lua_upvaluejoin(L: *mut lua_State, fidx1: c_int, n1: c_int, fidx2: c_int, n2: c_int);
 
-    pub fn lua_sethook(
-        L: *mut lua_State,
-        func: Option<lua_Hook>,
-        mask: c_int,
-        count: c_int,
-    ) -> c_int;
+    pub fn lua_sethook(L: *mut lua_State, func: Option<lua_Hook>, mask: c_int, count: c_int);
     pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
     pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
     pub fn lua_gethookcount(L: *mut lua_State) -> c_int;

src/ffi/lua52/lualib.rs

@@ -14,8 +14,7 @@ pub const LUA_MATHLIBNAME: &str = "math";
 pub const LUA_DBLIBNAME: &str = "debug";
 pub const LUA_LOADLIBNAME: &str = "package";
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaopen_base(L: *mut lua_State) -> c_int;
     pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
     pub fn luaopen_table(L: *mut lua_State) -> c_int;

src/ffi/lua53/compat.rs

@@ -1,4 +1,4 @@
-//! MLua compatibility layer for Lua 5.3
+//! MLua compatibility layer for Lua 5.2
 
 use std::os::raw::c_int;
 

src/ffi/lua53/lauxlib.rs

@@ -20,14 +20,12 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number, sz: usize);
 
     pub fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
     pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
-    #[link_name = "luaL_tolstring"]
-    pub fn luaL_tolstring_(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
     pub fn luaL_argerror(L: *mut lua_State, arg: c_int, extramsg: *const c_char) -> c_int;
     pub fn luaL_checklstring(L: *mut lua_State, arg: c_int, l: *mut usize) -> *const c_char;
     pub fn luaL_optlstring(
@@ -51,7 +49,7 @@ extern "C-unwind" {
     pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
 
     pub fn luaL_where(L: *mut lua_State, lvl: c_int);
-    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
 
     pub fn luaL_checkoption(
         L: *mut lua_State,
@@ -68,8 +66,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -2;
 pub const LUA_REFNIL: c_int = -1;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
     pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
 
@@ -82,8 +79,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
     luaL_loadfilex(L, f, ptr::null())
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,
@@ -171,11 +167,6 @@ pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
     lua::lua_getfield(L, lua::LUA_REGISTRYINDEX, n);
 }
 
-#[inline(always)]
-pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
-    luaL_tolstring_(L, lua::lua_absindex(L, idx), len)
-}
-
 // luaL_opt would be implemented here but it is undocumented, so it's omitted
 
 #[inline(always)]

src/ffi/lua53/lua.rs

@@ -82,27 +82,27 @@ pub type lua_Unsigned = u64;
 pub type lua_KContext = isize;
 
 /// Type for native C functions that can be passed to Lua
-pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
 
 /// Type for continuation functions
 pub type lua_KFunction =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
 
 // Type for functions that read/write blocks when loading/dumping Lua chunks
-#[rustfmt::skip]
 pub type lua_Reader =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
-#[rustfmt::skip]
+    unsafe extern "C" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
 pub type lua_Writer =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
 
 /// Type for memory-allocation functions
-#[rustfmt::skip]
-pub type lua_Alloc =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+pub type lua_Alloc = unsafe extern "C" fn(
+    ud: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // State manipulation
     //
@@ -167,19 +167,20 @@ pub const LUA_OPSHR: c_int = 11;
 pub const LUA_OPUNM: c_int = 12;
 pub const LUA_OPBNOT: c_int = 13;
 
+extern "C" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+}
+
 pub const LUA_OPEQ: c_int = 0;
 pub const LUA_OPLT: c_int = 1;
 pub const LUA_OPLE: c_int = 2;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
-    pub fn lua_arith(L: *mut lua_State, op: c_int);
+extern "C" {
     pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
     pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Push functions (C -> stack)
     //
@@ -269,8 +270,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
     lua_pcallk(L, n, r, f, 0, None)
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Coroutine functions
     //
@@ -304,18 +304,15 @@ pub const LUA_GCSETPAUSE: c_int = 6;
 pub const LUA_GCSETSTEPMUL: c_int = 7;
 pub const LUA_GCISRUNNING: c_int = 9;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Miscellaneous functions
     //
-    #[link_name = "lua_error"]
-    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_error(L: *mut lua_State) -> !;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_concat(L: *mut lua_State, n: c_int);
     pub fn lua_len(L: *mut lua_State, idx: c_int);
@@ -324,15 +321,6 @@ extern "C-unwind" {
     pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
 }
 
-// lua_error does not return but is declared to return int, and Rust translates
-// ! to void which can cause link-time errors if the platform linker is aware
-// of return types and requires they match (for example: wasm does this).
-#[inline(always)]
-pub unsafe fn lua_error(L: *mut lua_State) -> ! {
-    lua_error_(L);
-    unreachable!();
-}
-
 //
 // Some useful macros (implemented as Rust functions)
 //
@@ -424,14 +412,6 @@ pub unsafe fn lua_pushglobaltable(L: *mut lua_State) -> c_int {
     lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
 }
 
-#[inline(always)]
-pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
-    if lua_islightuserdata(L, idx) != 0 {
-        return lua_touserdata(L, idx);
-    }
-    ptr::null_mut()
-}
-
 #[inline(always)]
 pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
     lua_tolstring(L, i, ptr::null_mut())
@@ -481,10 +461,9 @@ pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
 pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 
 /// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;

src/ffi/lua53/lualib.rs

@@ -15,8 +15,7 @@ pub const LUA_MATHLIBNAME: &str = "math";
 pub const LUA_DBLIBNAME: &str = "debug";
 pub const LUA_LOADLIBNAME: &str = "package";
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaopen_base(L: *mut lua_State) -> c_int;
     pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
     pub fn luaopen_table(L: *mut lua_State) -> c_int;

src/ffi/lua54/lauxlib.rs

@@ -20,8 +20,7 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number, sz: usize);
 
     pub fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
@@ -50,7 +49,7 @@ extern "C-unwind" {
     pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
 
     pub fn luaL_where(L: *mut lua_State, lvl: c_int);
-    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
 
     pub fn luaL_checkoption(
         L: *mut lua_State,
@@ -67,8 +66,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -2;
 pub const LUA_REFNIL: c_int = -1;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
     pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
 
@@ -81,8 +79,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
     luaL_loadfilex(L, f, ptr::null())
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,

src/ffi/lua54/lua.rs

@@ -81,31 +81,31 @@ pub type lua_Unsigned = u64;
 pub type lua_KContext = isize;
 
 /// Type for native C functions that can be passed to Lua
-pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
 
 /// Type for continuation functions
 pub type lua_KFunction =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
 
 // Type for functions that read/write blocks when loading/dumping Lua chunks
-#[rustfmt::skip]
 pub type lua_Reader =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
-#[rustfmt::skip]
+    unsafe extern "C" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
 pub type lua_Writer =
-    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+    unsafe extern "C" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
 
 /// Type for memory-allocation functions
-#[rustfmt::skip]
-pub type lua_Alloc =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+pub type lua_Alloc = unsafe extern "C" fn(
+    ud: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void;
 
 /// Type for warning functions
 pub type lua_WarnFunction =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, msg: *const c_char, tocont: c_int);
+    unsafe extern "C" fn(ud: *mut c_void, msg: *const c_char, tocont: c_int);
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // State manipulation
     //
@@ -149,21 +149,13 @@ extern "C-unwind" {
     pub fn lua_tointegerx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
     pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
-    #[link_name = "lua_rawlen"]
-    fn lua_rawlen_(L: *mut lua_State, idx: c_int) -> lua_Unsigned;
+    pub fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize;
     pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
     pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
     pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
     pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
 }
 
-// lua_rawlen's return type changed from size_t to lua_Unsigned int in Lua 5.4.
-// This adapts the crate API to the new Lua ABI.
-#[inline(always)]
-pub unsafe fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize {
-    lua_rawlen_(L, idx) as usize
-}
-
 //
 // Comparison and arithmetic functions
 //
@@ -182,19 +174,20 @@ pub const LUA_OPSHR: c_int = 11;
 pub const LUA_OPUNM: c_int = 12;
 pub const LUA_OPBNOT: c_int = 13;
 
+extern "C" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+}
+
 pub const LUA_OPEQ: c_int = 0;
 pub const LUA_OPLT: c_int = 1;
 pub const LUA_OPLE: c_int = 2;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
-    pub fn lua_arith(L: *mut lua_State, op: c_int);
+extern "C" {
     pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
     pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Push functions (C -> stack)
     //
@@ -284,8 +277,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
     lua_pcallk(L, n, r, f, 0, None)
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Coroutine functions
     //
@@ -313,8 +305,7 @@ pub unsafe fn lua_yield(L: *mut lua_State, n: c_int) -> c_int {
 //
 // Warning-related functions
 //
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_setwarnf(L: *mut lua_State, f: Option<lua_WarnFunction>, ud: *mut c_void);
     pub fn lua_warning(L: *mut lua_State, msg: *const c_char, tocont: c_int);
 }
@@ -334,18 +325,15 @@ pub const LUA_GCISRUNNING: c_int = 9;
 pub const LUA_GCGEN: c_int = 10;
 pub const LUA_GCINC: c_int = 11;
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, ...) -> c_int;
 }
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     //
     // Miscellaneous functions
     //
-    #[link_name = "lua_error"]
-    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_error(L: *mut lua_State) -> !;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_concat(L: *mut lua_State, n: c_int);
     pub fn lua_len(L: *mut lua_State, idx: c_int);
@@ -357,15 +345,6 @@ extern "C-unwind" {
     pub fn lua_closeslot(L: *mut lua_State, idx: c_int);
 }
 
-// lua_error does not return but is declared to return int, and Rust translates
-// ! to void which can cause link-time errors if the platform linker is aware
-// of return types and requires they match (for example: wasm does this).
-#[inline(always)]
-pub unsafe fn lua_error(L: *mut lua_State) -> ! {
-    lua_error_(L);
-    unreachable!();
-}
-
 //
 // Some useful macros (implemented as Rust functions)
 //
@@ -457,14 +436,6 @@ pub unsafe fn lua_pushglobaltable(L: *mut lua_State) -> c_int {
     lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
 }
 
-#[inline(always)]
-pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
-    if lua_islightuserdata(L, idx) != 0 {
-        return lua_touserdata(L, idx);
-    }
-    ptr::null_mut()
-}
-
 #[inline(always)]
 pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
     lua_tolstring(L, i, ptr::null_mut())
@@ -529,10 +500,9 @@ pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
 pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 
 /// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;

src/ffi/lua54/lualib.rs

@@ -14,8 +14,7 @@ pub const LUA_MATHLIBNAME: &str = "math";
 pub const LUA_DBLIBNAME: &str = "debug";
 pub const LUA_LOADLIBNAME: &str = "package";
 
-#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+extern "C" {
     pub fn luaopen_base(L: *mut lua_State) -> c_int;
     pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
     pub fn luaopen_table(L: *mut lua_State) -> c_int;

src/ffi/luau/compat.rs

@@ -323,7 +323,7 @@ pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char)
 pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int {
     if luaL_newmetatable_(L, tname) != 0 {
         lua_pushstring(L, tname);
-        lua_setfield(L, -2, cstr!("__type"));
+        lua_setfield(L, -2, cstr!("__name"));
         1
     } else {
         0
@@ -436,10 +436,10 @@ pub unsafe fn luaL_traceback(
     lua_concat(L, lua_gettop(L) - top);
 }
 
-pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
-    idx = lua_absindex(L, idx);
+pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
-        match lua_type(L, idx) {
+        let t = lua_type(L, idx);
+        match t {
             LUA_TNIL => {
                 lua_pushliteral(L, "nil");
             }
@@ -453,8 +453,8 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                     lua_pushliteral(L, "true");
                 }
             }
-            t => {
-                let tt = luaL_getmetafield(L, idx, cstr!("__type"));
+            _ => {
+                let tt = luaL_getmetafield(L, idx, cstr!("__name"));
                 let name = if tt == LUA_TSTRING {
                     lua_tostring(L, -1)
                 } else {
@@ -462,7 +462,7 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
                 };
                 lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
                 if tt != LUA_TNIL {
-                    lua_replace(L, -2); // remove '__type'
+                    lua_replace(L, -2);
                 }
             }
         };

src/ffi/luau/lauxlib.rs

@@ -13,7 +13,7 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-extern "C-unwind" {
+extern "C" {
     pub fn luaL_register(L: *mut lua_State, libname: *const c_char, l: *const luaL_Reg);
     #[link_name = "luaL_getmetafield"]
     pub fn luaL_getmetafield_(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
@@ -52,8 +52,6 @@ extern "C-unwind" {
     pub fn luaL_newmetatable_(L: *mut lua_State, tname: *const c_char) -> c_int;
     pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
 
-    pub fn luaL_checkbuffer(L: *mut lua_State, narg: c_int, len: *mut usize) -> *mut c_void;
-
     pub fn luaL_where(L: *mut lua_State, lvl: c_int);
 
     #[link_name = "luaL_errorL"]
@@ -144,12 +142,9 @@ pub unsafe fn luaL_sandbox(L: *mut lua_State, enabled: c_int) {
 
     // set all builtin metatables to read-only
     lua_pushliteral(L, "");
-    if lua_getmetatable(L, -1) != 0 {
-        lua_setreadonly(L, -1, enabled);
-        lua_pop(L, 2);
-    } else {
-        lua_pop(L, 1);
-    }
+    lua_getmetatable(L, -1);
+    lua_setreadonly(L, -1, enabled);
+    lua_pop(L, 2);
 
     // set globals to readonly and activate safeenv since the env is immutable
     lua_setreadonly(L, LUA_GLOBALSINDEX, enabled);
@@ -157,48 +152,5 @@ pub unsafe fn luaL_sandbox(L: *mut lua_State, enabled: c_int) {
 }
 
 //
-// Generic Buffer Manipulation
+// TODO: Generic Buffer Manipulation
 //
-
-/// Buffer size used for on-stack string operations. This limit depends on native stack size.
-pub const LUA_BUFFERSIZE: usize = 512;
-
-#[repr(C)]
-pub struct luaL_Strbuf {
-    p: *mut c_char,   // current position in buffer
-    end: *mut c_char, // end of the current buffer
-    L: *mut lua_State,
-    storage: *mut c_void, // TString
-    buffer: [c_char; LUA_BUFFERSIZE],
-}
-
-// For compatibility
-pub type luaL_Buffer = luaL_Strbuf;
-
-extern "C-unwind" {
-    pub fn luaL_buffinit(L: *mut lua_State, B: *mut luaL_Strbuf);
-    pub fn luaL_buffinitsize(L: *mut lua_State, B: *mut luaL_Strbuf, size: usize) -> *mut c_char;
-    pub fn luaL_prepbuffsize(B: *mut luaL_Strbuf, size: usize) -> *mut c_char;
-    pub fn luaL_addlstring(B: *mut luaL_Strbuf, s: *const c_char, l: usize);
-    pub fn luaL_addvalue(B: *mut luaL_Strbuf);
-    pub fn luaL_addvalueany(B: *mut luaL_Strbuf, idx: c_int);
-    pub fn luaL_pushresult(B: *mut luaL_Strbuf);
-    pub fn luaL_pushresultsize(B: *mut luaL_Strbuf, size: usize);
-}
-
-pub unsafe fn luaL_addchar(B: *mut luaL_Strbuf, c: c_char) {
-    if (*B).p >= (*B).end {
-        luaL_prepbuffsize(B, 1);
-    }
-    *(*B).p = c;
-    (*B).p = (*B).p.add(1);
-}
-
-pub unsafe fn luaL_addstring(B: *mut luaL_Strbuf, s: *const c_char) {
-    // Calculate length of s
-    let mut len = 0;
-    while *s.add(len) != 0 {
-        len += 1;
-    }
-    luaL_addlstring(B, s, len);
-}

src/ffi/luau/lua.rs

@@ -2,19 +2,13 @@
 
 use std::marker::{PhantomData, PhantomPinned};
 use std::os::raw::{c_char, c_double, c_float, c_int, c_uint, c_void};
-use std::{mem, ptr};
+use std::ptr;
 
 // Option for multiple returns in 'lua_pcall' and 'lua_call'
 pub const LUA_MULTRET: c_int = -1;
 
 // Max number of Lua stack slots
-const LUAI_MAXCSTACK: c_int = 1000000;
-
-// Number of valid Lua userdata tags
-const LUA_UTAG_LIMIT: c_int = 128;
-
-// Number of valid Lua lightuserdata tags
-const LUA_LUTAG_LIMIT: c_int = 128;
+const LUAI_MAXCSTACK: c_int = 100000;
 
 //
 // Pseudo-indices
@@ -61,7 +55,6 @@ pub const LUA_TTABLE: c_int = 6;
 pub const LUA_TFUNCTION: c_int = 7;
 pub const LUA_TUSERDATA: c_int = 8;
 pub const LUA_TTHREAD: c_int = 9;
-pub const LUA_TBUFFER: c_int = 10;
 
 /// Guaranteed number of Lua stack slots available to a C function.
 pub const LUA_MINSTACK: c_int = 20;
@@ -76,27 +69,21 @@ pub type lua_Integer = c_int;
 pub type lua_Unsigned = c_uint;
 
 /// Type for native C functions that can be passed to Lua.
-pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
-pub type lua_Continuation = unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int) -> c_int;
+pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
+pub type lua_Continuation = unsafe extern "C" fn(L: *mut lua_State, status: c_int) -> c_int;
 
 /// Type for userdata destructor functions.
-pub type lua_Udestructor = unsafe extern "C-unwind" fn(*mut c_void);
-pub type lua_Destructor = unsafe extern "C-unwind" fn(L: *mut lua_State, *mut c_void);
+pub type lua_Udestructor = unsafe extern "C" fn(*mut c_void);
 
 /// Type for memory-allocation functions.
-pub type lua_Alloc = unsafe extern "C-unwind" fn(
+pub type lua_Alloc = unsafe extern "C" fn(
     ud: *mut c_void,
     ptr: *mut c_void,
     osize: usize,
     nsize: usize,
 ) -> *mut c_void;
 
-/// Returns Luau release version (eg. `0.xxx`).
-pub const fn luau_version() -> Option<&'static str> {
-    option_env!("LUAU_VERSION")
-}
-
-extern "C-unwind" {
+extern "C" {
     //
     // State manipulation
     //
@@ -150,13 +137,10 @@ extern "C-unwind" {
     pub fn lua_objlen(L: *mut lua_State, idx: c_int) -> usize;
     pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
     pub fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
-    pub fn lua_tolightuserdatatagged(L: *mut lua_State, idx: c_int, tag: c_int) -> *mut c_void;
     pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
     pub fn lua_touserdatatagged(L: *mut lua_State, idx: c_int, tag: c_int) -> *mut c_void;
     pub fn lua_userdatatag(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_lightuserdatatag(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
-    pub fn lua_tobuffer(L: *mut lua_State, idx: c_int, len: *mut usize) -> *mut c_void;
     pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
 
     //
@@ -166,10 +150,7 @@ extern "C-unwind" {
     pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
     pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
     pub fn lua_pushunsigned(L: *mut lua_State, n: lua_Unsigned);
-    #[cfg(not(feature = "luau-vector4"))]
     pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float);
-    #[cfg(feature = "luau-vector4")]
-    pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float, w: c_float);
     #[link_name = "lua_pushlstring"]
     pub fn lua_pushlstring_(L: *mut lua_State, s: *const c_char, l: usize);
     #[link_name = "lua_pushstring"]
@@ -187,12 +168,10 @@ extern "C-unwind" {
     pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
     pub fn lua_pushthread(L: *mut lua_State) -> c_int;
 
-    pub fn lua_pushlightuserdatatagged(L: *mut lua_State, p: *mut c_void, tag: c_int);
+    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
     pub fn lua_newuserdatatagged(L: *mut lua_State, sz: usize, tag: c_int) -> *mut c_void;
     pub fn lua_newuserdatadtor(L: *mut lua_State, sz: usize, dtor: lua_Udestructor) -> *mut c_void;
 
-    pub fn lua_newbuffer(L: *mut lua_State, sz: usize) -> *mut c_void;
-
     //
     // Get functions (Lua -> stack)
     //
@@ -263,14 +242,14 @@ pub const LUA_GCSETGOAL: c_int = 7;
 pub const LUA_GCSETSTEPMUL: c_int = 8;
 pub const LUA_GCSETSTEPSIZE: c_int = 9;
 
-extern "C-unwind" {
+extern "C" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
 //
 // Memory statistics
 //
-extern "C-unwind" {
+extern "C" {
     pub fn lua_setmemcat(L: *mut lua_State, category: c_int);
     pub fn lua_totalbytes(L: *mut lua_State, category: c_int) -> usize;
 }
@@ -278,7 +257,7 @@ extern "C-unwind" {
 //
 // Miscellaneous functions
 //
-extern "C-unwind" {
+extern "C" {
     pub fn lua_error(L: *mut lua_State) -> !;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_rawiter(L: *mut lua_State, idx: c_int, iter: c_int) -> c_int;
@@ -286,15 +265,13 @@ extern "C-unwind" {
     // TODO: lua_encodepointer
     pub fn lua_clock() -> c_double;
     pub fn lua_setuserdatatag(L: *mut lua_State, idx: c_int, tag: c_int);
-    pub fn lua_setuserdatadtor(L: *mut lua_State, tag: c_int, dtor: Option<lua_Destructor>);
-    pub fn lua_getuserdatadtor(L: *mut lua_State, tag: c_int) -> Option<lua_Destructor>;
-    pub fn lua_setuserdatametatable(L: *mut lua_State, tag: c_int, idx: c_int);
-    pub fn lua_getuserdatametatable(L: *mut lua_State, tag: c_int);
-    pub fn lua_setlightuserdataname(L: *mut lua_State, tag: c_int, name: *const c_char);
-    pub fn lua_getlightuserdataname(L: *mut lua_State, tag: c_int) -> *const c_char;
+    pub fn lua_setuserdatadtor(
+        L: *mut lua_State,
+        tag: c_int,
+        dtor: Option<unsafe extern "C" fn(*mut lua_State, *mut c_void)>,
+    );
     pub fn lua_clonefunction(L: *mut lua_State, idx: c_int);
     pub fn lua_cleartable(L: *mut lua_State, idx: c_int);
-    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
 }
 
 //
@@ -303,7 +280,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -1;
 pub const LUA_REFNIL: c_int = 0;
 
-extern "C-unwind" {
+extern "C" {
     pub fn lua_ref(L: *mut lua_State, idx: c_int) -> c_int;
     pub fn lua_unref(L: *mut lua_State, r#ref: c_int);
 }
@@ -342,15 +319,6 @@ pub unsafe fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void {
     lua_newuserdatatagged(L, sz, 0)
 }
 
-#[inline(always)]
-pub unsafe fn lua_newuserdata_t<T>(L: *mut lua_State) -> *mut T {
-    unsafe extern "C-unwind" fn destructor<T>(ud: *mut c_void) {
-        ptr::drop_in_place(ud as *mut T);
-    }
-
-    lua_newuserdatadtor(L, mem::size_of::<T>(), destructor::<T>) as *mut T
-}
-
 // TODO: lua_strlen
 
 #[inline(always)]
@@ -388,11 +356,6 @@ pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
     (lua_type(L, n) == LUA_TTHREAD) as c_int
 }
 
-#[inline(always)]
-pub unsafe fn lua_isbuffer(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TBUFFER) as c_int
-}
-
 #[inline(always)]
 pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
     (lua_type(L, n) == LUA_TNONE) as c_int
@@ -410,22 +373,18 @@ pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) {
     lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
 }
 
-#[inline(always)]
 pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
     lua_pushcclosurek(L, f, ptr::null(), 0, None)
 }
 
-#[inline(always)]
 pub unsafe fn lua_pushcfunctiond(L: *mut lua_State, f: lua_CFunction, debugname: *const c_char) {
     lua_pushcclosurek(L, f, debugname, 0, None)
 }
 
-#[inline(always)]
 pub unsafe fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, nup: c_int) {
     lua_pushcclosurek(L, f, ptr::null(), nup, None)
 }
 
-#[inline(always)]
 pub unsafe fn lua_pushcclosured(
     L: *mut lua_State,
     f: lua_CFunction,
@@ -435,11 +394,6 @@ pub unsafe fn lua_pushcclosured(
     lua_pushcclosurek(L, f, debugname, nup, None)
 }
 
-#[inline(always)]
-pub unsafe fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void) {
-    lua_pushlightuserdatatagged(L, p, 0)
-}
-
 #[inline(always)]
 pub unsafe fn lua_setglobal(L: *mut lua_State, var: *const c_char) {
     lua_setfield(L, LUA_GLOBALSINDEX, var)
@@ -463,9 +417,9 @@ pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
 const LUA_IDSIZE: usize = 256;
 
 /// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
-pub type lua_Coverage = unsafe extern "C-unwind" fn(
+pub type lua_Coverage = unsafe extern "C" fn(
     context: *mut c_void,
     function: *const c_char,
     linedefined: c_int,
@@ -474,7 +428,7 @@ pub type lua_Coverage = unsafe extern "C-unwind" fn(
     size: usize,
 );
 
-extern "C-unwind" {
+extern "C" {
     pub fn lua_stackdepth(L: *mut lua_State) -> c_int;
     pub fn lua_getinfo(
         L: *mut lua_State,
@@ -527,36 +481,30 @@ pub struct lua_Debug {
 //
 
 #[repr(C)]
-#[non_exhaustive]
 pub struct lua_Callbacks {
     /// arbitrary userdata pointer that is never overwritten by Luau
     pub userdata: *mut c_void,
 
     /// gets called at safepoints (loop back edges, call/ret, gc) if set
-    pub interrupt: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, gc: c_int)>,
+    pub interrupt: Option<unsafe extern "C" fn(L: *mut lua_State, gc: c_int)>,
     /// gets called when an unprotected error is raised (if longjmp is used)
-    pub panic: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, errcode: c_int)>,
+    pub panic: Option<unsafe extern "C" fn(L: *mut lua_State, errcode: c_int)>,
 
     /// gets called when L is created (LP == parent) or destroyed (LP == NULL)
-    pub userthread: Option<unsafe extern "C-unwind" fn(LP: *mut lua_State, L: *mut lua_State)>,
+    pub userthread: Option<unsafe extern "C" fn(LP: *mut lua_State, L: *mut lua_State)>,
     /// gets called when a string is created; returned atom can be retrieved via tostringatom
-    pub useratom: Option<unsafe extern "C-unwind" fn(s: *const c_char, l: usize) -> i16>,
+    pub useratom: Option<unsafe extern "C" fn(s: *const c_char, l: usize) -> i16>,
 
     /// gets called when BREAK instruction is encountered
-    pub debugbreak: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    pub debugbreak: Option<unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
     /// gets called after each instruction in single step mode
-    pub debugstep: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    pub debugstep: Option<unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
     /// gets called when thread execution is interrupted by break in another thread
-    pub debuginterrupt: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    pub debuginterrupt: Option<unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
     /// gets called when protected call results in an error
-    pub debugprotectederror: Option<unsafe extern "C-unwind" fn(L: *mut lua_State)>,
+    pub debugprotectederror: Option<unsafe extern "C" fn(L: *mut lua_State)>,
 }
 
 extern "C" {
     pub fn lua_callbacks(L: *mut lua_State) -> *mut lua_Callbacks;
 }
-
-// Functions from customization lib
-extern "C" {
-    pub fn luau_setfflag(name: *const c_char, value: c_int) -> c_int;
-}

src/ffi/luau/luacode.rs

@@ -1,39 +1,20 @@
 //! Contains definitions from `luacode.h`.
 
 use std::os::raw::{c_char, c_int, c_void};
-use std::{ptr, slice};
+use std::slice;
 
 #[repr(C)]
-#[non_exhaustive]
 pub struct lua_CompileOptions {
     pub optimizationLevel: c_int,
     pub debugLevel: c_int,
-    pub typeInfoLevel: c_int,
     pub coverageLevel: c_int,
     pub vectorLib: *const c_char,
     pub vectorCtor: *const c_char,
     pub vectorType: *const c_char,
     pub mutableGlobals: *const *const c_char,
-    pub userdataTypes: *const *const c_char,
 }
 
-impl Default for lua_CompileOptions {
-    fn default() -> Self {
-        Self {
-            optimizationLevel: 1,
-            debugLevel: 1,
-            typeInfoLevel: 0,
-            coverageLevel: 0,
-            vectorLib: ptr::null(),
-            vectorCtor: ptr::null(),
-            vectorType: ptr::null(),
-            mutableGlobals: ptr::null(),
-            userdataTypes: ptr::null(),
-        }
-    }
-}
-
-extern "C-unwind" {
+extern "C" {
     #[link_name = "luau_compile"]
     pub fn luau_compile_(
         source: *const c_char,
@@ -41,9 +22,7 @@ extern "C-unwind" {
         options: *mut lua_CompileOptions,
         outsize: *mut usize,
     ) -> *mut c_char;
-}
 
-extern "C" {
     fn free(p: *mut c_void);
 }
 
@@ -55,7 +34,6 @@ pub unsafe fn luau_compile(source: &[u8], mut options: lua_CompileOptions) -> Ve
         &mut options,
         &mut outsize,
     );
-    assert!(!data_ptr.is_null(), "luau_compile failed");
     let data = slice::from_raw_parts(data_ptr as *mut u8, outsize).to_vec();
     free(data_ptr as *mut c_void);
     data

src/ffi/luau/lualib.rs

@@ -9,19 +9,17 @@ pub const LUA_TABLIBNAME: &str = "table";
 pub const LUA_OSLIBNAME: &str = "os";
 pub const LUA_STRLIBNAME: &str = "string";
 pub const LUA_BITLIBNAME: &str = "bit32";
-pub const LUA_BUFFERLIBNAME: &str = "buffer";
 pub const LUA_UTF8LIBNAME: &str = "utf8";
 pub const LUA_MATHLIBNAME: &str = "math";
 pub const LUA_DBLIBNAME: &str = "debug";
 
-extern "C-unwind" {
+extern "C" {
     pub fn luaopen_base(L: *mut lua_State) -> c_int;
     pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
     pub fn luaopen_table(L: *mut lua_State) -> c_int;
     pub fn luaopen_os(L: *mut lua_State) -> c_int;
     pub fn luaopen_string(L: *mut lua_State) -> c_int;
     pub fn luaopen_bit32(L: *mut lua_State) -> c_int;
-    pub fn luaopen_buffer(L: *mut lua_State) -> c_int;
     pub fn luaopen_utf8(L: *mut lua_State) -> c_int;
     pub fn luaopen_math(L: *mut lua_State) -> c_int;
     pub fn luaopen_debug(L: *mut lua_State) -> c_int;

src/ffi/luau/mod.rs

@@ -4,12 +4,10 @@ pub use compat::*;
 pub use lauxlib::*;
 pub use lua::*;
 pub use luacode::*;
-pub use luacodegen::*;
 pub use lualib::*;
 
 pub mod compat;
 pub mod lauxlib;
 pub mod lua;
 pub mod luacode;
-pub mod luacodegen;
 pub mod lualib;

src/ffi/mod.rs

@@ -0,0 +1,103 @@
+//! Low level bindings to Lua 5.4/5.3/5.2/5.1 including LuaJIT.
+
+#![allow(non_camel_case_types, non_snake_case, dead_code)]
+
+use std::os::raw::c_int;
+
+#[cfg(feature = "lua54")]
+pub use lua54::*;
+
+#[cfg(feature = "lua53")]
+pub use lua53::*;
+
+#[cfg(feature = "lua52")]
+pub use lua52::*;
+
+#[cfg(any(feature = "lua51", feature = "luajit"))]
+pub use lua51::*;
+
+#[cfg(feature = "luau")]
+pub use luau::*;
+
+#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+pub const LUA_MAX_UPVALUES: c_int = 255;
+
+#[cfg(any(feature = "lua51", all(feature = "luajit", not(feature = "vendored"))))]
+pub const LUA_MAX_UPVALUES: c_int = 60;
+
+#[cfg(all(feature = "luajit", feature = "vendored"))]
+pub const LUA_MAX_UPVALUES: c_int = 120;
+
+#[cfg(feature = "luau")]
+pub const LUA_MAX_UPVALUES: c_int = 200;
+
+// I believe `luaL_traceback` < 5.4 requires this much free stack to not error.
+// 5.4 uses `luaL_Buffer`
+pub const LUA_TRACEBACK_STACK: c_int = 11;
+
+// The minimum alignment guaranteed by the architecture. This value is used to
+// add fast paths for low alignment values.
+// Copied from https://github.com/rust-lang/rust/blob/master/library/std/src/sys/common/alloc.rs
+#[cfg(all(any(
+    target_arch = "x86",
+    target_arch = "arm",
+    target_arch = "mips",
+    target_arch = "powerpc",
+    target_arch = "powerpc64",
+    target_arch = "sparc",
+    target_arch = "asmjs",
+    target_arch = "wasm32",
+    target_arch = "hexagon",
+    all(target_arch = "riscv32", not(target_os = "espidf")),
+    all(target_arch = "xtensa", not(target_os = "espidf")),
+)))]
+pub const SYS_MIN_ALIGN: usize = 8;
+#[cfg(all(any(
+    target_arch = "x86_64",
+    target_arch = "aarch64",
+    target_arch = "mips64",
+    target_arch = "s390x",
+    target_arch = "sparc64",
+    target_arch = "riscv64",
+    target_arch = "wasm64",
+)))]
+pub const SYS_MIN_ALIGN: usize = 16;
+// The allocator on the esp-idf platform guarentees 4 byte alignment.
+#[cfg(all(any(
+    all(target_arch = "riscv32", target_os = "espidf"),
+    all(target_arch = "xtensa", target_os = "espidf"),
+)))]
+pub const SYS_MIN_ALIGN: usize = 4;
+
+// Hack to avoid stripping a few unused Lua symbols that could be imported
+// by C modules in unsafe mode
+#[cfg(not(feature = "luau"))]
+pub(crate) fn keep_lua_symbols() {
+    let mut symbols: Vec<*const extern "C" fn()> = Vec::new();
+    symbols.push(lua_atpanic as _);
+    symbols.push(lua_isuserdata as _);
+    symbols.push(lua_tocfunction as _);
+    symbols.push(luaL_loadstring as _);
+    symbols.push(luaL_openlibs as _);
+    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+    {
+        symbols.push(lua_getglobal as _);
+        symbols.push(lua_setglobal as _);
+        symbols.push(luaL_setfuncs as _);
+    }
+}
+
+#[cfg(feature = "lua54")]
+pub mod lua54;
+
+#[cfg(feature = "lua53")]
+pub mod lua53;
+
+#[cfg(feature = "lua52")]
+pub mod lua52;
+
+#[cfg(any(feature = "lua51", feature = "luajit"))]
+pub mod lua51;
+
+#[cfg(feature = "luau")]
+pub mod luau;

src/function.rs

@@ -1,73 +1,33 @@
-use std::cell::RefCell;
 use std::mem;
 use std::os::raw::{c_int, c_void};
 use std::ptr;
 use std::slice;
 
 use crate::error::{Error, Result};
-use crate::lua::Lua;
-use crate::table::Table;
-use crate::types::{Callback, LuaRef, MaybeSend};
+use crate::ffi;
+use crate::types::LuaRef;
 use crate::util::{
-    assert_stack, check_stack, linenumber_to_usize, pop_error, ptr_to_lossy_str, ptr_to_str,
-    StackGuard,
+    assert_stack, check_stack, error_traceback, pop_error, ptr_to_cstr_bytes, StackGuard,
 };
-use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti, Value};
+use crate::value::{FromLuaMulti, ToLuaMulti};
 
 #[cfg(feature = "async")]
-use {
-    crate::types::AsyncCallback,
-    futures_util::future::{self, Future},
-};
+use {futures_core::future::LocalBoxFuture, futures_util::future};
 
 /// Handle to an internal Lua function.
 #[derive(Clone, Debug)]
 pub struct Function<'lua>(pub(crate) LuaRef<'lua>);
 
-/// Owned handle to an internal Lua function.
-///
-/// The owned handle holds a *strong* reference to the current Lua instance.
-/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
-/// to accidentally cause reference cycles that would prevent destroying Lua instance.
-///
-/// [`UserData`]: crate::UserData
-#[cfg(feature = "unstable")]
-#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
-#[derive(Clone, Debug)]
-pub struct OwnedFunction(pub(crate) crate::types::LuaOwnedRef);
-
-#[cfg(feature = "unstable")]
-impl OwnedFunction {
-    /// Get borrowed handle to the underlying Lua function.
-    #[cfg_attr(feature = "send", allow(unused))]
-    pub const fn to_ref(&self) -> Function {
-        Function(self.0.to_ref())
-    }
-}
-
-/// Contains information about a function.
-///
-/// Please refer to the [`Lua Debug Interface`] for more information.
-///
-/// [`Lua Debug Interface`]: https://www.lua.org/manual/5.4/manual.html#4.7
 #[derive(Clone, Debug)]
 pub struct FunctionInfo {
-    /// A (reasonable) name of the function (`None` if the name cannot be found).
-    pub name: Option<String>,
-    /// Explains the `name` field (can be `global`/`local`/`method`/`field`/`upvalue`/etc).
-    ///
-    /// Always `None` for Luau.
-    pub name_what: Option<&'static str>,
-    /// A string `Lua` if the function is a Lua function, `C` if it is a C function, `main` if it is the main part of a chunk.
-    pub what: &'static str,
-    /// Source of the chunk that created the function.
-    pub source: Option<String>,
-    /// A "printable" version of `source`, to be used in error messages.
-    pub short_src: Option<String>,
-    /// The line number where the definition of the function starts.
-    pub line_defined: Option<usize>,
-    /// The line number where the definition of the function ends (not set by Luau).
-    pub last_line_defined: Option<usize>,
+    pub name: Option<Vec<u8>>,
+    pub name_what: Option<Vec<u8>>,
+    pub what: Option<Vec<u8>>,
+    pub source: Option<Vec<u8>>,
+    pub short_src: Option<Vec<u8>>,
+    pub line_defined: i32,
+    #[cfg(not(feature = "luau"))]
+    pub last_line_defined: i32,
 }
 
 /// Luau function coverage snapshot.
@@ -75,7 +35,7 @@ pub struct FunctionInfo {
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CoverageInfo {
-    pub function: Option<String>,
+    pub function: Option<std::string::String>,
     pub line_defined: i32,
     pub depth: i32,
     pub hits: Vec<i32>,
@@ -122,28 +82,36 @@ impl<'lua> Function<'lua> {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn call<A: IntoLuaMulti<'lua>, R: FromLuaMulti<'lua>>(&self, args: A) -> Result<R> {
+    pub fn call<A: ToLuaMulti<'lua>, R: FromLuaMulti<'lua>>(&self, args: A) -> Result<R> {
         let lua = self.0.lua;
-        let state = lua.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, 2)?;
 
-            // Push error handler
-            lua.push_error_traceback();
-            let stack_start = ffi::lua_gettop(state);
-            // Push function and the arguments
+        let mut args = args.to_lua_multi(lua)?;
+        let nargs = args.len() as c_int;
+
+        let results = unsafe {
+            let _sg = StackGuard::new(lua.state);
+            check_stack(lua.state, nargs + 3)?;
+
+            ffi::lua_pushcfunction(lua.state, error_traceback);
+            let stack_start = ffi::lua_gettop(lua.state);
             lua.push_ref(&self.0);
-            let nargs = args.push_into_stack_multi(lua)?;
-            // Call the function
-            let ret = ffi::lua_pcall(state, nargs, ffi::LUA_MULTRET, stack_start);
-            if ret != ffi::LUA_OK {
-                return Err(pop_error(state, ret));
+            for arg in args.drain_all() {
+                lua.push_value(arg)?;
             }
-            // Get the results
-            let nresults = ffi::lua_gettop(state) - stack_start;
-            R::from_stack_multi(nresults, lua)
-        }
+            let ret = ffi::lua_pcall(lua.state, nargs, ffi::LUA_MULTRET, stack_start);
+            if ret != ffi::LUA_OK {
+                return Err(pop_error(lua.state, ret));
+            }
+            let nresults = ffi::lua_gettop(lua.state) - stack_start;
+            let mut results = args; // Reuse MultiValue container
+            assert_stack(lua.state, 2);
+            for _ in 0..nresults {
+                results.push_front(lua.pop_value());
+            }
+            ffi::lua_pop(lua.state, 1);
+            results
+        };
+        R::from_lua_multi(results, lua)
     }
 
     /// Returns a future that, when polled, calls `self`, passing `args` as function arguments,
@@ -157,13 +125,14 @@ impl<'lua> Function<'lua> {
     ///
     /// ```
     /// use std::time::Duration;
+    /// use futures_timer::Delay;
     /// # use mlua::{Lua, Result};
     /// # #[tokio::main]
     /// # async fn main() -> Result<()> {
     /// # let lua = Lua::new();
     ///
     /// let sleep = lua.create_async_function(move |_lua, n: u64| async move {
-    ///     tokio::time::sleep(Duration::from_millis(n)).await;
+    ///     Delay::new(Duration::from_millis(n)).await;
     ///     Ok(())
     /// })?;
     ///
@@ -176,18 +145,21 @@ impl<'lua> Function<'lua> {
     /// [`AsyncThread`]: crate::AsyncThread
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<A, R>(&self, args: A) -> impl Future<Output = Result<R>> + 'lua
+    pub fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
     where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
+        'lua: 'fut,
+        A: ToLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'fut,
     {
         let lua = self.0.lua;
-        let thread_res = lua.create_recycled_thread(self).map(|th| {
-            let mut th = th.into_async(args);
-            th.set_recyclable(true);
-            th
-        });
-        async move { thread_res?.await }
+        match lua.create_recycled_thread(self.clone()) {
+            Ok(t) => {
+                let mut t = t.into_async(args);
+                t.set_recyclable(true);
+                Box::pin(t)
+            }
+            Err(e) => Box::pin(future::err(e)),
+        }
     }
 
     /// Returns a function that, when called, calls `self`, passing `args` as the first set of
@@ -217,8 +189,8 @@ impl<'lua> Function<'lua> {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn bind<A: IntoLuaMulti<'lua>>(&self, args: A) -> Result<Function<'lua>> {
-        unsafe extern "C-unwind" fn args_wrapper_impl(state: *mut ffi::lua_State) -> c_int {
+    pub fn bind<A: ToLuaMulti<'lua>>(&self, args: A) -> Result<Function<'lua>> {
+        unsafe extern "C" fn args_wrapper_impl(state: *mut ffi::lua_State) -> c_int {
             let nargs = ffi::lua_gettop(state);
             let nbinds = ffi::lua_tointeger(state, ffi::lua_upvalueindex(1)) as c_int;
             ffi::luaL_checkstack(state, nbinds, ptr::null());
@@ -234,9 +206,8 @@ impl<'lua> Function<'lua> {
         }
 
         let lua = self.0.lua;
-        let state = lua.state();
 
-        let args = args.into_lua_multi(lua)?;
+        let args = args.to_lua_multi(lua)?;
         let nargs = args.len() as c_int;
 
         if nargs == 0 {
@@ -248,14 +219,14 @@ impl<'lua> Function<'lua> {
         }
 
         let args_wrapper = unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, nargs + 3)?;
+            let _sg = StackGuard::new(lua.state);
+            check_stack(lua.state, nargs + 3)?;
 
-            ffi::lua_pushinteger(state, nargs as ffi::lua_Integer);
+            ffi::lua_pushinteger(lua.state, nargs as ffi::lua_Integer);
             for arg in args {
                 lua.push_value(arg)?;
             }
-            protect_lua!(state, nargs + 1, 1, fn(state) {
+            protect_lua!(lua.state, nargs + 1, 1, fn(state) {
                 ffi::lua_pushcclosure(state, args_wrapper_impl, ffi::lua_gettop(state));
             })?;
 
@@ -271,93 +242,10 @@ impl<'lua> Function<'lua> {
             "#,
         )
         .try_cache()
-        .set_name("__mlua_bind")
+        .set_name("_mlua_bind")?
         .call((self.clone(), args_wrapper))
     }
 
-    /// Returns the environment of the Lua function.
-    ///
-    /// By default Lua functions shares a global environment.
-    ///
-    /// This function always returns `None` for Rust/C functions.
-    pub fn environment(&self) -> Option<Table> {
-        let lua = self.0.lua;
-        let state = lua.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 1);
-
-            lua.push_ref(&self.0);
-            if ffi::lua_iscfunction(state, -1) != 0 {
-                return None;
-            }
-
-            #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
-            ffi::lua_getfenv(state, -1);
-            #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-            for i in 1..=255 {
-                // Traverse upvalues until we find the _ENV one
-                match ffi::lua_getupvalue(state, -1, i) {
-                    s if s.is_null() => break,
-                    s if std::ffi::CStr::from_ptr(s as _).to_bytes() == b"_ENV" => break,
-                    _ => ffi::lua_pop(state, 1),
-                }
-            }
-
-            if ffi::lua_type(state, -1) != ffi::LUA_TTABLE {
-                return None;
-            }
-            Some(Table(lua.pop_ref()))
-        }
-    }
-
-    /// Sets the environment of the Lua function.
-    ///
-    /// The environment is a table that is used as the global environment for the function.
-    /// Returns `true` if environment successfully changed, `false` otherwise.
-    ///
-    /// This function does nothing for Rust/C functions.
-    pub fn set_environment(&self, env: Table) -> Result<bool> {
-        let lua = self.0.lua;
-        let state = lua.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, 2)?;
-
-            lua.push_ref(&self.0);
-            if ffi::lua_iscfunction(state, -1) != 0 {
-                return Ok(false);
-            }
-
-            #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
-            {
-                lua.push_ref(&env.0);
-                ffi::lua_setfenv(state, -2);
-            }
-            #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-            for i in 1..=255 {
-                match ffi::lua_getupvalue(state, -1, i) {
-                    s if s.is_null() => return Ok(false),
-                    s if std::ffi::CStr::from_ptr(s as _).to_bytes() == b"_ENV" => {
-                        ffi::lua_pop(state, 1);
-                        // Create an anonymous function with the new environment
-                        let f_with_env = lua
-                            .load("return _ENV")
-                            .set_environment(env)
-                            .try_cache()
-                            .into_function()?;
-                        lua.push_ref(&f_with_env.0);
-                        ffi::lua_upvaluejoin(state, -2, i, -1, 1);
-                        break;
-                    }
-                    _ => ffi::lua_pop(state, 1),
-                }
-            }
-
-            Ok(true)
-        }
-    }
-
     /// Returns information about the function.
     ///
     /// Corresponds to the `>Sn` what mask for [`lua_getinfo`] when applied to the function.
@@ -365,39 +253,33 @@ impl<'lua> Function<'lua> {
     /// [`lua_getinfo`]: https://www.lua.org/manual/5.4/manual.html#lua_getinfo
     pub fn info(&self) -> FunctionInfo {
         let lua = self.0.lua;
-        let state = lua.state();
         unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 1);
+            let _sg = StackGuard::new(lua.state);
+            assert_stack(lua.state, 1);
 
             let mut ar: ffi::lua_Debug = mem::zeroed();
             lua.push_ref(&self.0);
             #[cfg(not(feature = "luau"))]
-            let res = ffi::lua_getinfo(state, cstr!(">Sn"), &mut ar);
+            let res = ffi::lua_getinfo(lua.state, cstr!(">Sn"), &mut ar);
             #[cfg(feature = "luau")]
-            let res = ffi::lua_getinfo(state, -1, cstr!("sn"), &mut ar);
+            let res = ffi::lua_getinfo(lua.state, -1, cstr!("sn"), &mut ar);
             mlua_assert!(res != 0, "lua_getinfo failed with `>Sn`");
 
             FunctionInfo {
-                name: ptr_to_lossy_str(ar.name).map(|s| s.into_owned()),
+                name: ptr_to_cstr_bytes(ar.name).map(|s| s.to_vec()),
                 #[cfg(not(feature = "luau"))]
-                name_what: match ptr_to_str(ar.namewhat) {
-                    Some("") => None,
-                    val => val,
-                },
+                name_what: ptr_to_cstr_bytes(ar.namewhat).map(|s| s.to_vec()),
                 #[cfg(feature = "luau")]
                 name_what: None,
-                what: ptr_to_str(ar.what).unwrap_or("main"),
-                source: ptr_to_lossy_str(ar.source).map(|s| s.into_owned()),
+                what: ptr_to_cstr_bytes(ar.what).map(|s| s.to_vec()),
+                source: ptr_to_cstr_bytes(ar.source).map(|s| s.to_vec()),
                 #[cfg(not(feature = "luau"))]
-                short_src: ptr_to_lossy_str(ar.short_src.as_ptr()).map(|s| s.into_owned()),
+                short_src: ptr_to_cstr_bytes(ar.short_src.as_ptr()).map(|s| s.to_vec()),
                 #[cfg(feature = "luau")]
-                short_src: ptr_to_lossy_str(ar.short_src).map(|s| s.into_owned()),
-                line_defined: linenumber_to_usize(ar.linedefined),
+                short_src: ptr_to_cstr_bytes(ar.short_src).map(|s| s.to_vec()),
+                line_defined: ar.linedefined,
                 #[cfg(not(feature = "luau"))]
-                last_line_defined: linenumber_to_usize(ar.lastlinedefined),
-                #[cfg(feature = "luau")]
-                last_line_defined: None,
+                last_line_defined: ar.lastlinedefined,
             }
         }
     }
@@ -413,7 +295,7 @@ impl<'lua> Function<'lua> {
     #[cfg(not(feature = "luau"))]
     #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub fn dump(&self, strip: bool) -> Vec<u8> {
-        unsafe extern "C-unwind" fn writer(
+        unsafe extern "C" fn writer(
             _state: *mut ffi::lua_State,
             buf: *const c_void,
             buf_len: usize,
@@ -426,16 +308,15 @@ impl<'lua> Function<'lua> {
         }
 
         let lua = self.0.lua;
-        let state = lua.state();
         let mut data: Vec<u8> = Vec::new();
         unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 1);
+            let _sg = StackGuard::new(lua.state);
+            assert_stack(lua.state, 1);
 
             lua.push_ref(&self.0);
             let data_ptr = &mut data as *mut Vec<u8> as *mut c_void;
-            ffi::lua_dump(state, writer, data_ptr, strip as i32);
-            ffi::lua_pop(state, 1);
+            ffi::lua_dump(lua.state, writer, data_ptr, strip as i32);
+            ffi::lua_pop(lua.state, 1);
         }
 
         data
@@ -451,7 +332,7 @@ impl<'lua> Function<'lua> {
     /// Requires `feature = "luau"`
     ///
     /// [`Compiler::set_coverage_level`]: crate::chunk::Compiler::set_coverage_level
-    #[cfg(any(feature = "luau", doc))]
+    #[cfg(any(feature = "luau", docsrs))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     pub fn coverage<F>(&self, mut func: F)
     where
@@ -460,7 +341,7 @@ impl<'lua> Function<'lua> {
         use std::ffi::CStr;
         use std::os::raw::c_char;
 
-        unsafe extern "C-unwind" fn callback<F: FnMut(CoverageInfo)>(
+        unsafe extern "C" fn callback<F: FnMut(CoverageInfo)>(
             data: *mut c_void,
             function: *const c_char,
             line_defined: c_int,
@@ -483,55 +364,15 @@ impl<'lua> Function<'lua> {
         }
 
         let lua = self.0.lua;
-        let state = lua.state();
         unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 1);
+            let _sg = StackGuard::new(lua.state);
+            assert_stack(lua.state, 1);
 
             lua.push_ref(&self.0);
             let func_ptr = &mut func as *mut F as *mut c_void;
-            ffi::lua_getcoverage(state, -1, func_ptr, callback::<F>);
+            ffi::lua_getcoverage(lua.state, -1, func_ptr, callback::<F>);
         }
     }
-
-    /// Converts this function to a generic C pointer.
-    ///
-    /// There is no way to convert the pointer back to its original value.
-    ///
-    /// Typically this function is used only for hashing and debug information.
-    #[inline]
-    pub fn to_pointer(&self) -> *const c_void {
-        self.0.to_pointer()
-    }
-
-    /// Creates a deep clone of the Lua function.
-    ///
-    /// Copies the function prototype and all its upvalues to the
-    /// newly created function.
-    ///
-    /// This function returns shallow clone (same handle) for Rust/C functions.
-    /// Requires `feature = "luau"`
-    #[cfg(feature = "luau")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    pub fn deep_clone(&self) -> Self {
-        let ref_thread = self.0.lua.ref_thread();
-        unsafe {
-            if ffi::lua_iscfunction(ref_thread, self.0.index) != 0 {
-                return self.clone();
-            }
-
-            ffi::lua_clonefunction(ref_thread, self.0.index);
-            Function(self.0.lua.pop_ref_thread())
-        }
-    }
-
-    /// Convert this handle to owned version.
-    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-    #[inline]
-    pub fn into_owned(self) -> OwnedFunction {
-        OwnedFunction(self.0.into_owned())
-    }
 }
 
 impl<'lua> PartialEq for Function<'lua> {
@@ -539,118 +380,3 @@ impl<'lua> PartialEq for Function<'lua> {
         self.0 == other.0
     }
 }
-
-// Additional shortcuts
-#[cfg(feature = "unstable")]
-impl OwnedFunction {
-    /// Calls the function, passing `args` as function arguments.
-    ///
-    /// This is a shortcut for [`Function::call()`].
-    #[inline]
-    pub fn call<'lua, A, R>(&'lua self, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>,
-    {
-        self.to_ref().call(args)
-    }
-
-    /// Returns a future that, when polled, calls `self`, passing `args` as function arguments,
-    /// and drives the execution.
-    ///
-    /// This is a shortcut for [`Function::call_async()`].
-    #[cfg(feature = "async")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    #[inline]
-    pub async fn call_async<'lua, A, R>(&'lua self, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
-    {
-        self.to_ref().call_async(args).await
-    }
-}
-
-pub(crate) struct WrappedFunction<'lua>(pub(crate) Callback<'lua, 'static>);
-
-#[cfg(feature = "async")]
-pub(crate) struct WrappedAsyncFunction<'lua>(pub(crate) AsyncCallback<'lua, 'static>);
-
-impl<'lua> Function<'lua> {
-    /// Wraps a Rust function or closure, returning an opaque type that implements [`IntoLua`] trait.
-    #[inline]
-    pub fn wrap<A, R, F>(func: F) -> impl IntoLua<'lua>
-    where
-        A: FromLuaMulti<'lua>,
-        R: IntoLuaMulti<'lua>,
-        F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
-    {
-        WrappedFunction(Box::new(move |lua, nargs| unsafe {
-            let args = A::from_stack_args(nargs, 1, None, lua)?;
-            func(lua, args)?.push_into_stack_multi(lua)
-        }))
-    }
-
-    /// Wraps a Rust mutable closure, returning an opaque type that implements [`IntoLua`] trait.
-    #[inline]
-    pub fn wrap_mut<A, R, F>(func: F) -> impl IntoLua<'lua>
-    where
-        A: FromLuaMulti<'lua>,
-        R: IntoLuaMulti<'lua>,
-        F: FnMut(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
-    {
-        let func = RefCell::new(func);
-        WrappedFunction(Box::new(move |lua, nargs| unsafe {
-            let mut func = func
-                .try_borrow_mut()
-                .map_err(|_| Error::RecursiveMutCallback)?;
-            let args = A::from_stack_args(nargs, 1, None, lua)?;
-            func(lua, args)?.push_into_stack_multi(lua)
-        }))
-    }
-
-    /// Wraps a Rust async function or closure, returning an opaque type that implements [`IntoLua`] trait.
-    #[cfg(feature = "async")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn wrap_async<A, R, F, FR>(func: F) -> impl IntoLua<'lua>
-    where
-        A: FromLuaMulti<'lua>,
-        R: IntoLuaMulti<'lua>,
-        F: Fn(&'lua Lua, A) -> FR + MaybeSend + 'static,
-        FR: Future<Output = Result<R>> + 'lua,
-    {
-        WrappedAsyncFunction(Box::new(move |lua, args| unsafe {
-            let args = match A::from_lua_args(args, 1, None, lua) {
-                Ok(args) => args,
-                Err(e) => return Box::pin(future::err(e)),
-            };
-            let fut = func(lua, args);
-            Box::pin(async move { fut.await?.push_into_stack_multi(lua) })
-        }))
-    }
-}
-
-impl<'lua> IntoLua<'lua> for WrappedFunction<'lua> {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        lua.create_callback(self.0).map(Value::Function)
-    }
-}
-
-#[cfg(feature = "async")]
-impl<'lua> IntoLua<'lua> for WrappedAsyncFunction<'lua> {
-    #[inline]
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
-        lua.create_async_callback(self.0).map(Value::Function)
-    }
-}
-
-#[cfg(test)]
-mod assertions {
-    use super::*;
-
-    static_assertions::assert_not_impl_any!(Function: Send);
-
-    #[cfg(all(feature = "unstable", not(feature = "send")))]
-    static_assertions::assert_not_impl_any!(OwnedFunction: Send);
-}

src/hook.rs

@@ -1,13 +1,11 @@
-use std::borrow::Cow;
 use std::cell::UnsafeCell;
 #[cfg(not(feature = "luau"))]
 use std::ops::{BitOr, BitOrAssign};
 use std::os::raw::c_int;
 
-use ffi::lua_Debug;
-
+use crate::ffi::{self, lua_Debug};
 use crate::lua::Lua;
-use crate::util::{linenumber_to_usize, ptr_to_lossy_str, ptr_to_str};
+use crate::util::ptr_to_cstr_bytes;
 
 /// Contains information about currently executing Lua code.
 ///
@@ -69,22 +67,19 @@ impl<'lua> Debug<'lua> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("n"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, cstr!("n"), self.ar.get()) != 0,
                 "lua_getinfo failed with `n`"
             );
             #[cfg(feature = "luau")]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("n"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, self.level, cstr!("n"), self.ar.get()) != 0,
                 "lua_getinfo failed with `n`"
             );
 
             DebugNames {
-                name: ptr_to_lossy_str((*self.ar.get()).name),
+                name: ptr_to_cstr_bytes((*self.ar.get()).name),
                 #[cfg(not(feature = "luau"))]
-                name_what: match ptr_to_str((*self.ar.get()).namewhat) {
-                    Some("") => None,
-                    val => val,
-                },
+                name_what: ptr_to_cstr_bytes((*self.ar.get()).namewhat),
                 #[cfg(feature = "luau")]
                 name_what: None,
             }
@@ -96,27 +91,25 @@ impl<'lua> Debug<'lua> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("S"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, cstr!("S"), self.ar.get()) != 0,
                 "lua_getinfo failed with `S`"
             );
             #[cfg(feature = "luau")]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("s"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, self.level, cstr!("s"), self.ar.get()) != 0,
                 "lua_getinfo failed with `s`"
             );
 
             DebugSource {
-                source: ptr_to_lossy_str((*self.ar.get()).source),
+                source: ptr_to_cstr_bytes((*self.ar.get()).source),
                 #[cfg(not(feature = "luau"))]
-                short_src: ptr_to_lossy_str((*self.ar.get()).short_src.as_ptr()),
+                short_src: ptr_to_cstr_bytes((*self.ar.get()).short_src.as_ptr()),
                 #[cfg(feature = "luau")]
-                short_src: ptr_to_lossy_str((*self.ar.get()).short_src),
-                line_defined: linenumber_to_usize((*self.ar.get()).linedefined),
+                short_src: ptr_to_cstr_bytes((*self.ar.get()).short_src),
+                line_defined: (*self.ar.get()).linedefined,
                 #[cfg(not(feature = "luau"))]
-                last_line_defined: linenumber_to_usize((*self.ar.get()).lastlinedefined),
-                #[cfg(feature = "luau")]
-                last_line_defined: None,
-                what: ptr_to_str((*self.ar.get()).what).unwrap_or("main"),
+                last_line_defined: (*self.ar.get()).lastlinedefined,
+                what: ptr_to_cstr_bytes((*self.ar.get()).what),
             }
         }
     }
@@ -126,12 +119,12 @@ impl<'lua> Debug<'lua> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("l"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, cstr!("l"), self.ar.get()) != 0,
                 "lua_getinfo failed with `l`"
             );
             #[cfg(feature = "luau")]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("l"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, self.level, cstr!("l"), self.ar.get()) != 0,
                 "lua_getinfo failed with `l`"
             );
 
@@ -146,7 +139,7 @@ impl<'lua> Debug<'lua> {
     pub fn is_tail_call(&self) -> bool {
         unsafe {
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("t"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, cstr!("t"), self.ar.get()) != 0,
                 "lua_getinfo failed with `t`"
             );
             (*self.ar.get()).currentline != 0
@@ -158,20 +151,20 @@ impl<'lua> Debug<'lua> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("u"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, cstr!("u"), self.ar.get()) != 0,
                 "lua_getinfo failed with `u`"
             );
             #[cfg(feature = "luau")]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("a"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state, self.level, cstr!("a"), self.ar.get()) != 0,
                 "lua_getinfo failed with `a`"
             );
 
             #[cfg(not(feature = "luau"))]
             let stack = DebugStack {
-                num_ups: (*self.ar.get()).nups as _,
+                num_ups: (*self.ar.get()).nups as i32,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-                num_params: (*self.ar.get()).nparams as _,
+                num_params: (*self.ar.get()).nparams as i32,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
                 is_vararg: (*self.ar.get()).isvararg != 0,
             };
@@ -216,26 +209,18 @@ pub enum DebugEvent {
 
 #[derive(Clone, Debug)]
 pub struct DebugNames<'a> {
-    /// A (reasonable) name of the function (`None` if the name cannot be found).
-    pub name: Option<Cow<'a, str>>,
-    /// Explains the `name` field (can be `global`/`local`/`method`/`field`/`upvalue`/etc).
-    ///
-    /// Always `None` for Luau.
-    pub name_what: Option<&'static str>,
+    pub name: Option<&'a [u8]>,
+    pub name_what: Option<&'a [u8]>,
 }
 
 #[derive(Clone, Debug)]
 pub struct DebugSource<'a> {
-    /// Source of the chunk that created the function.
-    pub source: Option<Cow<'a, str>>,
-    /// A "printable" version of `source`, to be used in error messages.
-    pub short_src: Option<Cow<'a, str>>,
-    /// The line number where the definition of the function starts.
-    pub line_defined: Option<usize>,
-    /// The line number where the definition of the function ends (not set by Luau).
-    pub last_line_defined: Option<usize>,
-    /// A string `Lua` if the function is a Lua function, `C` if it is a C function, `main` if it is the main part of a chunk.
-    pub what: &'static str,
+    pub source: Option<&'a [u8]>,
+    pub short_src: Option<&'a [u8]>,
+    pub line_defined: i32,
+    #[cfg(not(feature = "luau"))]
+    pub last_line_defined: i32,
+    pub what: Option<&'a [u8]>,
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -281,59 +266,48 @@ pub struct HookTriggers {
 
 #[cfg(not(feature = "luau"))]
 impl HookTriggers {
-    /// An instance of `HookTriggers` with `on_calls` trigger set.
-    pub const ON_CALLS: Self = HookTriggers::new().on_calls();
-
-    /// An instance of `HookTriggers` with `on_returns` trigger set.
-    pub const ON_RETURNS: Self = HookTriggers::new().on_returns();
-
-    /// An instance of `HookTriggers` with `every_line` trigger set.
-    pub const EVERY_LINE: Self = HookTriggers::new().every_line();
-
-    /// Returns a new instance of `HookTriggers` with all triggers disabled.
-    pub const fn new() -> Self {
+    /// Returns a new instance of `HookTriggers` with [`on_calls`] trigger set.
+    ///
+    /// [`on_calls`]: #structfield.on_calls
+    pub fn on_calls() -> Self {
         HookTriggers {
-            on_calls: false,
-            on_returns: false,
-            every_line: false,
-            every_nth_instruction: None,
+            on_calls: true,
+            ..Default::default()
         }
     }
 
-    /// Returns an instance of `HookTriggers` with [`on_calls`] trigger set.
-    ///
-    /// [`on_calls`]: #structfield.on_calls
-    pub const fn on_calls(mut self) -> Self {
-        self.on_calls = true;
-        self
-    }
-
-    /// Returns an instance of `HookTriggers` with [`on_returns`] trigger set.
+    /// Returns a new instance of `HookTriggers` with [`on_returns`] trigger set.
     ///
     /// [`on_returns`]: #structfield.on_returns
-    pub const fn on_returns(mut self) -> Self {
-        self.on_returns = true;
-        self
+    pub fn on_returns() -> Self {
+        HookTriggers {
+            on_returns: true,
+            ..Default::default()
+        }
     }
 
-    /// Returns an instance of `HookTriggers` with [`every_line`] trigger set.
+    /// Returns a new instance of `HookTriggers` with [`every_line`] trigger set.
     ///
     /// [`every_line`]: #structfield.every_line
-    pub const fn every_line(mut self) -> Self {
-        self.every_line = true;
-        self
+    pub fn every_line() -> Self {
+        HookTriggers {
+            every_line: true,
+            ..Default::default()
+        }
     }
 
-    /// Returns an instance of `HookTriggers` with [`every_nth_instruction`] trigger set.
+    /// Returns a new instance of `HookTriggers` with [`every_nth_instruction`] trigger set.
     ///
     /// [`every_nth_instruction`]: #structfield.every_nth_instruction
-    pub const fn every_nth_instruction(mut self, n: u32) -> Self {
-        self.every_nth_instruction = Some(n);
-        self
+    pub fn every_nth_instruction(n: u32) -> Self {
+        HookTriggers {
+            every_nth_instruction: Some(n),
+            ..Default::default()
+        }
     }
 
     // Compute the mask to pass to `lua_sethook`.
-    pub(crate) const fn mask(&self) -> c_int {
+    pub(crate) fn mask(&self) -> c_int {
         let mut mask: c_int = 0;
         if self.on_calls {
             mask |= ffi::LUA_MASKCALL
@@ -352,11 +326,8 @@ impl HookTriggers {
 
     // Returns the `count` parameter to pass to `lua_sethook`, if applicable. Otherwise, zero is
     // returned.
-    pub(crate) const fn count(&self) -> c_int {
-        match self.every_nth_instruction {
-            Some(n) => n as c_int,
-            None => 0,
-        }
+    pub(crate) fn count(&self) -> c_int {
+        self.every_nth_instruction.unwrap_or(0) as c_int
     }
 }
 

src/lib.rs

@@ -10,10 +10,10 @@
 //!
 //! # Converting data
 //!
-//! The [`IntoLua`] and [`FromLua`] traits allow conversion from Rust types to Lua values and vice
+//! The [`ToLua`] and [`FromLua`] traits allow conversion from Rust types to Lua values and vice
 //! versa. They are implemented for many data structures found in Rust's standard library.
 //!
-//! For more general conversions, the [`IntoLuaMulti`] and [`FromLuaMulti`] traits allow converting
+//! For more general conversions, the [`ToLuaMulti`] and [`FromLuaMulti`] traits allow converting
 //! between Rust types and *any number* of Lua values.
 //!
 //! Most code in `mlua` is generic over implementors of those traits, so in most places the normal
@@ -54,9 +54,9 @@
 //! [executing]: crate::Chunk::exec
 //! [evaluating]: crate::Chunk::eval
 //! [globals]: crate::Lua::globals
-//! [`IntoLua`]: crate::IntoLua
+//! [`ToLua`]: crate::ToLua
 //! [`FromLua`]: crate::FromLua
-//! [`IntoLuaMulti`]: crate::IntoLuaMulti
+//! [`ToLuaMulti`]: crate::ToLuaMulti
 //! [`FromLuaMulti`]: crate::FromLuaMulti
 //! [`Function`]: crate::Function
 //! [`UserData`]: crate::UserData
@@ -73,7 +73,7 @@
 
 // Deny warnings inside doc tests / examples. When this isn't present, rustdoc doesn't show *any*
 // warnings at all.
-#![doc(test(attr(warn(warnings))))] // FIXME: Remove this when rust-lang/rust#123748 is fixed
+#![doc(test(attr(deny(warnings))))]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
 #[macro_use]
@@ -82,12 +82,12 @@ mod macros;
 mod chunk;
 mod conversion;
 mod error;
+mod ffi;
 mod function;
 mod hook;
 mod lua;
 #[cfg(feature = "luau")]
 mod luau;
-mod memory;
 mod multi;
 mod scope;
 mod stdlib;
@@ -96,17 +96,16 @@ mod table;
 mod thread;
 mod types;
 mod userdata;
-mod userdata_ext;
 mod userdata_impl;
 mod util;
 mod value;
 
 pub mod prelude;
 
-pub use ffi::{self, lua_CFunction, lua_State};
+pub use crate::{ffi::lua_CFunction, ffi::lua_State};
 
 pub use crate::chunk::{AsChunk, Chunk, ChunkMode};
-pub use crate::error::{Error, ErrorContext, ExternalError, ExternalResult, Result};
+pub use crate::error::{Error, ExternalError, ExternalResult, Result};
 pub use crate::function::{Function, FunctionInfo};
 pub use crate::hook::{Debug, DebugEvent, DebugNames, DebugSource, DebugStack};
 pub use crate::lua::{GCMode, Lua, LuaOptions};
@@ -116,25 +115,18 @@ pub use crate::stdlib::StdLib;
 pub use crate::string::String;
 pub use crate::table::{Table, TableExt, TablePairs, TableSequence};
 pub use crate::thread::{Thread, ThreadStatus};
-pub use crate::types::{AppDataRef, AppDataRefMut, Integer, LightUserData, Number, RegistryKey};
+pub use crate::types::{Integer, LightUserData, Number, RegistryKey};
 pub use crate::userdata::{
     AnyUserData, MetaMethod, UserData, UserDataFields, UserDataMetatable, UserDataMethods,
-    UserDataRef, UserDataRefMut,
 };
-pub use crate::userdata_ext::AnyUserDataExt;
-pub use crate::userdata_impl::UserDataRegistry;
-pub use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, MultiValue, Nil, Value};
+pub use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti, Value};
 
 #[cfg(not(feature = "luau"))]
 pub use crate::hook::HookTriggers;
 
 #[cfg(any(feature = "luau", doc))]
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-pub use crate::{
-    chunk::Compiler,
-    function::CoverageInfo,
-    types::{Vector, VmState},
-};
+pub use crate::{chunk::Compiler, function::CoverageInfo, types::VmState};
 
 #[cfg(feature = "async")]
 pub use crate::thread::AsyncThread;
@@ -149,24 +141,17 @@ pub use crate::serde::{
 #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
 pub mod serde;
 
-#[cfg(feature = "mlua_derive")]
+#[cfg(any(feature = "mlua_derive"))]
 #[allow(unused_imports)]
 #[macro_use]
 extern crate mlua_derive;
 
-// Unstable features
-#[cfg(feature = "unstable")]
-pub use crate::{
-    function::OwnedFunction, string::OwnedString, table::OwnedTable, thread::OwnedThread,
-    userdata::OwnedAnyUserData,
-};
-
 /// Create a type that implements [`AsChunk`] and can capture Rust variables.
 ///
 /// This macro allows to write Lua code directly in Rust code.
 ///
 /// Rust variables can be referenced from Lua using `$` prefix, as shown in the example below.
-/// User's Rust types needs to implement [`UserData`] or [`IntoLua`] traits.
+/// User's Rust types needs to implement [`UserData`] or [`ToLua`] traits.
 ///
 /// Captured variables are **moved** into the chunk.
 ///
@@ -212,19 +197,11 @@ pub use crate::{
 ///
 /// [`AsChunk`]: crate::AsChunk
 /// [`UserData`]: crate::UserData
-/// [`IntoLua`]: crate::IntoLua
-#[cfg(feature = "macros")]
+/// [`ToLua`]: crate::ToLua
+#[cfg(any(feature = "macros"))]
 #[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
 pub use mlua_derive::chunk;
 
-/// Derive [`FromLua`] for a Rust type.
-///
-/// Current implementation generate code that takes [`UserData`] value, borrow it (of the Rust type)
-/// and clone.
-#[cfg(feature = "macros")]
-#[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
-pub use mlua_derive::FromLua;
-
 /// Registers Lua module entrypoint.
 ///
 /// You can register multiple entrypoints as required.
@@ -242,43 +219,6 @@ pub use mlua_derive::FromLua;
 ///
 /// Internally in the code above the compiler defines C function `luaopen_my_module`.
 ///
-/// You can also pass options to the attribute:
-///
-/// * name - name of the module, defaults to the name of the function
-///
-/// ```ignore
-/// #[mlua::lua_module(name = "alt_module")]
-/// fn my_module(lua: &Lua) -> Result<Table> {
-///     ...
-/// }
-/// ```
-///
-/// * skip_memory_check - skip memory allocation checks for some operations.
-///
-/// In module mode, mlua runs in unknown environment and cannot say are there any memory
-/// limits or not. As result, some operations that require memory allocation runs in
-/// protected mode. Setting this attribute will improve performance of such operations
-/// with risk of having uncaught exceptions and memory leaks.
-///
-/// ```ignore
-/// #[mlua::lua_module(skip_memory_check)]
-/// fn my_module(lua: &Lua) -> Result<Table> {
-///     ...
-/// }
-/// ```
-///
 #[cfg(any(feature = "module", docsrs))]
 #[cfg_attr(docsrs, doc(cfg(feature = "module")))]
 pub use mlua_derive::lua_module;
-
-pub(crate) mod private {
-    use super::*;
-
-    pub trait Sealed {}
-
-    impl Sealed for Error {}
-    impl<T> Sealed for std::result::Result<T, Error> {}
-    impl Sealed for Lua {}
-    impl Sealed for Table<'_> {}
-    impl Sealed for AnyUserData<'_> {}
-}

src/luau.rs

@@ -0,0 +1,130 @@
+use std::ffi::CStr;
+use std::os::raw::{c_float, c_int};
+
+use crate::chunk::ChunkMode;
+use crate::error::{Error, Result};
+use crate::ffi;
+use crate::lua::Lua;
+use crate::table::Table;
+use crate::util::{check_stack, StackGuard};
+use crate::value::Value;
+
+// Since Luau has some missing standard function, we re-implement them here
+
+impl Lua {
+    pub(crate) unsafe fn prepare_luau_state(&self) -> Result<()> {
+        let globals = self.globals();
+
+        globals.raw_set(
+            "collectgarbage",
+            self.create_c_function(lua_collectgarbage)?,
+        )?;
+        globals.raw_set("require", self.create_function(lua_require)?)?;
+        globals.raw_set("vector", self.create_c_function(lua_vector)?)?;
+
+        // Set `_VERSION` global to include version number
+        // The environment variable `LUAU_VERSION` set by the build script
+        if let Some(version) = option_env!("LUAU_VERSION") {
+            globals.raw_set("_VERSION", format!("Luau {version}"))?;
+        }
+
+        Ok(())
+    }
+}
+
+unsafe extern "C" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_int {
+    let option = ffi::luaL_optstring(state, 1, cstr!("collect"));
+    let option = CStr::from_ptr(option);
+    let arg = ffi::luaL_optinteger(state, 2, 0);
+    match option.to_str() {
+        Ok("collect") => {
+            ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0);
+            0
+        }
+        Ok("stop") => {
+            ffi::lua_gc(state, ffi::LUA_GCSTOP, 0);
+            0
+        }
+        Ok("restart") => {
+            ffi::lua_gc(state, ffi::LUA_GCRESTART, 0);
+            0
+        }
+        Ok("count") => {
+            let kbytes = ffi::lua_gc(state, ffi::LUA_GCCOUNT, 0) as ffi::lua_Number;
+            let kbytes_rem = ffi::lua_gc(state, ffi::LUA_GCCOUNTB, 0) as ffi::lua_Number;
+            ffi::lua_pushnumber(state, kbytes + kbytes_rem / 1024.0);
+            1
+        }
+        Ok("step") => {
+            let res = ffi::lua_gc(state, ffi::LUA_GCSTEP, arg);
+            ffi::lua_pushboolean(state, res);
+            1
+        }
+        Ok("isrunning") => {
+            let res = ffi::lua_gc(state, ffi::LUA_GCISRUNNING, 0);
+            ffi::lua_pushboolean(state, res);
+            1
+        }
+        _ => ffi::luaL_error(state, cstr!("collectgarbage called with invalid option")),
+    }
+}
+
+fn lua_require(lua: &Lua, name: Option<std::string::String>) -> Result<Value> {
+    let name = name.ok_or_else(|| Error::RuntimeError("invalid module name".into()))?;
+
+    // Find module in the cache
+    let loaded = unsafe {
+        let _sg = StackGuard::new(lua.state);
+        check_stack(lua.state, 2)?;
+        protect_lua!(lua.state, 0, 1, fn(state) {
+            ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADED"));
+        })?;
+        Table(lua.pop_ref())
+    };
+    if let Some(v) = loaded.raw_get(name.clone())? {
+        return Ok(v);
+    }
+
+    // Load file from filesystem
+    let mut search_path = std::env::var("LUAU_PATH").unwrap_or_default();
+    if search_path.is_empty() {
+        search_path = "?.luau;?.lua".into();
+    }
+
+    let (mut source, mut source_name) = (None, String::new());
+    for path in search_path.split(';') {
+        let file_path = path.replacen('?', &name, 1);
+        if let Ok(buf) = std::fs::read(&file_path) {
+            source = Some(buf);
+            source_name = file_path;
+            break;
+        }
+    }
+    let source = source.ok_or_else(|| Error::RuntimeError(format!("cannot find '{}'", name)))?;
+
+    let value = lua
+        .load(&source)
+        .set_name(&format!("={}", source_name))?
+        .set_mode(ChunkMode::Text)
+        .call::<_, Value>(())?;
+
+    // Save in the cache
+    loaded.raw_set(
+        name,
+        match value.clone() {
+            Value::Nil => Value::Boolean(true),
+            v => v,
+        },
+    )?;
+
+    Ok(value)
+}
+
+// Luau vector datatype constructor
+unsafe extern "C" fn lua_vector(state: *mut ffi::lua_State) -> c_int {
+    let x = ffi::luaL_checknumber(state, 1) as c_float;
+    let y = ffi::luaL_checknumber(state, 2) as c_float;
+    let z = ffi::luaL_checknumber(state, 3) as c_float;
+    ffi::lua_pushvector(state, x, y, z);
+    1
+}

src/luau/mod.rs

@@ -1,88 +0,0 @@
-use std::ffi::CStr;
-use std::os::raw::{c_float, c_int};
-
-use crate::error::Result;
-use crate::lua::Lua;
-
-// Since Luau has some missing standard functions, we re-implement them here
-
-impl Lua {
-    pub(crate) unsafe fn configure_luau(&self) -> Result<()> {
-        let globals = self.globals();
-
-        globals.raw_set(
-            "collectgarbage",
-            self.create_c_function(lua_collectgarbage)?,
-        )?;
-        globals.raw_set("vector", self.create_c_function(lua_vector)?)?;
-
-        // Set `_VERSION` global to include version number
-        // The environment variable `LUAU_VERSION` set by the build script
-        if let Some(version) = ffi::luau_version() {
-            globals.raw_set("_VERSION", format!("Luau {version}"))?;
-        }
-
-        Ok(())
-    }
-
-    pub(crate) fn disable_c_modules(&self) -> Result<()> {
-        package::disable_dylibs(self);
-        Ok(())
-    }
-}
-
-unsafe extern "C-unwind" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_int {
-    let option = ffi::luaL_optstring(state, 1, cstr!("collect"));
-    let option = CStr::from_ptr(option);
-    let arg = ffi::luaL_optinteger(state, 2, 0);
-    match option.to_str() {
-        Ok("collect") => {
-            ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0);
-            0
-        }
-        Ok("stop") => {
-            ffi::lua_gc(state, ffi::LUA_GCSTOP, 0);
-            0
-        }
-        Ok("restart") => {
-            ffi::lua_gc(state, ffi::LUA_GCRESTART, 0);
-            0
-        }
-        Ok("count") => {
-            let kbytes = ffi::lua_gc(state, ffi::LUA_GCCOUNT, 0) as ffi::lua_Number;
-            let kbytes_rem = ffi::lua_gc(state, ffi::LUA_GCCOUNTB, 0) as ffi::lua_Number;
-            ffi::lua_pushnumber(state, kbytes + kbytes_rem / 1024.0);
-            1
-        }
-        Ok("step") => {
-            let res = ffi::lua_gc(state, ffi::LUA_GCSTEP, arg);
-            ffi::lua_pushboolean(state, res);
-            1
-        }
-        Ok("isrunning") => {
-            let res = ffi::lua_gc(state, ffi::LUA_GCISRUNNING, 0);
-            ffi::lua_pushboolean(state, res);
-            1
-        }
-        _ => ffi::luaL_error(state, cstr!("collectgarbage called with invalid option")),
-    }
-}
-
-// Luau vector datatype constructor
-unsafe extern "C-unwind" fn lua_vector(state: *mut ffi::lua_State) -> c_int {
-    let x = ffi::luaL_checknumber(state, 1) as c_float;
-    let y = ffi::luaL_checknumber(state, 2) as c_float;
-    let z = ffi::luaL_checknumber(state, 3) as c_float;
-    #[cfg(feature = "luau-vector4")]
-    let w = ffi::luaL_checknumber(state, 4) as c_float;
-
-    #[cfg(not(feature = "luau-vector4"))]
-    ffi::lua_pushvector(state, x, y, z);
-    #[cfg(feature = "luau-vector4")]
-    ffi::lua_pushvector(state, x, y, z, w);
-    1
-}
-
-pub(crate) use package::register_package_module;
-
-mod package;

src/luau/package.rs

@@ -1,269 +0,0 @@
-use std::ffi::CStr;
-use std::fmt::Write;
-use std::os::raw::c_int;
-use std::path::{PathBuf, MAIN_SEPARATOR_STR};
-use std::string::String as StdString;
-use std::{env, fs};
-
-use crate::chunk::ChunkMode;
-use crate::error::Result;
-use crate::lua::Lua;
-use crate::table::Table;
-use crate::types::RegistryKey;
-use crate::value::{IntoLua, Value};
-
-#[cfg(unix)]
-use {libloading::Library, rustc_hash::FxHashMap};
-
-//
-// Luau package module
-//
-
-#[cfg(unix)]
-const TARGET_MLUA_LUAU_ABI_VERSION: u32 = 1;
-
-#[cfg(all(unix, feature = "module"))]
-#[no_mangle]
-#[used]
-pub static MLUA_LUAU_ABI_VERSION: u32 = TARGET_MLUA_LUAU_ABI_VERSION;
-
-// We keep reference to the `package` table in registry under this key
-struct PackageKey(RegistryKey);
-
-// We keep reference to the loaded dylibs in application data
-#[cfg(unix)]
-struct LoadedDylibs(FxHashMap<PathBuf, Library>);
-
-#[cfg(unix)]
-impl std::ops::Deref for LoadedDylibs {
-    type Target = FxHashMap<PathBuf, Library>;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-#[cfg(unix)]
-impl std::ops::DerefMut for LoadedDylibs {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.0
-    }
-}
-
-pub(crate) fn register_package_module(lua: &Lua) -> Result<()> {
-    // Create the package table and store it in app_data for later use (bypassing globals lookup)
-    let package = lua.create_table()?;
-    lua.set_app_data(PackageKey(lua.create_registry_value(package.clone())?));
-
-    // Set `package.path`
-    let mut search_path = env::var("LUAU_PATH")
-        .or_else(|_| env::var("LUA_PATH"))
-        .unwrap_or_default();
-    if search_path.is_empty() {
-        search_path = "?.luau;?.lua".to_string();
-    }
-    package.raw_set("path", search_path)?;
-
-    // Set `package.cpath`
-    #[cfg(unix)]
-    {
-        let mut search_cpath = env::var("LUAU_CPATH")
-            .or_else(|_| env::var("LUA_CPATH"))
-            .unwrap_or_default();
-        if search_cpath.is_empty() {
-            if cfg!(any(target_os = "macos", target_os = "ios")) {
-                search_cpath = "?.dylib".to_string();
-            } else {
-                search_cpath = "?.so".to_string();
-            }
-        }
-        package.raw_set("cpath", search_cpath)?;
-    }
-
-    // Set `package.loaded` (table with a list of loaded modules)
-    let loaded = lua.create_table()?;
-    package.raw_set("loaded", loaded.clone())?;
-    lua.set_named_registry_value("_LOADED", loaded)?;
-
-    // Set `package.loaders`
-    let loaders = lua.create_sequence_from([lua.create_function(lua_loader)?])?;
-    package.raw_set("loaders", loaders.clone())?;
-    #[cfg(unix)]
-    {
-        loaders.push(lua.create_function(dylib_loader)?)?;
-        lua.set_app_data(LoadedDylibs(FxHashMap::default()));
-    }
-    lua.set_named_registry_value("_LOADERS", loaders)?;
-
-    // Register the module and `require` function in globals
-    let globals = lua.globals();
-    globals.raw_set("package", package)?;
-    globals.raw_set("require", unsafe { lua.create_c_function(lua_require)? })?;
-
-    Ok(())
-}
-
-#[allow(unused_variables)]
-pub(crate) fn disable_dylibs(lua: &Lua) {
-    // Presence of `LoadedDylibs` in app data is used as a flag
-    // to check whether binary modules are enabled
-    #[cfg(unix)]
-    lua.remove_app_data::<LoadedDylibs>();
-}
-
-unsafe extern "C-unwind" fn lua_require(state: *mut ffi::lua_State) -> c_int {
-    ffi::lua_settop(state, 1);
-    let name = ffi::luaL_checkstring(state, 1);
-    ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADED")); // _LOADED is at index 2
-    if ffi::lua_rawgetfield(state, 2, name) != ffi::LUA_TNIL {
-        return 1; // module is already loaded
-    }
-    ffi::lua_pop(state, 1); // remove nil
-
-    // load the module
-    let err_buf = ffi::lua_newuserdata_t::<StdString>(state);
-    err_buf.write(StdString::new());
-    ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADERS")); // _LOADERS is at index 3
-    for i in 1.. {
-        if ffi::lua_rawgeti(state, -1, i) == ffi::LUA_TNIL {
-            // no more loaders?
-            if (*err_buf).is_empty() {
-                ffi::luaL_error(state, cstr!("module '%s' not found"), name);
-            } else {
-                let bytes = (*err_buf).as_bytes();
-                let extra = ffi::lua_pushlstring(state, bytes.as_ptr() as *const _, bytes.len());
-                ffi::luaL_error(state, cstr!("module '%s' not found:%s"), name, extra);
-            }
-        }
-        ffi::lua_pushvalue(state, 1); // name arg
-        ffi::lua_call(state, 1, 2); // call loader
-        match ffi::lua_type(state, -2) {
-            ffi::LUA_TFUNCTION => break, // loader found
-            ffi::LUA_TSTRING => {
-                // error message
-                let msg = ffi::lua_tostring(state, -2);
-                let msg = CStr::from_ptr(msg).to_string_lossy();
-                _ = write!(&mut *err_buf, "\n\t{msg}");
-            }
-            _ => {}
-        }
-        ffi::lua_pop(state, 2); // remove both results
-    }
-    ffi::lua_pushvalue(state, 1); // name is 1st argument to module loader
-    ffi::lua_rotate(state, -2, 1); // loader data <-> name
-
-    // stack: ...; loader function; module name; loader data
-    ffi::lua_call(state, 2, 1);
-    // stack: ...; result from loader function
-    if ffi::lua_isnil(state, -1) != 0 {
-        ffi::lua_pop(state, 1);
-        ffi::lua_pushboolean(state, 1); // use true as result
-    }
-    ffi::lua_pushvalue(state, -1); // make copy of entrypoint result
-    ffi::lua_setfield(state, 2, name); /* _LOADED[name] = returned value */
-    1
-}
-
-/// Searches for the given `name` in the given `path`.
-///
-/// `path` is a string containing a sequence of templates separated by semicolons.
-fn package_searchpath(name: &str, search_path: &str, try_prefix: bool) -> Option<PathBuf> {
-    let mut names = vec![name.replace('.', MAIN_SEPARATOR_STR)];
-    if try_prefix && name.contains('.') {
-        let prefix = name.split_once('.').map(|(prefix, _)| prefix).unwrap();
-        names.push(prefix.to_string());
-    }
-    for path in search_path.split(';') {
-        for name in &names {
-            let file_path = PathBuf::from(path.replace('?', name));
-            if let Ok(true) = fs::metadata(&file_path).map(|m| m.is_file()) {
-                return Some(file_path);
-            }
-        }
-    }
-    None
-}
-
-//
-// Module loaders
-//
-
-/// Tries to load a lua (text) file
-fn lua_loader(lua: &Lua, modname: StdString) -> Result<Value> {
-    let package = {
-        let key = lua.app_data_ref::<PackageKey>().unwrap();
-        lua.registry_value::<Table>(&key.0)
-    }?;
-    let search_path = package.get::<_, StdString>("path").unwrap_or_default();
-
-    if let Some(file_path) = package_searchpath(&modname, &search_path, false) {
-        match fs::read(&file_path) {
-            Ok(buf) => {
-                return lua
-                    .load(&buf)
-                    .set_name(&format!("={}", file_path.display()))
-                    .set_mode(ChunkMode::Text)
-                    .into_function()
-                    .map(Value::Function);
-            }
-            Err(err) => {
-                return format!("cannot open '{}': {err}", file_path.display()).into_lua(lua);
-            }
-        }
-    }
-
-    Ok(Value::Nil)
-}
-
-/// Tries to load a dynamic library
-#[cfg(unix)]
-fn dylib_loader(lua: &Lua, modname: StdString) -> Result<Value> {
-    let package = {
-        let key = lua.app_data_ref::<PackageKey>().unwrap();
-        lua.registry_value::<Table>(&key.0)
-    }?;
-    let search_cpath = package.get::<_, StdString>("cpath").unwrap_or_default();
-
-    let find_symbol = |lib: &Library| unsafe {
-        if let Ok(entry) = lib.get::<ffi::lua_CFunction>(format!("luaopen_{modname}\0").as_bytes())
-        {
-            return lua.create_c_function(*entry).map(Value::Function);
-        }
-        // Try all in one mode
-        if let Ok(entry) = lib.get::<ffi::lua_CFunction>(
-            format!("luaopen_{}\0", modname.replace('.', "_")).as_bytes(),
-        ) {
-            return lua.create_c_function(*entry).map(Value::Function);
-        }
-        "cannot find module entrypoint".into_lua(lua)
-    };
-
-    if let Some(file_path) = package_searchpath(&modname, &search_cpath, true) {
-        let file_path = file_path.canonicalize()?;
-        // Load the library and check for symbol
-        unsafe {
-            let mut loaded_dylibs = match lua.app_data_mut::<LoadedDylibs>() {
-                Some(loaded_dylibs) => loaded_dylibs,
-                None => return "dynamic libraries are disabled in safe mode".into_lua(lua),
-            };
-            // Check if it's already loaded
-            if let Some(lib) = loaded_dylibs.get(&file_path) {
-                return find_symbol(lib);
-            }
-            if let Ok(lib) = Library::new(&file_path) {
-                // Check version
-                let mod_version = lib.get::<*const u32>(b"MLUA_LUAU_ABI_VERSION");
-                let mod_version = mod_version.map(|v| **v).unwrap_or_default();
-                if mod_version != TARGET_MLUA_LUAU_ABI_VERSION {
-                    let err = format!("wrong module ABI version (expected {TARGET_MLUA_LUAU_ABI_VERSION}, got {mod_version})");
-                    return err.into_lua(lua);
-                }
-                let symbol = find_symbol(&lib);
-                loaded_dylibs.insert(file_path, lib);
-                return symbol;
-            }
-        }
-    }
-
-    Ok(Value::Nil)
-}

src/macros.rs

@@ -101,15 +101,9 @@ macro_rules! protect_lua {
     };
 
     ($state:expr, $nargs:expr, $nresults:expr, fn($state_inner:ident) $code:expr) => {{
-        use ::std::os::raw::c_int;
-        unsafe extern "C-unwind" fn do_call($state_inner: *mut ffi::lua_State) -> c_int {
+        unsafe extern "C" fn do_call($state_inner: *mut ffi::lua_State) -> ::std::os::raw::c_int {
             $code;
-            let nresults = $nresults;
-            if nresults == ::ffi::LUA_MULTRET {
-                ffi::lua_gettop($state_inner)
-            } else {
-                nresults
-            }
+            $nresults
         }
 
         crate::util::protect_lua_call($state, $nargs, do_call)

src/memory.rs

@@ -1,147 +0,0 @@
-use std::alloc::{self, Layout};
-use std::os::raw::c_void;
-use std::ptr;
-
-pub(crate) static ALLOCATOR: ffi::lua_Alloc = allocator;
-
-#[repr(C)]
-#[derive(Default)]
-pub(crate) struct MemoryState {
-    used_memory: isize,
-    memory_limit: isize,
-    // Can be set to temporary ignore the memory limit.
-    // This is used when calling `lua_pushcfunction` for lua5.1/jit/luau.
-    ignore_limit: bool,
-    // Indicates that the memory limit was reached on the last allocation.
-    #[cfg(feature = "luau")]
-    limit_reached: bool,
-}
-
-impl MemoryState {
-    #[inline]
-    pub(crate) unsafe fn get(state: *mut ffi::lua_State) -> *mut Self {
-        let mut mem_state = ptr::null_mut();
-        #[cfg(feature = "luau")]
-        {
-            ffi::lua_getallocf(state, &mut mem_state);
-            mlua_assert!(!mem_state.is_null(), "Luau state has no allocator userdata");
-        }
-        #[cfg(not(feature = "luau"))]
-        if ffi::lua_getallocf(state, &mut mem_state) != ALLOCATOR {
-            mem_state = ptr::null_mut();
-        }
-        mem_state as *mut MemoryState
-    }
-
-    #[inline]
-    pub(crate) fn used_memory(&self) -> usize {
-        self.used_memory as usize
-    }
-
-    #[inline]
-    pub(crate) fn memory_limit(&self) -> usize {
-        self.memory_limit as usize
-    }
-
-    #[inline]
-    pub(crate) fn set_memory_limit(&mut self, limit: usize) -> usize {
-        let prev_limit = self.memory_limit;
-        self.memory_limit = limit as isize;
-        prev_limit as usize
-    }
-
-    // This function is used primarily for calling `lua_pushcfunction` in lua5.1/jit/luau
-    // to bypass the memory limit (if set).
-    #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
-    #[inline]
-    pub(crate) unsafe fn relax_limit_with(state: *mut ffi::lua_State, f: impl FnOnce()) {
-        let mem_state = Self::get(state);
-        if !mem_state.is_null() {
-            (*mem_state).ignore_limit = true;
-            f();
-            (*mem_state).ignore_limit = false;
-        } else {
-            f();
-        }
-    }
-
-    // Does nothing apart from calling `f()`, we don't need to bypass any limits
-    #[cfg(any(feature = "lua52", feature = "lua53", feature = "lua54"))]
-    #[inline]
-    pub(crate) unsafe fn relax_limit_with(_state: *mut ffi::lua_State, f: impl FnOnce()) {
-        f();
-    }
-
-    // Returns `true` if the memory limit was reached on the last memory operation
-    #[cfg(feature = "luau")]
-    #[inline]
-    pub(crate) unsafe fn limit_reached(state: *mut ffi::lua_State) -> bool {
-        (*Self::get(state)).limit_reached
-    }
-}
-
-unsafe extern "C-unwind" fn allocator(
-    extra: *mut c_void,
-    ptr: *mut c_void,
-    osize: usize,
-    nsize: usize,
-) -> *mut c_void {
-    let mem_state = &mut *(extra as *mut MemoryState);
-    #[cfg(feature = "luau")]
-    {
-        // Reset the flag
-        mem_state.limit_reached = false;
-    }
-
-    if nsize == 0 {
-        // Free memory
-        if !ptr.is_null() {
-            let layout = Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
-            alloc::dealloc(ptr as *mut u8, layout);
-            mem_state.used_memory -= osize as isize;
-        }
-        return ptr::null_mut();
-    }
-
-    // Do not allocate more than isize::MAX
-    if nsize > isize::MAX as usize {
-        return ptr::null_mut();
-    }
-
-    // Are we fit to the memory limits?
-    let mut mem_diff = nsize as isize;
-    if !ptr.is_null() {
-        mem_diff -= osize as isize;
-    }
-    let mem_limit = mem_state.memory_limit;
-    let new_used_memory = mem_state.used_memory + mem_diff;
-    if mem_limit > 0 && new_used_memory > mem_limit && !mem_state.ignore_limit {
-        #[cfg(feature = "luau")]
-        {
-            mem_state.limit_reached = true;
-        }
-        return ptr::null_mut();
-    }
-    mem_state.used_memory += mem_diff;
-
-    if ptr.is_null() {
-        // Allocate new memory
-        let new_layout = match Layout::from_size_align(nsize, ffi::SYS_MIN_ALIGN) {
-            Ok(layout) => layout,
-            Err(_) => return ptr::null_mut(),
-        };
-        let new_ptr = alloc::alloc(new_layout) as *mut c_void;
-        if new_ptr.is_null() {
-            alloc::handle_alloc_error(new_layout);
-        }
-        return new_ptr;
-    }
-
-    // Reallocate memory
-    let old_layout = Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
-    let new_ptr = alloc::realloc(ptr as *mut u8, old_layout, nsize) as *mut c_void;
-    if new_ptr.is_null() {
-        alloc::handle_alloc_error(old_layout);
-    }
-    new_ptr
-}

src/multi.rs

@@ -1,128 +1,51 @@
+#![allow(clippy::wrong_self_convention)]
+
+use std::iter::FromIterator;
 use std::ops::{Deref, DerefMut};
-use std::os::raw::c_int;
 use std::result::Result as StdResult;
 
 use crate::error::Result;
 use crate::lua::Lua;
-use crate::util::check_stack;
-use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, MultiValue, Nil};
+use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti};
 
 /// Result is convertible to `MultiValue` following the common Lua idiom of returning the result
 /// on success, or in the case of an error, returning `nil` and an error message.
-impl<'lua, T: IntoLua<'lua>, E: IntoLua<'lua>> IntoLuaMulti<'lua> for StdResult<T, E> {
+impl<'lua, T: ToLua<'lua>, E: ToLua<'lua>> ToLuaMulti<'lua> for StdResult<T, E> {
     #[inline]
-    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut result = MultiValue::with_lua_and_capacity(lua, 2);
+    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut result = MultiValue::new_or_cached(lua);
         match self {
-            Ok(v) => result.push_front(v.into_lua(lua)?),
+            Ok(v) => result.push_front(v.to_lua(lua)?),
             Err(e) => {
-                result.push_front(e.into_lua(lua)?);
+                result.push_front(e.to_lua(lua)?);
                 result.push_front(Nil);
             }
         }
         Ok(result)
     }
-
-    #[inline]
-    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
-        match self {
-            Ok(v) => v.push_into_stack(lua).map(|_| 1),
-            Err(e) => {
-                let state = lua.state();
-                check_stack(state, 3)?;
-                ffi::lua_pushnil(state);
-                e.push_into_stack(lua)?;
-                Ok(2)
-            }
-        }
-    }
 }
 
-impl<'lua, E: IntoLua<'lua>> IntoLuaMulti<'lua> for StdResult<(), E> {
+impl<'lua, T: ToLua<'lua>> ToLuaMulti<'lua> for T {
     #[inline]
-    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        match self {
-            Ok(_) => return Ok(MultiValue::new()),
-            Err(e) => {
-                let mut result = MultiValue::with_lua_and_capacity(lua, 2);
-                result.push_front(e.into_lua(lua)?);
-                result.push_front(Nil);
-                Ok(result)
-            }
-        }
-    }
-
-    #[inline]
-    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
-        match self {
-            Ok(_) => Ok(0),
-            Err(e) => {
-                let state = lua.state();
-                check_stack(state, 3)?;
-                ffi::lua_pushnil(state);
-                e.push_into_stack(lua)?;
-                Ok(2)
-            }
-        }
-    }
-}
-
-impl<'lua, T: IntoLua<'lua>> IntoLuaMulti<'lua> for T {
-    #[inline]
-    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut v = MultiValue::with_lua_and_capacity(lua, 1);
-        v.push_front(self.into_lua(lua)?);
+    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut v = MultiValue::new_or_cached(lua);
+        v.push_front(self.to_lua(lua)?);
         Ok(v)
     }
-
-    #[inline]
-    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
-        self.push_into_stack(lua)?;
-        Ok(1)
-    }
 }
 
 impl<'lua, T: FromLua<'lua>> FromLuaMulti<'lua> for T {
     #[inline]
     fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-        T::from_lua(values.pop_front().unwrap_or(Nil), lua)
-    }
-
-    #[inline]
-    fn from_lua_args(
-        mut args: MultiValue<'lua>,
-        i: usize,
-        to: Option<&str>,
-        lua: &'lua Lua,
-    ) -> Result<Self> {
-        T::from_lua_arg(args.pop_front().unwrap_or(Nil), i, to, lua)
-    }
-
-    #[inline]
-    unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
-        if nvals == 0 {
-            return T::from_lua(Nil, lua);
-        }
-        T::from_stack(-nvals, lua)
-    }
-
-    #[inline]
-    unsafe fn from_stack_args(
-        nargs: c_int,
-        i: usize,
-        to: Option<&str>,
-        lua: &'lua Lua,
-    ) -> Result<Self> {
-        if nargs == 0 {
-            return T::from_lua_arg(Nil, i, to, lua);
-        }
-        T::from_stack_arg(-nargs, i, to, lua)
+        let res = T::from_lua(values.pop_front().unwrap_or(Nil), lua);
+        lua.cache_multivalue(values);
+        res
     }
 }
 
-impl<'lua> IntoLuaMulti<'lua> for MultiValue<'lua> {
+impl<'lua> ToLuaMulti<'lua> for MultiValue<'lua> {
     #[inline]
-    fn into_lua_multi(self, _: &'lua Lua) -> Result<MultiValue<'lua>> {
+    fn to_lua_multi(self, _: &'lua Lua) -> Result<MultiValue<'lua>> {
         Ok(self)
     }
 }
@@ -205,11 +128,11 @@ impl<T> DerefMut for Variadic<T> {
     }
 }
 
-impl<'lua, T: IntoLua<'lua>> IntoLuaMulti<'lua> for Variadic<T> {
+impl<'lua, T: ToLua<'lua>> ToLuaMulti<'lua> for Variadic<T> {
     #[inline]
-    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut values = MultiValue::with_lua_and_capacity(lua, self.0.len());
-        values.refill(self.0.into_iter().map(|e| e.into_lua(lua)))?;
+    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut values = MultiValue::new_or_cached(lua);
+        values.refill(self.0.into_iter().map(|e| e.to_lua(lua)))?;
         Ok(values)
     }
 }
@@ -217,74 +140,48 @@ impl<'lua, T: IntoLua<'lua>> IntoLuaMulti<'lua> for Variadic<T> {
 impl<'lua, T: FromLua<'lua>> FromLuaMulti<'lua> for Variadic<T> {
     #[inline]
     fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-        values
+        let res = values
             .drain_all()
             .map(|e| T::from_lua(e, lua))
             .collect::<Result<Vec<T>>>()
-            .map(Variadic)
+            .map(Variadic);
+        lua.cache_multivalue(values);
+        res
     }
 }
 
 macro_rules! impl_tuple {
     () => (
-        impl<'lua> IntoLuaMulti<'lua> for () {
+        impl<'lua> ToLuaMulti<'lua> for () {
             #[inline]
-            fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-                Ok(MultiValue::with_lua_and_capacity(lua, 0))
-            }
-
-            #[inline]
-            unsafe fn push_into_stack_multi(self, _lua: &'lua Lua) -> Result<c_int> {
-                Ok(0)
+            fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+                Ok(MultiValue::new_or_cached(lua))
             }
         }
 
         impl<'lua> FromLuaMulti<'lua> for () {
             #[inline]
-            fn from_lua_multi(_values: MultiValue<'lua>, _lua: &'lua Lua) -> Result<Self> {
-                Ok(())
-            }
-
-            #[inline]
-            unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
-                if nvals > 0 {
-                    ffi::lua_pop(lua.state(), nvals);
-                }
+            fn from_lua_multi(values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
+                lua.cache_multivalue(values);
                 Ok(())
             }
         }
     );
 
     ($last:ident $($name:ident)*) => (
-        impl<'lua, $($name,)* $last> IntoLuaMulti<'lua> for ($($name,)* $last,)
-            where $($name: IntoLua<'lua>,)*
-                  $last: IntoLuaMulti<'lua>
+        impl<'lua, $($name,)* $last> ToLuaMulti<'lua> for ($($name,)* $last,)
+            where $($name: ToLua<'lua>,)*
+                  $last: ToLuaMulti<'lua>
         {
-            #[allow(unused_mut, non_snake_case)]
-            #[inline]
-            fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-                let ($($name,)* $last,) = self;
-
-                let mut results = $last.into_lua_multi(lua)?;
-                push_reverse!(results, $($name.into_lua(lua)?,)*);
-                Ok(results)
-            }
-
+            #[allow(unused_mut)]
             #[allow(non_snake_case)]
             #[inline]
-            unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+            fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
                 let ($($name,)* $last,) = self;
-                let mut nresults = 0;
-                $(
-                    _ = $name;
-                    nresults += 1;
-                )*
-                check_stack(lua.state(), nresults + 1)?;
-                $(
-                    $name.push_into_stack(lua)?;
-                )*
-                nresults += $last.push_into_stack_multi(lua)?;
-                Ok(nresults)
+
+                let mut results = $last.to_lua_multi(lua)?;
+                push_reverse!(results, $($name.to_lua(lua)?,)*);
+                Ok(results)
             }
         }
 
@@ -292,54 +189,13 @@ macro_rules! impl_tuple {
             where $($name: FromLua<'lua>,)*
                   $last: FromLuaMulti<'lua>
         {
-            #[allow(unused_mut, non_snake_case)]
+            #[allow(unused_mut)]
+            #[allow(non_snake_case)]
             #[inline]
             fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-                $(let $name = FromLua::from_lua(values.pop_front().unwrap_or(Nil), lua)?;)*
+                $(let $name = values.pop_front().unwrap_or(Nil);)*
                 let $last = FromLuaMulti::from_lua_multi(values, lua)?;
-                Ok(($($name,)* $last,))
-            }
-
-            #[allow(unused_mut, non_snake_case)]
-            #[inline]
-            fn from_lua_args(mut args: MultiValue<'lua>, mut i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
-                $(
-                    let $name = FromLua::from_lua_arg(args.pop_front().unwrap_or(Nil), i, to, lua)?;
-                    i += 1;
-                )*
-                let $last = FromLuaMulti::from_lua_args(args, i, to, lua)?;
-                Ok(($($name,)* $last,))
-            }
-
-            #[allow(unused_mut, non_snake_case)]
-            #[inline]
-            unsafe fn from_stack_multi(mut nvals: c_int, lua: &'lua Lua) -> Result<Self> {
-                $(
-                    let $name = if nvals > 0 {
-                        nvals -= 1;
-                        FromLua::from_stack(-(nvals + 1), lua)
-                    } else {
-                        FromLua::from_lua(Nil, lua)
-                    }?;
-                )*
-                let $last = FromLuaMulti::from_stack_multi(nvals, lua)?;
-                Ok(($($name,)* $last,))
-            }
-
-            #[allow(unused_mut, non_snake_case)]
-            #[inline]
-            unsafe fn from_stack_args(mut nargs: c_int, mut i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
-                $(
-                    let $name = if nargs > 0 {
-                        nargs -= 1;
-                        FromLua::from_stack_arg(-(nargs + 1), i, to, lua)
-                    } else {
-                        FromLua::from_lua_arg(Nil, i, to, lua)
-                    }?;
-                    i += 1;
-                )*
-                let $last = FromLuaMulti::from_stack_args(nargs, i, to, lua)?;
-                Ok(($($name,)* $last,))
+                Ok(($(FromLua::from_lua($name, lua)?,)* $last,))
             }
         }
     );

src/prelude.rs

@@ -2,18 +2,16 @@
 
 #[doc(no_inline)]
 pub use crate::{
-    AnyUserData as LuaAnyUserData, AnyUserDataExt as LuaAnyUserDataExt, Chunk as LuaChunk,
-    Error as LuaError, ErrorContext as LuaErrorContext, ExternalError as LuaExternalError,
-    ExternalResult as LuaExternalResult, FromLua, FromLuaMulti, Function as LuaFunction,
-    FunctionInfo as LuaFunctionInfo, GCMode as LuaGCMode, Integer as LuaInteger, IntoLua,
-    IntoLuaMulti, LightUserData as LuaLightUserData, Lua, LuaOptions, MetaMethod as LuaMetaMethod,
-    MultiValue as LuaMultiValue, Nil as LuaNil, Number as LuaNumber, RegistryKey as LuaRegistryKey,
-    Result as LuaResult, StdLib as LuaStdLib, String as LuaString, Table as LuaTable,
-    TableExt as LuaTableExt, TablePairs as LuaTablePairs, TableSequence as LuaTableSequence,
-    Thread as LuaThread, ThreadStatus as LuaThreadStatus, UserData as LuaUserData,
-    UserDataFields as LuaUserDataFields, UserDataMetatable as LuaUserDataMetatable,
-    UserDataMethods as LuaUserDataMethods, UserDataRef as LuaUserDataRef,
-    UserDataRefMut as LuaUserDataRefMut, UserDataRegistry as LuaUserDataRegistry,
+    AnyUserData as LuaAnyUserData, Chunk as LuaChunk, Error as LuaError,
+    ExternalError as LuaExternalError, ExternalResult as LuaExternalResult, FromLua, FromLuaMulti,
+    Function as LuaFunction, FunctionInfo as LuaFunctionInfo, GCMode as LuaGCMode,
+    Integer as LuaInteger, LightUserData as LuaLightUserData, Lua, LuaOptions,
+    MetaMethod as LuaMetaMethod, MultiValue as LuaMultiValue, Nil as LuaNil, Number as LuaNumber,
+    RegistryKey as LuaRegistryKey, Result as LuaResult, StdLib as LuaStdLib, String as LuaString,
+    Table as LuaTable, TableExt as LuaTableExt, TablePairs as LuaTablePairs,
+    TableSequence as LuaTableSequence, Thread as LuaThread, ThreadStatus as LuaThreadStatus, ToLua,
+    ToLuaMulti, UserData as LuaUserData, UserDataFields as LuaUserDataFields,
+    UserDataMetatable as LuaUserDataMetatable, UserDataMethods as LuaUserDataMethods,
     Value as LuaValue,
 };
 
@@ -23,7 +21,7 @@ pub use crate::HookTriggers as LuaHookTriggers;
 
 #[cfg(feature = "luau")]
 #[doc(no_inline)]
-pub use crate::{CoverageInfo as LuaCoverageInfo, Vector as LuaVector, VmState as LuaVmState};
+pub use crate::{CoverageInfo as LuaCoverageInfo, VmState as LuaVmState};
 
 #[cfg(feature = "async")]
 #[doc(no_inline)]
@@ -35,10 +33,3 @@ pub use crate::{
     DeserializeOptions as LuaDeserializeOptions, LuaSerdeExt,
     SerializeOptions as LuaSerializeOptions,
 };
-
-#[cfg(feature = "unstable")]
-#[doc(no_inline)]
-pub use crate::{
-    OwnedAnyUserData as LuaOwnedAnyUserData, OwnedFunction as LuaOwnedFunction,
-    OwnedString as LuaOwnedString, OwnedTable as LuaOwnedTable, OwnedThread as LuaOwnedThread,
-};

src/serde/de.rs

@@ -1,7 +1,7 @@
 use std::cell::RefCell;
+use std::convert::TryInto;
 use std::os::raw::c_void;
 use std::rc::Rc;
-use std::result::Result as StdResult;
 use std::string::String as StdString;
 
 use rustc_hash::FxHashSet;
@@ -9,7 +9,6 @@ use serde::de::{self, IntoDeserializer};
 
 use crate::error::{Error, Result};
 use crate::table::{Table, TablePairs, TableSequence};
-use crate::userdata::AnyUserData;
 use crate::value::Value;
 
 /// A struct for deserializing Lua values into Rust values.
@@ -24,14 +23,14 @@ pub struct Deserializer<'lua> {
 #[derive(Debug, Clone, Copy)]
 #[non_exhaustive]
 pub struct Options {
-    /// If true, an attempt to serialize types such as [`Function`], [`Thread`], [`LightUserData`]
+    /// If true, an attempt to serialize types such as [`Thread`], [`UserData`], [`LightUserData`]
     /// and [`Error`] will cause an error.
     /// Otherwise these types skipped when iterating or serialized as unit type.
     ///
     /// Default: **true**
     ///
-    /// [`Function`]: crate::Function
     /// [`Thread`]: crate::Thread
+    /// [`UserData`]: crate::UserData
     /// [`LightUserData`]: crate::LightUserData
     /// [`Error`]: crate::Error
     pub deny_unsupported_types: bool,
@@ -42,11 +41,6 @@ pub struct Options {
     ///
     /// Default: **true**
     pub deny_recursive_tables: bool,
-
-    /// If true, keys in tables will be iterated in sorted order.
-    ///
-    /// Default: **false**
-    pub sort_keys: bool,
 }
 
 impl Default for Options {
@@ -61,7 +55,6 @@ impl Options {
         Options {
             deny_unsupported_types: true,
             deny_recursive_tables: true,
-            sort_keys: false,
         }
     }
 
@@ -82,15 +75,6 @@ impl Options {
         self.deny_recursive_tables = enabled;
         self
     }
-
-    /// Sets [`sort_keys`] option.
-    ///
-    /// [`sort_keys`]: #structfield.sort_keys
-    #[must_use]
-    pub const fn sort_keys(mut self, enabled: bool) -> Self {
-        self.sort_keys = enabled;
-        self
-    }
 }
 
 impl<'lua> Deserializer<'lua> {
@@ -133,11 +117,13 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             Value::Nil => visitor.visit_unit(),
             Value::Boolean(b) => visitor.visit_bool(b),
             #[allow(clippy::useless_conversion)]
-            Value::Integer(i) => visitor.visit_i64(i.into()),
+            Value::Integer(i) => {
+                visitor.visit_i64(i.try_into().expect("cannot convert lua_Integer to i64"))
+            }
             #[allow(clippy::useless_conversion)]
             Value::Number(n) => visitor.visit_f64(n.into()),
             #[cfg(feature = "luau")]
-            Value::Vector(_) => self.deserialize_seq(visitor),
+            Value::Vector(_, _, _) => self.deserialize_seq(visitor),
             Value::String(s) => match s.to_str() {
                 Ok(s) => visitor.visit_str(s),
                 Err(_) => visitor.visit_bytes(s.as_bytes()),
@@ -145,25 +131,16 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             Value::Table(ref t) if t.raw_len() > 0 || t.is_array() => self.deserialize_seq(visitor),
             Value::Table(_) => self.deserialize_map(visitor),
             Value::LightUserData(ud) if ud.0.is_null() => visitor.visit_none(),
-            Value::UserData(ud) if ud.is_serializable() => {
-                serde_userdata(ud, |value| value.deserialize_any(visitor))
-            }
-            #[cfg(feature = "luau")]
-            Value::UserData(ud) if ud.1 == crate::types::SubtypeId::Buffer => unsafe {
-                let mut size = 0usize;
-                let buf = ffi::lua_tobuffer(ud.0.lua.ref_thread(), ud.0.index, &mut size);
-                mlua_assert!(!buf.is_null(), "invalid Luau buffer");
-                let buf = std::slice::from_raw_parts(buf as *const u8, size);
-                visitor.visit_bytes(buf)
-            },
             Value::Function(_)
             | Value::Thread(_)
             | Value::UserData(_)
             | Value::LightUserData(_)
             | Value::Error(_) => {
                 if self.options.deny_unsupported_types {
-                    let msg = format!("unsupported value type `{}`", self.value.type_name());
-                    Err(de::Error::custom(msg))
+                    Err(de::Error::custom(format!(
+                        "unsupported value type `{}`",
+                        self.value.type_name()
+                    )))
                 } else {
                     visitor.visit_unit()
                 }
@@ -186,8 +163,8 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
     #[inline]
     fn deserialize_enum<V>(
         self,
-        name: &'static str,
-        variants: &'static [&'static str],
+        _name: &str,
+        _variants: &'static [&'static str],
         visitor: V,
     ) -> Result<V::Value>
     where
@@ -214,18 +191,13 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                         &"map with a single key",
                     ));
                 }
-                let skip = check_value_for_skip(&value, self.options, &self.visited)
-                    .map_err(|err| Error::DeserializeError(err.to_string()))?;
-                if skip {
+                if check_value_if_skip(&value, self.options, &self.visited)? {
                     return Err(de::Error::custom("bad enum value"));
                 }
 
                 (variant, Some(value), Some(_guard))
             }
             Value::String(variant) => (variant.to_str()?.to_owned(), None, None),
-            Value::UserData(ud) if ud.is_serializable() => {
-                return serde_userdata(ud, |value| value.deserialize_enum(name, variants, visitor));
-            }
             _ => return Err(de::Error::custom("bad enum value")),
         };
 
@@ -244,9 +216,9 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
     {
         match self.value {
             #[cfg(feature = "luau")]
-            Value::Vector(vec) => {
+            Value::Vector(x, y, z) => {
                 let mut deserializer = VecDeserializer {
-                    vec,
+                    vec: [x, y, z],
                     next: 0,
                     options: self.options,
                     visited: self.visited,
@@ -256,9 +228,9 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             Value::Table(t) => {
                 let _guard = RecursionGuard::new(&t, &self.visited);
 
-                let len = t.raw_len();
+                let len = t.raw_len() as usize;
                 let mut deserializer = SeqDeserializer {
-                    seq: t.sequence_values(),
+                    seq: t.raw_sequence_values(),
                     options: self.options,
                     visited: self.visited,
                 };
@@ -272,9 +244,6 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                     ))
                 }
             }
-            Value::UserData(ud) if ud.is_serializable() => {
-                serde_userdata(ud, |value| value.deserialize_seq(visitor))
-            }
             value => Err(de::Error::invalid_type(
                 de::Unexpected::Other(value.type_name()),
                 &"table",
@@ -313,7 +282,7 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                 let _guard = RecursionGuard::new(&t, &self.visited);
 
                 let mut deserializer = MapDeserializer {
-                    pairs: MapPairs::new(t, self.options.sort_keys)?,
+                    pairs: t.pairs(),
                     value: None,
                     options: self.options,
                     visited: self.visited,
@@ -330,9 +299,6 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                     ))
                 }
             }
-            Value::UserData(ud) if ud.is_serializable() => {
-                serde_userdata(ud, |value| value.deserialize_map(visitor))
-            }
             value => Err(de::Error::invalid_type(
                 de::Unexpected::Other(value.type_name()),
                 &"table",
@@ -354,16 +320,11 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
     }
 
     #[inline]
-    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    fn deserialize_newtype_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
     where
         V: de::Visitor<'de>,
     {
-        match self.value {
-            Value::UserData(ud) if ud.is_serializable() => {
-                serde_userdata(ud, |value| value.deserialize_newtype_struct(name, visitor))
-            }
-            _ => visitor.visit_newtype_struct(self),
-        }
+        visitor.visit_newtype_struct(self)
     }
 
     #[inline]
@@ -411,9 +372,7 @@ impl<'lua, 'de> de::SeqAccess<'de> for SeqDeserializer<'lua> {
             match self.seq.next() {
                 Some(value) => {
                     let value = value?;
-                    let skip = check_value_for_skip(&value, self.options, &self.visited)
-                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
-                    if skip {
+                    if check_value_if_skip(&value, self.options, &self.visited)? {
                         continue;
                     }
                     let visited = Rc::clone(&self.visited);
@@ -435,7 +394,7 @@ impl<'lua, 'de> de::SeqAccess<'de> for SeqDeserializer<'lua> {
 
 #[cfg(feature = "luau")]
 struct VecDeserializer {
-    vec: crate::types::Vector,
+    vec: [f32; 3],
     next: usize,
     options: Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
@@ -449,7 +408,7 @@ impl<'de> de::SeqAccess<'de> for VecDeserializer {
     where
         T: de::DeserializeSeed<'de>,
     {
-        match self.vec.0.get(self.next) {
+        match self.vec.get(self.next) {
             Some(&n) => {
                 self.next += 1;
                 let visited = Rc::clone(&self.visited);
@@ -462,54 +421,12 @@ impl<'de> de::SeqAccess<'de> for VecDeserializer {
     }
 
     fn size_hint(&self) -> Option<usize> {
-        Some(crate::types::Vector::SIZE)
-    }
-}
-
-pub(crate) enum MapPairs<'lua> {
-    Iter(TablePairs<'lua, Value<'lua>, Value<'lua>>),
-    Vec(Vec<(Value<'lua>, Value<'lua>)>),
-}
-
-impl<'lua> MapPairs<'lua> {
-    pub(crate) fn new(t: Table<'lua>, sort_keys: bool) -> Result<Self> {
-        if sort_keys {
-            let mut pairs = t.pairs::<Value, Value>().collect::<Result<Vec<_>>>()?;
-            pairs.sort_by(|(a, _), (b, _)| b.cmp(a)); // reverse order as we pop values from the end
-            Ok(MapPairs::Vec(pairs))
-        } else {
-            Ok(MapPairs::Iter(t.pairs::<Value, Value>()))
-        }
-    }
-
-    pub(crate) fn count(self) -> usize {
-        match self {
-            MapPairs::Iter(iter) => iter.count(),
-            MapPairs::Vec(vec) => vec.len(),
-        }
-    }
-
-    pub(crate) fn size_hint(&self) -> (usize, Option<usize>) {
-        match self {
-            MapPairs::Iter(iter) => iter.size_hint(),
-            MapPairs::Vec(vec) => (vec.len(), Some(vec.len())),
-        }
-    }
-}
-
-impl<'lua> Iterator for MapPairs<'lua> {
-    type Item = Result<(Value<'lua>, Value<'lua>)>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        match self {
-            MapPairs::Iter(iter) => iter.next(),
-            MapPairs::Vec(vec) => vec.pop().map(Ok),
-        }
+        Some(3)
     }
 }
 
 struct MapDeserializer<'lua> {
-    pairs: MapPairs<'lua>,
+    pairs: TablePairs<'lua, Value<'lua>, Value<'lua>>,
     value: Option<Value<'lua>>,
     options: Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
@@ -527,11 +444,9 @@ impl<'lua, 'de> de::MapAccess<'de> for MapDeserializer<'lua> {
             match self.pairs.next() {
                 Some(item) => {
                     let (key, value) = item?;
-                    let skip_key = check_value_for_skip(&key, self.options, &self.visited)
-                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
-                    let skip_value = check_value_for_skip(&value, self.options, &self.visited)
-                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
-                    if skip_key || skip_value {
+                    if check_value_if_skip(&key, self.options, &self.visited)?
+                        || check_value_if_skip(&value, self.options, &self.visited)?
+                    {
                         continue;
                     }
                     self.processed += 1;
@@ -660,14 +575,14 @@ impl<'lua, 'de> de::VariantAccess<'de> for VariantDeserializer<'lua> {
 
 // Adds `ptr` to the `visited` map and removes on drop
 // Used to track recursive tables but allow to traverse same tables multiple times
-pub(crate) struct RecursionGuard {
+struct RecursionGuard {
     ptr: *const c_void,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
 }
 
 impl RecursionGuard {
     #[inline]
-    pub(crate) fn new(table: &Table, visited: &Rc<RefCell<FxHashSet<*const c_void>>>) -> Self {
+    fn new(table: &Table, visited: &Rc<RefCell<FxHashSet<*const c_void>>>) -> Self {
         let visited = Rc::clone(visited);
         let ptr = table.to_pointer();
         visited.borrow_mut().insert(ptr);
@@ -682,22 +597,21 @@ impl Drop for RecursionGuard {
 }
 
 // Checks `options` and decides should we emit an error or skip next element
-pub(crate) fn check_value_for_skip(
+fn check_value_if_skip(
     value: &Value,
     options: Options,
     visited: &RefCell<FxHashSet<*const c_void>>,
-) -> StdResult<bool, &'static str> {
+) -> Result<bool> {
     match value {
         Value::Table(table) => {
             let ptr = table.to_pointer();
             if visited.borrow().contains(&ptr) {
                 if options.deny_recursive_tables {
-                    return Err("recursive table detected");
+                    return Err(de::Error::custom("recursive table detected"));
                 }
                 return Ok(true); // skip
             }
         }
-        Value::UserData(ud) if ud.is_serializable() => {}
         Value::Function(_)
         | Value::Thread(_)
         | Value::UserData(_)
@@ -711,11 +625,3 @@ pub(crate) fn check_value_for_skip(
     }
     Ok(false) // do not skip
 }
-
-fn serde_userdata<V>(
-    ud: AnyUserData,
-    f: impl FnOnce(serde_value::Value) -> std::result::Result<V, serde_value::DeserializerError>,
-) -> Result<V> {
-    let value = serde_value::to_value(ud).map_err(|err| Error::SerializeError(err.to_string()))?;
-    f(value).map_err(|err| Error::DeserializeError(err.to_string()))
-}

src/serde/mod.rs

@@ -1,19 +1,21 @@
 //! (De)Serialization support using serde.
 
 use std::os::raw::c_void;
+use std::ptr;
 
-use serde::{de::DeserializeOwned, ser::Serialize};
+use serde::{Deserialize, Serialize};
 
 use crate::error::Result;
+use crate::ffi;
 use crate::lua::Lua;
-use crate::private::Sealed;
 use crate::table::Table;
+use crate::types::LightUserData;
 use crate::util::check_stack;
 use crate::value::Value;
 
 /// Trait for serializing/deserializing Lua values using Serde.
 #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
-pub trait LuaSerdeExt: Sealed {
+pub trait LuaSerdeExt<'lua> {
     /// A special value (lightuserdata) to encode/decode optional (none) values.
     ///
     /// Requires `feature = "serialize"`
@@ -35,7 +37,7 @@ pub trait LuaSerdeExt: Sealed {
     ///     Ok(())
     /// }
     /// ```
-    fn null(&self) -> Value;
+    fn null(&'lua self) -> Value<'lua>;
 
     /// A metatable attachable to a Lua table to systematically encode it as Array (instead of Map).
     /// As result, encoded Array will contain only sequence part of the table, with the same length
@@ -66,7 +68,7 @@ pub trait LuaSerdeExt: Sealed {
     ///     Ok(())
     /// }
     /// ```
-    fn array_metatable(&self) -> Table;
+    fn array_metatable(&'lua self) -> Table<'lua>;
 
     /// Converts `T` into a [`Value`] instance.
     ///
@@ -99,7 +101,7 @@ pub trait LuaSerdeExt: Sealed {
     ///     "#).exec()
     /// }
     /// ```
-    fn to_value<'lua, T: Serialize + ?Sized>(&'lua self, t: &T) -> Result<Value<'lua>>;
+    fn to_value<T: Serialize + ?Sized>(&'lua self, t: &T) -> Result<Value<'lua>>;
 
     /// Converts `T` into a [`Value`] instance with options.
     ///
@@ -124,7 +126,7 @@ pub trait LuaSerdeExt: Sealed {
     ///     "#).exec()
     /// }
     /// ```
-    fn to_value_with<'lua, T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
+    fn to_value_with<T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized;
 
@@ -157,7 +159,7 @@ pub trait LuaSerdeExt: Sealed {
     /// }
     /// ```
     #[allow(clippy::wrong_self_convention)]
-    fn from_value<T: DeserializeOwned>(&self, value: Value) -> Result<T>;
+    fn from_value<T: Deserialize<'lua>>(&'lua self, value: Value<'lua>) -> Result<T>;
 
     /// Deserializes a [`Value`] into any serde deserializable object with options.
     ///
@@ -189,46 +191,49 @@ pub trait LuaSerdeExt: Sealed {
     /// }
     /// ```
     #[allow(clippy::wrong_self_convention)]
-    fn from_value_with<T: DeserializeOwned>(&self, value: Value, options: de::Options)
-        -> Result<T>;
+    fn from_value_with<T: Deserialize<'lua>>(
+        &'lua self,
+        value: Value<'lua>,
+        options: de::Options,
+    ) -> Result<T>;
 }
 
-impl LuaSerdeExt for Lua {
-    fn null(&self) -> Value {
-        Value::NULL
+impl<'lua> LuaSerdeExt<'lua> for Lua {
+    fn null(&'lua self) -> Value<'lua> {
+        Value::LightUserData(LightUserData(ptr::null_mut()))
     }
 
-    fn array_metatable(&self) -> Table {
+    fn array_metatable(&'lua self) -> Table<'lua> {
         unsafe {
             push_array_metatable(self.ref_thread());
             Table(self.pop_ref_thread())
         }
     }
 
-    fn to_value<'lua, T>(&'lua self, t: &T) -> Result<Value<'lua>>
+    fn to_value<T>(&'lua self, t: &T) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized,
     {
         t.serialize(ser::Serializer::new(self))
     }
 
-    fn to_value_with<'lua, T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
+    fn to_value_with<T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized,
     {
         t.serialize(ser::Serializer::new_with_options(self, options))
     }
 
-    fn from_value<T>(&self, value: Value) -> Result<T>
+    fn from_value<T>(&'lua self, value: Value<'lua>) -> Result<T>
     where
-        T: DeserializeOwned,
+        T: Deserialize<'lua>,
     {
         T::deserialize(de::Deserializer::new(value))
     }
 
-    fn from_value_with<T>(&self, value: Value, options: de::Options) -> Result<T>
+    fn from_value_with<T>(&'lua self, value: Value<'lua>, options: de::Options) -> Result<T>
     where
-        T: DeserializeOwned,
+        T: Deserialize<'lua>,
     {
         T::deserialize(de::Deserializer::new_with_options(value, options))
     }

src/serde/ser.rs

@@ -1,10 +1,16 @@
+use std::os::raw::c_int;
+
 use serde::{ser, Serialize};
 
 use super::LuaSerdeExt;
 use crate::error::{Error, Result};
+use crate::ffi;
 use crate::lua::Lua;
+use crate::string::String;
 use crate::table::Table;
-use crate::value::{IntoLua, Value};
+use crate::types::Integer;
+use crate::util::{check_stack, StackGuard};
+use crate::value::{ToLua, Value};
 
 /// A struct for serializing Rust values into Lua values.
 #[derive(Debug)]
@@ -42,12 +48,6 @@ pub struct Options {
     /// [`null`]: crate::LuaSerdeExt::null
     /// [`Nil`]: crate::Value::Nil
     pub serialize_unit_to_null: bool,
-
-    /// If true, serialize `serde_json::Number` with arbitrary_precision to a Lua number.
-    /// Otherwise it will be serialized as an object (what serde does).
-    ///
-    /// Default: **false**
-    pub detect_serde_json_arbitrary_precision: bool,
 }
 
 impl Default for Options {
@@ -63,7 +63,6 @@ impl Options {
             set_array_metatable: true,
             serialize_none_to_null: true,
             serialize_unit_to_null: true,
-            detect_serde_json_arbitrary_precision: false,
         }
     }
 
@@ -93,20 +92,6 @@ impl Options {
         self.serialize_unit_to_null = enabled;
         self
     }
-
-    /// Sets [`detect_serde_json_arbitrary_precision`] option.
-    ///
-    /// This option is used to serialize `serde_json::Number` with arbitrary precision to a Lua number.
-    /// Otherwise it will be serialized as an object (what serde does).
-    ///
-    /// This option is disabled by default.
-    ///
-    /// [`detect_serde_json_arbitrary_precision`]: #structfield.detect_serde_json_arbitrary_precision
-    #[must_use]
-    pub const fn detect_serde_json_arbitrary_precision(mut self, enabled: bool) -> Self {
-        self.detect_serde_json_arbitrary_precision = enabled;
-        self
-    }
 }
 
 impl<'lua> Serializer<'lua> {
@@ -125,7 +110,7 @@ macro_rules! lua_serialize_number {
     ($name:ident, $t:ty) => {
         #[inline]
         fn $name(self, value: $t) -> Result<Value<'lua>> {
-            value.into_lua(self.lua)
+            value.to_lua(self.lua)
         }
     };
 }
@@ -136,12 +121,12 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     // Associated types for keeping track of additional state while serializing
     // compound data structures like sequences and maps.
-    type SerializeSeq = SerializeSeq<'lua>;
-    type SerializeTuple = SerializeSeq<'lua>;
-    type SerializeTupleStruct = SerializeSeq<'lua>;
+    type SerializeSeq = SerializeVec<'lua>;
+    type SerializeTuple = SerializeVec<'lua>;
+    type SerializeTupleStruct = SerializeVec<'lua>;
     type SerializeTupleVariant = SerializeTupleVariant<'lua>;
     type SerializeMap = SerializeMap<'lua>;
-    type SerializeStruct = SerializeStruct<'lua>;
+    type SerializeStruct = SerializeMap<'lua>;
     type SerializeStructVariant = SerializeStructVariant<'lua>;
 
     #[inline]
@@ -251,11 +236,13 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     #[inline]
     fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
-        let table = self.lua.create_table_with_capacity(len.unwrap_or(0), 0)?;
+        let len = len.unwrap_or(0) as c_int;
+        let table = self.lua.create_table_with_capacity(len, 0)?;
         if self.options.set_array_metatable {
             table.set_metatable(Some(self.lua.array_metatable()));
         }
-        Ok(SerializeSeq::new(table, self.options))
+        let options = self.options;
+        Ok(SerializeVec { table, options })
     }
 
     #[inline]
@@ -266,14 +253,9 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
     #[inline]
     fn serialize_tuple_struct(
         self,
-        name: &'static str,
+        _name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeTupleStruct> {
-        #[cfg(feature = "luau")]
-        if name == "Vector" && len == crate::types::Vector::SIZE {
-            return Ok(SerializeSeq::new_vector(self.lua, self.options));
-        }
-        _ = name;
         self.serialize_seq(Some(len))
     }
 
@@ -286,7 +268,7 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
         _len: usize,
     ) -> Result<Self::SerializeTupleVariant> {
         Ok(SerializeTupleVariant {
-            variant,
+            name: self.lua.create_string(variant)?,
             table: self.lua.create_table()?,
             options: self.options,
         })
@@ -294,31 +276,17 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     #[inline]
     fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
+        let len = len.unwrap_or(0) as c_int;
         Ok(SerializeMap {
             key: None,
-            table: self.lua.create_table_with_capacity(0, len.unwrap_or(0))?,
+            table: self.lua.create_table_with_capacity(0, len)?,
             options: self.options,
         })
     }
 
     #[inline]
-    fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
-        if self.options.detect_serde_json_arbitrary_precision
-            && name == "$serde_json::private::Number"
-            && len == 1
-        {
-            return Ok(SerializeStruct {
-                lua: self.lua,
-                inner: None,
-                options: self.options,
-            });
-        }
-
-        Ok(SerializeStruct {
-            lua: self.lua,
-            inner: Some(Value::Table(self.lua.create_table_with_capacity(0, len)?)),
-            options: self.options,
-        })
+    fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
+        self.serialize_map(Some(len))
     }
 
     #[inline]
@@ -330,48 +298,20 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
         len: usize,
     ) -> Result<Self::SerializeStructVariant> {
         Ok(SerializeStructVariant {
-            variant,
-            table: self.lua.create_table_with_capacity(0, len)?,
+            name: self.lua.create_string(variant)?,
+            table: self.lua.create_table_with_capacity(0, len as c_int)?,
             options: self.options,
         })
     }
 }
 
 #[doc(hidden)]
-pub struct SerializeSeq<'lua> {
-    lua: &'lua Lua,
-    #[cfg(feature = "luau")]
-    vector: Option<crate::types::Vector>,
-    table: Option<Table<'lua>>,
-    next: usize,
+pub struct SerializeVec<'lua> {
+    table: Table<'lua>,
     options: Options,
 }
 
-impl<'lua> SerializeSeq<'lua> {
-    const fn new(table: Table<'lua>, options: Options) -> Self {
-        Self {
-            lua: table.0.lua,
-            #[cfg(feature = "luau")]
-            vector: None,
-            table: Some(table),
-            next: 0,
-            options,
-        }
-    }
-
-    #[cfg(feature = "luau")]
-    const fn new_vector(lua: &'lua Lua, options: Options) -> Self {
-        Self {
-            lua,
-            vector: Some(crate::types::Vector::zero()),
-            table: None,
-            next: 0,
-            options,
-        }
-    }
-}
-
-impl<'lua> ser::SerializeSeq for SerializeSeq<'lua> {
+impl<'lua> ser::SerializeSeq for SerializeVec<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -379,19 +319,34 @@ impl<'lua> ser::SerializeSeq for SerializeSeq<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        let value = self.lua.to_value_with(value, self.options)?;
-        let table = self.table.as_ref().unwrap();
-        table.raw_seti(self.next + 1, value)?;
-        self.next += 1;
-        Ok(())
+        let lua = self.table.0.lua;
+        let value = lua.to_value_with(value, self.options)?;
+        unsafe {
+            let _sg = StackGuard::new(lua.state);
+            check_stack(lua.state, 4)?;
+
+            lua.push_ref(&self.table.0);
+            lua.push_value(value)?;
+            if lua.unlikely_memory_error() {
+                let len = ffi::lua_rawlen(lua.state, -2) as Integer;
+                ffi::lua_rawseti(lua.state, -2, len + 1);
+                ffi::lua_pop(lua.state, 1);
+                Ok(())
+            } else {
+                protect_lua!(lua.state, 2, 0, fn(state) {
+                    let len = ffi::lua_rawlen(state, -2) as Integer;
+                    ffi::lua_rawseti(state, -2, len + 1);
+                })
+            }
+        }
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        Ok(Value::Table(self.table.unwrap()))
+        Ok(Value::Table(self.table))
     }
 }
 
-impl<'lua> ser::SerializeTuple for SerializeSeq<'lua> {
+impl<'lua> ser::SerializeTuple for SerializeVec<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -407,7 +362,7 @@ impl<'lua> ser::SerializeTuple for SerializeSeq<'lua> {
     }
 }
 
-impl<'lua> ser::SerializeTupleStruct for SerializeSeq<'lua> {
+impl<'lua> ser::SerializeTupleStruct for SerializeVec<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -415,29 +370,17 @@ impl<'lua> ser::SerializeTupleStruct for SerializeSeq<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        #[cfg(feature = "luau")]
-        if let Some(vector) = self.vector.as_mut() {
-            let value = self.lua.to_value_with(value, self.options)?;
-            let value = self.lua.unpack(value)?;
-            vector.0[self.next] = value;
-            self.next += 1;
-            return Ok(());
-        }
         ser::SerializeSeq::serialize_element(self, value)
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        #[cfg(feature = "luau")]
-        if let Some(vector) = self.vector {
-            return Ok(Value::Vector(vector));
-        }
         ser::SerializeSeq::end(self)
     }
 }
 
 #[doc(hidden)]
 pub struct SerializeTupleVariant<'lua> {
-    variant: &'static str,
+    name: String<'lua>,
     table: Table<'lua>,
     options: Options,
 }
@@ -451,13 +394,15 @@ impl<'lua> ser::SerializeTupleVariant for SerializeTupleVariant<'lua> {
         T: Serialize + ?Sized,
     {
         let lua = self.table.0.lua;
-        self.table.raw_push(lua.to_value_with(value, self.options)?)
+        let idx = self.table.raw_len() + 1;
+        self.table
+            .raw_insert(idx, lua.to_value_with(value, self.options)?)
     }
 
     fn end(self) -> Result<Value<'lua>> {
         let lua = self.table.0.lua;
         let table = lua.create_table()?;
-        table.raw_set(self.variant, self.table)?;
+        table.raw_set(self.name, self.table)?;
         Ok(Value::Table(table))
     }
 }
@@ -500,14 +445,7 @@ impl<'lua> ser::SerializeMap for SerializeMap<'lua> {
     }
 }
 
-#[doc(hidden)]
-pub struct SerializeStruct<'lua> {
-    lua: &'lua Lua,
-    inner: Option<Value<'lua>>,
-    options: Options,
-}
-
-impl<'lua> ser::SerializeStruct for SerializeStruct<'lua> {
+impl<'lua> ser::SerializeStruct for SerializeMap<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -515,44 +453,18 @@ impl<'lua> ser::SerializeStruct for SerializeStruct<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        match self.inner {
-            Some(Value::Table(ref table)) => {
-                table.raw_set(key, self.lua.to_value_with(value, self.options)?)?;
-            }
-            None if self.options.detect_serde_json_arbitrary_precision => {
-                // A special case for `serde_json::Number` with arbitrary precision.
-                assert_eq!(key, "$serde_json::private::Number");
-                self.inner = Some(self.lua.to_value_with(value, self.options)?);
-            }
-            _ => unreachable!(),
-        }
-        Ok(())
+        ser::SerializeMap::serialize_key(self, key)?;
+        ser::SerializeMap::serialize_value(self, value)
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        match self.inner {
-            Some(table @ Value::Table(_)) => Ok(table),
-            Some(value) if self.options.detect_serde_json_arbitrary_precision => {
-                let number_s = value.as_str().expect("not an arbitrary precision number");
-                if number_s.contains(['.', 'e', 'E']) {
-                    if let Ok(number) = number_s.parse().map(Value::Number) {
-                        return Ok(number);
-                    }
-                }
-                Ok(number_s
-                    .parse()
-                    .map(Value::Integer)
-                    .or_else(|_| number_s.parse().map(Value::Number))
-                    .unwrap_or(value))
-            }
-            _ => unreachable!(),
-        }
+        ser::SerializeMap::end(self)
     }
 }
 
 #[doc(hidden)]
 pub struct SerializeStructVariant<'lua> {
-    variant: &'static str,
+    name: String<'lua>,
     table: Table<'lua>,
     options: Options,
 }
@@ -573,8 +485,8 @@ impl<'lua> ser::SerializeStructVariant for SerializeStructVariant<'lua> {
 
     fn end(self) -> Result<Value<'lua>> {
         let lua = self.table.0.lua;
-        let table = lua.create_table_with_capacity(0, 1)?;
-        table.raw_set(self.variant, self.table)?;
+        let table = lua.create_table()?;
+        table.raw_set(self.name, self.table)?;
         Ok(Value::Table(table))
     }
 }

src/stdlib.rs

@@ -1,4 +1,5 @@
 use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign};
+use std::u32;
 
 /// Flags describing the set of lua standard libraries to load.
 #[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
@@ -15,44 +16,32 @@ impl StdLib {
         feature = "luau"
     ))]
     pub const COROUTINE: StdLib = StdLib(1);
-
     /// [`table`](https://www.lua.org/manual/5.4/manual.html#6.6) library
     pub const TABLE: StdLib = StdLib(1 << 1);
-
     /// [`io`](https://www.lua.org/manual/5.4/manual.html#6.8) library
     #[cfg(not(feature = "luau"))]
     #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub const IO: StdLib = StdLib(1 << 2);
-
     /// [`os`](https://www.lua.org/manual/5.4/manual.html#6.9) library
     pub const OS: StdLib = StdLib(1 << 3);
-
     /// [`string`](https://www.lua.org/manual/5.4/manual.html#6.4) library
     pub const STRING: StdLib = StdLib(1 << 4);
-
     /// [`utf8`](https://www.lua.org/manual/5.4/manual.html#6.5) library
     ///
     /// Requires `feature = "lua54/lua53/luau"`
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
     pub const UTF8: StdLib = StdLib(1 << 5);
-
     /// [`bit`](https://www.lua.org/manual/5.2/manual.html#6.7) library
     ///
     /// Requires `feature = "lua52/luajit/luau"`
     #[cfg(any(feature = "lua52", feature = "luajit", feature = "luau", doc))]
     pub const BIT: StdLib = StdLib(1 << 6);
-
     /// [`math`](https://www.lua.org/manual/5.4/manual.html#6.7) library
     pub const MATH: StdLib = StdLib(1 << 7);
-
     /// [`package`](https://www.lua.org/manual/5.4/manual.html#6.3) library
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub const PACKAGE: StdLib = StdLib(1 << 8);
-
-    /// [`buffer`](https://luau-lang.org/library#buffer-library) library
-    #[cfg(any(feature = "luau", doc))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    pub const BUFFER: StdLib = StdLib(1 << 9);
-
     /// [`jit`](http://luajit.org/ext_jit.html) library
     ///
     /// Requires `feature = "luajit"`
@@ -66,7 +55,6 @@ impl StdLib {
     #[cfg(any(feature = "luajit", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
     pub const FFI: StdLib = StdLib(1 << 30);
-
     /// (**unsafe**) [`debug`](https://www.lua.org/manual/5.4/manual.html#6.10) library
     pub const DEBUG: StdLib = StdLib(1 << 31);
 

src/string.rs

@@ -2,7 +2,7 @@ use std::borrow::{Borrow, Cow};
 use std::hash::{Hash, Hasher};
 use std::os::raw::c_void;
 use std::string::String as StdString;
-use std::{fmt, slice, str};
+use std::{slice, str};
 
 #[cfg(feature = "serialize")]
 use {
@@ -11,35 +11,15 @@ use {
 };
 
 use crate::error::{Error, Result};
+use crate::ffi;
 use crate::types::LuaRef;
 
 /// Handle to an internal Lua string.
 ///
 /// Unlike Rust strings, Lua strings may not be valid UTF-8.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct String<'lua>(pub(crate) LuaRef<'lua>);
 
-/// Owned handle to an internal Lua string.
-///
-/// The owned handle holds a *strong* reference to the current Lua instance.
-/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
-/// to accidentally cause reference cycles that would prevent destroying Lua instance.
-///
-/// [`UserData`]: crate::UserData
-#[cfg(feature = "unstable")]
-#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
-#[derive(Clone)]
-pub struct OwnedString(pub(crate) crate::types::LuaOwnedRef);
-
-#[cfg(feature = "unstable")]
-impl OwnedString {
-    /// Get borrowed handle to the underlying Lua string.
-    #[cfg_attr(feature = "send", allow(unused))]
-    pub const fn to_ref(&self) -> String {
-        String(self.0.to_ref())
-    }
-}
-
 impl<'lua> String<'lua> {
     /// Get a `&str` slice if the Lua string is valid UTF-8.
     ///
@@ -132,51 +112,15 @@ impl<'lua> String<'lua> {
         }
     }
 
-    /// Converts this string to a generic C pointer.
+    /// Converts the string to a generic C pointer.
     ///
     /// There is no way to convert the pointer back to its original value.
     ///
     /// Typically this function is used only for hashing and debug information.
     #[inline]
     pub fn to_pointer(&self) -> *const c_void {
-        self.0.to_pointer()
-    }
-
-    /// Convert this handle to owned version.
-    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-    #[inline]
-    pub fn into_owned(self) -> OwnedString {
-        OwnedString(self.0.into_owned())
-    }
-}
-
-impl<'lua> fmt::Debug for String<'lua> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let bytes = self.as_bytes();
-        // Check if the string is valid utf8
-        if let Ok(s) = str::from_utf8(bytes) {
-            return s.fmt(f);
-        }
-
-        // Format as bytes
-        write!(f, "b\"")?;
-        for &b in bytes {
-            // https://doc.rust-lang.org/reference/tokens.html#byte-escapes
-            match b {
-                b'\n' => write!(f, "\\n")?,
-                b'\r' => write!(f, "\\r")?,
-                b'\t' => write!(f, "\\t")?,
-                b'\\' | b'"' => write!(f, "\\{}", b as char)?,
-                b'\0' => write!(f, "\\0")?,
-                // ASCII printable
-                0x20..=0x7e => write!(f, "{}", b as char)?,
-                _ => write!(f, "\\x{b:02x}")?,
-            }
-        }
-        write!(f, "\"")?;
-
-        Ok(())
+        let ref_thread = self.0.lua.ref_thread();
+        unsafe { ffi::lua_topointer(ref_thread, self.0.index) }
     }
 }
 
@@ -202,7 +146,7 @@ impl<'lua> Borrow<[u8]> for String<'lua> {
 // in other ways.
 impl<'lua, T> PartialEq<T> for String<'lua>
 where
-    T: AsRef<[u8]> + ?Sized,
+    T: AsRef<[u8]>,
 {
     fn eq(&self, other: &T) -> bool {
         self.as_bytes() == other.as_ref()
@@ -229,41 +173,3 @@ impl<'lua> Serialize for String<'lua> {
         }
     }
 }
-
-// Additional shortcuts
-#[cfg(feature = "unstable")]
-impl OwnedString {
-    /// Get a `&str` slice if the Lua string is valid UTF-8.
-    ///
-    /// This is a shortcut for [`String::to_str()`].
-    #[inline]
-    pub fn to_str(&self) -> Result<&str> {
-        let s = self.to_ref();
-        // Reattach lifetime to &self
-        unsafe { std::mem::transmute(s.to_str()) }
-    }
-
-    /// Get the bytes that make up this string.
-    ///
-    /// This is a shortcut for [`String::as_bytes()`].
-    #[inline]
-    pub fn as_bytes(&self) -> &[u8] {
-        let s = self.to_ref();
-        // Reattach lifetime to &self
-        unsafe { std::mem::transmute(s.as_bytes()) }
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl fmt::Debug for OwnedString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.to_ref().fmt(f)
-    }
-}
-
-#[cfg(test)]
-mod assertions {
-    use super::*;
-
-    static_assertions::assert_not_impl_any!(String: Send);
-}

src/thread.rs

@@ -1,32 +1,35 @@
-use std::os::raw::{c_int, c_void};
+use std::cmp;
+use std::os::raw::c_int;
 
 use crate::error::{Error, Result};
-#[allow(unused)]
-use crate::lua::Lua;
+use crate::ffi;
 use crate::types::LuaRef;
 use crate::util::{check_stack, error_traceback_thread, pop_error, StackGuard};
-use crate::value::{FromLuaMulti, IntoLuaMulti};
+use crate::value::{FromLuaMulti, ToLuaMulti};
 
-#[cfg(not(feature = "luau"))]
-use crate::{
-    hook::{Debug, HookTriggers},
-    types::MaybeSend,
-};
+#[cfg(any(
+    feature = "lua54",
+    all(feature = "luajit", feature = "vendored"),
+    feature = "luau",
+))]
+use crate::function::Function;
 
 #[cfg(feature = "async")]
 use {
-    crate::value::MultiValue,
-    futures_util::stream::Stream,
+    crate::{
+        lua::{Lua, ASYNC_POLL_PENDING},
+        value::{MultiValue, Value},
+    },
+    futures_core::{future::Future, stream::Stream},
     std::{
-        future::Future,
+        cell::RefCell,
         marker::PhantomData,
         pin::Pin,
-        ptr::NonNull,
         task::{Context, Poll, Waker},
     },
 };
 
-/// Status of a Lua thread (coroutine).
+/// Status of a Lua thread (or coroutine).
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub enum ThreadStatus {
     /// The thread was just created, or is suspended because it has called `coroutine.yield`.
@@ -41,61 +44,27 @@ pub enum ThreadStatus {
     Error,
 }
 
-/// Handle to an internal Lua thread (coroutine).
+/// Handle to an internal Lua thread (or coroutine).
 #[derive(Clone, Debug)]
-pub struct Thread<'lua>(pub(crate) LuaRef<'lua>, pub(crate) *mut ffi::lua_State);
-
-/// Owned handle to an internal Lua thread (coroutine).
-///
-/// The owned handle holds a *strong* reference to the current Lua instance.
-/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
-/// to accidentally cause reference cycles that would prevent destroying Lua instance.
-///
-/// [`UserData`]: crate::UserData
-#[cfg(feature = "unstable")]
-#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
-#[derive(Clone, Debug)]
-pub struct OwnedThread(
-    pub(crate) crate::types::LuaOwnedRef,
-    pub(crate) *mut ffi::lua_State,
-);
-
-#[cfg(feature = "unstable")]
-impl OwnedThread {
-    /// Get borrowed handle to the underlying Lua table.
-    #[cfg_attr(feature = "send", allow(unused))]
-    pub const fn to_ref(&self) -> Thread {
-        Thread(self.0.to_ref(), self.1)
-    }
-}
+pub struct Thread<'lua>(pub(crate) LuaRef<'lua>);
 
 /// Thread (coroutine) representation as an async [`Future`] or [`Stream`].
 ///
 /// Requires `feature = "async"`
 ///
-/// [`Future`]: std::future::Future
-/// [`Stream`]: futures_util::stream::Stream
+/// [`Future`]: futures_core::future::Future
+/// [`Stream`]: futures_core::stream::Stream
 #[cfg(feature = "async")]
 #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-#[must_use = "futures do nothing unless you `.await` or poll them"]
+#[derive(Debug)]
 pub struct AsyncThread<'lua, R> {
     thread: Thread<'lua>,
-    init_args: Option<Result<MultiValue<'lua>>>,
+    args0: RefCell<Option<Result<MultiValue<'lua>>>>,
     ret: PhantomData<R>,
     recycle: bool,
 }
 
 impl<'lua> Thread<'lua> {
-    #[inline(always)]
-    pub(crate) fn new(r#ref: LuaRef<'lua>) -> Self {
-        let state = unsafe { ffi::lua_tothread(r#ref.lua.ref_thread(), r#ref.index) };
-        Thread(r#ref, state)
-    }
-
-    const fn state(&self) -> *mut ffi::lua_State {
-        self.1
-    }
-
     /// Resumes execution of this thread.
     ///
     /// Equivalent to `coroutine.resume`.
@@ -139,68 +108,59 @@ impl<'lua> Thread<'lua> {
     /// ```
     pub fn resume<A, R>(&self, args: A) -> Result<R>
     where
-        A: IntoLuaMulti<'lua>,
+        A: ToLuaMulti<'lua>,
         R: FromLuaMulti<'lua>,
     {
-        if self.status() != ThreadStatus::Resumable {
-            return Err(Error::CoroutineInactive);
-        }
-
         let lua = self.0.lua;
-        let state = lua.state();
-        let thread_state = self.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            let _thread_sg = StackGuard::with_top(thread_state, 0);
+        let mut args = args.to_lua_multi(lua)?;
+        let nargs = args.len() as c_int;
+        let results = unsafe {
+            let _sg = StackGuard::new(lua.state);
+            check_stack(lua.state, cmp::max(nargs + 1, 3))?;
 
-            let nresults = self.resume_inner(args)?;
-            check_stack(state, nresults + 1)?;
-            ffi::lua_xmove(thread_state, state, nresults);
+            let thread_state = ffi::lua_tothread(lua.ref_thread(), self.0.index);
 
-            R::from_stack_multi(nresults, lua)
-        }
-    }
-
-    /// Resumes execution of this thread.
-    ///
-    /// It's similar to `resume()` but leaves `nresults` values on the thread stack.
-    unsafe fn resume_inner<A: IntoLuaMulti<'lua>>(&self, args: A) -> Result<c_int> {
-        let lua = self.0.lua;
-        let state = lua.state();
-        let thread_state = self.state();
-
-        let nargs = args.push_into_stack_multi(lua)?;
-        if nargs > 0 {
-            check_stack(thread_state, nargs)?;
-            ffi::lua_xmove(state, thread_state, nargs);
-        }
-
-        let mut nresults = 0;
-        let ret = ffi::lua_resume(thread_state, state, nargs, &mut nresults as *mut c_int);
-        if ret != ffi::LUA_OK && ret != ffi::LUA_YIELD {
-            if ret == ffi::LUA_ERRMEM {
-                // Don't call error handler for memory errors
-                return Err(pop_error(thread_state, ret));
+            let status = ffi::lua_status(thread_state);
+            if status != ffi::LUA_YIELD && ffi::lua_gettop(thread_state) == 0 {
+                return Err(Error::CoroutineInactive);
             }
-            check_stack(state, 3)?;
-            protect_lua!(state, 0, 1, |state| error_traceback_thread(
-                state,
-                thread_state
-            ))?;
-            return Err(pop_error(state, ret));
-        }
 
-        Ok(nresults)
+            check_stack(thread_state, nargs)?;
+            for arg in args.drain_all() {
+                lua.push_value(arg)?;
+            }
+            ffi::lua_xmove(lua.state, thread_state, nargs);
+
+            let mut nresults = 0;
+
+            let ret = ffi::lua_resume(thread_state, lua.state, nargs, &mut nresults as *mut c_int);
+            if ret != ffi::LUA_OK && ret != ffi::LUA_YIELD {
+                check_stack(lua.state, 3)?;
+                protect_lua!(lua.state, 0, 1, |state| error_traceback_thread(
+                    state,
+                    thread_state
+                ))?;
+                return Err(pop_error(lua.state, ret));
+            }
+
+            let mut results = args; // Reuse MultiValue container
+            check_stack(lua.state, nresults + 2)?; // 2 is extra for `lua.pop_value()` below
+            ffi::lua_xmove(thread_state, lua.state, nresults);
+
+            for _ in 0..nresults {
+                results.push_front(lua.pop_value());
+            }
+            results
+        };
+        R::from_lua_multi(results, lua)
     }
 
     /// Gets the status of the thread.
     pub fn status(&self) -> ThreadStatus {
-        let thread_state = self.state();
-        if thread_state == self.0.lua.state() {
-            // The coroutine is currently running
-            return ThreadStatus::Unresumable;
-        }
+        let lua = self.0.lua;
         unsafe {
+            let thread_state = ffi::lua_tothread(lua.ref_thread(), self.0.index);
+
             let status = ffi::lua_status(thread_state);
             if status != ffi::LUA_OK && status != ffi::LUA_YIELD {
                 ThreadStatus::Error
@@ -212,63 +172,55 @@ impl<'lua> Thread<'lua> {
         }
     }
 
-    /// Sets a 'hook' function that will periodically be called as Lua code executes.
-    ///
-    /// This function is similar or [`Lua::set_hook()`] except that it sets for the thread.
-    /// To remove a hook call [`Lua::remove_hook()`].
-    #[cfg(not(feature = "luau"))]
-    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
-    pub fn set_hook<F>(&self, triggers: HookTriggers, callback: F)
-    where
-        F: Fn(&Lua, Debug) -> Result<()> + MaybeSend + 'static,
-    {
-        let lua = self.0.lua;
-        unsafe {
-            lua.set_thread_hook(self.state(), triggers, callback);
-        }
-    }
-
     /// Resets a thread
     ///
     /// In [Lua 5.4]: cleans its call stack and closes all pending to-be-closed variables.
     /// Returns a error in case of either the original error that stopped the thread or errors
     /// in closing methods.
     ///
-    /// In Luau: resets to the initial state of a newly created Lua thread.
+    /// In [LuaJIT] and Luau: resets to the initial state of a newly created Lua thread.
     /// Lua threads in arbitrary states (like yielded or errored) can be reset properly.
     ///
     /// Sets a Lua function for the thread afterwards.
     ///
-    /// Requires `feature = "lua54"` OR `feature = "luau"`.
+    /// Requires `feature = "lua54"` OR `feature = "luajit,vendored"` OR `feature = "luau"`
     ///
-    /// [Lua 5.4]: https://www.lua.org/manual/5.4/manual.html#lua_closethread
-    #[cfg(any(feature = "lua54", feature = "luau"))]
-    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "luau"))))]
-    pub fn reset(&self, func: crate::function::Function<'lua>) -> Result<()> {
+    /// [Lua 5.4]: https://www.lua.org/manual/5.4/manual.html#lua_resetthread
+    /// [LuaJIT]: https://github.com/openresty/luajit2#lua_resetthread
+    #[cfg(any(
+        feature = "lua54",
+        all(feature = "luajit", feature = "vendored"),
+        feature = "luau",
+    ))]
+    pub fn reset(&self, func: Function<'lua>) -> Result<()> {
         let lua = self.0.lua;
-        let thread_state = self.state();
-        if thread_state == lua.state() {
-            return Err(Error::runtime("cannot reset a running thread"));
-        }
         unsafe {
+            let _sg = StackGuard::new(lua.state);
+            check_stack(lua.state, 2)?;
+
+            lua.push_ref(&self.0);
+            let thread_state = ffi::lua_tothread(lua.state, -1);
+
             #[cfg(all(feature = "lua54", not(feature = "vendored")))]
             let status = ffi::lua_resetthread(thread_state);
             #[cfg(all(feature = "lua54", feature = "vendored"))]
-            let status = ffi::lua_closethread(thread_state, lua.state());
+            let status = ffi::lua_closethread(thread_state, lua.state);
             #[cfg(feature = "lua54")]
             if status != ffi::LUA_OK {
                 return Err(pop_error(thread_state, status));
             }
+            #[cfg(all(feature = "luajit", feature = "vendored"))]
+            ffi::lua_resetthread(lua.state, thread_state);
             #[cfg(feature = "luau")]
             ffi::lua_resetthread(thread_state);
 
-            // Push function to the top of the thread stack
-            ffi::lua_xpush(lua.ref_thread(), thread_state, func.0.index);
+            lua.push_ref(&func.0);
+            ffi::lua_xmove(lua.state, thread_state, 1);
 
             #[cfg(feature = "luau")]
             {
-                // Inherit `LUA_GLOBALSINDEX` from the main thread
-                ffi::lua_xpush(lua.main_state(), thread_state, ffi::LUA_GLOBALSINDEX);
+                // Inherit `LUA_GLOBALSINDEX` from the caller
+                ffi::lua_xpush(lua.state, thread_state, ffi::LUA_GLOBALSINDEX);
                 ffi::lua_replace(thread_state, ffi::LUA_GLOBALSINDEX);
             }
 
@@ -288,8 +240,8 @@ impl<'lua> Thread<'lua> {
     ///
     /// Requires `feature = "async"`
     ///
-    /// [`Future`]: std::future::Future
-    /// [`Stream`]: futures_util::stream::Stream
+    /// [`Future`]: futures_core::future::Future
+    /// [`Stream`]: futures_core::stream::Stream
     /// [`resume()`]: https://www.lua.org/manual/5.4/manual.html#lua_resume
     ///
     /// # Examples
@@ -325,13 +277,13 @@ impl<'lua> Thread<'lua> {
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
     pub fn into_async<A, R>(self, args: A) -> AsyncThread<'lua, R>
     where
-        A: IntoLuaMulti<'lua>,
+        A: ToLuaMulti<'lua>,
         R: FromLuaMulti<'lua>,
     {
-        let args = args.into_lua_multi(self.0.lua);
+        let args = args.to_lua_multi(self.0.lua);
         AsyncThread {
             thread: self,
-            init_args: Some(args),
+            args0: RefCell::new(Some(args)),
             ret: PhantomData,
             recycle: false,
         }
@@ -373,32 +325,16 @@ impl<'lua> Thread<'lua> {
     #[doc(hidden)]
     pub fn sandbox(&self) -> Result<()> {
         let lua = self.0.lua;
-        let state = lua.state();
-        let thread_state = self.state();
         unsafe {
-            check_stack(thread_state, 3)?;
-            check_stack(state, 3)?;
-            protect_lua!(state, 0, 0, |_| ffi::luaL_sandboxthread(thread_state))
+            let thread = ffi::lua_tothread(lua.ref_thread(), self.0.index);
+            check_stack(thread, 1)?;
+            check_stack(lua.state, 3)?;
+            // Inherit `LUA_GLOBALSINDEX` from the caller
+            ffi::lua_xpush(lua.state, thread, ffi::LUA_GLOBALSINDEX);
+            ffi::lua_replace(thread, ffi::LUA_GLOBALSINDEX);
+            protect_lua!(lua.state, 0, 0, |_| ffi::luaL_sandboxthread(thread))
         }
     }
-
-    /// Converts this thread to a generic C pointer.
-    ///
-    /// There is no way to convert the pointer back to its original value.
-    ///
-    /// Typically this function is used only for hashing and debug information.
-    #[inline]
-    pub fn to_pointer(&self) -> *const c_void {
-        self.0.to_pointer()
-    }
-
-    /// Convert this handle to owned version.
-    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
-    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
-    #[inline]
-    pub fn into_owned(self) -> OwnedThread {
-        OwnedThread(self.0.into_owned(), self.1)
-    }
 }
 
 impl<'lua> PartialEq for Thread<'lua> {
@@ -407,26 +343,6 @@ impl<'lua> PartialEq for Thread<'lua> {
     }
 }
 
-// Additional shortcuts
-#[cfg(feature = "unstable")]
-impl OwnedThread {
-    /// Resumes execution of this thread.
-    ///
-    /// See [`Thread::resume()`] for more details.
-    pub fn resume<'lua, A, R>(&'lua self, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>,
-    {
-        self.to_ref().resume(args)
-    }
-
-    /// Gets the status of the thread.
-    pub fn status(&self) -> ThreadStatus {
-        self.to_ref().status()
-    }
-}
-
 #[cfg(feature = "async")]
 impl<'lua, R> AsyncThread<'lua, R> {
     #[inline]
@@ -436,7 +352,11 @@ impl<'lua, R> AsyncThread<'lua, R> {
 }
 
 #[cfg(feature = "async")]
-#[cfg(any(feature = "lua54", feature = "luau"))]
+#[cfg(any(
+    feature = "lua54",
+    all(feature = "luajit", feature = "vendored"),
+    feature = "luau",
+))]
 impl<'lua, R> Drop for AsyncThread<'lua, R> {
     fn drop(&mut self) {
         if self.recycle {
@@ -446,10 +366,8 @@ impl<'lua, R> Drop for AsyncThread<'lua, R> {
                 if !lua.recycle_thread(&mut self.thread) {
                     #[cfg(feature = "lua54")]
                     if self.thread.status() == ThreadStatus::Error {
-                        #[cfg(not(feature = "vendored"))]
-                        ffi::lua_resetthread(self.thread.state());
-                        #[cfg(feature = "vendored")]
-                        ffi::lua_closethread(self.thread.state(), lua.state());
+                        let thread_state = ffi::lua_tothread(lua.ref_thread(), self.thread.0.index);
+                        ffi::lua_resetthread(thread_state);
                     }
                 }
             }
@@ -465,36 +383,26 @@ where
     type Item = Result<R>;
 
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        if self.thread.status() != ThreadStatus::Resumable {
-            return Poll::Ready(None);
-        }
-
         let lua = self.thread.0.lua;
-        let state = lua.state();
-        let thread_state = self.thread.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            let _thread_sg = StackGuard::with_top(thread_state, 0);
-            let _wg = WakerGuard::new(lua, cx.waker());
 
-            // This is safe as we are not moving the whole struct
-            let this = self.get_unchecked_mut();
-            let nresults = if let Some(args) = this.init_args.take() {
-                this.thread.resume_inner(args?)?
-            } else {
-                this.thread.resume_inner(())?
-            };
+        match self.thread.status() {
+            ThreadStatus::Resumable => {}
+            _ => return Poll::Ready(None),
+        };
 
-            if nresults == 1 && is_poll_pending(thread_state) {
-                return Poll::Pending;
-            }
+        let _wg = WakerGuard::new(lua, cx.waker().clone());
+        let ret: MultiValue = if let Some(args) = self.args0.borrow_mut().take() {
+            self.thread.resume(args?)?
+        } else {
+            self.thread.resume(())?
+        };
 
-            check_stack(state, nresults + 1)?;
-            ffi::lua_xmove(thread_state, state, nresults);
-
-            cx.waker().wake_by_ref();
-            Poll::Ready(Some(R::from_stack_multi(nresults, lua)))
+        if is_poll_pending(&ret) {
+            return Poll::Pending;
         }
+
+        cx.waker().wake_by_ref();
+        Poll::Ready(Some(R::from_lua_multi(ret, lua)))
     }
 }
 
@@ -506,80 +414,67 @@ where
     type Output = Result<R>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        if self.thread.status() != ThreadStatus::Resumable {
-            return Poll::Ready(Err(Error::CoroutineInactive));
-        }
-
         let lua = self.thread.0.lua;
-        let state = lua.state();
-        let thread_state = self.thread.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            let _thread_sg = StackGuard::with_top(thread_state, 0);
-            let _wg = WakerGuard::new(lua, cx.waker());
 
-            // This is safe as we are not moving the whole struct
-            let this = self.get_unchecked_mut();
-            let nresults = if let Some(args) = this.init_args.take() {
-                this.thread.resume_inner(args?)?
-            } else {
-                this.thread.resume_inner(())?
-            };
+        match self.thread.status() {
+            ThreadStatus::Resumable => {}
+            _ => return Poll::Ready(Err(Error::CoroutineInactive)),
+        };
 
-            if nresults == 1 && is_poll_pending(thread_state) {
-                return Poll::Pending;
-            }
+        let _wg = WakerGuard::new(lua, cx.waker().clone());
+        let ret: MultiValue = if let Some(args) = self.args0.borrow_mut().take() {
+            self.thread.resume(args?)?
+        } else {
+            self.thread.resume(())?
+        };
 
-            if ffi::lua_status(thread_state) == ffi::LUA_YIELD {
-                // Ignore value returned via yield()
-                cx.waker().wake_by_ref();
-                return Poll::Pending;
-            }
-
-            check_stack(state, nresults + 1)?;
-            ffi::lua_xmove(thread_state, state, nresults);
-
-            Poll::Ready(R::from_stack_multi(nresults, lua))
+        if is_poll_pending(&ret) {
+            return Poll::Pending;
         }
+
+        if let ThreadStatus::Resumable = self.thread.status() {
+            // Ignore value returned via yield()
+            cx.waker().wake_by_ref();
+            return Poll::Pending;
+        }
+
+        Poll::Ready(R::from_lua_multi(ret, lua))
     }
 }
 
 #[cfg(feature = "async")]
 #[inline(always)]
-unsafe fn is_poll_pending(state: *mut ffi::lua_State) -> bool {
-    ffi::lua_tolightuserdata(state, -1) == Lua::poll_pending().0
+fn is_poll_pending(val: &MultiValue) -> bool {
+    match val.iter().enumerate().last() {
+        Some((0, Value::LightUserData(ud))) => {
+            std::ptr::eq(ud.0 as *const u8, &ASYNC_POLL_PENDING as *const u8)
+        }
+        _ => false,
+    }
 }
 
 #[cfg(feature = "async")]
-struct WakerGuard<'lua, 'a> {
+struct WakerGuard<'lua> {
     lua: &'lua Lua,
-    prev: NonNull<Waker>,
-    _phantom: PhantomData<&'a ()>,
+    prev: Option<Waker>,
 }
 
 #[cfg(feature = "async")]
-impl<'lua, 'a> WakerGuard<'lua, 'a> {
+impl<'lua> WakerGuard<'lua> {
     #[inline]
-    pub fn new(lua: &'lua Lua, waker: &'a Waker) -> Result<WakerGuard<'lua, 'a>> {
-        let prev = unsafe { lua.set_waker(NonNull::from(waker)) };
-        Ok(WakerGuard {
-            lua,
-            prev,
-            _phantom: PhantomData,
-        })
+    pub fn new(lua: &Lua, waker: Waker) -> Result<WakerGuard> {
+        unsafe {
+            let prev = lua.set_waker(Some(waker));
+            Ok(WakerGuard { lua, prev })
+        }
     }
 }
 
 #[cfg(feature = "async")]
-impl<'lua, 'a> Drop for WakerGuard<'lua, 'a> {
+impl<'lua> Drop for WakerGuard<'lua> {
     fn drop(&mut self) {
-        unsafe { self.lua.set_waker(self.prev) };
+        unsafe {
+            self.lua.set_waker(self.prev.take());
+        }
     }
 }
-
-#[cfg(test)]
-mod assertions {
-    use super::*;
-
-    static_assertions::assert_not_impl_any!(Thread: Send);
-}

src/types.rs

@@ -1,49 +1,35 @@
-use std::any::{Any, TypeId};
-use std::cell::{Cell, Ref, RefCell, RefMut, UnsafeCell};
+use std::cell::UnsafeCell;
 use std::hash::{Hash, Hasher};
-use std::ops::{Deref, DerefMut};
 use std::os::raw::{c_int, c_void};
-use std::result::Result as StdResult;
-use std::sync::atomic::{AtomicI32, Ordering};
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::{fmt, mem, ptr};
 
-use rustc_hash::FxHashMap;
+#[cfg(feature = "lua54")]
+use std::ffi::CStr;
+
+#[cfg(feature = "async")]
+use futures_core::future::LocalBoxFuture;
 
 use crate::error::Result;
+use crate::ffi;
 #[cfg(not(feature = "luau"))]
 use crate::hook::Debug;
 use crate::lua::{ExtraData, Lua};
-
-#[cfg(feature = "async")]
-use {crate::value::MultiValue, futures_util::future::LocalBoxFuture};
-
-#[cfg(feature = "unstable")]
-use {crate::lua::LuaInner, std::marker::PhantomData};
-
-#[cfg(all(feature = "luau", feature = "serialize"))]
-use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
+use crate::util::{assert_stack, StackGuard};
+use crate::value::MultiValue;
 
 /// Type of Lua integer numbers.
 pub type Integer = ffi::lua_Integer;
 /// Type of Lua floating point numbers.
 pub type Number = ffi::lua_Number;
 
-// Represents different subtypes wrapped to AnyUserData
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-pub(crate) enum SubtypeId {
-    None,
-    #[cfg(feature = "luau")]
-    Buffer,
-    #[cfg(feature = "luajit")]
-    CData,
-}
-
 /// A "light" userdata value. Equivalent to an unmanaged raw pointer.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct LightUserData(pub *mut c_void);
 
-pub(crate) type Callback<'lua, 'a> = Box<dyn Fn(&'lua Lua, c_int) -> Result<c_int> + 'a>;
+pub(crate) type Callback<'lua, 'a> =
+    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> Result<MultiValue<'lua>> + 'a>;
 
 pub(crate) struct Upvalue<T> {
     pub(crate) data: T,
@@ -54,13 +40,13 @@ pub(crate) type CallbackUpvalue = Upvalue<Callback<'static, 'static>>;
 
 #[cfg(feature = "async")]
 pub(crate) type AsyncCallback<'lua, 'a> =
-    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> LocalBoxFuture<'lua, Result<c_int>> + 'a>;
+    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> LocalBoxFuture<'lua, Result<MultiValue<'lua>>> + 'a>;
 
 #[cfg(feature = "async")]
 pub(crate) type AsyncCallbackUpvalue = Upvalue<AsyncCallback<'static, 'static>>;
 
 #[cfg(feature = "async")]
-pub(crate) type AsyncPollUpvalue = Upvalue<LocalBoxFuture<'static, Result<c_int>>>;
+pub(crate) type AsyncPollUpvalue = Upvalue<LocalBoxFuture<'static, Result<MultiValue<'static>>>>;
 
 /// Type to set next Luau VM action after executing interrupt function.
 #[cfg(any(feature = "luau", doc))]
@@ -77,16 +63,16 @@ pub(crate) type HookCallback = Arc<dyn Fn(&Lua, Debug) -> Result<()> + Send>;
 pub(crate) type HookCallback = Arc<dyn Fn(&Lua, Debug) -> Result<()>>;
 
 #[cfg(all(feature = "luau", feature = "send"))]
-pub(crate) type InterruptCallback = Arc<dyn Fn(&Lua) -> Result<VmState> + Send>;
+pub(crate) type InterruptCallback = Arc<dyn Fn() -> Result<VmState> + Send>;
 
 #[cfg(all(feature = "luau", not(feature = "send")))]
-pub(crate) type InterruptCallback = Arc<dyn Fn(&Lua) -> Result<VmState>>;
+pub(crate) type InterruptCallback = Arc<dyn Fn() -> Result<VmState>>;
 
 #[cfg(all(feature = "send", feature = "lua54"))]
-pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &str, bool) -> Result<()> + Send>;
+pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &CStr, bool) -> Result<()> + Send>;
 
 #[cfg(all(not(feature = "send"), feature = "lua54"))]
-pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &str, bool) -> Result<()>>;
+pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &CStr, bool) -> Result<()>>;
 
 #[cfg(feature = "send")]
 pub trait MaybeSend: Send {}
@@ -98,92 +84,6 @@ pub trait MaybeSend {}
 #[cfg(not(feature = "send"))]
 impl<T> MaybeSend for T {}
 
-/// A Luau vector type.
-///
-/// By default vectors are 3-dimensional, but can be 4-dimensional
-/// if the `luau-vector4` feature is enabled.
-#[cfg(any(feature = "luau", doc))]
-#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-#[derive(Debug, Default, Clone, Copy, PartialEq)]
-pub struct Vector(pub(crate) [f32; Self::SIZE]);
-
-#[cfg(any(feature = "luau", doc))]
-impl fmt::Display for Vector {
-    #[rustfmt::skip]
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        #[cfg(not(feature = "luau-vector4"))]
-        return write!(f, "vector({}, {}, {})", self.x(), self.y(), self.z());
-        #[cfg(feature = "luau-vector4")]
-        return write!(f, "vector({}, {}, {}, {})", self.x(), self.y(), self.z(), self.w());
-    }
-}
-
-#[cfg(any(feature = "luau", doc))]
-impl Vector {
-    pub(crate) const SIZE: usize = if cfg!(feature = "luau-vector4") { 4 } else { 3 };
-
-    /// Creates a new vector.
-    #[cfg(not(feature = "luau-vector4"))]
-    pub const fn new(x: f32, y: f32, z: f32) -> Self {
-        Self([x, y, z])
-    }
-
-    /// Creates a new vector.
-    #[cfg(feature = "luau-vector4")]
-    pub const fn new(x: f32, y: f32, z: f32, w: f32) -> Self {
-        Self([x, y, z, w])
-    }
-
-    /// Creates a new vector with all components set to `0.0`.
-    #[doc(hidden)]
-    pub const fn zero() -> Self {
-        Self([0.0; Self::SIZE])
-    }
-
-    /// Returns 1st component of the vector.
-    pub const fn x(&self) -> f32 {
-        self.0[0]
-    }
-
-    /// Returns 2nd component of the vector.
-    pub const fn y(&self) -> f32 {
-        self.0[1]
-    }
-
-    /// Returns 3rd component of the vector.
-    pub const fn z(&self) -> f32 {
-        self.0[2]
-    }
-
-    /// Returns 4th component of the vector.
-    #[cfg(any(feature = "luau-vector4", doc))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "luau-vector4")))]
-    pub const fn w(&self) -> f32 {
-        self.0[3]
-    }
-}
-
-#[cfg(all(feature = "luau", feature = "serialize"))]
-impl Serialize for Vector {
-    fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
-        let mut ts = serializer.serialize_tuple_struct("Vector", Self::SIZE)?;
-        ts.serialize_field(&self.x())?;
-        ts.serialize_field(&self.y())?;
-        ts.serialize_field(&self.z())?;
-        #[cfg(feature = "luau-vector4")]
-        ts.serialize_field(&self.w())?;
-        ts.end()
-    }
-}
-
-#[cfg(any(feature = "luau", doc))]
-impl PartialEq<[f32; Self::SIZE]> for Vector {
-    #[inline]
-    fn eq(&self, other: &[f32; Self::SIZE]) -> bool {
-        self.0 == *other
-    }
-}
-
 pub(crate) struct DestructedUserdata;
 
 /// An auto generated key into the Lua registry.
@@ -195,34 +95,35 @@ pub(crate) struct DestructedUserdata;
 /// Be warned, If you place this into Lua via a [`UserData`] type or a rust callback, it is *very
 /// easy* to accidentally cause reference cycles that the Lua garbage collector cannot resolve.
 /// Instead of placing a [`RegistryKey`] into a [`UserData`] type, prefer instead to use
-/// [`AnyUserData::set_user_value`] / [`AnyUserData::user_value`].
+/// [`AnyUserData::set_user_value`] / [`AnyUserData::get_user_value`].
 ///
 /// [`UserData`]: crate::UserData
 /// [`RegistryKey`]: crate::RegistryKey
 /// [`Lua::remove_registry_value`]: crate::Lua::remove_registry_value
 /// [`Lua::expire_registry_values`]: crate::Lua::expire_registry_values
 /// [`AnyUserData::set_user_value`]: crate::AnyUserData::set_user_value
-/// [`AnyUserData::user_value`]: crate::AnyUserData::user_value
+/// [`AnyUserData::get_user_value`]: crate::AnyUserData::get_user_value
 pub struct RegistryKey {
-    pub(crate) registry_id: AtomicI32,
+    pub(crate) registry_id: c_int,
+    pub(crate) is_nil: AtomicBool,
     pub(crate) unref_list: Arc<Mutex<Option<Vec<c_int>>>>,
 }
 
 impl fmt::Debug for RegistryKey {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "RegistryKey({})", self.id())
+        write!(f, "RegistryKey({})", self.registry_id)
     }
 }
 
 impl Hash for RegistryKey {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        self.id().hash(state)
+        self.registry_id.hash(state)
     }
 }
 
 impl PartialEq for RegistryKey {
     fn eq(&self, other: &RegistryKey) -> bool {
-        self.id() == other.id() && Arc::ptr_eq(&self.unref_list, &other.unref_list)
+        self.registry_id == other.registry_id && Arc::ptr_eq(&self.unref_list, &other.unref_list)
     }
 }
 
@@ -230,82 +131,60 @@ impl Eq for RegistryKey {}
 
 impl Drop for RegistryKey {
     fn drop(&mut self) {
-        let registry_id = self.id();
         // We don't need to collect nil slot
-        if registry_id > ffi::LUA_REFNIL {
+        if self.registry_id > ffi::LUA_REFNIL {
             let mut unref_list = mlua_expect!(self.unref_list.lock(), "unref list poisoned");
             if let Some(list) = unref_list.as_mut() {
-                list.push(registry_id);
+                list.push(self.registry_id);
             }
         }
     }
 }
 
 impl RegistryKey {
-    /// Creates a new instance of `RegistryKey`
+    // Creates a new instance of `RegistryKey`
     pub(crate) const fn new(id: c_int, unref_list: Arc<Mutex<Option<Vec<c_int>>>>) -> Self {
         RegistryKey {
-            registry_id: AtomicI32::new(id),
+            registry_id: id,
+            is_nil: AtomicBool::new(id == ffi::LUA_REFNIL),
             unref_list,
         }
     }
 
-    /// Returns the underlying Lua reference of this `RegistryKey`
-    #[inline(always)]
-    pub fn id(&self) -> c_int {
-        self.registry_id.load(Ordering::Relaxed)
-    }
-
-    /// Sets the unique Lua reference key of this `RegistryKey`
-    #[inline(always)]
-    pub(crate) fn set_id(&self, id: c_int) {
-        self.registry_id.store(id, Ordering::Relaxed);
-    }
-
-    /// Destroys the `RegistryKey` without adding to the unref list
-    pub(crate) fn take(self) -> i32 {
-        let registry_id = self.id();
+    // Destroys the `RegistryKey` without adding to the unref list
+    pub(crate) fn take(self) -> c_int {
+        let registry_id = self.registry_id;
         unsafe {
             ptr::read(&self.unref_list);
             mem::forget(self);
         }
         registry_id
     }
+
+    // Returns true if this `RegistryKey` holds a nil value
+    #[inline(always)]
+    pub(crate) fn is_nil(&self) -> bool {
+        self.is_nil.load(Ordering::Relaxed)
+    }
+
+    // Marks value of this `RegistryKey` as `Nil`
+    #[inline(always)]
+    pub(crate) fn set_nil(&self, enabled: bool) {
+        // We cannot replace previous value with nil in as this will break
+        // Lua mechanism to find free keys.
+        // Instead, we set a special flag to mark value as nil.
+        self.is_nil.store(enabled, Ordering::Relaxed);
+    }
 }
 
 pub(crate) struct LuaRef<'lua> {
     pub(crate) lua: &'lua Lua,
     pub(crate) index: c_int,
-    pub(crate) drop: bool,
-}
-
-impl<'lua> LuaRef<'lua> {
-    pub(crate) const fn new(lua: &'lua Lua, index: c_int) -> Self {
-        LuaRef {
-            lua,
-            index,
-            drop: true,
-        }
-    }
-
-    #[inline]
-    pub(crate) fn to_pointer(&self) -> *const c_void {
-        unsafe { ffi::lua_topointer(self.lua.ref_thread(), self.index) }
-    }
-
-    #[cfg(feature = "unstable")]
-    #[inline]
-    pub(crate) fn into_owned(self) -> LuaOwnedRef {
-        assert!(self.drop, "Cannot turn non-drop reference into owned");
-        let owned_ref = LuaOwnedRef::new(self.lua.clone(), self.index);
-        mem::forget(self);
-        owned_ref
-    }
 }
 
 impl<'lua> fmt::Debug for LuaRef<'lua> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "Ref({:p})", self.to_pointer())
+        write!(f, "Ref({})", self.index)
     }
 }
 
@@ -317,222 +196,21 @@ impl<'lua> Clone for LuaRef<'lua> {
 
 impl<'lua> Drop for LuaRef<'lua> {
     fn drop(&mut self) {
-        if self.drop {
-            self.lua.drop_ref_index(self.index);
+        if self.index > 0 {
+            self.lua.drop_ref(self);
         }
     }
 }
 
 impl<'lua> PartialEq for LuaRef<'lua> {
     fn eq(&self, other: &Self) -> bool {
-        let ref_thread = self.lua.ref_thread();
-        assert!(
-            ref_thread == other.lua.ref_thread(),
-            "Lua instance passed Value created from a different main Lua state"
-        );
-        unsafe { ffi::lua_rawequal(ref_thread, self.index, other.index) == 1 }
-    }
-}
-
-#[cfg(feature = "unstable")]
-pub(crate) struct LuaOwnedRef {
-    pub(crate) inner: Arc<LuaInner>,
-    pub(crate) index: c_int,
-    _non_send: PhantomData<*const ()>,
-}
-
-#[cfg(feature = "unstable")]
-impl fmt::Debug for LuaOwnedRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "OwnedRef({:p})", self.to_ref().to_pointer())
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl Clone for LuaOwnedRef {
-    fn clone(&self) -> Self {
-        self.to_ref().clone().into_owned()
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl Drop for LuaOwnedRef {
-    fn drop(&mut self) {
-        let lua: &Lua = unsafe { mem::transmute(&self.inner) };
-        lua.drop_ref_index(self.index);
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl LuaOwnedRef {
-    pub(crate) const fn new(inner: Arc<LuaInner>, index: c_int) -> Self {
-        LuaOwnedRef {
-            inner,
-            index,
-            _non_send: PhantomData,
-        }
-    }
-
-    pub(crate) const fn to_ref(&self) -> LuaRef {
-        LuaRef {
-            lua: unsafe { mem::transmute(&self.inner) },
-            index: self.index,
-            drop: false,
+        let lua = self.lua;
+        unsafe {
+            let _sg = StackGuard::new(lua.state);
+            assert_stack(lua.state, 2);
+            lua.push_ref(self);
+            lua.push_ref(other);
+            ffi::lua_rawequal(lua.state, -1, -2) == 1
         }
     }
 }
-
-#[derive(Debug, Default)]
-pub(crate) struct AppData {
-    #[cfg(not(feature = "send"))]
-    container: UnsafeCell<FxHashMap<TypeId, RefCell<Box<dyn Any>>>>,
-    #[cfg(feature = "send")]
-    container: UnsafeCell<FxHashMap<TypeId, RefCell<Box<dyn Any + Send>>>>,
-    borrow: Cell<usize>,
-}
-
-impl AppData {
-    #[track_caller]
-    pub(crate) fn insert<T: MaybeSend + 'static>(&self, data: T) -> Option<T> {
-        match self.try_insert(data) {
-            Ok(data) => data,
-            Err(_) => panic!("cannot mutably borrow app data container"),
-        }
-    }
-
-    pub(crate) fn try_insert<T: MaybeSend + 'static>(&self, data: T) -> StdResult<Option<T>, T> {
-        if self.borrow.get() != 0 {
-            return Err(data);
-        }
-        // SAFETY: we checked that there are no other references to the container
-        Ok(unsafe { &mut *self.container.get() }
-            .insert(TypeId::of::<T>(), RefCell::new(Box::new(data)))
-            .and_then(|data| data.into_inner().downcast::<T>().ok().map(|data| *data)))
-    }
-
-    #[track_caller]
-    pub(crate) fn borrow<T: 'static>(&self) -> Option<AppDataRef<T>> {
-        let data = unsafe { &*self.container.get() }
-            .get(&TypeId::of::<T>())?
-            .borrow();
-        self.borrow.set(self.borrow.get() + 1);
-        Some(AppDataRef {
-            data: Ref::filter_map(data, |data| data.downcast_ref()).ok()?,
-            borrow: &self.borrow,
-        })
-    }
-
-    #[track_caller]
-    pub(crate) fn borrow_mut<T: 'static>(&self) -> Option<AppDataRefMut<T>> {
-        let data = unsafe { &*self.container.get() }
-            .get(&TypeId::of::<T>())?
-            .borrow_mut();
-        self.borrow.set(self.borrow.get() + 1);
-        Some(AppDataRefMut {
-            data: RefMut::filter_map(data, |data| data.downcast_mut()).ok()?,
-            borrow: &self.borrow,
-        })
-    }
-
-    #[track_caller]
-    pub(crate) fn remove<T: 'static>(&self) -> Option<T> {
-        if self.borrow.get() != 0 {
-            panic!("cannot mutably borrow app data container");
-        }
-        // SAFETY: we checked that there are no other references to the container
-        unsafe { &mut *self.container.get() }
-            .remove(&TypeId::of::<T>())?
-            .into_inner()
-            .downcast::<T>()
-            .ok()
-            .map(|data| *data)
-    }
-}
-
-/// A wrapper type for an immutably borrowed value from an app data container.
-///
-/// This type is similar to [`Ref`].
-pub struct AppDataRef<'a, T: ?Sized + 'a> {
-    data: Ref<'a, T>,
-    borrow: &'a Cell<usize>,
-}
-
-impl<T: ?Sized> Drop for AppDataRef<'_, T> {
-    fn drop(&mut self) {
-        self.borrow.set(self.borrow.get() - 1);
-    }
-}
-
-impl<T: ?Sized> Deref for AppDataRef<'_, T> {
-    type Target = T;
-
-    #[inline]
-    fn deref(&self) -> &Self::Target {
-        &self.data
-    }
-}
-
-impl<T: ?Sized + fmt::Display> fmt::Display for AppDataRef<'_, T> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        (**self).fmt(f)
-    }
-}
-
-impl<T: ?Sized + fmt::Debug> fmt::Debug for AppDataRef<'_, T> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        (**self).fmt(f)
-    }
-}
-
-/// A wrapper type for a mutably borrowed value from an app data container.
-///
-/// This type is similar to [`RefMut`].
-pub struct AppDataRefMut<'a, T: ?Sized + 'a> {
-    data: RefMut<'a, T>,
-    borrow: &'a Cell<usize>,
-}
-
-impl<T: ?Sized> Drop for AppDataRefMut<'_, T> {
-    fn drop(&mut self) {
-        self.borrow.set(self.borrow.get() - 1);
-    }
-}
-
-impl<T: ?Sized> Deref for AppDataRefMut<'_, T> {
-    type Target = T;
-
-    #[inline]
-    fn deref(&self) -> &Self::Target {
-        &self.data
-    }
-}
-
-impl<T: ?Sized> DerefMut for AppDataRefMut<'_, T> {
-    #[inline]
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.data
-    }
-}
-
-impl<T: ?Sized + fmt::Display> fmt::Display for AppDataRefMut<'_, T> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        (**self).fmt(f)
-    }
-}
-
-impl<T: ?Sized + fmt::Debug> fmt::Debug for AppDataRefMut<'_, T> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        (**self).fmt(f)
-    }
-}
-
-#[cfg(test)]
-mod assertions {
-    use super::*;
-
-    static_assertions::assert_impl_all!(RegistryKey: Send, Sync);
-    static_assertions::assert_not_impl_any!(LuaRef: Send);
-
-    #[cfg(feature = "unstable")]
-    static_assertions::assert_not_impl_any!(LuaOwnedRef: Send);
-}

src/userdata_ext.rs

@@ -1,190 +0,0 @@
-use crate::error::{Error, Result};
-use crate::private::Sealed;
-use crate::userdata::{AnyUserData, MetaMethod};
-use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, Value};
-
-#[cfg(feature = "async")]
-use futures_util::future::{self, LocalBoxFuture};
-
-/// An extension trait for [`AnyUserData`] that provides a variety of convenient functionality.
-pub trait AnyUserDataExt<'lua>: Sealed {
-    /// Gets the value associated to `key` from the userdata, assuming it has `__index` metamethod.
-    fn get<K: IntoLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V>;
-
-    /// Sets the value associated to `key` in the userdata, assuming it has `__newindex` metamethod.
-    fn set<K: IntoLua<'lua>, V: IntoLua<'lua>>(&self, key: K, value: V) -> Result<()>;
-
-    /// Calls the userdata as a function assuming it has `__call` metamethod.
-    ///
-    /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
-    fn call<A, R>(&self, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>;
-
-    /// Asynchronously calls the userdata as a function assuming it has `__call` metamethod.
-    ///
-    /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
-    #[cfg(feature = "async")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua;
-
-    /// Calls the userdata method, assuming it has `__index` metamethod
-    /// and a function associated to `name`.
-    fn call_method<A, R>(&self, name: &str, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>;
-
-    /// Gets the function associated to `key` from the table and asynchronously executes it,
-    /// passing the table itself along with `args` as function arguments and returning Future.
-    ///
-    /// Requires `feature = "async"`
-    ///
-    /// This might invoke the `__index` metamethod.
-    #[cfg(feature = "async")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua;
-
-    /// Gets the function associated to `key` from the table and executes it,
-    /// passing `args` as function arguments.
-    ///
-    /// This is a shortcut for
-    /// `table.get::<_, Function>(key)?.call(args)`
-    ///
-    /// This might invoke the `__index` metamethod.
-    fn call_function<A, R>(&self, name: &str, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>;
-
-    /// Gets the function associated to `key` from the table and asynchronously executes it,
-    /// passing `args` as function arguments and returning Future.
-    ///
-    /// Requires `feature = "async"`
-    ///
-    /// This might invoke the `__index` metamethod.
-    #[cfg(feature = "async")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua;
-}
-
-impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
-    fn get<K: IntoLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V> {
-        let metatable = self.get_metatable()?;
-        match metatable.get::<Value>(MetaMethod::Index)? {
-            Value::Table(table) => table.raw_get(key),
-            Value::Function(func) => func.call((self.clone(), key)),
-            _ => Err(Error::runtime("attempt to index a userdata value")),
-        }
-    }
-
-    fn set<K: IntoLua<'lua>, V: IntoLua<'lua>>(&self, key: K, value: V) -> Result<()> {
-        let metatable = self.get_metatable()?;
-        match metatable.get::<Value>(MetaMethod::NewIndex)? {
-            Value::Table(table) => table.raw_set(key, value),
-            Value::Function(func) => func.call((self.clone(), key, value)),
-            _ => Err(Error::runtime("attempt to index a userdata value")),
-        }
-    }
-
-    fn call<A, R>(&self, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>,
-    {
-        let metatable = self.get_metatable()?;
-        match metatable.get::<Value>(MetaMethod::Call)? {
-            Value::Function(func) => func.call((self.clone(), args)),
-            _ => Err(Error::runtime("attempt to call a userdata value")),
-        }
-    }
-
-    #[cfg(feature = "async")]
-    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
-    {
-        let metatable = match self.get_metatable() {
-            Ok(metatable) => metatable,
-            Err(err) => return Box::pin(future::err(err)),
-        };
-        match metatable.get::<Value>(MetaMethod::Call) {
-            Ok(Value::Function(func)) => {
-                let mut args = match args.into_lua_multi(self.0.lua) {
-                    Ok(args) => args,
-                    Err(e) => return Box::pin(future::err(e)),
-                };
-                args.push_front(Value::UserData(self.clone()));
-                Box::pin(async move { func.call_async(args).await })
-            }
-            Ok(_) => Box::pin(future::err(Error::runtime(
-                "attempt to call a userdata value",
-            ))),
-            Err(err) => Box::pin(future::err(err)),
-        }
-    }
-
-    fn call_method<A, R>(&self, name: &str, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>,
-    {
-        self.call_function(name, (self.clone(), args))
-    }
-
-    #[cfg(feature = "async")]
-    fn call_async_method<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
-    {
-        self.call_async_function(name, (self.clone(), args))
-    }
-
-    fn call_function<A, R>(&self, name: &str, args: A) -> Result<R>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua>,
-    {
-        match self.get(name)? {
-            Value::Function(func) => func.call(args),
-            val => {
-                let msg = format!("attempt to call a {} value", val.type_name());
-                Err(Error::runtime(msg))
-            }
-        }
-    }
-
-    #[cfg(feature = "async")]
-    fn call_async_function<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
-    where
-        A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'lua,
-    {
-        match self.get(name) {
-            Ok(Value::Function(func)) => {
-                let args = match args.into_lua_multi(self.0.lua) {
-                    Ok(args) => args,
-                    Err(e) => return Box::pin(future::err(e)),
-                };
-                Box::pin(async move { func.call_async(args).await })
-            }
-            Ok(val) => {
-                let msg = format!("attempt to call a {} value", val.type_name());
-                Box::pin(future::err(Error::runtime(msg)))
-            }
-            Err(err) => Box::pin(future::err(err)),
-        }
-    }
-}

src/util.rs

@@ -1,20 +1,17 @@
 use std::any::{Any, TypeId};
-use std::borrow::Cow;
 use std::ffi::CStr;
 use std::fmt::Write;
 use std::mem::MaybeUninit;
 use std::os::raw::{c_char, c_int, c_void};
 use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe};
 use std::sync::Arc;
-use std::{ptr, slice, str};
+use std::{mem, ptr, slice};
 
 use once_cell::sync::Lazy;
 use rustc_hash::FxHashMap;
 
 use crate::error::{Error, Result};
-use crate::memory::MemoryState;
-
-pub(crate) use short_names::short_type_name;
+use crate::ffi;
 
 static METATABLE_CACHE: Lazy<FxHashMap<TypeId, u8>> = Lazy::new(|| {
     let mut map = FxHashMap::with_capacity_and_hasher(32, Default::default());
@@ -50,6 +47,7 @@ pub unsafe fn check_stack(state: *mut ffi::lua_State, amount: c_int) -> Result<(
 pub struct StackGuard {
     state: *mut ffi::lua_State,
     top: c_int,
+    extra: c_int,
 }
 
 impl StackGuard {
@@ -61,12 +59,18 @@ impl StackGuard {
         StackGuard {
             state,
             top: ffi::lua_gettop(state),
+            extra: 0,
         }
     }
 
-    // Same as `new()`, but allows specifying the expected stack size at the end of the scope.
-    pub const fn with_top(state: *mut ffi::lua_State, top: c_int) -> StackGuard {
-        StackGuard { state, top }
+    // Similar to `new`, but checks and keeps `extra` elements from top of the stack on Drop.
+    #[inline]
+    pub unsafe fn new_extra(state: *mut ffi::lua_State, extra: c_int) -> StackGuard {
+        StackGuard {
+            state,
+            top: ffi::lua_gettop(state),
+            extra,
+        }
     }
 }
 
@@ -74,11 +78,14 @@ impl Drop for StackGuard {
     fn drop(&mut self) {
         unsafe {
             let top = ffi::lua_gettop(self.state);
-            if top < self.top {
+            if top < self.top + self.extra {
                 mlua_panic!("{} too many stack values popped", self.top - top)
             }
-            if top > self.top {
-                ffi::lua_settop(self.state, self.top);
+            if top > self.top + self.extra {
+                if self.extra > 0 {
+                    ffi::lua_rotate(self.state, self.top + 1, self.extra);
+                }
+                ffi::lua_settop(self.state, self.top + self.extra);
             }
         }
     }
@@ -93,14 +100,12 @@ impl Drop for StackGuard {
 pub unsafe fn protect_lua_call(
     state: *mut ffi::lua_State,
     nargs: c_int,
-    f: unsafe extern "C-unwind" fn(*mut ffi::lua_State) -> c_int,
+    f: unsafe extern "C" fn(*mut ffi::lua_State) -> c_int,
 ) -> Result<()> {
     let stack_start = ffi::lua_gettop(state) - nargs;
 
-    MemoryState::relax_limit_with(state, || {
-        ffi::lua_pushcfunction(state, error_traceback);
-        ffi::lua_pushcfunction(state, f);
-    });
+    ffi::lua_pushcfunction(state, error_traceback);
+    ffi::lua_pushcfunction(state, f);
     if nargs > 0 {
         ffi::lua_rotate(state, stack_start + 1, 2);
     }
@@ -138,7 +143,7 @@ where
         nresults: c_int,
     }
 
-    unsafe extern "C-unwind" fn do_call<F, R>(state: *mut ffi::lua_State) -> c_int
+    unsafe extern "C" fn do_call<F, R>(state: *mut ffi::lua_State) -> c_int
     where
         F: Fn(*mut ffi::lua_State) -> R,
         R: Copy,
@@ -157,10 +162,8 @@ where
 
     let stack_start = ffi::lua_gettop(state) - nargs;
 
-    MemoryState::relax_limit_with(state, || {
-        ffi::lua_pushcfunction(state, error_traceback);
-        ffi::lua_pushcfunction(state, do_call::<F, R>);
-    });
+    ffi::lua_pushcfunction(state, error_traceback);
+    ffi::lua_pushcfunction(state, do_call::<F, R>);
     if nargs > 0 {
         ffi::lua_rotate(state, stack_start + 1, 2);
     }
@@ -253,30 +256,14 @@ pub unsafe fn push_string(state: *mut ffi::lua_State, s: &[u8], protect: bool) -
     }
 }
 
-// Uses 3 stack spaces (when protect), does not call checkstack.
-#[cfg(feature = "luau")]
-#[inline(always)]
-pub unsafe fn push_buffer(state: *mut ffi::lua_State, b: &[u8], protect: bool) -> Result<()> {
-    let data = if protect {
-        protect_lua!(state, 0, 1, |state| ffi::lua_newbuffer(state, b.len()))?
-    } else {
-        ffi::lua_newbuffer(state, b.len())
-    };
-    let buf = slice::from_raw_parts_mut(data as *mut u8, b.len());
-    buf.copy_from_slice(b);
-    Ok(())
-}
-
 // Uses 3 stack spaces, does not call checkstack.
 #[inline]
 pub unsafe fn push_table(
     state: *mut ffi::lua_State,
-    narr: usize,
-    nrec: usize,
+    narr: c_int,
+    nrec: c_int,
     protect: bool,
 ) -> Result<()> {
-    let narr: c_int = narr.try_into().unwrap_or(c_int::MAX);
-    let nrec: c_int = nrec.try_into().unwrap_or(c_int::MAX);
     if protect {
         protect_lua!(state, 0, 1, |state| ffi::lua_createtable(state, narr, nrec))
     } else {
@@ -286,7 +273,11 @@ pub unsafe fn push_table(
 }
 
 // Uses 4 stack spaces, does not call checkstack.
-pub unsafe fn rawset_field(state: *mut ffi::lua_State, table: c_int, field: &str) -> Result<()> {
+pub unsafe fn rawset_field<S>(state: *mut ffi::lua_State, table: c_int, field: &S) -> Result<()>
+where
+    S: AsRef<[u8]> + ?Sized,
+{
+    let field = field.as_ref();
     ffi::lua_pushvalue(state, table);
     protect_lua!(state, 2, 0, |state| {
         ffi::lua_pushlstring(state, field.as_ptr() as *const c_char, field.len());
@@ -296,26 +287,41 @@ pub unsafe fn rawset_field(state: *mut ffi::lua_State, table: c_int, field: &str
 }
 
 // Internally uses 3 stack spaces, does not call checkstack.
+#[cfg(not(feature = "luau"))]
 #[inline]
 pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T, protect: bool) -> Result<()> {
-    #[cfg(not(feature = "luau"))]
     let ud = if protect {
         protect_lua!(state, 0, 1, |state| {
-            ffi::lua_newuserdata(state, std::mem::size_of::<T>()) as *mut T
+            ffi::lua_newuserdata(state, mem::size_of::<T>()) as *mut T
         })?
     } else {
-        ffi::lua_newuserdata(state, std::mem::size_of::<T>()) as *mut T
-    };
-    #[cfg(feature = "luau")]
-    let ud = if protect {
-        protect_lua!(state, 0, 1, |state| { ffi::lua_newuserdata_t::<T>(state) })?
-    } else {
-        ffi::lua_newuserdata_t::<T>(state)
+        ffi::lua_newuserdata(state, mem::size_of::<T>()) as *mut T
     };
     ptr::write(ud, t);
     Ok(())
 }
 
+// Internally uses 3 stack spaces, does not call checkstack.
+#[cfg(feature = "luau")]
+#[inline]
+pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T, protect: bool) -> Result<()> {
+    unsafe extern "C" fn destructor<T>(ud: *mut c_void) {
+        ptr::drop_in_place(ud as *mut T);
+    }
+
+    let size = mem::size_of::<T>();
+    let ud = if protect {
+        protect_lua!(state, 0, 1, |state| {
+            ffi::lua_newuserdatadtor(state, size, destructor::<T>) as *mut T
+        })?
+    } else {
+        ffi::lua_newuserdatadtor(state, size, destructor::<T>) as *mut T
+    };
+    ptr::write(ud, t);
+
+    Ok(())
+}
+
 // Internally uses 3 stack spaces, does not call checkstack.
 #[cfg(feature = "lua54")]
 #[inline]
@@ -327,10 +333,10 @@ pub unsafe fn push_userdata_uv<T>(
 ) -> Result<()> {
     let ud = if protect {
         protect_lua!(state, 0, 1, |state| {
-            ffi::lua_newuserdatauv(state, std::mem::size_of::<T>(), nuvalue) as *mut T
+            ffi::lua_newuserdatauv(state, mem::size_of::<T>(), nuvalue) as *mut T
         })?
     } else {
-        ffi::lua_newuserdatauv(state, std::mem::size_of::<T>(), nuvalue) as *mut T
+        ffi::lua_newuserdatauv(state, mem::size_of::<T>(), nuvalue) as *mut T
     };
     ptr::write(ud, t);
     Ok(())
@@ -404,17 +410,14 @@ pub unsafe fn get_gc_userdata<T: Any>(
     ud
 }
 
-unsafe extern "C-unwind" fn lua_error_impl(state: *mut ffi::lua_State) -> c_int {
+unsafe extern "C" fn lua_error_impl(state: *mut ffi::lua_State) -> c_int {
     ffi::lua_error(state);
 }
 
-unsafe extern "C-unwind" fn lua_isfunction_impl(state: *mut ffi::lua_State) -> c_int {
-    ffi::lua_pushboolean(state, ffi::lua_isfunction(state, -1));
-    1
-}
-
-unsafe extern "C-unwind" fn lua_istable_impl(state: *mut ffi::lua_State) -> c_int {
-    ffi::lua_pushboolean(state, ffi::lua_istable(state, -1));
+unsafe extern "C" fn lua_isfunction_impl(state: *mut ffi::lua_State) -> c_int {
+    let t = ffi::lua_type(state, -1);
+    ffi::lua_pop(state, 1);
+    ffi::lua_pushboolean(state, (t == ffi::LUA_TFUNCTION) as c_int);
     1
 }
 
@@ -428,19 +431,14 @@ unsafe fn init_userdata_metatable_index(state: *mut ffi::lua_State) -> Result<()
     // Create and cache `__index` generator
     let code = cstr!(
         r#"
-            local error, isfunction, istable = ...
+            local error, isfunction = ...
             return function (__index, field_getters, methods)
-                -- Common case: has field getters and index is a table
-                if field_getters ~= nil and methods == nil and istable(__index) then
-                    return function (self, key)
-                        local field_getter = field_getters[key]
-                        if field_getter ~= nil then
-                            return field_getter(self)
-                        end
-                        return __index[key]
-                    end
+                -- Fastpath to return methods table for index access
+                if __index == nil and field_getters == nil then
+                    return methods
                 end
 
+                -- Alternatively return a function for index access
                 return function (self, key)
                     if field_getters ~= nil then
                         local field_getter = field_getters[key]
@@ -475,13 +473,7 @@ unsafe fn init_userdata_metatable_index(state: *mut ffi::lua_State) -> Result<()
         }
         ffi::lua_pushcfunction(state, lua_error_impl);
         ffi::lua_pushcfunction(state, lua_isfunction_impl);
-        ffi::lua_pushcfunction(state, lua_istable_impl);
-        ffi::lua_call(state, 3, 1);
-
-        #[cfg(feature = "luau-jit")]
-        if ffi::luau_codegen_supported() != 0 {
-            ffi::luau_codegen_compile(state, -1);
-        }
+        ffi::lua_call(state, 2, 1);
 
         // Store in the registry
         ffi::lua_pushvalue(state, -1);
@@ -531,11 +523,6 @@ pub unsafe fn init_userdata_metatable_newindex(state: *mut ffi::lua_State) -> Re
         ffi::lua_pushcfunction(state, lua_isfunction_impl);
         ffi::lua_call(state, 2, 1);
 
-        #[cfg(feature = "luau-jit")]
-        if ffi::luau_codegen_supported() != 0 {
-            ffi::luau_codegen_compile(state, -1);
-        }
-
         // Store in the registry
         ffi::lua_pushvalue(state, -1);
         ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, newindex_key);
@@ -550,13 +537,12 @@ pub unsafe fn init_userdata_metatable_newindex(state: *mut ffi::lua_State) -> Re
 // captured `__index` if no matches found.
 // The same is also applicable for `__newindex` metamethod and `field_setters` table.
 // Internally uses 9 stack spaces and does not call checkstack.
-pub unsafe fn init_userdata_metatable(
+pub unsafe fn init_userdata_metatable<T>(
     state: *mut ffi::lua_State,
     metatable: c_int,
     field_getters: Option<c_int>,
     field_setters: Option<c_int>,
     methods: Option<c_int>,
-    extra_init: Option<fn(*mut ffi::lua_State) -> Result<()>>,
 ) -> Result<()> {
     ffi::lua_pushvalue(state, metatable);
 
@@ -603,9 +589,10 @@ pub unsafe fn init_userdata_metatable(
         rawset_field(state, -2, "__newindex")?;
     }
 
-    // Additional initialization
-    if let Some(extra_init) = extra_init {
-        extra_init(state)?;
+    #[cfg(not(feature = "luau"))]
+    {
+        ffi::lua_pushcfunction(state, userdata_destructor::<T>);
+        rawset_field(state, -2, "__gc")?;
     }
 
     ffi::lua_pushboolean(state, 0);
@@ -617,7 +604,7 @@ pub unsafe fn init_userdata_metatable(
 }
 
 #[cfg(not(feature = "luau"))]
-pub unsafe extern "C-unwind" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
     // It's probably NOT a good idea to catch Rust panics in finalizer
     // Lua 5.4 ignores it, other versions generates `LUA_ERRGCMM` without calling message handler
     take_userdata::<T>(state);
@@ -662,6 +649,8 @@ where
         Ok(Err(err)) => {
             ffi::lua_settop(state, 1);
 
+            let wrapped_error = ud as *mut WrappedFailure;
+
             // Build `CallbackError` with traceback
             let traceback = if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
                 ffi::luaL_traceback(state, state, ptr::null(), 0);
@@ -672,8 +661,10 @@ where
                 "<not enough stack space for traceback>".to_string()
             };
             let cause = Arc::new(err);
-            let wrapped_error = WrappedFailure::Error(Error::CallbackError { traceback, cause });
-            ptr::write(ud, wrapped_error);
+            ptr::write(
+                wrapped_error,
+                WrappedFailure::Error(Error::CallbackError { traceback, cause }),
+            );
             get_gc_metatable::<WrappedFailure>(state);
             ffi::lua_setmetatable(state, -2);
 
@@ -681,7 +672,7 @@ where
         }
         Err(p) => {
             ffi::lua_settop(state, 1);
-            ptr::write(ud, WrappedFailure::Panic(Some(p)));
+            ptr::write(ud as *mut WrappedFailure, WrappedFailure::Panic(Some(p)));
             get_gc_metatable::<WrappedFailure>(state);
             ffi::lua_setmetatable(state, -2);
             ffi::lua_error(state)
@@ -689,14 +680,7 @@ where
     }
 }
 
-pub unsafe extern "C-unwind" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
-    // Luau calls error handler for memory allocation errors, skip it
-    // See https://github.com/Roblox/luau/issues/880
-    #[cfg(feature = "luau")]
-    if MemoryState::limit_reached(state) {
-        return 0;
-    }
-
+pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
     if ffi::lua_checkstack(state, 2) == 0 {
         // If we don't have enough stack space to even check the error type, do
         // nothing so we don't risk shadowing a rust panic.
@@ -729,7 +713,7 @@ pub unsafe fn error_traceback_thread(state: *mut ffi::lua_State, thread: *mut ff
 }
 
 // A variant of `pcall` that does not allow Lua to catch Rust panics from `callback_error`.
-pub unsafe extern "C-unwind" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
     ffi::luaL_checkstack(state, 2, ptr::null());
 
     let top = ffi::lua_gettop(state);
@@ -755,8 +739,8 @@ pub unsafe extern "C-unwind" fn safe_pcall(state: *mut ffi::lua_State) -> c_int
 }
 
 // A variant of `xpcall` that does not allow Lua to catch Rust panics from `callback_error`.
-pub unsafe extern "C-unwind" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
-    unsafe extern "C-unwind" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
         ffi::luaL_checkstack(state, 2, ptr::null());
 
         if let Some(WrappedFailure::Panic(_)) =
@@ -870,7 +854,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 
     // Create error and panic metatables
 
-    unsafe extern "C-unwind" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
         callback_error(state, |_| {
             check_stack(state, 3)?;
 
@@ -885,7 +869,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
                     // Depending on how the API is used and what error types scripts are given, it may
                     // be possible to make this consume arbitrary amounts of memory (for example, some
                     // kind of recursive error structure?)
-                    let _ = write!(&mut (*err_buf), "{error}");
+                    let _ = write!(&mut (*err_buf), "{}", error);
                     Ok(err_buf)
                 }
                 Some(WrappedFailure::Panic(Some(ref panic))) => {
@@ -896,9 +880,9 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
                     ffi::lua_pop(state, 2);
 
                     if let Some(msg) = panic.downcast_ref::<&str>() {
-                        let _ = write!(&mut (*err_buf), "{msg}");
+                        let _ = write!(&mut (*err_buf), "{}", msg);
                     } else if let Some(msg) = panic.downcast_ref::<String>() {
-                        let _ = write!(&mut (*err_buf), "{msg}");
+                        let _ = write!(&mut (*err_buf), "{}", msg);
                     } else {
                         let _ = write!(&mut (*err_buf), "<panic>");
                     };
@@ -928,7 +912,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 
     // Create destructed userdata metatable
 
-    unsafe extern "C-unwind" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
         callback_error(state, |_| Err(Error::CallbackDestructed))
     }
 
@@ -942,7 +926,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
         "__mod",
         "__pow",
         "__unm",
-        #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
+        #[cfg(any(feature = "lua54", feature = "lua53"))]
         "__idiv",
         #[cfg(any(feature = "lua54", feature = "lua53"))]
         "__band",
@@ -1008,10 +992,16 @@ pub(crate) enum WrappedFailure {
 
 impl WrappedFailure {
     pub(crate) unsafe fn new_userdata(state: *mut ffi::lua_State) -> *mut Self {
+        let size = mem::size_of::<WrappedFailure>();
         #[cfg(feature = "luau")]
-        let ud = ffi::lua_newuserdata_t::<Self>(state);
+        let ud = {
+            unsafe extern "C" fn destructor(p: *mut c_void) {
+                ptr::drop_in_place(p as *mut WrappedFailure);
+            }
+            ffi::lua_newuserdatadtor(state, size, destructor) as *mut Self
+        };
         #[cfg(not(feature = "luau"))]
-        let ud = ffi::lua_newuserdata(state, std::mem::size_of::<Self>()) as *mut Self;
+        let ud = ffi::lua_newuserdata(state, size) as *mut Self;
         ptr::write(ud, WrappedFailure::None);
         ud
     }
@@ -1041,10 +1031,7 @@ pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> Stri
             let v = ffi::lua_tovector(state, index);
             mlua_debug_assert!(!v.is_null(), "vector is null");
             let (x, y, z) = (*v, *v.add(1), *v.add(2));
-            #[cfg(not(feature = "luau-vector4"))]
-            return format!("vector({x}, {y}, {z})");
-            #[cfg(feature = "luau-vector4")]
-            return format!("vector({x}, {y}, {z}, {w})", w = *v.add(3));
+            format!("vector({},{},{})", x, y, z)
         }
         ffi::LUA_TSTRING => {
             let mut size = 0;
@@ -1057,10 +1044,6 @@ pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> Stri
         ffi::LUA_TFUNCTION => format!("<function {:?}>", ffi::lua_topointer(state, index)),
         ffi::LUA_TUSERDATA => format!("<userdata {:?}>", ffi::lua_topointer(state, index)),
         ffi::LUA_TTHREAD => format!("<thread {:?}>", ffi::lua_topointer(state, index)),
-        #[cfg(feature = "luau")]
-        ffi::LUA_TBUFFER => format!("<buffer {:?}>", ffi::lua_topointer(state, index)),
-        #[cfg(feature = "luajit")]
-        ffi::LUA_TCDATA => format!("<cdata {:?}>", ffi::lua_topointer(state, index)),
         _ => "<unknown>".to_string(),
     }
 }
@@ -1070,30 +1053,14 @@ pub(crate) unsafe fn get_destructed_userdata_metatable(state: *mut ffi::lua_Stat
     ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, key);
 }
 
-pub(crate) unsafe fn ptr_to_str<'a>(input: *const c_char) -> Option<&'a str> {
+pub(crate) unsafe fn ptr_to_cstr_bytes<'a>(input: *const c_char) -> Option<&'a [u8]> {
     if input.is_null() {
         return None;
     }
-    str::from_utf8(CStr::from_ptr(input).to_bytes()).ok()
-}
-
-pub(crate) unsafe fn ptr_to_lossy_str<'a>(input: *const c_char) -> Option<Cow<'a, str>> {
-    if input.is_null() {
-        return None;
-    }
-    Some(String::from_utf8_lossy(CStr::from_ptr(input).to_bytes()))
-}
-
-pub(crate) fn linenumber_to_usize(n: c_int) -> Option<usize> {
-    match n {
-        n if n < 0 => None,
-        n => Some(n as usize),
-    }
+    Some(CStr::from_ptr(input).to_bytes())
 }
 
 static DESTRUCTED_USERDATA_METATABLE: u8 = 0;
 static ERROR_PRINT_BUFFER_KEY: u8 = 0;
 static USERDATA_METATABLE_INDEX: u8 = 0;
 static USERDATA_METATABLE_NEWINDEX: u8 = 0;
-
-mod short_names;

src/util/short_names.rs

@@ -1,85 +0,0 @@
-//! Mostly copied from [bevy_utils]
-//!
-//! [bevy_utils]: https://github.com/bevyengine/bevy/blob/main/crates/bevy_utils/src/short_names.rs
-
-use std::any::type_name;
-
-/// Returns a short version of a type name `T` without all module paths.
-///
-/// The short name of a type is its full name as returned by
-/// [`std::any::type_name`], but with the prefix of all paths removed. For
-/// example, the short name of `alloc::vec::Vec<core::option::Option<u32>>`
-/// would be `Vec<Option<u32>>`.
-pub(crate) fn short_type_name<T: ?Sized>() -> String {
-    let full_name = type_name::<T>();
-
-    // Generics result in nested paths within <..> blocks.
-    // Consider "core::option::Option<alloc::string::String>".
-    // To tackle this, we parse the string from left to right, collapsing as we go.
-    let mut index: usize = 0;
-    let end_of_string = full_name.len();
-    let mut parsed_name = String::new();
-
-    while index < end_of_string {
-        let rest_of_string = full_name.get(index..end_of_string).unwrap_or_default();
-
-        // Collapse everything up to the next special character,
-        // then skip over it
-        if let Some(special_character_index) = rest_of_string
-            .find(|c: char| [' ', '<', '>', '(', ')', '[', ']', ',', ';'].contains(&c))
-        {
-            let segment_to_collapse = rest_of_string
-                .get(0..special_character_index)
-                .unwrap_or_default();
-            parsed_name += collapse_type_name(segment_to_collapse);
-            // Insert the special character
-            let special_character =
-                &rest_of_string[special_character_index..=special_character_index];
-            parsed_name.push_str(special_character);
-
-            match special_character {
-                ">" | ")" | "]"
-                    if rest_of_string[special_character_index + 1..].starts_with("::") =>
-                {
-                    parsed_name.push_str("::");
-                    // Move the index past the "::"
-                    index += special_character_index + 3;
-                }
-                // Move the index just past the special character
-                _ => index += special_character_index + 1,
-            }
-        } else {
-            // If there are no special characters left, we're done!
-            parsed_name += collapse_type_name(rest_of_string);
-            index = end_of_string;
-        }
-    }
-    parsed_name
-}
-
-#[inline(always)]
-fn collapse_type_name(string: &str) -> &str {
-    string.rsplit("::").next().unwrap()
-}
-
-#[cfg(test)]
-mod tests {
-    use super::short_type_name;
-    use std::collections::HashMap;
-
-    #[test]
-    fn tests() {
-        assert_eq!(short_type_name::<String>(), "String");
-        assert_eq!(short_type_name::<Option<String>>(), "Option<String>");
-        assert_eq!(short_type_name::<(String, &str)>(), "(String, &str)");
-        assert_eq!(short_type_name::<[i32; 3]>(), "[i32; 3]");
-        assert_eq!(
-            short_type_name::<HashMap<String, Option<[i32; 3]>>>(),
-            "HashMap<String, Option<[i32; 3]>>"
-        );
-        assert_eq!(
-            short_type_name::<dyn Fn(i32) -> i32>(),
-            "dyn Fn(i32) -> i32"
-        );
-    }
-}

src/value.rs

@@ -1,37 +1,29 @@
-use std::borrow::Cow;
-use std::cmp::Ordering;
-use std::collections::HashSet;
-use std::iter;
+use std::iter::{self, FromIterator};
 use std::ops::Index;
-use std::os::raw::{c_int, c_void};
-use std::string::String as StdString;
-use std::sync::Arc;
-use std::{fmt, mem, ptr, slice, str, vec};
-
-use num_traits::FromPrimitive;
+use std::os::raw::c_void;
+use std::{ptr, slice, str, vec};
 
 #[cfg(feature = "serialize")]
 use {
-    crate::table::SerializableTable,
-    rustc_hash::FxHashSet,
     serde::ser::{self, Serialize, Serializer},
-    std::{cell::RefCell, rc::Rc, result::Result as StdResult},
+    std::convert::TryInto,
+    std::result::Result as StdResult,
 };
 
 use crate::error::{Error, Result};
+use crate::ffi;
 use crate::function::Function;
 use crate::lua::Lua;
 use crate::string::String;
 use crate::table::Table;
 use crate::thread::Thread;
-use crate::types::{Integer, LightUserData, Number, SubtypeId};
+use crate::types::{Integer, LightUserData, Number};
 use crate::userdata::AnyUserData;
-use crate::util::{check_stack, StackGuard};
 
 /// A dynamically typed Lua value. The `String`, `Table`, `Function`, `Thread`, and `UserData`
 /// variants contain handle types into the internal Lua state. It is a logic error to mix handle
 /// types between separate `Lua` instances, and doing so will result in a panic.
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub enum Value<'lua> {
     /// The Lua value `nil`.
     Nil,
@@ -48,7 +40,7 @@ pub enum Value<'lua> {
     /// A Luau vector.
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    Vector(crate::types::Vector),
+    Vector(f32, f32, f32),
     /// An interned string, managed by Lua.
     ///
     /// Unlike Rust strings, Lua strings may not be valid UTF-8.
@@ -69,12 +61,6 @@ pub enum Value<'lua> {
 pub use self::Value::Nil;
 
 impl<'lua> Value<'lua> {
-    /// A special value (lightuserdata) to represent null value.
-    ///
-    /// It can be used in Lua tables without downsides of `nil`.
-    pub const NULL: Value<'static> = Value::LightUserData(LightUserData(ptr::null_mut()));
-
-    /// Returns type name of this value.
     pub const fn type_name(&self) -> &'static str {
         match *self {
             Value::Nil => "nil",
@@ -83,16 +69,12 @@ impl<'lua> Value<'lua> {
             Value::Integer(_) => "integer",
             Value::Number(_) => "number",
             #[cfg(feature = "luau")]
-            Value::Vector(_) => "vector",
+            Value::Vector(_, _, _) => "vector",
             Value::String(_) => "string",
             Value::Table(_) => "table",
             Value::Function(_) => "function",
             Value::Thread(_) => "thread",
-            Value::UserData(AnyUserData(_, SubtypeId::None)) => "userdata",
-            #[cfg(feature = "luau")]
-            Value::UserData(AnyUserData(_, SubtypeId::Buffer)) => "buffer",
-            #[cfg(feature = "luajit")]
-            Value::UserData(AnyUserData(_, SubtypeId::CData)) => "cdata",
+            Value::UserData(_) => "userdata",
             Value::Error(_) => "error",
         }
     }
@@ -111,7 +93,7 @@ impl<'lua> Value<'lua> {
         match (self, other.as_ref()) {
             (Value::Table(a), Value::Table(b)) => a.equals(b),
             (Value::UserData(a), Value::UserData(b)) => a.equals(b),
-            (a, b) => Ok(a == b),
+            _ => Ok(self == other.as_ref()),
         }
     }
 
@@ -124,425 +106,19 @@ impl<'lua> Value<'lua> {
     /// Typically this function is used only for hashing and debug information.
     #[inline]
     pub fn to_pointer(&self) -> *const c_void {
-        match self {
-            Value::LightUserData(ud) => ud.0,
-            Value::String(String(r))
-            | Value::Table(Table(r))
-            | Value::Function(Function(r))
-            | Value::Thread(Thread(r, ..))
-            | Value::UserData(AnyUserData(r, ..)) => r.to_pointer(),
-            _ => ptr::null(),
-        }
-    }
-
-    /// Converts the value to a string.
-    ///
-    /// If the value has a metatable with a `__tostring` method, then it will be called to get the result.
-    pub fn to_string(&self) -> Result<StdString> {
-        match self {
-            Value::Nil => Ok("nil".to_string()),
-            Value::Boolean(b) => Ok(b.to_string()),
-            Value::LightUserData(ud) if ud.0.is_null() => Ok("null".to_string()),
-            Value::LightUserData(ud) => Ok(format!("lightuserdata: {:p}", ud.0)),
-            Value::Integer(i) => Ok(i.to_string()),
-            Value::Number(n) => Ok(n.to_string()),
-            #[cfg(feature = "luau")]
-            Value::Vector(v) => Ok(v.to_string()),
-            Value::String(s) => Ok(s.to_str()?.to_string()),
-            Value::Table(Table(r))
-            | Value::Function(Function(r))
-            | Value::Thread(Thread(r, ..))
-            | Value::UserData(AnyUserData(r, ..)) => unsafe {
-                let state = r.lua.state();
-                let _guard = StackGuard::new(state);
-                check_stack(state, 3)?;
-
-                r.lua.push_ref(r);
-                protect_lua!(state, 1, 1, fn(state) {
-                    ffi::luaL_tolstring(state, -1, ptr::null_mut());
-                })?;
-                Ok(String(r.lua.pop_ref()).to_str()?.to_string())
-            },
-            Value::Error(err) => Ok(err.to_string()),
-        }
-    }
-
-    /// Returns `true` if the value is a [`Nil`].
-    #[inline]
-    pub fn is_nil(&self) -> bool {
-        self == &Nil
-    }
-
-    /// Returns `true` if the value is a [`NULL`].
-    #[inline]
-    pub fn is_null(&self) -> bool {
-        self == &Self::NULL
-    }
-
-    /// Returns `true` if the value is a boolean.
-    #[inline]
-    pub fn is_boolean(&self) -> bool {
-        self.as_boolean().is_some()
-    }
-
-    /// Cast the value to boolean.
-    ///
-    /// If the value is a Boolean, returns it or `None` otherwise.
-    #[inline]
-    pub fn as_boolean(&self) -> Option<bool> {
-        match *self {
-            Value::Boolean(b) => Some(b),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is a [`LightUserData`].
-    #[inline]
-    pub fn is_light_userdata(&self) -> bool {
-        self.as_light_userdata().is_some()
-    }
-
-    /// Cast the value to [`LightUserData`].
-    ///
-    /// If the value is a [`LightUserData`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_light_userdata(&self) -> Option<LightUserData> {
-        match *self {
-            Value::LightUserData(l) => Some(l),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is an [`Integer`].
-    #[inline]
-    pub fn is_integer(&self) -> bool {
-        self.as_integer().is_some()
-    }
-
-    /// Cast the value to [`Integer`].
-    ///
-    /// If the value is a Lua [`Integer`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_integer(&self) -> Option<Integer> {
-        match *self {
-            Value::Integer(i) => Some(i),
-            _ => None,
-        }
-    }
-
-    /// Cast the value to `i32`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `i32` or return `None` otherwise.
-    #[inline]
-    pub fn as_i32(&self) -> Option<i32> {
-        #[allow(clippy::useless_conversion)]
-        self.as_integer().and_then(|i| i32::try_from(i).ok())
-    }
-
-    /// Cast the value to `u32`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `u32` or return `None` otherwise.
-    #[inline]
-    pub fn as_u32(&self) -> Option<u32> {
-        self.as_integer().and_then(|i| u32::try_from(i).ok())
-    }
-
-    /// Cast the value to `i64`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `i64` or return `None` otherwise.
-    #[inline]
-    pub fn as_i64(&self) -> Option<i64> {
-        self.as_integer().map(i64::from)
-    }
-
-    /// Cast the value to `u64`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `u64` or return `None` otherwise.
-    #[inline]
-    pub fn as_u64(&self) -> Option<u64> {
-        self.as_integer().and_then(|i| u64::try_from(i).ok())
-    }
-
-    /// Cast the value to `isize`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `isize` or return `None` otherwise.
-    #[inline]
-    pub fn as_isize(&self) -> Option<isize> {
-        self.as_integer().and_then(|i| isize::try_from(i).ok())
-    }
-
-    /// Cast the value to `usize`.
-    ///
-    /// If the value is a Lua [`Integer`], try to convert it to `usize` or return `None` otherwise.
-    #[inline]
-    pub fn as_usize(&self) -> Option<usize> {
-        self.as_integer().and_then(|i| usize::try_from(i).ok())
-    }
-
-    /// Returns `true` if the value is a Lua [`Number`].
-    #[inline]
-    pub fn is_number(&self) -> bool {
-        self.as_number().is_some()
-    }
-
-    /// Cast the value to [`Number`].
-    ///
-    /// If the value is a Lua [`Number`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_number(&self) -> Option<Number> {
-        match *self {
-            Value::Number(n) => Some(n),
-            _ => None,
-        }
-    }
-
-    /// Cast the value to `f32`.
-    ///
-    /// If the value is a Lua [`Number`], try to convert it to `f32` or return `None` otherwise.
-    #[inline]
-    pub fn as_f32(&self) -> Option<f32> {
-        self.as_number().and_then(f32::from_f64)
-    }
-
-    /// Cast the value to `f64`.
-    ///
-    /// If the value is a Lua [`Number`], try to convert it to `f64` or return `None` otherwise.
-    #[inline]
-    pub fn as_f64(&self) -> Option<f64> {
-        self.as_number()
-    }
-
-    /// Returns `true` if the value is a Lua [`String`].
-    #[inline]
-    pub fn is_string(&self) -> bool {
-        self.as_string().is_some()
-    }
-
-    /// Cast the value to Lua [`String`].
-    ///
-    /// If the value is a Lua [`String`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_string(&self) -> Option<&String> {
-        match self {
-            Value::String(s) => Some(s),
-            _ => None,
-        }
-    }
-
-    /// Cast the value to [`str`].
-    ///
-    /// If the value is a Lua [`String`], try to convert it to [`str`] or return `None` otherwise.
-    #[inline]
-    pub fn as_str(&self) -> Option<&str> {
-        self.as_string().and_then(|s| s.to_str().ok())
-    }
-
-    /// Cast the value to [`Cow<str>`].
-    ///
-    /// If the value is a Lua [`String`], converts it to [`Cow<str>`] or returns `None` otherwise.
-    #[inline]
-    pub fn as_string_lossy(&self) -> Option<Cow<str>> {
-        self.as_string().map(|s| s.to_string_lossy())
-    }
-
-    /// Returns `true` if the value is a Lua [`Table`].
-    #[inline]
-    pub fn is_table(&self) -> bool {
-        self.as_table().is_some()
-    }
-
-    /// Cast the value to [`Table`].
-    ///
-    /// If the value is a Lua [`Table`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_table(&self) -> Option<&Table> {
-        match self {
-            Value::Table(t) => Some(t),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is a Lua [`Thread`].
-    #[inline]
-    pub fn is_thread(&self) -> bool {
-        self.as_thread().is_some()
-    }
-
-    /// Cast the value to [`Thread`].
-    ///
-    /// If the value is a Lua [`Thread`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_thread(&self) -> Option<&Thread> {
-        match self {
-            Value::Thread(t) => Some(t),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is a Lua [`Function`].
-    #[inline]
-    pub fn is_function(&self) -> bool {
-        self.as_function().is_some()
-    }
-
-    /// Cast the value to [`Function`].
-    ///
-    /// If the value is a Lua [`Function`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_function(&self) -> Option<&Function> {
-        match self {
-            Value::Function(f) => Some(f),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is an [`AnyUserData`].
-    #[inline]
-    pub fn is_userdata(&self) -> bool {
-        self.as_userdata().is_some()
-    }
-
-    /// Cast the value to [`AnyUserData`].
-    ///
-    /// If the value is an [`AnyUserData`], returns it or `None` otherwise.
-    #[inline]
-    pub fn as_userdata(&self) -> Option<&AnyUserData> {
-        match self {
-            Value::UserData(ud) => Some(ud),
-            _ => None,
-        }
-    }
-
-    /// Returns `true` if the value is a Buffer wrapped in [`AnyUserData`].
-    #[cfg(any(feature = "luau", doc))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    #[doc(hidden)]
-    #[inline]
-    pub fn is_buffer(&self) -> bool {
-        self.as_userdata()
-            .map(|ud| ud.1 == SubtypeId::Buffer)
-            .unwrap_or_default()
-    }
-
-    /// Returns `true` if the value is a CData wrapped in [`AnyUserData`].
-    #[cfg(any(feature = "luajit", doc))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
-    #[doc(hidden)]
-    #[inline]
-    pub fn is_cdata(&self) -> bool {
-        self.as_userdata()
-            .map(|ud| ud.1 == SubtypeId::CData)
-            .unwrap_or_default()
-    }
-
-    /// Wrap reference to this Value into [`SerializableValue`].
-    ///
-    /// This allows customizing serialization behavior using serde.
-    #[cfg(feature = "serialize")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
-    #[doc(hidden)]
-    pub fn to_serializable(&self) -> SerializableValue<'_, 'lua> {
-        SerializableValue::new(self, Default::default(), None)
-    }
-
-    // Compares two values.
-    // Used to sort values for Debug printing.
-    pub(crate) fn cmp(&self, other: &Self) -> Ordering {
-        fn cmp_num(a: Number, b: Number) -> Ordering {
-            match (a, b) {
-                _ if a < b => Ordering::Less,
-                _ if a > b => Ordering::Greater,
-                _ => Ordering::Equal,
+        unsafe {
+            match self {
+                Value::LightUserData(ud) => ud.0,
+                Value::Table(t) => t.to_pointer(),
+                Value::String(s) => s.to_pointer(),
+                Value::Function(Function(r))
+                | Value::Thread(Thread(r))
+                | Value::UserData(AnyUserData(r)) => {
+                    ffi::lua_topointer(r.lua.ref_thread(), r.index)
+                }
+                _ => ptr::null(),
             }
         }
-
-        match (self, other) {
-            // Nil
-            (Value::Nil, Value::Nil) => Ordering::Equal,
-            (Value::Nil, _) => Ordering::Less,
-            (_, Value::Nil) => Ordering::Greater,
-            // Null (a special case)
-            (Value::LightUserData(ud1), Value::LightUserData(ud2)) if ud1 == ud2 => Ordering::Equal,
-            (Value::LightUserData(ud1), _) if ud1.0.is_null() => Ordering::Less,
-            (_, Value::LightUserData(ud2)) if ud2.0.is_null() => Ordering::Greater,
-            // Boolean
-            (Value::Boolean(a), Value::Boolean(b)) => a.cmp(b),
-            (Value::Boolean(_), _) => Ordering::Less,
-            (_, Value::Boolean(_)) => Ordering::Greater,
-            // Integer && Number
-            (Value::Integer(a), Value::Integer(b)) => a.cmp(b),
-            (&Value::Integer(a), &Value::Number(b)) => cmp_num(a as Number, b),
-            (&Value::Number(a), &Value::Integer(b)) => cmp_num(a, b as Number),
-            (&Value::Number(a), &Value::Number(b)) => cmp_num(a, b),
-            (Value::Integer(_) | Value::Number(_), _) => Ordering::Less,
-            (_, Value::Integer(_) | Value::Number(_)) => Ordering::Greater,
-            // String
-            (Value::String(a), Value::String(b)) => a.as_bytes().cmp(b.as_bytes()),
-            (Value::String(_), _) => Ordering::Less,
-            (_, Value::String(_)) => Ordering::Greater,
-            // Other variants can be randomly ordered
-            (a, b) => a.to_pointer().cmp(&b.to_pointer()),
-        }
-    }
-
-    pub(crate) fn fmt_pretty(
-        &self,
-        fmt: &mut fmt::Formatter,
-        recursive: bool,
-        ident: usize,
-        visited: &mut HashSet<*const c_void>,
-    ) -> fmt::Result {
-        match self {
-            Value::Nil => write!(fmt, "nil"),
-            Value::Boolean(b) => write!(fmt, "{b}"),
-            Value::LightUserData(ud) if ud.0.is_null() => write!(fmt, "null"),
-            Value::LightUserData(ud) => write!(fmt, "lightuserdata: {:?}", ud.0),
-            Value::Integer(i) => write!(fmt, "{i}"),
-            Value::Number(n) => write!(fmt, "{n}"),
-            #[cfg(feature = "luau")]
-            Value::Vector(v) => write!(fmt, "{v}"),
-            Value::String(s) => write!(fmt, "{s:?}"),
-            Value::Table(t) if recursive && !visited.contains(&t.to_pointer()) => {
-                t.fmt_pretty(fmt, ident, visited)
-            }
-            t @ Value::Table(_) => write!(fmt, "table: {:?}", t.to_pointer()),
-            f @ Value::Function(_) => write!(fmt, "function: {:?}", f.to_pointer()),
-            t @ Value::Thread(_) => write!(fmt, "thread: {:?}", t.to_pointer()),
-            u @ Value::UserData(ud) => {
-                // Try `__name/__type` first then `__tostring`
-                let name = ud.type_name().ok().flatten();
-                let s = name
-                    .map(|name| format!("{name}: {:?}", u.to_pointer()))
-                    .or_else(|| u.to_string().ok())
-                    .unwrap_or_else(|| format!("userdata: {:?}", u.to_pointer()));
-                write!(fmt, "{s}")
-            }
-            Value::Error(e) if recursive => write!(fmt, "{e:?}"),
-            Value::Error(_) => write!(fmt, "error"),
-        }
-    }
-}
-
-impl fmt::Debug for Value<'_> {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        if fmt.alternate() {
-            return self.fmt_pretty(fmt, true, 0, &mut HashSet::new());
-        }
-        match self {
-            Value::Nil => write!(fmt, "Nil"),
-            Value::Boolean(b) => write!(fmt, "Boolean({b})"),
-            Value::LightUserData(ud) => write!(fmt, "{ud:?}"),
-            Value::Integer(i) => write!(fmt, "Integer({i})"),
-            Value::Number(n) => write!(fmt, "Number({n})"),
-            #[cfg(feature = "luau")]
-            Value::Vector(v) => write!(fmt, "{v:?}"),
-            Value::String(s) => write!(fmt, "String({s:?})"),
-            Value::Table(t) => write!(fmt, "{t:?}"),
-            Value::Function(f) => write!(fmt, "{f:?}"),
-            Value::Thread(t) => write!(fmt, "{t:?}"),
-            Value::UserData(ud) => write!(fmt, "{ud:?}"),
-            Value::Error(e) => write!(fmt, "Error({e:?})"),
-        }
     }
 }
 
@@ -557,7 +133,7 @@ impl<'lua> PartialEq for Value<'lua> {
             (Value::Number(a), Value::Integer(b)) => *a == *b as Number,
             (Value::Number(a), Value::Number(b)) => *a == *b,
             #[cfg(feature = "luau")]
-            (Value::Vector(v1), Value::Vector(v2)) => v1 == v2,
+            (Value::Vector(x1, y1, z1), Value::Vector(x2, y2, z2)) => (x1, y1, z1) == (x2, y2, z2),
             (Value::String(a), Value::String(b)) => a == b,
             (Value::Table(a), Value::Table(b)) => a == b,
             (Value::Function(a), Value::Function(b)) => a == b,
@@ -575,218 +151,60 @@ impl<'lua> AsRef<Value<'lua>> for Value<'lua> {
     }
 }
 
-/// A wrapped [`Value`] with customized serialization behavior.
-#[cfg(feature = "serialize")]
-#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
-pub struct SerializableValue<'a, 'lua> {
-    value: &'a Value<'lua>,
-    options: crate::serde::de::Options,
-    // In many cases we don't need `visited` map, so don't allocate memory by default
-    visited: Option<Rc<RefCell<FxHashSet<*const c_void>>>>,
-}
-
 #[cfg(feature = "serialize")]
 impl<'lua> Serialize for Value<'lua> {
-    #[inline]
-    fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
-        SerializableValue::new(self, Default::default(), None).serialize(serializer)
-    }
-}
-
-#[cfg(feature = "serialize")]
-impl<'a, 'lua> SerializableValue<'a, 'lua> {
-    #[inline]
-    pub(crate) fn new(
-        value: &'a Value<'lua>,
-        options: crate::serde::de::Options,
-        visited: Option<&Rc<RefCell<FxHashSet<*const c_void>>>>,
-    ) -> Self {
-        if let Value::Table(_) = value {
-            return Self {
-                value,
-                options,
-                // We need to always initialize the `visited` map for Tables
-                visited: visited.cloned().or_else(|| Some(Default::default())),
-            };
-        }
-        Self {
-            value,
-            options,
-            visited: None,
-        }
-    }
-
-    /// If true, an attempt to serialize types such as [`Function`], [`Thread`], [`LightUserData`]
-    /// and [`Error`] will cause an error.
-    /// Otherwise these types skipped when iterating or serialized as unit type.
-    ///
-    /// Default: **true**
-    #[must_use]
-    pub const fn deny_unsupported_types(mut self, enabled: bool) -> Self {
-        self.options.deny_unsupported_types = enabled;
-        self
-    }
-
-    /// If true, an attempt to serialize a recursive table (table that refers to itself)
-    /// will cause an error.
-    /// Otherwise subsequent attempts to serialize the same table will be ignored.
-    ///
-    /// Default: **true**
-    #[must_use]
-    pub const fn deny_recursive_tables(mut self, enabled: bool) -> Self {
-        self.options.deny_recursive_tables = enabled;
-        self
-    }
-
-    /// If true, keys in tables will be iterated (and serialized) in sorted order.
-    ///
-    /// Default: **false**
-    #[must_use]
-    pub const fn sort_keys(mut self, enabled: bool) -> Self {
-        self.options.sort_keys = enabled;
-        self
-    }
-}
-
-#[cfg(feature = "serialize")]
-impl<'a, 'lua> Serialize for SerializableValue<'a, 'lua> {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where
         S: Serializer,
     {
-        match self.value {
+        match self {
             Value::Nil => serializer.serialize_unit(),
             Value::Boolean(b) => serializer.serialize_bool(*b),
             #[allow(clippy::useless_conversion)]
-            Value::Integer(i) => serializer.serialize_i64((*i).into()),
+            Value::Integer(i) => serializer
+                .serialize_i64((*i).try_into().expect("cannot convert lua_Integer to i64")),
+            #[allow(clippy::useless_conversion)]
             Value::Number(n) => serializer.serialize_f64(*n),
             #[cfg(feature = "luau")]
-            Value::Vector(v) => v.serialize(serializer),
+            Value::Vector(x, y, z) => (x, y, z).serialize(serializer),
             Value::String(s) => s.serialize(serializer),
-            Value::Table(t) => {
-                let visited = self.visited.as_ref().unwrap().clone();
-                SerializableTable::new(t, self.options, visited).serialize(serializer)
-            }
+            Value::Table(t) => t.serialize(serializer),
+            Value::UserData(ud) => ud.serialize(serializer),
             Value::LightUserData(ud) if ud.0.is_null() => serializer.serialize_none(),
-            Value::UserData(ud) if ud.is_serializable() || self.options.deny_unsupported_types => {
-                ud.serialize(serializer)
-            }
-            Value::Function(_)
-            | Value::Thread(_)
-            | Value::UserData(_)
-            | Value::LightUserData(_)
-            | Value::Error(_) => {
-                if self.options.deny_unsupported_types {
-                    let msg = format!("cannot serialize <{}>", self.value.type_name());
-                    Err(ser::Error::custom(msg))
-                } else {
-                    serializer.serialize_unit()
-                }
+            Value::Error(_) | Value::LightUserData(_) | Value::Function(_) | Value::Thread(_) => {
+                let msg = format!("cannot serialize <{}>", self.type_name());
+                Err(ser::Error::custom(msg))
             }
         }
     }
 }
 
 /// Trait for types convertible to `Value`.
-pub trait IntoLua<'lua>: Sized {
+pub trait ToLua<'lua> {
     /// Performs the conversion.
-    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>>;
-
-    /// Pushes the value into the Lua stack.
-    ///
-    /// # Safety
-    /// This method does not check Lua stack space.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
-        lua.push_value(self.into_lua(lua)?)
-    }
+    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>>;
 }
 
 /// Trait for types convertible from `Value`.
 pub trait FromLua<'lua>: Sized {
     /// Performs the conversion.
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self>;
-
-    /// Performs the conversion for an argument (eg. function argument).
-    ///
-    /// `i` is the argument index (position),
-    /// `to` is a function name that received the argument.
-    #[doc(hidden)]
-    #[inline]
-    fn from_lua_arg(arg: Value<'lua>, i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
-        Self::from_lua(arg, lua).map_err(|err| Error::BadArgument {
-            to: to.map(|s| s.to_string()),
-            pos: i,
-            name: None,
-            cause: Arc::new(err),
-        })
-    }
-
-    /// Performs the conversion for a value in the Lua stack at index `idx`.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
-        Self::from_lua(lua.stack_value(idx), lua)
-    }
-
-    /// Same as `from_lua_arg` but for a value in the Lua stack at index `idx`.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn from_stack_arg(
-        idx: c_int,
-        i: usize,
-        to: Option<&str>,
-        lua: &'lua Lua,
-    ) -> Result<Self> {
-        Self::from_stack(idx, lua).map_err(|err| Error::BadArgument {
-            to: to.map(|s| s.to_string()),
-            pos: i,
-            name: None,
-            cause: Arc::new(err),
-        })
-    }
+    fn from_lua(lua_value: Value<'lua>, lua: &'lua Lua) -> Result<Self>;
 }
 
 /// Multiple Lua values used for both argument passing and also for multiple return values.
 #[derive(Debug, Clone)]
-pub struct MultiValue<'lua> {
-    vec: Vec<Value<'lua>>,
-    lua: Option<&'lua Lua>,
-}
-
-impl Drop for MultiValue<'_> {
-    fn drop(&mut self) {
-        if let Some(lua) = self.lua {
-            let vec = mem::take(&mut self.vec);
-            lua.push_multivalue_to_pool(vec);
-        }
-    }
-}
+pub struct MultiValue<'lua>(Vec<Value<'lua>>);
 
 impl<'lua> MultiValue<'lua> {
     /// Creates an empty `MultiValue` containing no values.
     pub const fn new() -> MultiValue<'lua> {
-        MultiValue {
-            vec: Vec::new(),
-            lua: None,
-        }
+        MultiValue(Vec::new())
     }
 
-    /// Similar to `new` but can reuse previously used container with allocated capacity.
+    /// Similar to `new` but can return previously used container with allocated capacity.
     #[inline]
-    pub(crate) fn with_lua_and_capacity(lua: &'lua Lua, capacity: usize) -> MultiValue<'lua> {
-        let vec = lua
-            .pop_multivalue_from_pool()
-            .map(|mut vec| {
-                vec.reserve(capacity);
-                vec
-            })
-            .unwrap_or_else(|| Vec::with_capacity(capacity));
-        MultiValue {
-            vec,
-            lua: Some(lua),
-        }
+    pub(crate) fn new_or_cached(lua: &'lua Lua) -> MultiValue<'lua> {
+        lua.new_or_cached_multivalue()
     }
 }
 
@@ -809,10 +227,8 @@ impl<'lua> IntoIterator for MultiValue<'lua> {
     type IntoIter = iter::Rev<vec::IntoIter<Value<'lua>>>;
 
     #[inline]
-    fn into_iter(mut self) -> Self::IntoIter {
-        let vec = mem::take(&mut self.vec);
-        mem::forget(self);
-        vec.into_iter().rev()
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter().rev()
     }
 }
 
@@ -822,7 +238,7 @@ impl<'a, 'lua> IntoIterator for &'a MultiValue<'lua> {
 
     #[inline]
     fn into_iter(self) -> Self::IntoIter {
-        self.vec.iter().rev()
+        self.0.iter().rev()
     }
 }
 
@@ -845,60 +261,64 @@ impl<'lua> Index<usize> for MultiValue<'lua> {
 
 impl<'lua> MultiValue<'lua> {
     #[inline]
-    pub fn from_vec(mut vec: Vec<Value<'lua>>) -> MultiValue<'lua> {
-        vec.reverse();
-        MultiValue { vec, lua: None }
+    pub fn from_vec(mut v: Vec<Value<'lua>>) -> MultiValue<'lua> {
+        v.reverse();
+        MultiValue(v)
     }
 
     #[inline]
-    pub fn into_vec(mut self) -> Vec<Value<'lua>> {
-        let mut vec = mem::take(&mut self.vec);
-        mem::forget(self);
-        vec.reverse();
-        vec
+    pub fn into_vec(self) -> Vec<Value<'lua>> {
+        let mut v = self.0;
+        v.reverse();
+        v
     }
 
     #[inline]
     pub fn get(&self, index: usize) -> Option<&Value<'lua>> {
-        if index < self.vec.len() {
-            return self.vec.get(self.vec.len() - index - 1);
+        if index < self.0.len() {
+            return self.0.get(self.0.len() - index - 1);
         }
         None
     }
 
+    #[inline]
+    pub(crate) fn reserve(&mut self, size: usize) {
+        self.0.reserve(size);
+    }
+
     #[inline]
     pub fn pop_front(&mut self) -> Option<Value<'lua>> {
-        self.vec.pop()
+        self.0.pop()
     }
 
     #[inline]
     pub fn push_front(&mut self, value: Value<'lua>) {
-        self.vec.push(value);
+        self.0.push(value);
     }
 
     #[inline]
     pub fn clear(&mut self) {
-        self.vec.clear();
+        self.0.clear();
     }
 
     #[inline]
     pub fn len(&self) -> usize {
-        self.vec.len()
+        self.0.len()
     }
 
     #[inline]
     pub fn is_empty(&self) -> bool {
-        self.vec.is_empty()
+        self.0.is_empty()
     }
 
     #[inline]
     pub fn iter(&self) -> iter::Rev<slice::Iter<Value<'lua>>> {
-        self.vec.iter().rev()
+        self.0.iter().rev()
     }
 
     #[inline]
     pub(crate) fn drain_all(&mut self) -> iter::Rev<vec::Drain<Value<'lua>>> {
-        self.vec.drain(..).rev()
+        self.0.drain(..).rev()
     }
 
     #[inline]
@@ -906,39 +326,22 @@ impl<'lua> MultiValue<'lua> {
         &mut self,
         iter: impl IntoIterator<Item = Result<Value<'lua>>>,
     ) -> Result<()> {
-        self.vec.clear();
+        self.0.clear();
         for value in iter {
-            self.vec.push(value?);
+            self.0.push(value?);
         }
-        self.vec.reverse();
+        self.0.reverse();
         Ok(())
     }
 }
 
 /// Trait for types convertible to any number of Lua values.
 ///
-/// This is a generalization of `IntoLua`, allowing any number of resulting Lua values instead of just
-/// one. Any type that implements `IntoLua` will automatically implement this trait.
-pub trait IntoLuaMulti<'lua>: Sized {
+/// This is a generalization of `ToLua`, allowing any number of resulting Lua values instead of just
+/// one. Any type that implements `ToLua` will automatically implement this trait.
+pub trait ToLuaMulti<'lua> {
     /// Performs the conversion.
-    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>>;
-
-    /// Pushes the values into the Lua stack.
-    ///
-    /// Returns number of pushed values.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
-        let mut values = self.into_lua_multi(lua)?;
-        let len: c_int = values.len().try_into().unwrap();
-        unsafe {
-            check_stack(lua.state(), len + 1)?;
-            for v in values.drain_all() {
-                lua.push_value(v)?;
-            }
-        }
-        Ok(len)
-    }
+    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>>;
 }
 
 /// Trait for types that can be created from an arbitrary number of Lua values.
@@ -953,56 +356,4 @@ pub trait FromLuaMulti<'lua>: Sized {
     /// assigning values. Similarly, if not enough values are given, conversions should assume that
     /// any missing values are nil.
     fn from_lua_multi(values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self>;
-
-    /// Performs the conversion for a list of arguments.
-    ///
-    /// `i` is an index (position) of the first argument,
-    /// `to` is a function name that received the arguments.
-    #[doc(hidden)]
-    #[inline]
-    fn from_lua_args(
-        args: MultiValue<'lua>,
-        i: usize,
-        to: Option<&str>,
-        lua: &'lua Lua,
-    ) -> Result<Self> {
-        let _ = (i, to);
-        Self::from_lua_multi(args, lua)
-    }
-
-    /// Performs the conversion for a number of values in the Lua stack.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
-        let mut values = MultiValue::with_lua_and_capacity(lua, nvals as usize);
-        for idx in 1..=nvals {
-            values.push_front(lua.stack_value(-idx));
-        }
-        if nvals > 0 {
-            // It's safe to clear the stack as all references moved to ref thread
-            ffi::lua_pop(lua.state(), nvals);
-        }
-        Self::from_lua_multi(values, lua)
-    }
-
-    /// Same as `from_lua_args` but for a number of values in the Lua stack.
-    #[doc(hidden)]
-    #[inline]
-    unsafe fn from_stack_args(
-        nargs: c_int,
-        i: usize,
-        to: Option<&str>,
-        lua: &'lua Lua,
-    ) -> Result<Self> {
-        let _ = (i, to);
-        Self::from_stack_multi(nargs, lua)
-    }
-}
-
-#[cfg(test)]
-mod assertions {
-    use super::*;
-
-    static_assertions::assert_not_impl_any!(Value: Send);
-    static_assertions::assert_not_impl_any!(MultiValue: Send);
 }

tarpaulin.toml

@@ -1,8 +1,8 @@
 [lua54_coverage]
-features = "lua54,vendored,async,serialize,macros,unstable"
+features = "lua54,vendored,async,serialize,macros"
 
 [lua51_coverage]
-features = "lua51,vendored,async,serialize,macros,unstable"
+features = "lua51,vendored,async,serialize,macros"
 
 [luau_coverage]
-features = "luau,async,serialize,macros,unstable"
+features = "luau,async,serialize,macros"

tests/async.rs

@@ -1,26 +1,21 @@
 #![cfg(feature = "async")]
 
-use std::sync::{Arc, Mutex};
+use std::cell::Cell;
+use std::rc::Rc;
+use std::sync::{
+    atomic::{AtomicI64, AtomicU64, Ordering},
+    Arc,
+};
 use std::time::Duration;
 
+use futures_timer::Delay;
 use futures_util::stream::TryStreamExt;
 
 use mlua::{
-    AnyUserDataExt, Error, Function, Lua, LuaOptions, MultiValue, Result, StdLib, Table, TableExt,
-    UserData, UserDataMethods, Value,
+    Error, Function, Lua, LuaOptions, Result, StdLib, Table, TableExt, Thread, UserData,
+    UserDataMethods, Value,
 };
 
-#[cfg(not(target_arch = "wasm32"))]
-async fn sleep_ms(ms: u64) {
-    tokio::time::sleep(Duration::from_millis(ms)).await;
-}
-
-#[cfg(target_arch = "wasm32")]
-async fn sleep_ms(_ms: u64) {
-    // I was unable to make sleep() work in wasm32-emscripten target
-    tokio::task::yield_now().await;
-}
-
 #[tokio::test]
 async fn test_async_function() -> Result<()> {
     let lua = Lua::new();
@@ -35,25 +30,12 @@ async fn test_async_function() -> Result<()> {
     Ok(())
 }
 
-#[tokio::test]
-async fn test_async_function_wrap() -> Result<()> {
-    let lua = Lua::new();
-
-    let f = Function::wrap_async(|_, s: String| async move { Ok(s) });
-    lua.globals().set("f", f)?;
-
-    let res: String = lua.load(r#"f("hello")"#).eval_async().await?;
-    assert_eq!(res, "hello");
-
-    Ok(())
-}
-
 #[tokio::test]
 async fn test_async_sleep() -> Result<()> {
     let lua = Lua::new();
 
     let sleep = lua.create_async_function(move |_lua, n: u64| async move {
-        sleep_ms(n).await;
+        Delay::new(Duration::from_millis(n)).await;
         Ok(format!("elapsed:{}ms", n))
     })?;
     lua.globals().set("sleep", sleep)?;
@@ -69,7 +51,7 @@ async fn test_async_call() -> Result<()> {
     let lua = Lua::new();
 
     let hello = lua.create_async_function(|_lua, name: String| async move {
-        sleep_ms(10).await;
+        Delay::new(Duration::from_millis(10)).await;
         Ok(format!("hello, {}!", name))
     })?;
 
@@ -89,25 +71,6 @@ async fn test_async_call() -> Result<()> {
     Ok(())
 }
 
-#[tokio::test]
-async fn test_async_call_many_returns() -> Result<()> {
-    let lua = Lua::new();
-
-    let hello = lua.create_async_function(|_lua, ()| async move {
-        sleep_ms(10).await;
-        Ok(("a", "b", "c", 1))
-    })?;
-
-    let vals = hello.call_async::<_, MultiValue>(()).await?;
-    assert_eq!(vals.len(), 4);
-    assert_eq!(vals[0].to_string()?, "a");
-    assert_eq!(vals[1].to_string()?, "b");
-    assert_eq!(vals[2].to_string()?, "c");
-    assert_eq!(vals[3], Value::Integer(1));
-
-    Ok(())
-}
-
 #[tokio::test]
 async fn test_async_bind_call() -> Result<()> {
     let lua = Lua::new();
@@ -131,7 +94,7 @@ async fn test_async_handle_yield() -> Result<()> {
     let lua = Lua::new();
 
     let sum = lua.create_async_function(|_lua, (a, b): (i64, i64)| async move {
-        sleep_ms(10).await;
+        Delay::new(Duration::from_millis(10)).await;
         Ok(a + b)
     })?;
 
@@ -189,10 +152,10 @@ async fn test_async_return_async_closure() -> Result<()> {
     let lua = Lua::new();
 
     let f = lua.create_async_function(|lua, a: i64| async move {
-        sleep_ms(10).await;
+        Delay::new(Duration::from_millis(10)).await;
 
         let g = lua.create_async_function(move |_, b: i64| async move {
-            sleep_ms(10).await;
+            Delay::new(Duration::from_millis(10)).await;
             return Ok(a + b);
         })?;
 
@@ -282,7 +245,7 @@ async fn test_async_thread() -> Result<()> {
     let f = lua.create_async_function(move |_lua, ()| {
         let cnt3 = cnt2.clone();
         async move {
-            sleep_ms(*cnt3.as_ref()).await;
+            Delay::new(Duration::from_millis(*cnt3.as_ref())).await;
             Ok("done")
         }
     })?;
@@ -298,61 +261,49 @@ async fn test_async_thread() -> Result<()> {
     Ok(())
 }
 
-#[test]
-fn test_async_thread_capture() -> Result<()> {
-    let lua = Lua::new();
-
-    let f = lua.create_async_function(move |_lua, v: Value| async move {
-        tokio::task::yield_now().await;
-        drop(v);
-        Ok(())
-    })?;
-
-    let thread = lua.create_thread(f)?;
-    // After first resume, `v: Value` is captured in the coroutine
-    thread.resume::<_, ()>("abc").unwrap();
-    drop(thread);
-
-    Ok(())
-}
-
 #[tokio::test]
 async fn test_async_table() -> Result<()> {
-    let options = LuaOptions::new().thread_pool_size(4);
+    let options = LuaOptions::new().thread_cache_size(4);
     let lua = Lua::new_with(StdLib::ALL_SAFE, options)?;
 
     let table = lua.create_table()?;
     table.set("val", 10)?;
 
     let get_value = lua.create_async_function(|_, table: Table| async move {
-        sleep_ms(10).await;
+        Delay::new(Duration::from_millis(10)).await;
         table.get::<_, i64>("val")
     })?;
     table.set("get_value", get_value)?;
 
     let set_value = lua.create_async_function(|_, (table, n): (Table, i64)| async move {
-        sleep_ms(10).await;
+        Delay::new(Duration::from_millis(10)).await;
         table.set("val", n)
     })?;
     table.set("set_value", set_value)?;
 
     let sleep = lua.create_async_function(|_, n| async move {
-        sleep_ms(n).await;
+        Delay::new(Duration::from_millis(n)).await;
         Ok(format!("elapsed:{}ms", n))
     })?;
     table.set("sleep", sleep)?;
 
     assert_eq!(
-        table.call_async_method::<_, i64>("get_value", ()).await?,
+        table
+            .call_async_method::<_, _, i64>("get_value", ())
+            .await?,
         10
     );
     table.call_async_method("set_value", 15).await?;
     assert_eq!(
-        table.call_async_method::<_, i64>("get_value", ()).await?,
+        table
+            .call_async_method::<_, _, i64>("get_value", ())
+            .await?,
         15
     );
     assert_eq!(
-        table.call_async_function::<_, String>("sleep", 7).await?,
+        table
+            .call_async_function::<_, _, String>("sleep", 7)
+            .await?,
         "elapsed:7ms"
     );
 
@@ -360,17 +311,17 @@ async fn test_async_table() -> Result<()> {
 }
 
 #[tokio::test]
-async fn test_async_thread_pool() -> Result<()> {
-    let options = LuaOptions::new().thread_pool_size(4);
+async fn test_async_thread_cache() -> Result<()> {
+    let options = LuaOptions::new().thread_cache_size(4);
     let lua = Lua::new_with(StdLib::ALL_SAFE, options)?;
 
     let error_f = lua.create_async_function(|_, ()| async move {
-        sleep_ms(10).await;
-        Err::<(), _>(Error::runtime("test"))
+        Delay::new(Duration::from_millis(10)).await;
+        Err::<(), _>(Error::RuntimeError("test".to_string()))
     })?;
 
     let sleep = lua.create_async_function(|_, n| async move {
-        sleep_ms(n).await;
+        Delay::new(Duration::from_millis(n)).await;
         Ok(format!("elapsed:{}ms", n))
     })?;
 
@@ -383,30 +334,31 @@ async fn test_async_thread_pool() -> Result<()> {
 
 #[tokio::test]
 async fn test_async_userdata() -> Result<()> {
-    struct MyUserData(u64);
+    #[derive(Clone)]
+    struct MyUserData(Arc<AtomicU64>);
 
     impl UserData for MyUserData {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
             methods.add_async_method("get_value", |_, data, ()| async move {
-                sleep_ms(10).await;
-                Ok(data.0)
+                Delay::new(Duration::from_millis(10)).await;
+                Ok(data.0.load(Ordering::Relaxed))
             });
 
-            methods.add_async_method_mut("set_value", |_, data, n| async move {
-                sleep_ms(10).await;
-                data.0 = n;
+            methods.add_async_method("set_value", |_, data, n| async move {
+                Delay::new(Duration::from_millis(10)).await;
+                data.0.store(n, Ordering::Relaxed);
                 Ok(())
             });
 
             methods.add_async_function("sleep", |_, n| async move {
-                sleep_ms(n).await;
+                Delay::new(Duration::from_millis(n)).await;
                 Ok(format!("elapsed:{}ms", n))
             });
 
             #[cfg(not(any(feature = "lua51", feature = "luau")))]
             methods.add_async_meta_method(mlua::MetaMethod::Call, |_, data, ()| async move {
-                let n = data.0;
-                sleep_ms(n).await;
+                let n = data.0.load(Ordering::Relaxed);
+                Delay::new(Duration::from_millis(n)).await;
                 Ok(format!("elapsed:{}ms", n))
             });
 
@@ -414,26 +366,25 @@ async fn test_async_userdata() -> Result<()> {
             methods.add_async_meta_method(
                 mlua::MetaMethod::Index,
                 |_, data, key: String| async move {
-                    sleep_ms(10).await;
+                    Delay::new(Duration::from_millis(10)).await;
                     match key.as_str() {
-                        "ms" => Ok(Some(data.0 as f64)),
-                        "s" => Ok(Some((data.0 as f64) / 1000.0)),
+                        "ms" => Ok(Some(data.0.load(Ordering::Relaxed) as f64)),
+                        "s" => Ok(Some((data.0.load(Ordering::Relaxed) as f64) / 1000.0)),
                         _ => Ok(None),
                     }
                 },
             );
 
             #[cfg(not(any(feature = "lua51", feature = "luau")))]
-            methods.add_async_meta_method_mut(
+            methods.add_async_meta_method(
                 mlua::MetaMethod::NewIndex,
                 |_, data, (key, value): (String, f64)| async move {
-                    sleep_ms(10).await;
+                    Delay::new(Duration::from_millis(10)).await;
                     match key.as_str() {
-                        "ms" => data.0 = value as u64,
-                        "s" => data.0 = (value * 1000.0) as u64,
-                        _ => return Err(Error::external(format!("key '{}' not found", key))),
+                        "ms" => Ok(data.0.store(value as u64, Ordering::Relaxed)),
+                        "s" => Ok(data.0.store((value * 1000.0) as u64, Ordering::Relaxed)),
+                        _ => Err(Error::external(format!("key '{}' not found", key))),
                     }
-                    Ok(())
                 },
             );
         }
@@ -442,8 +393,8 @@ async fn test_async_userdata() -> Result<()> {
     let lua = Lua::new();
     let globals = lua.globals();
 
-    let userdata = lua.create_userdata(MyUserData(11))?;
-    globals.set("userdata", &userdata)?;
+    let userdata = lua.create_userdata(MyUserData(Arc::new(AtomicU64::new(11))))?;
+    globals.set("userdata", userdata.clone())?;
 
     lua.load(
         r#"
@@ -472,14 +423,6 @@ async fn test_async_userdata() -> Result<()> {
     .exec_async()
     .await?;
 
-    userdata.call_async_method("set_value", 24).await?;
-    let n: u64 = userdata.call_async_method("get_value", ()).await?;
-    assert_eq!(n, 24);
-    userdata.call_async_function("sleep", 15).await?;
-
-    #[cfg(not(any(feature = "lua51", feature = "luau")))]
-    assert_eq!(userdata.call_async::<_, String>(()).await?, "elapsed:24ms");
-
     Ok(())
 }
 
@@ -496,7 +439,7 @@ async fn test_async_thread_error() -> Result<()> {
     let lua = Lua::new();
     let result = lua
         .load("function x(...) error(...) end x(...)")
-        .set_name("chunk")
+        .set_name("chunk")?
         .call_async::<_, ()>(MyUserData)
         .await;
     assert!(
@@ -507,42 +450,120 @@ async fn test_async_thread_error() -> Result<()> {
     Ok(())
 }
 
-#[cfg(all(feature = "unstable", not(feature = "send")))]
 #[tokio::test]
-async fn test_owned_async_call() -> Result<()> {
-    let lua = Lua::new();
+async fn test_async_scope() -> Result<()> {
+    let ref lua = Lua::new();
 
-    let hello = lua
-        .create_async_function(|_, name: String| async move {
-            sleep_ms(10).await;
-            Ok(format!("hello, {}!", name))
-        })?
-        .into_owned();
-    drop(lua);
+    let ref rc = Rc::new(Cell::new(0));
 
-    assert_eq!(hello.call_async::<_, String>("alex").await?, "hello, alex!");
+    let fut = lua.async_scope(|scope| async move {
+        let f = scope.create_async_function(move |_, n: u64| {
+            let rc2 = rc.clone();
+            async move {
+                rc2.set(42);
+                Delay::new(Duration::from_millis(n)).await;
+                assert_eq!(Rc::strong_count(&rc2), 2);
+                Ok(())
+            }
+        })?;
+
+        lua.globals().set("f", f.clone())?;
+
+        assert_eq!(Rc::strong_count(rc), 1);
+        let _ = f.call_async::<u64, ()>(10).await?;
+        assert_eq!(Rc::strong_count(rc), 1);
+
+        // Create future in partialy polled state (Poll::Pending)
+        let g = lua.create_thread(f)?;
+        g.resume::<u64, ()>(10)?;
+        lua.globals().set("g", g)?;
+        assert_eq!(Rc::strong_count(rc), 2);
+
+        Ok(())
+    });
+
+    assert_eq!(Rc::strong_count(rc), 1);
+    let _ = fut.await?;
+    assert_eq!(Rc::strong_count(rc), 1);
+
+    match lua
+        .globals()
+        .get::<_, Function>("f")?
+        .call_async::<_, ()>(10)
+        .await
+    {
+        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
+            Error::CallbackDestructed => {}
+            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
+        },
+        r => panic!("improper return for destructed function: {:?}", r),
+    };
+
+    match lua.globals().get::<_, Thread>("g")?.resume::<_, Value>(()) {
+        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
+            Error::CallbackDestructed => {}
+            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
+        },
+        r => panic!("improper return for destructed function: {:?}", r),
+    };
 
     Ok(())
 }
 
 #[tokio::test]
-async fn test_async_terminate() -> Result<()> {
-    let lua = Lua::new();
+async fn test_async_scope_userdata() -> Result<()> {
+    #[derive(Clone)]
+    struct MyUserData(Arc<AtomicI64>);
 
-    let mutex = Arc::new(Mutex::new(0u32));
-    let mutex2 = mutex.clone();
-    let func = lua.create_async_function(move |_, ()| {
-        let mutex = mutex2.clone();
-        async move {
-            let _guard = mutex.lock();
-            sleep_ms(100).await;
-            Ok(())
+    impl UserData for MyUserData {
+        fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+            methods.add_async_method("get_value", |_, data, ()| async move {
+                Delay::new(Duration::from_millis(10)).await;
+                Ok(data.0.load(Ordering::Relaxed))
+            });
+
+            methods.add_async_method("set_value", |_, data, n| async move {
+                Delay::new(Duration::from_millis(10)).await;
+                data.0.store(n, Ordering::Relaxed);
+                Ok(())
+            });
+
+            methods.add_async_function("sleep", |_, n| async move {
+                Delay::new(Duration::from_millis(n)).await;
+                Ok(format!("elapsed:{}ms", n))
+            });
         }
-    })?;
+    }
 
-    let _ = tokio::time::timeout(Duration::from_millis(30), func.call_async::<_, ()>(())).await;
-    lua.gc_collect()?;
-    assert!(mutex.try_lock().is_ok());
+    let ref lua = Lua::new();
+
+    let ref arc = Arc::new(AtomicI64::new(11));
+
+    lua.async_scope(|scope| async move {
+        let ud = scope.create_userdata(MyUserData(arc.clone()))?;
+        lua.globals().set("userdata", ud)?;
+        lua.load(
+            r#"
+            assert(userdata:get_value() == 11)
+            userdata:set_value(12)
+            assert(userdata.sleep(5) == "elapsed:5ms")
+            assert(userdata:get_value() == 12)
+        "#,
+        )
+        .exec_async()
+        .await
+    })
+    .await?;
+
+    assert_eq!(Arc::strong_count(arc), 1);
+
+    match lua.load("userdata:get_value()").exec_async().await {
+        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
+            Error::CallbackDestructed => {}
+            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
+        },
+        r => panic!("improper return for destructed userdata: {:?}", r),
+    };
 
     Ok(())
 }

tests/chunk.rs

@@ -1,18 +1,12 @@
 use std::fs;
 use std::io;
 
-use mlua::{Lua, Result};
+use mlua::{Error, Lua, Result};
 
 #[test]
 fn test_chunk_path() -> Result<()> {
     let lua = Lua::new();
 
-    if cfg!(target_arch = "wasm32") {
-        // TODO: figure out why emscripten fails on file operations
-        // Also see https://github.com/rust-lang/rust/issues/119250
-        return Ok(());
-    }
-
     let temp_dir = tempfile::tempdir().unwrap();
     fs::write(
         temp_dir.path().join("module.lua"),
@@ -20,11 +14,12 @@ fn test_chunk_path() -> Result<()> {
         return 321
     "#,
     )?;
-    let i: i32 = lua.load(&*temp_dir.path().join("module.lua")).eval()?;
+    let i: i32 = lua.load(&temp_dir.path().join("module.lua")).eval()?;
     assert_eq!(i, 321);
 
-    match lua.load(&*temp_dir.path().join("module2.lua")).exec() {
-        Err(err) if err.downcast_ref::<io::Error>().unwrap().kind() == io::ErrorKind::NotFound => {}
+    match lua.load(&temp_dir.path().join("module2.lua")).exec() {
+        Err(Error::ExternalError(err))
+            if err.downcast_ref::<io::Error>().unwrap().kind() == io::ErrorKind::NotFound => {}
         res => panic!("expected io::Error, got {:?}", res),
     };
 
@@ -42,24 +37,12 @@ fn test_chunk_macro() -> Result<()> {
     let data = lua.create_table()?;
     data.raw_set("num", 1)?;
 
-    let ud = mlua::AnyUserData::wrap("hello");
-    let f = mlua::Function::wrap(|_lua, ()| Ok(()));
-
     lua.globals().set("g", 123)?;
 
-    let string = String::new();
-    let str = string.as_str();
-
     lua.load(mlua::chunk! {
         assert($name == "Rustacean")
-        assert(type($table) == "table")
         assert($table[1] == 1)
-        assert(type($data) == "table")
         assert($data.num == 1)
-        assert(type($ud) == "userdata")
-        assert(type($f) == "function")
-        assert(type($str) == "string")
-        assert($str == "")
         assert(g == 123)
         s = 321
     })

tests/compile.rs

@@ -15,11 +15,7 @@ fn test_compilation() {
     t.compile_fail("tests/compile/static_callback_args.rs");
 
     #[cfg(feature = "async")]
-    {
-        t.compile_fail("tests/compile/async_any_userdata_method.rs");
-        t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
-        t.compile_fail("tests/compile/async_userdata_method.rs");
-    }
+    t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
 
     #[cfg(feature = "send")]
     t.compile_fail("tests/compile/non_send.rs");

tests/compile/async_any_userdata_method.rs

@@ -1,14 +0,0 @@
-use mlua::{UserDataMethods, Lua};
-
-fn main() {
-    let lua = Lua::new();
-
-    lua.register_userdata_type::<String>(|reg| {
-        let s = String::new();
-        let mut s = &s;
-        reg.add_async_method("t", |_, this: &String, ()| async {
-            s = this;
-            Ok(())
-        });
-    }).unwrap();
-}

tests/compile/async_any_userdata_method.stderr

@@ -1,83 +0,0 @@
-error: lifetime may not live long enough
-  --> tests/compile/async_any_userdata_method.rs:9:58
-   |
-9  |           reg.add_async_method("t", |_, this: &String, ()| async {
-   |  ___________________________________----------------------_^
-   | |                                   |                    |
-   | |                                   |                    return type of closure `{async block@$DIR/tests/compile/async_any_userdata_method.rs:9:58: 12:10}` contains a lifetime `'2`
-   | |                                   lifetime `'1` represents this closure's body
-10 | |             s = this;
-11 | |             Ok(())
-12 | |         });
-   | |_________^ returning this value requires that `'1` must outlive `'2`
-   |
-   = note: closure implements `Fn`, so references to captured variables can't escape the closure
-
-error[E0596]: cannot borrow `s` as mutable, as it is a captured variable in a `Fn` closure
-  --> tests/compile/async_any_userdata_method.rs:9:58
-   |
-9  |           reg.add_async_method("t", |_, this: &String, ()| async {
-   |  __________________________________________________________^
-10 | |             s = this;
-   | |             - mutable borrow occurs due to use of `s` in closure
-11 | |             Ok(())
-12 | |         });
-   | |_________^ cannot borrow as mutable
-
-error[E0597]: `s` does not live long enough
-  --> tests/compile/async_any_userdata_method.rs:8:21
-   |
-7  |           let s = String::new();
-   |               - binding `s` declared here
-8  |           let mut s = &s;
-   |                       ^^ borrowed value does not live long enough
-9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
-10 | |             s = this;
-11 | |             Ok(())
-12 | |         });
-   | |__________- argument requires that `s` is borrowed for `'static`
-13 |       }).unwrap();
-   |       - `s` dropped here while still borrowed
-
-error[E0521]: borrowed data escapes outside of closure
-  --> tests/compile/async_any_userdata_method.rs:9:9
-   |
-6  |       lua.register_userdata_type::<String>(|reg| {
-   |                                             ---
-   |                                             |
-   |                                             `reg` is a reference that is only valid in the closure body
-   |                                             has type `&mut LuaUserDataRegistry<'1, std::string::String>`
-...
-9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
-10 | |             s = this;
-11 | |             Ok(())
-12 | |         });
-   | |          ^
-   | |          |
-   | |__________`reg` escapes the closure body here
-   |            argument requires that `'1` must outlive `'static`
-   |
-   = note: requirement occurs because of a mutable reference to `LuaUserDataRegistry<'_, std::string::String>`
-   = note: mutable references are invariant over their type parameter
-   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
-
-error[E0373]: closure may outlive the current function, but it borrows `s`, which is owned by the current function
-  --> tests/compile/async_any_userdata_method.rs:9:35
-   |
-9  |         reg.add_async_method("t", |_, this: &String, ()| async {
-   |                                   ^^^^^^^^^^^^^^^^^^^^^^ may outlive borrowed value `s`
-10 |             s = this;
-   |             - `s` is borrowed here
-   |
-note: function requires argument type to outlive `'static`
-  --> tests/compile/async_any_userdata_method.rs:9:9
-   |
-9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
-10 | |             s = this;
-11 | |             Ok(())
-12 | |         });
-   | |__________^
-help: to force the closure to take ownership of `s` (and any other referenced variables), use the `move` keyword
-   |
-9  |         reg.add_async_method("t", move |_, this: &String, ()| async {
-   |                                   ++++

tests/compile/async_nonstatic_userdata.stderr

@@ -4,8 +4,11 @@ error: lifetime may not live long enough
 7  |       impl<'a> UserData for MyUserData<'a> {
    |            -- lifetime `'a` defined here
 8  |           fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+   |                          ---- lifetime `'lua` defined here
 9  | /             methods.add_async_method("print", |_, data, ()| async move {
 10 | |                 println!("{}", data.0);
 11 | |                 Ok(())
 12 | |             });
-   | |______________^ requires that `'a` must outlive `'static`
+   | |______________^ argument requires that `'a` must outlive `'lua`
+   |
+   = help: consider adding the following bound: `'a: 'lua`

tests/compile/async_userdata_method.rs

@@ -1,14 +0,0 @@
-use mlua::{UserData, UserDataMethods};
-
-struct MyUserData;
-
-impl UserData for MyUserData {
-    fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        methods.add_async_method("method", |_, this: &'static Self, ()| async {
-            Ok(())
-        });
-        // ^ lifetime may not live long enough
-    }
-}
-
-fn main() {}

tests/compile/async_userdata_method.stderr

@@ -1,17 +0,0 @@
-warning: unused variable: `this`
- --> tests/compile/async_userdata_method.rs:7:48
-  |
-7 |         methods.add_async_method("method", |_, this: &'static Self, ()| async {
-  |                                                ^^^^ help: if this is intentional, prefix it with an underscore: `_this`
-  |
-  = note: `#[warn(unused_variables)]` on by default
-
-error: lifetime may not live long enough
- --> tests/compile/async_userdata_method.rs:7:9
-  |
-6 |       fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-  |                      ---- lifetime `'lua` defined here
-7 | /         methods.add_async_method("method", |_, this: &'static Self, ()| async {
-8 | |             Ok(())
-9 | |         });
-  | |__________^ argument requires that `'lua` must outlive `'static`

tests/compile/lua_norefunwindsafe.stderr

@@ -1,60 +1,22 @@
-error[E0277]: the type `UnsafeCell<mlua::lua::ExtraData>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
- --> tests/compile/lua_norefunwindsafe.rs:7:18
-  |
-7 |     catch_unwind(|| lua.create_table().unwrap());
-  |     ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<mlua::lua::ExtraData>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  |     |
-  |     required by a bound introduced by this call
-  |
-  = help: within `Lua`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<mlua::lua::ExtraData>`
-note: required because it appears within the type `ArcInner<UnsafeCell<ExtraData>>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | struct ArcInner<T: ?Sized> {
-  |        ^^^^^^^^
-note: required because it appears within the type `PhantomData<ArcInner<UnsafeCell<ExtraData>>>`
- --> $RUST/core/src/marker.rs
-  |
-  | pub struct PhantomData<T: ?Sized>;
-  |            ^^^^^^^^^^^
-note: required because it appears within the type `Arc<UnsafeCell<ExtraData>>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | pub struct Arc<
-  |            ^^^
-note: required because it appears within the type `LuaInner`
- --> src/lua.rs
-  |
-  | pub struct LuaInner {
-  |            ^^^^^^^^
-note: required because it appears within the type `ArcInner<LuaInner>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | struct ArcInner<T: ?Sized> {
-  |        ^^^^^^^^
-note: required because it appears within the type `PhantomData<ArcInner<LuaInner>>`
- --> $RUST/core/src/marker.rs
-  |
-  | pub struct PhantomData<T: ?Sized>;
-  |            ^^^^^^^^^^^
-note: required because it appears within the type `Arc<LuaInner>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | pub struct Arc<
-  |            ^^^
-note: required because it appears within the type `Lua`
- --> src/lua.rs
-  |
-  | pub struct Lua(Arc<LuaInner>);
-  |            ^^^
-  = note: required for `&Lua` to implement `UnwindSafe`
+error[E0277]: the type `UnsafeCell<mlua::lua::LuaInner>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   --> tests/compile/lua_norefunwindsafe.rs:7:5
+    |
+7   |     catch_unwind(|| lua.create_table().unwrap());
+    |     ^^^^^^^^^^^^ `UnsafeCell<mlua::lua::LuaInner>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+    |
+    = help: within `Lua`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<mlua::lua::LuaInner>`
+    = note: required because it appears within the type `alloc::sync::ArcInner<UnsafeCell<mlua::lua::LuaInner>>`
+    = note: required because it appears within the type `PhantomData<alloc::sync::ArcInner<UnsafeCell<mlua::lua::LuaInner>>>`
+    = note: required because it appears within the type `Arc<UnsafeCell<mlua::lua::LuaInner>>`
+    = note: required because it appears within the type `Lua`
+    = note: required because of the requirements on the impl of `UnwindSafe` for `&Lua`
 note: required because it's used within this closure
- --> tests/compile/lua_norefunwindsafe.rs:7:18
-  |
-7 |     catch_unwind(|| lua.create_table().unwrap());
-  |                  ^^
+   --> tests/compile/lua_norefunwindsafe.rs:7:18
+    |
+7   |     catch_unwind(|| lua.create_table().unwrap());
+    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `catch_unwind`
- --> $RUST/std/src/panic.rs
-  |
-  | pub fn catch_unwind<F: FnOnce() -> R + UnwindSafe, R>(f: F) -> Result<R> {
-  |                                        ^^^^^^^^^^ required by this bound in `catch_unwind`
+   --> $RUST/std/src/panic.rs
+    |
+    | pub fn catch_unwind<F: FnOnce() -> R + UnwindSafe, R>(f: F) -> Result<R> {
+    |                                        ^^^^^^^^^^ required by this bound in `catch_unwind`

tests/compile/non_send.stderr

@@ -1,28 +1,26 @@
 error[E0277]: `Rc<Cell<i32>>` cannot be sent between threads safely
-  --> tests/compile/non_send.rs:11:25
-   |
-11 |       lua.create_function(move |_, ()| {
-   |           --------------- ^-----------
-   |           |               |
-   |  _________|_______________within this `{closure@$DIR/tests/compile/non_send.rs:11:25: 11:37}`
-   | |         |
-   | |         required by a bound introduced by this call
-12 | |         Ok(data.get())
-13 | |     })?
-   | |_____^ `Rc<Cell<i32>>` cannot be sent between threads safely
-   |
-   = help: within `{closure@$DIR/tests/compile/non_send.rs:11:25: 11:37}`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
+    --> tests/compile/non_send.rs:11:9
+     |
+11   |       lua.create_function(move |_, ()| {
+     |  _________^^^^^^^^^^^^^^^_-
+     | |         |
+     | |         `Rc<Cell<i32>>` cannot be sent between threads safely
+12   | |         Ok(data.get())
+13   | |     })?
+     | |_____- within this `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`
+     |
+     = help: within `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
 note: required because it's used within this closure
-  --> tests/compile/non_send.rs:11:25
-   |
-11 |     lua.create_function(move |_, ()| {
-   |                         ^^^^^^^^^^^^
-   = note: required for `{closure@$DIR/tests/compile/non_send.rs:11:25: 11:37}` to implement `mlua::types::MaybeSend`
+    --> tests/compile/non_send.rs:11:25
+     |
+11   |       lua.create_function(move |_, ()| {
+     |  _________________________^
+12   | |         Ok(data.get())
+13   | |     })?
+     | |_____^
+     = note: required because of the requirements on the impl of `mlua::types::MaybeSend` for `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`
 note: required by a bound in `Lua::create_function`
-  --> src/lua.rs
-   |
-   |     pub fn create_function<'lua, A, R, F>(&'lua self, func: F) -> Result<Function<'lua>>
-   |            --------------- required by a bound in this associated function
-...
-   |         F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
-   |                                            ^^^^^^^^^ required by this bound in `Lua::create_function`
+    --> src/lua.rs
+     |
+     |         F: 'static + MaybeSend + Fn(&'lua Lua, A) -> Result<R>,
+     |                      ^^^^^^^^^ required by this bound in `Lua::create_function`

tests/compile/ref_nounwindsafe.stderr

@@ -1,70 +1,24 @@
-error[E0277]: the type `UnsafeCell<mlua::lua::ExtraData>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
- --> tests/compile/ref_nounwindsafe.rs:8:18
-  |
-8 |     catch_unwind(move || table.set("a", "b").unwrap());
-  |     ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<mlua::lua::ExtraData>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  |     |
-  |     required by a bound introduced by this call
-  |
-  = help: within `Lua`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<mlua::lua::ExtraData>`
-note: required because it appears within the type `ArcInner<UnsafeCell<ExtraData>>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | struct ArcInner<T: ?Sized> {
-  |        ^^^^^^^^
-note: required because it appears within the type `PhantomData<ArcInner<UnsafeCell<ExtraData>>>`
- --> $RUST/core/src/marker.rs
-  |
-  | pub struct PhantomData<T: ?Sized>;
-  |            ^^^^^^^^^^^
-note: required because it appears within the type `Arc<UnsafeCell<ExtraData>>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | pub struct Arc<
-  |            ^^^
-note: required because it appears within the type `LuaInner`
- --> src/lua.rs
-  |
-  | pub struct LuaInner {
-  |            ^^^^^^^^
-note: required because it appears within the type `ArcInner<LuaInner>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | struct ArcInner<T: ?Sized> {
-  |        ^^^^^^^^
-note: required because it appears within the type `PhantomData<ArcInner<LuaInner>>`
- --> $RUST/core/src/marker.rs
-  |
-  | pub struct PhantomData<T: ?Sized>;
-  |            ^^^^^^^^^^^
-note: required because it appears within the type `Arc<LuaInner>`
- --> $RUST/alloc/src/sync.rs
-  |
-  | pub struct Arc<
-  |            ^^^
-note: required because it appears within the type `Lua`
- --> src/lua.rs
-  |
-  | pub struct Lua(Arc<LuaInner>);
-  |            ^^^
-  = note: required for `&Lua` to implement `UnwindSafe`
-note: required because it appears within the type `LuaRef<'_>`
- --> src/types.rs
-  |
-  | pub(crate) struct LuaRef<'lua> {
-  |                   ^^^^^^
-note: required because it appears within the type `Table<'_>`
- --> src/table.rs
-  |
-  | pub struct Table<'lua>(pub(crate) LuaRef<'lua>);
-  |            ^^^^^
+error[E0277]: the type `UnsafeCell<mlua::lua::LuaInner>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   --> tests/compile/ref_nounwindsafe.rs:8:5
+    |
+8   |     catch_unwind(move || table.set("a", "b").unwrap());
+    |     ^^^^^^^^^^^^ `UnsafeCell<mlua::lua::LuaInner>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+    |
+    = help: within `Lua`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<mlua::lua::LuaInner>`
+    = note: required because it appears within the type `alloc::sync::ArcInner<UnsafeCell<mlua::lua::LuaInner>>`
+    = note: required because it appears within the type `PhantomData<alloc::sync::ArcInner<UnsafeCell<mlua::lua::LuaInner>>>`
+    = note: required because it appears within the type `Arc<UnsafeCell<mlua::lua::LuaInner>>`
+    = note: required because it appears within the type `Lua`
+    = note: required because of the requirements on the impl of `UnwindSafe` for `&Lua`
+    = note: required because it appears within the type `mlua::types::LuaRef<'_>`
+    = note: required because it appears within the type `LuaTable<'_>`
 note: required because it's used within this closure
- --> tests/compile/ref_nounwindsafe.rs:8:18
-  |
-8 |     catch_unwind(move || table.set("a", "b").unwrap());
-  |                  ^^^^^^^
+   --> tests/compile/ref_nounwindsafe.rs:8:18
+    |
+8   |     catch_unwind(move || table.set("a", "b").unwrap());
+    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `catch_unwind`
- --> $RUST/std/src/panic.rs
-  |
-  | pub fn catch_unwind<F: FnOnce() -> R + UnwindSafe, R>(f: F) -> Result<R> {
-  |                                        ^^^^^^^^^^ required by this bound in `catch_unwind`
+   --> $RUST/std/src/panic.rs
+    |
+    | pub fn catch_unwind<F: FnOnce() -> R + UnwindSafe, R>(f: F) -> Result<R> {
+    |                                        ^^^^^^^^^^ required by this bound in `catch_unwind`

tests/compile/scope_userdata_borrow.stderr

@@ -4,8 +4,6 @@ error[E0597]: `ibad` does not live long enough
 11 |     lua.scope(|scope| {
    |                ----- has type `&mlua::Scope<'_, '1>`
 ...
-14 |             let ibad = 42;
-   |                 ---- binding `ibad` declared here
 15 |             scope.create_nonstatic_userdata(MyUserData(&ibad)).unwrap();
    |             -------------------------------------------^^^^^--
    |             |                                          |