v0.11.4

This option would allow detecting mixed tables (with array-like and map-like entries or several borders)
to encoding them chosing the best method (as a map or as a table).

.github/workflows/main.yml

@@ -27,8 +27,8 @@ jobs:
       - name: Build ${{ matrix.lua }} vendored
         run: |
           cargo build --features "${{ matrix.lua }},vendored"
-          cargo build --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers"
-          cargo build --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers,send"
+          cargo build --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers"
+          cargo build --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers,send"
         shell: bash
       - name: Build ${{ matrix.lua }} pkg-config
         if: ${{ matrix.os == 'ubuntu-latest' }}
@@ -51,7 +51,7 @@ jobs:
           toolchain: stable
           target: aarch64-apple-darwin
       - name: Cross-compile
-        run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+        run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serde,macros,anyhow,userdata-wrappers"
 
   build_aarch64_cross_ubuntu:
     name: Cross-compile to aarch64-unknown-linux-gnu
@@ -72,7 +72,7 @@ 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 "${{ matrix.lua }},vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+        run: cargo build --target aarch64-unknown-linux-gnu --features "${{ matrix.lua }},vendored,async,send,serde,macros,anyhow,userdata-wrappers"
         shell: bash
 
   build_armv7_cross_ubuntu:
@@ -94,7 +94,7 @@ 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 "${{ matrix.lua }},vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+        run: cargo build --target armv7-unknown-linux-gnueabihf --features "${{ matrix.lua }},vendored,async,send,serde,macros,anyhow,userdata-wrappers"
         shell: bash
 
   test:
@@ -123,14 +123,14 @@ jobs:
       - name: Run ${{ matrix.lua }} tests
         run: |
           cargo test --features "${{ matrix.lua }},vendored"
-          cargo test --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers"
-          cargo test --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers,send"
+          cargo test --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers"
+          cargo test --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers,send"
         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" --tests -- --ignored
-          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros" --tests -- --ignored
+          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serde,macros" --tests -- --ignored
         shell: bash
 
   test_with_sanitizer:
@@ -154,8 +154,8 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: Run ${{ matrix.lua }} tests with address sanitizer
         run: |
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers,send" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers,send" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
         shell: bash
         env:
           RUSTFLAGS: -Z sanitizer=address
@@ -181,7 +181,7 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: Run ${{ matrix.lua }} tests with forced memory limit
         run: |
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serde,macros,anyhow,userdata-wrappers"
         shell: bash
         env:
           RUSTFLAGS: --cfg=force_memory_limit
@@ -194,7 +194,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau]
+        lua: [lua54, lua53, lua52, lua51, luajit]
         include:
           - os: ubuntu-latest
             target: x86_64-unknown-linux-gnu
@@ -254,7 +254,7 @@ jobs:
       - name: Run ${{ matrix.lua }} tests
         run: |
           cargo test --tests --features "${{ matrix.lua }},vendored"
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,serialize,macros,anyhow,userdata-wrappers"
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,serde,macros,anyhow,userdata-wrappers"
 
   rustfmt:
     name: Rustfmt
@@ -281,4 +281,4 @@ jobs:
       - uses: giraffate/clippy-action@v1
         with:
           reporter: 'github-pr-review'
-          clippy_flags: --features "${{ matrix.lua }},vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+          clippy_flags: --features "${{ matrix.lua }},vendored,async,send,serde,macros,anyhow,userdata-wrappers"

.github/workflows/typos.yml

@@ -0,0 +1,17 @@
+name: Typos Check
+on:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  run:
+    name: Spell Check with Typos
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout Actions Repository
+      uses: actions/checkout@v4
+
+    - name: Check spelling
+      uses: crate-ci/typos@master
+      with:
+        config: ./typos.toml

CHANGELOG.md

@@ -1,13 +1,80 @@
-## v0.10.5 (May 24th, 2025)
+## v0.11.4 (Sep 29, 2025)
 
-- mlua-sys is back to 0.6.x (Luau 0.663)
-- Reverted: Trigger abort when Luau userdata destructors are panic (requires new mlua-sys)
-- Reverted: Added large (52bit) integers support for Luau (breaking change)
+- Make `Value::to_serializable` public
+- Add new serde option `detect_mixed_tables` (to encode mixed array+map tables)
+- Add `ObjectLike::get_path` helper (for tables and userdata)
+
+## v0.11.3 (Aug 30, 2025)
+
+- Add `Lua::yield_with` to use as `coroutine.yield` functional replacement in async functions for any Lua
+- Do not try to yield at non-yielable points in Luau interrupt (#632)
+- Add `Buffer::cursor` method (Luau)
+- Add `Lua::create_buffer_with_capacity` method (Luau)
+- Make Lua reference values cheap to clone (only increments ref count)
+- Fix panic on large (>67M entries) table creation
+
+## v0.11.2 (Aug 10, 2025)
+
+- Faster stack push for `Variadic<T>`
+- Fix handling Windows paths with drive letter in Luau require (#623)
+- Make Luau registered aliases ascii case-insensitive (#620)
+- Fix deserializing negative zeros `-0.0` (#618)
+
+## v0.11.1 (Jul 15, 2025)
+
+- Fixed bug exhausting Lua auxiliary stack and leaving it without reserve (#615)
+- `Lua::push_c_function` now correctly handles OOM for Lua 5.1 and Luau
+
+## v0.11.0 (Jul 14, 2025)
+
+Changes since v0.11.0-beta.3
+
+- Allow linking external Lua libraries in a build script (e.g. pluto) using `external` mlua-sys feature flag
+- `Lua::inspect_stack` takes a callback with `&Debug` argument, instead of returning `Debug` directly
+- Added `Debug::function` method to get function running at a given level
+- `Debug::curr_line` is deprecated in favour of `Debug::current_line` that returns `Option<usize>`
+- Added `Lua::set_globals` method to replace global environment
+- `Table::set_metatable` now returns `Result<()>` (this operation can fail in sandboxed Luau mode)
+- `impl ToString` replaced with `Into<StdString>`  in `UserData` registration
+- `Value::as_str` and `Value::as_string_lossy` methods are deprecated (as they are non-idiomatic)
+- Bugfixes and improvements
+
+## v0.11.0-beta.3 (Jun 23, 2025)
+
+- Luau in sandboxed mode has reduced options in `collectgarbage` function (to follow the official doc)
+- `Function::deep_clone` now returns `Result<Function>` as this operation can trigger memory errors
+- Luau "Require" resolves included Lua files relative to the current directory (#605)
+- Fixed bug when finalizing `AsyncThread` on drop (`call_async` methods family)
+
+## v0.11.0-beta.2 (Jun 12, 2025)
+
+- Lua 5.4 updated to 5.4.8
+- Terminate Rust `Future` when `AsyncThread` is dropped (without relying on Lua GC)
+- Added `loadstring` function to Luau
+- Make `AsChunk` trait dyn-friendly
+- Luau `Require` trait synced with Luau 0.674
+- Luau `Require` trait methods now can return `Error` variant (in `NavigateError` enum)
+- Added `__type` to `Error`'s userdata metatable (for `typeof` function)
+- `parking_log/send_guard` is moved to `userdata-wrappers` feature flag
+- New `serde` feature flag to replace `serialize` (the old one is still available)
+
+## v0.11.0-beta.1 (May 7th, 2025)
+
+- New "require-by-string" for Luau (with `Require` trait and async support)
+- Added `Thread::resume_error` support for Luau
+- 52 bit integers support for Luau (this is a breaking change)
+- New features for Luau compiler (constants, disabled builtins, known members)
+- `AsyncThread<A, R>` changed to `AsyncThread<R>` (`A` pushed to stack immediately)
+- Lifetime `'a` moved from `AsChunk<'a>` to `AsChunk::source where Self: 'a`
+- `Lua::scope` pass `&Scope` instead of `&mut Scope` to closure
+- Added global hooks support (Lua 5.1+)
+- Added per-thread hooks support (Lua 5.1+)
+- `Lua::init_from_ptr` renamed to `Lua::get_or_init_from_ptr` and returns `&Lua`
+- `Lua:load_from_function` is deprecated (this is `register_module` now)
+- Added `Lua::register_module` and `Lua::preload_module`
 
 ## v0.10.4 (May 5th, 2025)
 
-_yanked_ because of semver-breaking changes
-
 - Luau updated to 0.672
 - New serde option `encode_empty_tables_as_array` to serialize empty tables as arrays
 - Added `WeakLua` and `Lua::weak()` to create weak references to Lua state

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mlua"
-version = "0.10.5" # remember to update mlua_derive
+version = "0.11.4" # remember to update mlua_derive
 authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@kyju.org>"]
 rust-version = "1.79.0"
 edition = "2021"
@@ -16,7 +16,7 @@ with async/await features and support of writing native Lua modules in Rust.
 """
 
 [package.metadata.docs.rs]
-features = ["lua54", "vendored", "async", "send", "serialize", "macros"]
+features = ["lua54", "vendored", "async", "send", "serde", "macros"]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [workspace]
@@ -32,21 +32,24 @@ lua52 = ["ffi/lua52"]
 lua51 = ["ffi/lua51"]
 luajit = ["ffi/luajit"]
 luajit52 = ["luajit", "ffi/luajit52"]
-luau = ["ffi/luau", "dep:libloading"]
+luau = ["ffi/luau"]
 luau-jit = ["luau", "ffi/luau-codegen"]
 luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
 module = ["mlua_derive", "ffi/module"]
 async = ["dep:futures-util"]
-send = ["parking_lot/send_guard", "error-send"]
+send = ["error-send"]
 error-send = []
-serialize = ["dep:serde", "dep:erased-serde", "dep:serde-value", "bstr/serde"]
+serde = ["dep:serde", "dep:erased-serde", "dep:serde-value", "bstr/serde"]
 macros = ["mlua_derive/macros"]
 anyhow = ["dep:anyhow", "error-send"]
-userdata-wrappers = []
+userdata-wrappers = ["parking_lot/send_guard"]
+
+# deprecated features
+serialize = ["serde"]
 
 [dependencies]
-mlua_derive = { version = "=0.10.1", optional = true, path = "mlua_derive" }
+mlua_derive = { version = "=0.11.0", optional = true, path = "mlua_derive" }
 bstr = { version = "1.0", features = ["std"], default-features = false }
 either = "1.0"
 num-traits = { version = "0.2.14" }
@@ -59,10 +62,7 @@ parking_lot = { version = "0.12", features = ["arc_lock"] }
 anyhow = { version = "1.0", optional = true }
 rustversion = "1.0"
 
-ffi = { package = "mlua-sys", version = "0.6.8", path = "mlua-sys" }
-
-[target.'cfg(unix)'.dependencies]
-libloading = { version = "0.8", optional = true }
+ffi = { package = "mlua-sys", version = "0.8.3", path = "mlua-sys" }
 
 [dev-dependencies]
 trybuild = "1.0"
@@ -78,8 +78,8 @@ tempfile = "3"
 static_assertions = "1.0"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
-criterion = { version = "0.5", features = ["async_tokio"] }
-rustyline = "15.0"
+criterion = { version = "0.7", features = ["async_tokio"] }
+rustyline = "17.0"
 tokio = { version = "1.0", features = ["full"] }
 
 [lints.rust]
@@ -93,7 +93,7 @@ required-features = ["async"]
 [[bench]]
 name = "serde"
 harness = false
-required-features = ["serialize"]
+required-features = ["serde"]
 
 [[example]]
 name = "async_http_client"
@@ -101,7 +101,7 @@ required-features = ["async", "macros"]
 
 [[example]]
 name = "async_http_reqwest"
-required-features = ["async", "serialize", "macros"]
+required-features = ["async", "serde", "macros"]
 
 [[example]]
 name = "async_http_server"
@@ -116,8 +116,8 @@ name = "guided_tour"
 required-features = ["macros"]
 
 [[example]]
-name = "serialize"
-required-features = ["serialize"]
+name = "serde"
+required-features = ["serde"]
 
 [[example]]
 name = "userdata"

README.md

@@ -17,18 +17,14 @@
 [Benchmarks]: https://github.com/khvzak/script-bench-rs
 [FAQ]: FAQ.md
 
-> **Note**
->
-> See v0.10 [release notes](https://github.com/mlua-rs/mlua/blob/main/docs/release_notes/v0.10.md).
+`mlua` is a set of bindings to the [Lua](https://www.lua.org) programming language for Rust with a goal of providing a
+_safe_ (as much as possible), high level, easy to use, practical and flexible API.
 
-`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.
+Started as an `rlua` fork, `mlua` supports Lua 5.4, 5.3, 5.2, 5.1 (including LuaJIT) and [Luau] and allows writing native Lua modules in Rust as well as using Lua in a standalone mode.
 
-Started as `rlua` fork, `mlua` supports Lua 5.4, 5.3, 5.2, 5.1 (including LuaJIT) and [Luau] and allows to write native Lua modules in Rust as well as use Lua in a standalone mode.
+`mlua` is tested on Windows/macOS/Linux including module mode in [GitHub Actions] on `x86_64` platforms and cross-compilation to `aarch64` (other targets are also supported).
 
-`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/Luau versions excluding JIT.
+WebAssembly (WASM) is supported through the `wasm32-unknown-emscripten` target for all Lua/Luau versions excluding JIT.
 
 [GitHub Actions]: https://github.com/mlua-rs/mlua/actions
 [Luau]: https://luau.org
@@ -37,7 +33,7 @@ WebAssembly (WASM) is supported through `wasm32-unknown-emscripten` target for a
 
 ### Feature flags
 
-`mlua` uses feature flags to reduce the amount of dependencies, compiled code and allow to choose only required set of features.
+`mlua` uses feature flags to reduce the number of dependencies and compiled code, and allow choosing only the required set of features.
 Below is a list of the available feature flags. By default `mlua` does not enable any features.
 
 * `lua54`: enable Lua [5.4] support
@@ -49,12 +45,12 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 * `luau`: enable [Luau] support (auto vendored mode)
 * `luau-jit`: enable [Luau] support with JIT backend.
 * `luau-vector4`: enable [Luau] support with 4-dimensional vector.
-* `vendored`: build static Lua(JIT) library from sources during `mlua` compilation using [lua-src] or [luajit-src] crates
+* `vendored`: build static Lua(JIT) libraries from sources during `mlua` compilation using [lua-src] or [luajit-src]
 * `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])
 * `send`: make `mlua::Lua: Send + Sync` (adds [`Send`] requirement to `mlua::Function` and `mlua::UserData`)
 * `error-send`: make `mlua:Error: Send + Sync`
-* `serialize`: add serialization and deserialization support to `mlua` types using [serde] framework
+* `serde`: add serialization and deserialization support to `mlua` types using [serde]
 * `macros`: enable procedural macros (such as `chunk!`)
 * `anyhow`: enable `anyhow::Error` conversion into Lua
 * `userdata-wrappers`: opt into `impl UserData` for `Rc<T>`/`Arc<T>`/`Rc<RefCell<T>>`/`Arc<Mutex<T>>` where `T: UserData`
@@ -76,7 +72,7 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 
 `mlua` supports async/await for all Lua versions including Luau.
 
-This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6) and require running [Thread](https://docs.rs/mlua/latest/mlua/struct.Thread.html) along with enabling `feature = "async"` in `Cargo.toml`.
+This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6) and requires running [Thread](https://docs.rs/mlua/latest/mlua/struct.Thread.html) along with enabling `feature = "async"` in `Cargo.toml`.
 
 **Examples**:
 - [HTTP Client](examples/async_http_client.rs)
@@ -91,18 +87,18 @@ This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6
 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
+cargo run --example async_http_reqwest --features=lua54,async,macros,serde
 
 # async http server
 cargo run --example async_http_server --features=lua54,async,macros,send
 curl -v http://localhost:3000
 ```
 
-### Serialization (serde) support
+### 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).
+With the `serde` 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 the [`serde::Serialize`] trait implementation for `mlua::Value` (including `UserData` support).
 
-[Example](examples/serialize.rs)
+[Example](examples/serde.rs)
 
 [`serde::Serialize`]: https://docs.serde.rs/serde/ser/trait.Serialize.html
 [`serde::Deserialize`]: https://docs.serde.rs/serde/de/trait.Deserialize.html
@@ -112,28 +108,28 @@ With `serialize` feature flag enabled, `mlua` allows you to serialize/deserializ
 
 You have to enable one of the features: `lua54`, `lua53`, `lua52`, `lua51`, `luajit(52)` or `luau`, according to the chosen Lua version.
 
-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.
+By default `mlua` uses `pkg-config` to find Lua includes and libraries for the chosen Lua version.
+In most cases it works as desired, although sometimes it may be preferable to use a custom Lua library.
+To achieve this, mlua supports the `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:
+An example of 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
 ```
 
-`mlua` also supports vendored lua/luajit using the auxiliary crates [lua-src](https://crates.io/crates/lua-src) and
+`mlua` also supports vendored Lua/LuaJIT using the auxiliary crates [lua-src](https://crates.io/crates/lua-src) and
 [luajit-src](https://crates.io/crates/luajit-src).
-Just enable the `vendored` feature and cargo will automatically build and link specified lua/luajit version. This is the easiest way to get started with `mlua`.
+Just enable the `vendored` feature and cargo will automatically build and link the specified Lua/LuaJIT version. This is the easiest way to get started with `mlua`.
 
 ### Standalone mode
-In a standalone mode `mlua` allows to add to your application scripting support with a gently configured Lua runtime to ensure  safety and soundness.
+In standalone mode, `mlua` allows adding scripting support to your application with a gently configured Lua runtime to ensure safety and soundness.
 
-Add to `Cargo.toml` :
+Add to `Cargo.toml`:
 
 ``` toml
 [dependencies]
-mlua = { version = "0.10", features = ["lua54", "vendored"] }
+mlua = { version = "0.11", features = ["lua54", "vendored"] }
 ```
 
 `main.rs`
@@ -157,21 +153,21 @@ fn main() -> LuaResult<()> {
 ```
 
 ### Module mode
-In a module mode `mlua` allows to create a compiled Lua module that can be loaded from Lua code using [`require`](https://www.lua.org/manual/5.4/manual.html#pdf-require). In this case `mlua` uses an external Lua runtime which could lead to potential unsafety due to unpredictability of the Lua environment and usage of libraries such as [`debug`](https://www.lua.org/manual/5.4/manual.html#6.10).
+In module mode, `mlua` allows creating a compiled Lua module that can be loaded from Lua code using [`require`](https://www.lua.org/manual/5.4/manual.html#pdf-require). In this case `mlua` uses an external Lua runtime which could lead to potential unsafety due to the unpredictability of the Lua environment and usage of libraries such as [`debug`](https://www.lua.org/manual/5.4/manual.html#6.10).
 
 [Example](examples/module)
 
-Add to `Cargo.toml` :
+Add to `Cargo.toml`:
 
 ``` toml
 [lib]
 crate-type = ["cdylib"]
 
 [dependencies]
-mlua = { version = "0.10", features = ["lua54", "module"] }
+mlua = { version = "0.11", features = ["lua54", "module"] }
 ```
 
-`lib.rs` :
+`lib.rs`:
 
 ``` rust
 use mlua::prelude::*;
@@ -214,14 +210,14 @@ rustflags = [
 ```
 On Linux you can build modules normally with `cargo build --release`.
 
-On Windows the target module will be linked with `lua5x.dll` library (depending on your feature flags).
+On Windows the target module will be linked with the `lua5x.dll` library (depending on your feature flags).
 Your main application should provide this library.
 
-Module builds don't require Lua lib or headers to be installed on the system.
+Module builds don't require Lua binaries or headers to be installed on the system.
 
 ### Publishing to luarocks.org
 
-There is a LuaRocks build backend for mlua modules [`luarocks-build-rust-mlua`].
+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)
@@ -234,10 +230,10 @@ Modules written in Rust and published to luarocks:
 
 ## Safety
 
-One of the `mlua` goals is to provide *safe* API between Rust and Lua.
-Every place where the Lua C API may trigger an error longjmp in any way is protected by `lua_pcall`,
-and the user of the library is protected from directly interacting with unsafe things like the Lua stack,
-and there is overhead associated with this safety.
+One of `mlua`'s goals is to provide a *safe* API between Rust and Lua.
+Every place where the Lua C API may trigger an error longjmp is protected by `lua_pcall`,
+and the user of the library is protected from directly interacting with unsafe things like the Lua stack.
+There is overhead associated with this safety.
 
 Unfortunately, `mlua` does not provide absolute safety even without using `unsafe` .
 This library contains a huge amount of unsafe code. There are almost certainly bugs still lurking in this library!
@@ -245,8 +241,8 @@ It is surprisingly, fiendishly difficult to use the Lua C API without the potent
 
 ## Panic handling
 
-`mlua` wraps panics that are generated inside Rust callbacks in a regular Lua error. Panics could be
-resumed then by returning or propagating the Lua error to Rust code.
+`mlua` wraps panics that are generated inside Rust callbacks in a regular Lua error. Panics can then be
+resumed by returning or propagating the Lua error to Rust code.
 
 For example:
 ``` rust
@@ -265,16 +261,16 @@ let _ = lua.load(r#"
 unreachable!()
 ```
 
-Optionally `mlua` can disable Rust panics catching in Lua via `pcall`/`xpcall` and automatically resume
+Optionally, `mlua` can disable Rust panic catching in Lua via `pcall`/`xpcall` and automatically resume
 them across the Lua API boundary. This is controlled via `LuaOptions` and done by wrapping the Lua `pcall`/`xpcall`
-functions on a way to prevent catching errors that are wrapped Rust panics.
+functions to prevent catching errors that are wrapped Rust panics.
 
 `mlua` should also be panic safe in another way as well, which is that any `Lua` instances or handles
-remains usable after a user generated panic, and such panics should not break internal invariants or
+remain usable after a user generated panic, and such panics should not break internal invariants or
 leak Lua stack space. This is mostly important to safely use `mlua` types in Drop impls, as you should not be
 using panics for general error handling.
 
-Below is a list of `mlua` behaviors that should be considered a bug.
+Below is a list of `mlua` behaviors that should be considered bugs.
 If you encounter them, a bug report would be very welcome:
 
   + If you can cause UB with `mlua` without typing the word "unsafe", this is a bug.
@@ -287,12 +283,12 @@ If you encounter them, a bug report would be very welcome:
 
 ## Sandboxing
 
-Please check the [Luau Sandboxing] page if you are interested in running untrusted Lua scripts in controlled environment.
+Please check the [Luau Sandboxing] page if you are interested in running untrusted Lua scripts in a controlled environment.
 
-`mlua` provides `Lua::sandbox` method for enabling sandbox mode (Luau only).
+`mlua` provides the `Lua::sandbox` method for enabling sandbox mode (Luau only).
 
 [Luau Sandboxing]: https://luau.org/sandbox
 
 ## License
 
-This project is licensed under the [MIT license](LICENSE)
+This project is licensed under the [MIT license](LICENSE).

benches/benchmark.rs

@@ -128,6 +128,22 @@ fn table_traversal_sequence(c: &mut Criterion) {
     });
 }
 
+fn table_ref_clone(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let t = lua.create_table().unwrap();
+
+    c.bench_function("table [ref clone]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                let _t2 = t.clone();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 fn function_create(c: &mut Criterion) {
     let lua = Lua::new();
 
@@ -350,6 +366,42 @@ fn userdata_call_method(c: &mut Criterion) {
     });
 }
 
+// A userdata method call that goes through an implicit `__index` function
+fn userdata_call_method_complex(c: &mut Criterion) {
+    struct UserData(u64);
+    impl LuaUserData for UserData {
+        fn register(registry: &mut LuaUserDataRegistry<Self>) {
+            registry.add_field_method_get("val", |_, this| Ok(this.0));
+            registry.add_method_mut("inc_by", |_, this, by: u64| {
+                this.0 += by;
+                Ok(this.0)
+            });
+
+            #[cfg(feature = "luau")]
+            registry.enable_namecall();
+        }
+    }
+
+    let lua = Lua::new();
+    let ud = lua.create_userdata(UserData(0)).unwrap();
+    let inc_by = lua
+        .load("function(ud, s) return ud:inc_by(s) end")
+        .eval::<LuaFunction>()
+        .unwrap();
+
+    c.bench_function("userdata [call method complex]", |b| {
+        b.iter_batched(
+            || {
+                collect_gc_twice(&lua);
+            },
+            |_| {
+                inc_by.call::<()>((&ud, 1)).unwrap();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 fn userdata_async_call_method(c: &mut Criterion) {
     struct UserData(i64);
     impl LuaUserData for UserData {
@@ -399,6 +451,7 @@ criterion_group! {
         table_traversal_pairs,
         table_traversal_for_each,
         table_traversal_sequence,
+        table_ref_clone,
 
         function_create,
         function_call_sum,
@@ -413,6 +466,7 @@ criterion_group! {
         userdata_create,
         userdata_call_index,
         userdata_call_method,
+        userdata_call_method_complex,
         userdata_async_call_method,
 }
 

examples/repl.rs

@@ -20,14 +20,16 @@ fn main() {
             match lua.load(&line).eval::<MultiValue>() {
                 Ok(values) => {
                     editor.add_history_entry(line).unwrap();
-                    println!(
-                        "{}",
-                        values
-                            .iter()
-                            .map(|value| format!("{:#?}", value))
-                            .collect::<Vec<_>>()
-                            .join("\t")
-                    );
+                    if values.len() > 0 {
+                        println!(
+                            "{}",
+                            values
+                                .iter()
+                                .map(|value| format!("{:#?}", value))
+                                .collect::<Vec<_>>()
+                                .join("\t")
+                        );
+                    }
                     break;
                 }
                 Err(Error::SyntaxError {

mlua-sys/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mlua-sys"
-version = "0.6.8"
+version = "0.8.3"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
 rust-version = "1.71"
 edition = "2021"
@@ -30,6 +30,7 @@ luau = ["luau0-src"]
 luau-codegen = ["luau"]
 luau-vector4 = ["luau"]
 vendored = ["lua-src", "luajit-src"]
+external = []
 module = []
 
 [dependencies]
@@ -38,9 +39,9 @@ module = []
 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 = "0.12.0", optional = true }
+lua-src = { version = ">= 548.1.0, < 548.2.0", optional = true }
+luajit-src = { version = ">= 210.6.0, < 210.7.0", optional = true }
+luau0-src = { version = "0.15.6", optional = true }
 
 [lints.rust]
 unexpected_cfgs = { level = "allow", check-cfg = ['cfg(raw_dylib)'] }

mlua-sys/build/main_inner.rs

@@ -14,22 +14,29 @@ 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");
+    #[cfg(any(
+        all(feature = "vendored", any(feature = "external", feature = "module")),
+        all(feature = "external", any(feature = "vendored", feature = "module")),
+        all(feature = "module", any(feature = "vendored", feature = "external"))
+    ))]
+    compile_error!("`vendored`, `external` 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;
+    // Check if compilation and linking is handled by external crate
+    if cfg!(not(feature = "external")) {
+        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");
         }
 
-        println!("cargo:rustc-cfg=raw_dylib");
+        #[cfg(not(feature = "module"))]
+        find::probe_lua();
     }
-
-    #[cfg(not(feature = "module"))]
-    find::probe_lua();
 }

mlua-sys/src/lib.rs

@@ -1,7 +1,8 @@
 //! Low level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Luau.
 
-#![allow(non_camel_case_types, non_snake_case, dead_code)]
+#![allow(non_camel_case_types, non_snake_case)]
 #![allow(clippy::missing_safety_doc)]
+#![allow(unsafe_op_in_unsafe_fn)]
 #![doc(test(attr(deny(warnings))))]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 

mlua-sys/src/lua51/compat.rs

@@ -90,7 +90,7 @@ unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) ->
             } else if compat53_findfield(L, objidx, level - 1) != 0 {
                 // try recursively
                 lua_remove(L, -2); // remove table (but keep name)
-                lua_pushliteral(L, ".");
+                lua_pushliteral(L, c".");
                 lua_insert(L, -2); // place '.' between the two names
                 lua_concat(L, 3);
                 return 1;
@@ -121,13 +121,13 @@ unsafe fn compat53_pushfuncname(L: *mut lua_State, ar: *mut lua_Debug) {
         lua_pushfstring(L, cstr!("function '%s'"), (*ar).name);
     } else if *(*ar).what == b'm' as c_char {
         // main?
-        lua_pushliteral(L, "main chunk");
+        lua_pushliteral(L, c"main chunk");
     } else if *(*ar).what == b'C' as c_char {
         if compat53_pushglobalfuncname(L, ar) != 0 {
             lua_pushfstring(L, cstr!("function '%s'"), lua_tostring(L, -1));
             lua_remove(L, -2); // remove name
         } else {
-            lua_pushliteral(L, "?");
+            lua_pushliteral(L, c"?");
         }
     } else {
         lua_pushfstring(
@@ -186,7 +186,8 @@ pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
     if lua_type(L, idx) == LUA_TNUMBER {
         let n = lua_tonumber(L, idx);
         let i = lua_tointeger(L, idx);
-        if (n - i as lua_Number).abs() < lua_Number::EPSILON {
+        // Lua 5.3+ returns "false" for `-0.0`
+        if n.to_bits() == (i as lua_Number).to_bits() {
             return 1;
         }
     }
@@ -377,7 +378,7 @@ pub unsafe fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char)
         if !msg.is_null() {
             luaL_error(L, cstr!("stack overflow (%s)"), msg);
         } else {
-            lua_pushliteral(L, "stack overflow");
+            lua_pushliteral(L, c"stack overflow");
             lua_error(L);
         }
     }
@@ -467,12 +468,12 @@ pub unsafe fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const
     if !msg.is_null() {
         lua_pushfstring(L, cstr!("%s\n"), msg);
     }
-    lua_pushliteral(L, "stack traceback:");
+    lua_pushliteral(L, c"stack traceback:");
     while lua_getstack(L1, level, &mut ar) != 0 {
         level += 1;
         if level == mark {
             // too many levels?
-            lua_pushliteral(L, "\n\t..."); // add a '...'
+            lua_pushliteral(L, c"\n\t..."); // add a '...'
             level = numlevels - COMPAT53_LEVELS2; // and skip to last ones
         } else {
             lua_getinfo(L1, cstr!("Slnt"), &mut ar);
@@ -480,7 +481,7 @@ pub unsafe fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const
             if ar.currentline > 0 {
                 lua_pushfstring(L, cstr!("%d:"), ar.currentline);
             }
-            lua_pushliteral(L, " in ");
+            lua_pushliteral(L, c" in ");
             compat53_pushfuncname(L, &mut ar);
             lua_concat(L, lua_gettop(L) - top);
         }
@@ -493,16 +494,16 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
         match lua_type(L, idx) {
             LUA_TNIL => {
-                lua_pushliteral(L, "nil");
+                lua_pushliteral(L, c"nil");
             }
             LUA_TSTRING | LUA_TNUMBER => {
                 lua_pushvalue(L, idx);
             }
             LUA_TBOOLEAN => {
                 if lua_toboolean(L, idx) == 0 {
-                    lua_pushliteral(L, "false");
+                    lua_pushliteral(L, c"false");
                 } else {
-                    lua_pushliteral(L, "true");
+                    lua_pushliteral(L, c"true");
                 }
             }
             t => {

mlua-sys/src/lua51/lauxlib.rs

@@ -18,7 +18,7 @@ pub struct luaL_Reg {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;
@@ -61,7 +61,7 @@ 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" {
+unsafe extern "C-unwind" {
     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);
 

mlua-sys/src/lua51/lua.rs

@@ -1,5 +1,6 @@
 //! Contains definitions from `lua.h`.
 
+use std::ffi::CStr;
 use std::marker::{PhantomData, PhantomPinned};
 use std::os::raw::{c_char, c_double, c_int, c_void};
 use std::ptr;
@@ -83,13 +84,13 @@ pub type lua_Reader =
 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;
 
-/// Type for memory-allocation functions
+/// Type for memory-allocation functions (no unwinding)
 #[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;
+    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" {
+unsafe extern "C-unwind" {
     //
     // State manipulation
     //
@@ -219,7 +220,7 @@ 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" {
+unsafe extern "C-unwind" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
@@ -227,7 +228,7 @@ extern "C-unwind" {
 // Miscellaneous functions
 //
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     #[link_name = "lua_error"]
     fn lua_error_(L: *mut lua_State) -> c_int;
     pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
@@ -312,10 +313,8 @@ pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
 }
 
 #[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static CStr) {
+    lua_pushstring_(L, s.as_ptr());
 }
 
 #[inline(always)]
@@ -371,7 +370,7 @@ pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua51/lualib.rs

@@ -1,27 +1,27 @@
 //! Contains definitions from `lualib.h`.
 
-use std::os::raw::c_int;
+use std::os::raw::{c_char, c_int};
 
 use super::lua::lua_State;
 
-pub const LUA_COLIBNAME: &str = "coroutine";
-pub const LUA_TABLIBNAME: &str = "table";
-pub const LUA_IOLIBNAME: &str = "io";
-pub const LUA_OSLIBNAME: &str = "os";
-pub const LUA_STRLIBNAME: &str = "string";
-pub const LUA_MATHLIBNAME: &str = "math";
-pub const LUA_DBLIBNAME: &str = "debug";
-pub const LUA_LOADLIBNAME: &str = "package";
+pub const LUA_COLIBNAME: *const c_char = cstr!("coroutine");
+pub const LUA_TABLIBNAME: *const c_char = cstr!("table");
+pub const LUA_IOLIBNAME: *const c_char = cstr!("io");
+pub const LUA_OSLIBNAME: *const c_char = cstr!("os");
+pub const LUA_STRLIBNAME: *const c_char = cstr!("string");
+pub const LUA_MATHLIBNAME: *const c_char = cstr!("math");
+pub const LUA_DBLIBNAME: *const c_char = cstr!("debug");
+pub const LUA_LOADLIBNAME: *const c_char = cstr!("package");
 
 #[cfg(feature = "luajit")]
-pub const LUA_BITLIBNAME: &str = "bit";
+pub const LUA_BITLIBNAME: *const c_char = cstr!("bit");
 #[cfg(feature = "luajit")]
-pub const LUA_JITLIBNAME: &str = "jit";
+pub const LUA_JITLIBNAME: *const c_char = cstr!("jit");
 #[cfg(feature = "luajit")]
-pub const LUA_FFILIBNAME: &str = "ffi";
+pub const LUA_FFILIBNAME: *const c_char = cstr!("ffi");
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua52/compat.rs

@@ -51,7 +51,8 @@ pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
     if lua_type(L, idx) == LUA_TNUMBER {
         let n = lua_tonumber(L, idx);
         let i = lua_tointeger(L, idx);
-        if (n - i as lua_Number).abs() < lua_Number::EPSILON {
+        // Lua 5.3+ returns "false" for `-0.0`
+        if n.to_bits() == (i as lua_Number).to_bits() {
             return 1;
         }
     }
@@ -199,16 +200,16 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
         match lua_type(L, idx) {
             LUA_TNIL => {
-                lua_pushliteral(L, "nil");
+                lua_pushliteral(L, c"nil");
             }
             LUA_TSTRING | LUA_TNUMBER => {
                 lua_pushvalue(L, idx);
             }
             LUA_TBOOLEAN => {
                 if lua_toboolean(L, idx) == 0 {
-                    lua_pushliteral(L, "false");
+                    lua_pushliteral(L, c"false");
                 } else {
-                    lua_pushliteral(L, "true");
+                    lua_pushliteral(L, c"true");
                 }
             }
             t => {

mlua-sys/src/lua52/lauxlib.rs

@@ -21,7 +21,7 @@ pub struct luaL_Reg {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number);
 
     #[link_name = "luaL_getmetafield"]
@@ -69,7 +69,7 @@ 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" {
+unsafe extern "C-unwind" {
     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);
 
@@ -82,7 +82,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,

mlua-sys/src/lua52/lua.rs

@@ -1,5 +1,6 @@
 //! Contains definitions from `lua.h`.
 
+use std::ffi::CStr;
 use std::marker::{PhantomData, PhantomPinned};
 use std::os::raw::{c_char, c_double, c_int, c_uchar, c_uint, c_void};
 use std::ptr;
@@ -88,13 +89,13 @@ pub type lua_Reader =
 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;
 
-/// Type for memory-allocation functions
+/// Type for memory-allocation functions (no unwinding)
 #[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;
+    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" {
+unsafe extern "C-unwind" {
     //
     // State manipulation
     //
@@ -160,14 +161,14 @@ 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" {
+unsafe extern "C-unwind" {
     pub fn lua_arith(L: *mut lua_State, op: c_int);
     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" {
+unsafe extern "C-unwind" {
     //
     // Push functions (C -> stack)
     //
@@ -256,7 +257,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     //
     // Coroutine functions
     //
@@ -288,12 +289,12 @@ 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" {
+unsafe extern "C-unwind" {
     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" {
+unsafe extern "C-unwind" {
     //
     // Miscellaneous functions
     //
@@ -395,10 +396,8 @@ pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
 }
 
 #[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static CStr) {
+    lua_pushstring(L, s.as_ptr());
 }
 
 #[inline(always)]
@@ -449,7 +448,7 @@ pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua52/lualib.rs

@@ -1,21 +1,21 @@
 //! Contains definitions from `lualib.h`.
 
-use std::os::raw::c_int;
+use std::os::raw::{c_char, c_int};
 
 use super::lua::lua_State;
 
-pub const LUA_COLIBNAME: &str = "coroutine";
-pub const LUA_TABLIBNAME: &str = "table";
-pub const LUA_IOLIBNAME: &str = "io";
-pub const LUA_OSLIBNAME: &str = "os";
-pub const LUA_STRLIBNAME: &str = "string";
-pub const LUA_BITLIBNAME: &str = "bit32";
-pub const LUA_MATHLIBNAME: &str = "math";
-pub const LUA_DBLIBNAME: &str = "debug";
-pub const LUA_LOADLIBNAME: &str = "package";
+pub const LUA_COLIBNAME: *const c_char = cstr!("coroutine");
+pub const LUA_TABLIBNAME: *const c_char = cstr!("table");
+pub const LUA_IOLIBNAME: *const c_char = cstr!("io");
+pub const LUA_OSLIBNAME: *const c_char = cstr!("os");
+pub const LUA_STRLIBNAME: *const c_char = cstr!("string");
+pub const LUA_BITLIBNAME: *const c_char = cstr!("bit32");
+pub const LUA_MATHLIBNAME: *const c_char = cstr!("math");
+pub const LUA_DBLIBNAME: *const c_char = cstr!("debug");
+pub const LUA_LOADLIBNAME: *const c_char = cstr!("package");
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua53/lauxlib.rs

@@ -9,10 +9,10 @@ use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
 pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
 
 // Key, in the registry, for table of loaded modules
-pub const LUA_LOADED_TABLE: &str = "_LOADED";
+pub const LUA_LOADED_TABLE: *const c_char = cstr!("_LOADED");
 
 // Key, in the registry, for table of preloaded loaders
-pub const LUA_PRELOAD_TABLE: &str = "_PRELOAD";
+pub const LUA_PRELOAD_TABLE: *const c_char = cstr!("_PRELOAD");
 
 #[repr(C)]
 pub struct luaL_Reg {
@@ -21,7 +21,7 @@ pub struct luaL_Reg {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;
@@ -65,7 +65,7 @@ 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" {
+unsafe extern "C-unwind" {
     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);
 
@@ -78,7 +78,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,

mlua-sys/src/lua53/lua.rs

@@ -1,5 +1,6 @@
 //! Contains definitions from `lua.h`.
 
+use std::ffi::CStr;
 use std::marker::{PhantomData, PhantomPinned};
 use std::os::raw::{c_char, c_double, c_int, c_uchar, c_void};
 use std::{mem, ptr};
@@ -95,13 +96,13 @@ pub type lua_Reader =
 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;
 
-/// Type for memory-allocation functions
+/// Type for memory-allocation functions (no unwinding)
 #[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;
+    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" {
+unsafe extern "C-unwind" {
     //
     // State manipulation
     //
@@ -171,14 +172,14 @@ 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" {
+unsafe extern "C-unwind" {
     pub fn lua_arith(L: *mut lua_State, op: c_int);
     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" {
+unsafe extern "C-unwind" {
     //
     // Push functions (C -> stack)
     //
@@ -264,7 +265,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     //
     // Coroutine functions
     //
@@ -299,12 +300,12 @@ 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" {
+unsafe extern "C-unwind" {
     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" {
+unsafe extern "C-unwind" {
     //
     // Miscellaneous functions
     //
@@ -407,10 +408,8 @@ pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
 }
 
 #[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring(L, c_str.as_ptr(), c_str.as_bytes().len())
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static CStr) {
+    lua_pushstring(L, s.as_ptr());
 }
 
 #[inline(always)]
@@ -478,7 +477,7 @@ pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua53/lualib.rs

@@ -1,22 +1,22 @@
 //! Contains definitions from `lualib.h`.
 
-use std::os::raw::c_int;
+use std::os::raw::{c_char, c_int};
 
 use super::lua::lua_State;
 
-pub const LUA_COLIBNAME: &str = "coroutine";
-pub const LUA_TABLIBNAME: &str = "table";
-pub const LUA_IOLIBNAME: &str = "io";
-pub const LUA_OSLIBNAME: &str = "os";
-pub const LUA_STRLIBNAME: &str = "string";
-pub const LUA_UTF8LIBNAME: &str = "utf8";
-pub const LUA_BITLIBNAME: &str = "bit32";
-pub const LUA_MATHLIBNAME: &str = "math";
-pub const LUA_DBLIBNAME: &str = "debug";
-pub const LUA_LOADLIBNAME: &str = "package";
+pub const LUA_COLIBNAME: *const c_char = cstr!("coroutine");
+pub const LUA_TABLIBNAME: *const c_char = cstr!("table");
+pub const LUA_IOLIBNAME: *const c_char = cstr!("io");
+pub const LUA_OSLIBNAME: *const c_char = cstr!("os");
+pub const LUA_STRLIBNAME: *const c_char = cstr!("string");
+pub const LUA_UTF8LIBNAME: *const c_char = cstr!("utf8");
+pub const LUA_BITLIBNAME: *const c_char = cstr!("bit32");
+pub const LUA_MATHLIBNAME: *const c_char = cstr!("math");
+pub const LUA_DBLIBNAME: *const c_char = cstr!("debug");
+pub const LUA_LOADLIBNAME: *const c_char = cstr!("package");
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua54/lauxlib.rs

@@ -9,10 +9,10 @@ use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
 pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
 
 // Key, in the registry, for table of loaded modules
-pub const LUA_LOADED_TABLE: &str = "_LOADED";
+pub const LUA_LOADED_TABLE: *const c_char = cstr!("_LOADED");
 
 // Key, in the registry, for table of preloaded loaders
-pub const LUA_PRELOAD_TABLE: &str = "_PRELOAD";
+pub const LUA_PRELOAD_TABLE: *const c_char = cstr!("_PRELOAD");
 
 #[repr(C)]
 pub struct luaL_Reg {
@@ -21,7 +21,7 @@ pub struct luaL_Reg {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;
@@ -64,7 +64,7 @@ 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" {
+unsafe extern "C-unwind" {
     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);
 
@@ -77,7 +77,7 @@ pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn luaL_loadbufferx(
         L: *mut lua_State,
         buff: *const c_char,

mlua-sys/src/lua54/lua.rs

@@ -1,5 +1,6 @@
 //! Contains definitions from `lua.h`.
 
+use std::ffi::CStr;
 use std::marker::{PhantomData, PhantomPinned};
 use std::os::raw::{c_char, c_double, c_int, c_uchar, c_ushort, c_void};
 use std::{mem, ptr};
@@ -94,16 +95,16 @@ pub type lua_Reader =
 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;
 
-/// Type for memory-allocation functions
+/// Type for memory-allocation functions (no unwinding)
 #[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;
+    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);
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     //
     // State manipulation
     //
@@ -185,14 +186,14 @@ 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" {
+unsafe extern "C-unwind" {
     pub fn lua_arith(L: *mut lua_State, op: c_int);
     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" {
+unsafe extern "C-unwind" {
     //
     // Push functions (C -> stack)
     //
@@ -278,7 +279,7 @@ pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_in
 }
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     //
     // Coroutine functions
     //
@@ -302,7 +303,7 @@ 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" {
+unsafe extern "C-unwind" {
     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);
 }
@@ -323,12 +324,12 @@ 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" {
+unsafe extern "C-unwind" {
     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" {
+unsafe extern "C-unwind" {
     //
     // Miscellaneous functions
     //
@@ -434,10 +435,8 @@ pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
 }
 
 #[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring(L, c_str.as_ptr(), c_str.as_bytes().len())
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static CStr) {
+    lua_pushstring(L, s.as_ptr());
 }
 
 #[inline(always)]
@@ -520,7 +519,7 @@ pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
 pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/lua54/lualib.rs

@@ -1,21 +1,21 @@
 //! Contains definitions from `lualib.h`.
 
-use std::os::raw::c_int;
+use std::os::raw::{c_char, c_int};
 
 use super::lua::lua_State;
 
-pub const LUA_COLIBNAME: &str = "coroutine";
-pub const LUA_TABLIBNAME: &str = "table";
-pub const LUA_IOLIBNAME: &str = "io";
-pub const LUA_OSLIBNAME: &str = "os";
-pub const LUA_STRLIBNAME: &str = "string";
-pub const LUA_UTF8LIBNAME: &str = "utf8";
-pub const LUA_MATHLIBNAME: &str = "math";
-pub const LUA_DBLIBNAME: &str = "debug";
-pub const LUA_LOADLIBNAME: &str = "package";
+pub const LUA_COLIBNAME: *const c_char = cstr!("coroutine");
+pub const LUA_TABLIBNAME: *const c_char = cstr!("table");
+pub const LUA_IOLIBNAME: *const c_char = cstr!("io");
+pub const LUA_OSLIBNAME: *const c_char = cstr!("os");
+pub const LUA_STRLIBNAME: *const c_char = cstr!("string");
+pub const LUA_UTF8LIBNAME: *const c_char = cstr!("utf8");
+pub const LUA_MATHLIBNAME: *const c_char = cstr!("math");
+pub const LUA_DBLIBNAME: *const c_char = cstr!("debug");
+pub const LUA_LOADLIBNAME: *const c_char = cstr!("package");
 
 #[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/luau/compat.rs

@@ -10,6 +10,8 @@ use super::lauxlib::*;
 use super::lua::*;
 use super::luacode::*;
 
+pub const LUA_RESUMEERROR: c_int = -1;
+
 unsafe fn compat53_reverse(L: *mut lua_State, mut a: c_int, mut b: c_int) {
     while a < b {
         lua_pushvalue(L, a);
@@ -41,7 +43,7 @@ unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) ->
             } else if compat53_findfield(L, objidx, level - 1) != 0 {
                 // try recursively
                 lua_remove(L, -2); // remove table (but keep name)
-                lua_pushliteral(L, ".");
+                lua_pushliteral(L, c".");
                 lua_insert(L, -2); // place '.' between the two names
                 lua_concat(L, 3);
                 return 1;
@@ -75,7 +77,7 @@ unsafe fn compat53_pushfuncname(L: *mut lua_State, level: c_int, ar: *mut lua_De
         lua_pushfstring(L, cstr!("function '%s'"), lua_tostring(L, -1));
         lua_remove(L, -2); // remove name
     } else {
-        lua_pushliteral(L, "?");
+        lua_pushliteral(L, c"?");
     }
 }
 
@@ -118,13 +120,19 @@ pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
     if lua_type(L, idx) == LUA_TNUMBER {
         let n = lua_tonumber(L, idx);
         let i = lua_tointeger(L, idx);
-        if (n - i as lua_Number).abs() < lua_Number::EPSILON {
+        // Lua 5.3+ returns "false" for `-0.0`
+        if n.to_bits() == (i as lua_Number).to_bits() {
             return 1;
         }
     }
     0
 }
 
+#[inline(always)]
+pub unsafe fn lua_pushinteger(L: *mut lua_State, i: lua_Integer) {
+    lua_pushnumber(L, i as lua_Number);
+}
+
 #[inline(always)]
 pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
     lua_tointegerx(L, i, ptr::null_mut())
@@ -176,6 +184,7 @@ pub unsafe fn lua_geti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) -> c_i
 
 #[inline(always)]
 pub unsafe fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int {
+    let n = n.try_into().expect("cannot convert index from lua_Integer");
     lua_rawgeti_(L, idx, n)
 }
 
@@ -190,7 +199,7 @@ pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_
 pub unsafe fn lua_getuservalue(L: *mut lua_State, mut idx: c_int) -> c_int {
     luaL_checkstack(L, 2, cstr!("not enough stack slots available"));
     idx = lua_absindex(L, idx);
-    lua_pushliteral(L, "__mlua_uservalues");
+    lua_pushliteral(L, c"__mlua_uservalues");
     if lua_rawget(L, LUA_REGISTRYINDEX) != LUA_TTABLE {
         return LUA_TNIL;
     }
@@ -211,6 +220,7 @@ pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
 
 #[inline(always)]
 pub unsafe fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer) {
+    let n = n.try_into().expect("cannot convert index from lua_Integer");
     lua_rawseti_(L, idx, n)
 }
 
@@ -227,13 +237,13 @@ pub unsafe fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void) {
 pub unsafe fn lua_setuservalue(L: *mut lua_State, mut idx: c_int) {
     luaL_checkstack(L, 4, cstr!("not enough stack slots available"));
     idx = lua_absindex(L, idx);
-    lua_pushliteral(L, "__mlua_uservalues");
+    lua_pushliteral(L, c"__mlua_uservalues");
     lua_pushvalue(L, -1);
     if lua_rawget(L, LUA_REGISTRYINDEX) != LUA_TTABLE {
         lua_pop(L, 1);
         lua_createtable(L, 0, 2); // main table
         lua_createtable(L, 0, 1); // metatable
-        lua_pushliteral(L, "k");
+        lua_pushliteral(L, c"k");
         lua_setfield(L, -2, cstr!("__mode"));
         lua_setmetatable(L, -2);
         lua_pushvalue(L, -2);
@@ -284,6 +294,19 @@ pub unsafe fn lua_resume(L: *mut lua_State, from: *mut lua_State, narg: c_int, n
     ret
 }
 
+#[inline(always)]
+pub unsafe fn lua_resumex(L: *mut lua_State, from: *mut lua_State, narg: c_int, nres: *mut c_int) -> c_int {
+    let ret = if narg == LUA_RESUMEERROR {
+        lua_resumeerror(L, from)
+    } else {
+        lua_resume_(L, from, narg)
+    };
+    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
+        *nres = lua_gettop(L);
+    }
+    ret
+}
+
 //
 // lauxlib ported functions
 //
@@ -294,12 +317,30 @@ pub unsafe fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char)
         if !msg.is_null() {
             luaL_error(L, cstr!("stack overflow (%s)"), msg);
         } else {
-            lua_pushliteral(L, "stack overflow");
+            lua_pushliteral(L, c"stack overflow");
             lua_error(L);
         }
     }
 }
 
+#[inline(always)]
+pub unsafe fn luaL_checkinteger(L: *mut lua_State, narg: c_int) -> lua_Integer {
+    let mut isnum = 0;
+    let int = lua_tointegerx(L, narg, &mut isnum);
+    if isnum == 0 {
+        luaL_typeerror(L, narg, lua_typename(L, LUA_TNUMBER));
+    }
+    int
+}
+
+pub unsafe fn luaL_optinteger(L: *mut lua_State, narg: c_int, def: lua_Integer) -> lua_Integer {
+    if lua_isnoneornil(L, narg) != 0 {
+        def
+    } else {
+        luaL_checkinteger(L, narg)
+    }
+}
+
 #[inline(always)]
 pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int {
     if luaL_getmetafield_(L, obj, e) != 0 {
@@ -328,11 +369,11 @@ pub unsafe fn luaL_loadbufferenv(
     mode: *const c_char,
     mut env: c_int,
 ) -> c_int {
-    extern "C" {
+    unsafe extern "C" {
         fn free(p: *mut c_void);
     }
 
-    unsafe extern "C-unwind" fn data_dtor(data: *mut c_void) {
+    unsafe extern "C" fn data_dtor(_: *mut lua_State, data: *mut c_void) {
         free(*(data as *mut *mut c_char) as *mut c_void);
     }
 
@@ -348,7 +389,7 @@ pub unsafe fn luaL_loadbufferenv(
         }
     }
 
-    if chunk_is_text {
+    let status = if chunk_is_text {
         if env < 0 {
             env -= 1;
         }
@@ -357,14 +398,21 @@ pub unsafe fn luaL_loadbufferenv(
         ptr::write(data_ud, data);
         // By deferring the `free(data)` to the userdata destructor, we ensure that
         // even if `luau_load` throws an error, the `data` is still released.
-        let ok = luau_load(L, name, data, size, env) == 0;
+        let status = luau_load(L, name, data, size, env);
         lua_replace(L, -2); // replace data with the result
-        if !ok {
-            return LUA_ERRSYNTAX;
+        status
+    } else {
+        luau_load(L, name, data, size, env)
+    };
+
+    if status != 0 {
+        if lua_isstring(L, -1) != 0 && CStr::from_ptr(lua_tostring(L, -1)) == c"not enough memory" {
+            // A case for Luau >= 0.679
+            return LUA_ERRMEM;
         }
-    } else if luau_load(L, name, data, size, env) != 0 {
         return LUA_ERRSYNTAX;
     }
+
     LUA_OK
 }
 
@@ -415,11 +463,11 @@ pub unsafe fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const
     if !msg.is_null() {
         lua_pushfstring(L, cstr!("%s\n"), msg);
     }
-    lua_pushliteral(L, "stack traceback:");
+    lua_pushliteral(L, c"stack traceback:");
     while lua_getinfo(L1, level, cstr!(""), &mut ar) != 0 {
         if level + 1 == mark {
             // too many levels?
-            lua_pushliteral(L, "\n\t..."); // add a '...'
+            lua_pushliteral(L, c"\n\t..."); // add a '...'
             level = numlevels - COMPAT53_LEVELS2; // and skip to last ones
         } else {
             lua_getinfo(L1, level, cstr!("sln"), &mut ar);
@@ -427,7 +475,7 @@ pub unsafe fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const
             if ar.currentline > 0 {
                 lua_pushfstring(L, cstr!("%d:"), ar.currentline);
             }
-            lua_pushliteral(L, " in ");
+            lua_pushliteral(L, c" in ");
             compat53_pushfuncname(L, level, &mut ar);
             lua_concat(L, lua_gettop(L) - top);
         }
@@ -441,16 +489,16 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize)
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
         match lua_type(L, idx) {
             LUA_TNIL => {
-                lua_pushliteral(L, "nil");
+                lua_pushliteral(L, c"nil");
             }
             LUA_TSTRING | LUA_TNUMBER => {
                 lua_pushvalue(L, idx);
             }
             LUA_TBOOLEAN => {
                 if lua_toboolean(L, idx) == 0 {
-                    lua_pushliteral(L, "false");
+                    lua_pushliteral(L, c"false");
                 } else {
-                    lua_pushliteral(L, "true");
+                    lua_pushliteral(L, c"true");
                 }
             }
             t => {

mlua-sys/src/luau/lauxlib.rs

@@ -3,7 +3,7 @@
 use std::os::raw::{c_char, c_float, c_int, c_void};
 use std::ptr;
 
-use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State, lua_Unsigned, LUA_REGISTRYINDEX};
+use super::lua::{self, lua_CFunction, lua_Number, lua_State, lua_Unsigned, LUA_REGISTRYINDEX};
 
 #[repr(C)]
 pub struct luaL_Reg {
@@ -11,7 +11,7 @@ pub struct luaL_Reg {
     pub func: lua_CFunction,
 }
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;
@@ -33,8 +33,10 @@ extern "C-unwind" {
     pub fn luaL_checkboolean(L: *mut lua_State, narg: c_int) -> c_int;
     pub fn luaL_optboolean(L: *mut lua_State, narg: c_int, def: c_int) -> c_int;
 
-    pub fn luaL_checkinteger(L: *mut lua_State, narg: c_int) -> lua_Integer;
-    pub fn luaL_optinteger(L: *mut lua_State, narg: c_int, def: lua_Integer) -> lua_Integer;
+    #[link_name = "luaL_checkinteger"]
+    pub fn luaL_checkinteger_(L: *mut lua_State, narg: c_int) -> c_int;
+    #[link_name = "luaL_optinteger"]
+    pub fn luaL_optinteger_(L: *mut lua_State, narg: c_int, def: c_int) -> c_int;
     pub fn luaL_checkunsigned(L: *mut lua_State, narg: c_int) -> lua_Unsigned;
     pub fn luaL_optunsigned(L: *mut lua_State, narg: c_int, def: lua_Unsigned) -> lua_Unsigned;
 
@@ -69,10 +71,17 @@ extern "C-unwind" {
 
     pub fn luaL_newstate() -> *mut lua_State;
 
-    // TODO: luaL_findtable
+    pub fn luaL_findtable(
+        L: *mut lua_State,
+        idx: c_int,
+        fname: *const c_char,
+        szhint: c_int,
+    ) -> *const c_char;
 
     pub fn luaL_typename(L: *mut lua_State, idx: c_int) -> *const c_char;
 
+    pub fn luaL_callyieldable(L: *mut lua_State, nargs: c_int, nresults: c_int) -> c_int;
+
     // sandbox libraries and globals
     #[link_name = "luaL_sandbox"]
     pub fn luaL_sandbox_(L: *mut lua_State);
@@ -141,7 +150,7 @@ pub unsafe fn luaL_sandbox(L: *mut lua_State, enabled: c_int) {
     }
 
     // set all builtin metatables to read-only
-    lua_pushliteral(L, "");
+    lua_pushliteral(L, c"");
     if lua_getmetatable(L, -1) != 0 {
         lua_setreadonly(L, -1, enabled);
         lua_pop(L, 2);
@@ -173,7 +182,7 @@ pub struct luaL_Strbuf {
 // For compatibility
 pub type luaL_Buffer = luaL_Strbuf;
 
-extern "C-unwind" {
+unsafe 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;

mlua-sys/src/luau/lua.rs

@@ -1,5 +1,6 @@
 //! Contains definitions from `lua.h`.
 
+use std::ffi::CStr;
 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};
@@ -11,10 +12,10 @@ pub const LUA_MULTRET: c_int = -1;
 const LUAI_MAXCSTACK: c_int = 1000000;
 
 // Number of valid Lua userdata tags
-const LUA_UTAG_LIMIT: c_int = 128;
+pub const LUA_UTAG_LIMIT: c_int = 128;
 
 // Number of valid Lua lightuserdata tags
-const LUA_LUTAG_LIMIT: c_int = 128;
+pub const LUA_LUTAG_LIMIT: c_int = 128;
 
 //
 // Pseudo-indices
@@ -69,8 +70,11 @@ pub const LUA_MINSTACK: c_int = 20;
 /// A Lua number, usually equivalent to `f64`.
 pub type lua_Number = c_double;
 
-/// A Lua integer, equivalent to `i32`.
-pub type lua_Integer = c_int;
+/// A Lua integer, usually equivalent to `i64`
+#[cfg(target_pointer_width = "32")]
+pub type lua_Integer = i32;
+#[cfg(target_pointer_width = "64")]
+pub type lua_Integer = i64;
 
 /// A Lua unsigned integer, equivalent to `u32`.
 pub type lua_Unsigned = c_uint;
@@ -79,20 +83,19 @@ pub type lua_Unsigned = c_uint;
 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;
 
-/// 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);
+/// Type for userdata destructor functions (no unwinding).
+pub type lua_Destructor = unsafe extern "C" fn(L: *mut lua_State, *mut c_void);
 
-/// Type for memory-allocation functions.
+/// Type for memory-allocation functions (no unwinding).
 pub type lua_Alloc =
-    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+    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" {
+unsafe extern "C-unwind" {
     //
     // State manipulation
     //
@@ -136,7 +139,7 @@ extern "C-unwind" {
 
     pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
     #[link_name = "lua_tointegerx"]
-    pub fn lua_tointegerx_(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
+    pub fn lua_tointegerx_(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> c_int;
     pub fn lua_tounsignedx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Unsigned;
     pub fn lua_tovector(L: *mut lua_State, idx: c_int) -> *const c_float;
     pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
@@ -160,7 +163,8 @@ extern "C-unwind" {
     //
     pub fn lua_pushnil(L: *mut lua_State);
     pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
-    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    #[link_name = "lua_pushinteger"]
+    pub fn lua_pushinteger_(L: *mut lua_State, n: c_int);
     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);
@@ -186,7 +190,7 @@ extern "C-unwind" {
     pub fn lua_pushlightuserdatatagged(L: *mut lua_State, p: *mut c_void, tag: c_int);
     pub fn lua_newuserdatatagged(L: *mut lua_State, sz: usize, tag: c_int) -> *mut c_void;
     pub fn lua_newuserdatataggedwithmetatable(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_newuserdatadtor(L: *mut lua_State, sz: usize, dtor: lua_Destructor) -> *mut c_void;
 
     pub fn lua_newbuffer(L: *mut lua_State, sz: usize) -> *mut c_void;
 
@@ -231,6 +235,7 @@ extern "C-unwind" {
     ) -> c_int;
     pub fn lua_call(L: *mut lua_State, nargs: c_int, nresults: c_int);
     pub fn lua_pcall(L: *mut lua_State, nargs: c_int, nresults: c_int, errfunc: c_int) -> c_int;
+    pub fn lua_cpcall(L: *mut lua_State, f: lua_CFunction, ud: *mut c_void) -> c_int;
 
     //
     // Coroutine functions
@@ -260,14 +265,14 @@ pub const LUA_GCSETGOAL: c_int = 7;
 pub const LUA_GCSETSTEPMUL: c_int = 8;
 pub const LUA_GCSETSTEPSIZE: c_int = 9;
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
 }
 
 //
 // Memory statistics
 //
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn lua_setmemcat(L: *mut lua_State, category: c_int);
     pub fn lua_totalbytes(L: *mut lua_State, category: c_int) -> usize;
 }
@@ -275,7 +280,7 @@ extern "C-unwind" {
 //
 // Miscellaneous functions
 //
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;
@@ -285,7 +290,7 @@ extern "C-unwind" {
     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_setuserdatametatable(L: *mut lua_State, tag: 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;
@@ -300,7 +305,7 @@ extern "C-unwind" {
 pub const LUA_NOREF: c_int = -1;
 pub const LUA_REFNIL: c_int = 0;
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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);
 }
@@ -310,13 +315,13 @@ extern "C-unwind" {
 //
 
 #[inline(always)]
-pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
-    lua_tonumberx(L, i, ptr::null_mut())
+pub unsafe fn lua_tonumber(L: *mut lua_State, idx: c_int) -> lua_Number {
+    lua_tonumberx(L, idx, ptr::null_mut())
 }
 
 #[inline(always)]
-pub unsafe fn lua_tointeger_(L: *mut lua_State, i: c_int) -> lua_Integer {
-    lua_tointegerx_(L, i, ptr::null_mut())
+pub unsafe fn lua_tointeger_(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_tointegerx_(L, idx, ptr::null_mut())
 }
 
 #[inline(always)]
@@ -340,12 +345,14 @@ pub unsafe fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void {
 }
 
 #[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) {
+pub unsafe fn lua_newuserdata_t<T>(L: *mut lua_State, data: T) -> *mut T {
+    unsafe extern "C" fn destructor<T>(_: *mut lua_State, ud: *mut c_void) {
         ptr::drop_in_place(ud as *mut T);
     }
 
-    lua_newuserdatadtor(L, mem::size_of::<T>(), destructor::<T>) as *mut T
+    let ud_ptr = lua_newuserdatadtor(L, const { mem::size_of::<T>() }, destructor::<T>) as *mut T;
+    ptr::write(ud_ptr, data);
+    ud_ptr
 }
 
 // TODO: lua_strlen
@@ -401,10 +408,8 @@ pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
 }
 
 #[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static CStr) {
+    lua_pushstring_(L, s.as_ptr());
 }
 
 #[inline(always)]
@@ -466,7 +471,7 @@ pub type lua_Coverage = unsafe extern "C-unwind" fn(
     size: usize,
 );
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     pub fn lua_stackdepth(L: *mut lua_State) -> c_int;
     pub fn lua_getinfo(L: *mut lua_State, level: c_int, what: *const c_char, ar: *mut lua_Debug) -> c_int;
     pub fn lua_getargument(L: *mut lua_State, level: c_int, n: c_int) -> c_int;
@@ -532,12 +537,12 @@ pub struct lua_Callbacks {
     pub onallocate: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, osize: usize, nsize: usize)>,
 }
 
-extern "C" {
+unsafe extern "C" {
     pub fn lua_callbacks(L: *mut lua_State) -> *mut lua_Callbacks;
 }
 
 // Functions from customization lib
-extern "C" {
+unsafe extern "C" {
     pub fn luau_setfflag(name: *const c_char, value: c_int) -> c_int;
     pub fn lua_getmetatablepointer(L: *mut lua_State, idx: c_int) -> *const c_void;
 }

mlua-sys/src/luau/luacode.rs

@@ -76,7 +76,7 @@ pub type lua_LibraryMemberConstantCallback = unsafe extern "C-unwind" fn(
     constant: *mut lua_CompileConstant,
 );
 
-extern "C" {
+unsafe extern "C" {
     pub fn luau_set_compile_constant_nil(cons: *mut lua_CompileConstant);
     pub fn luau_set_compile_constant_boolean(cons: *mut lua_CompileConstant, b: c_int);
     pub fn luau_set_compile_constant_number(cons: *mut lua_CompileConstant, n: f64);
@@ -84,7 +84,7 @@ extern "C" {
     pub fn luau_set_compile_constant_string(cons: *mut lua_CompileConstant, s: *const c_char, l: usize);
 }
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     #[link_name = "luau_compile"]
     pub fn luau_compile_(
         source: *const c_char,
@@ -94,7 +94,7 @@ extern "C-unwind" {
     ) -> *mut c_char;
 }
 
-extern "C" {
+unsafe extern "C" {
     fn free(p: *mut c_void);
 }
 

mlua-sys/src/luau/luacodegen.rs

@@ -4,7 +4,7 @@ use std::os::raw::c_int;
 
 use super::lua::lua_State;
 
-extern "C-unwind" {
+unsafe 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/luau/lualib.rs

@@ -1,21 +1,21 @@
 //! Contains definitions from `lualib.h`.
 
-use std::os::raw::c_int;
+use std::os::raw::{c_char, c_int};
 
 use super::lua::lua_State;
 
-pub const LUA_COLIBNAME: &str = "coroutine";
-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";
-pub const LUA_VECLIBNAME: &str = "vector";
+pub const LUA_COLIBNAME: *const c_char = cstr!("coroutine");
+pub const LUA_TABLIBNAME: *const c_char = cstr!("table");
+pub const LUA_OSLIBNAME: *const c_char = cstr!("os");
+pub const LUA_STRLIBNAME: *const c_char = cstr!("string");
+pub const LUA_BITLIBNAME: *const c_char = cstr!("bit32");
+pub const LUA_BUFFERLIBNAME: *const c_char = cstr!("buffer");
+pub const LUA_UTF8LIBNAME: *const c_char = cstr!("utf8");
+pub const LUA_MATHLIBNAME: *const c_char = cstr!("math");
+pub const LUA_DBLIBNAME: *const c_char = cstr!("debug");
+pub const LUA_VECLIBNAME: *const c_char = cstr!("vector");
 
-extern "C-unwind" {
+unsafe extern "C-unwind" {
     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;

mlua-sys/src/luau/luarequire.rs

@@ -0,0 +1,177 @@
+//! Contains definitions from `Require.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+
+use super::lua::lua_State;
+
+pub const LUA_REGISTERED_MODULES_TABLE: *const c_char = cstr!("_REGISTEREDMODULES");
+
+#[repr(C)]
+pub enum luarequire_NavigateResult {
+    Success,
+    Ambiguous,
+    NotFound,
+}
+
+// Functions returning WriteSuccess are expected to set their size_out argument
+// to the number of bytes written to the buffer. If WriteBufferTooSmall is
+// returned, size_out should be set to the required buffer size.
+#[repr(C)]
+pub enum luarequire_WriteResult {
+    Success,
+    BufferTooSmall,
+    Failure,
+}
+
+#[repr(C)]
+pub struct luarequire_Configuration {
+    // Returns whether requires are permitted from the given chunkname.
+    pub is_require_allowed: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        requirer_chunkname: *const c_char,
+    ) -> bool,
+
+    // Resets the internal state to point at the requirer module.
+    pub reset: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        requirer_chunkname: *const c_char,
+    ) -> luarequire_NavigateResult,
+
+    // Resets the internal state to point at an aliased module, given its exact path from a configuration
+    // file. This function is only called when an alias's path cannot be resolved relative to its
+    // configuration file.
+    pub jump_to_alias: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        path: *const c_char,
+    ) -> luarequire_NavigateResult,
+
+    // Navigates through the context by making mutations to the internal state.
+    pub to_parent:
+        unsafe extern "C-unwind" fn(L: *mut lua_State, ctx: *mut c_void) -> luarequire_NavigateResult,
+    pub to_child: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        name: *const c_char,
+    ) -> luarequire_NavigateResult,
+
+    // Returns whether the context is currently pointing at a module.
+    pub is_module_present: unsafe extern "C-unwind" fn(L: *mut lua_State, ctx: *mut c_void) -> bool,
+
+    // Provides a chunkname for the current module. This will be accessible through the debug library. This
+    // function is only called if is_module_present returns true.
+    pub get_chunkname: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> luarequire_WriteResult,
+
+    // Provides a loadname that identifies the current module and is passed to load. This function
+    // is only called if is_module_present returns true.
+    pub get_loadname: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> luarequire_WriteResult,
+
+    // Provides a cache key representing the current module. This function is only called if
+    // is_module_present returns true.
+    pub get_cache_key: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> luarequire_WriteResult,
+
+    // Returns whether a configuration file is present in the current context.
+    // If not, require-by-string will call to_parent until either a configuration file is present or
+    // NAVIGATE_FAILURE is returned (at root).
+    pub is_config_present: unsafe extern "C-unwind" fn(L: *mut lua_State, ctx: *mut c_void) -> bool,
+
+    // Parses the configuration file in the current context for the given alias and returns its
+    // value or WRITE_FAILURE if not found. This function is only called if is_config_present
+    // returns true. If this function pointer is set, get_config must not be set. Opting in to this
+    // function pointer disables parsing configuration files internally and can be used for finer
+    // control over the configuration file parsing process.
+    pub get_alias: Option<
+        unsafe extern "C-unwind" fn(
+            L: *mut lua_State,
+            ctx: *mut c_void,
+            alias: *const c_char,
+            buffer: *mut c_char,
+            buffer_size: usize,
+            size_out: *mut usize,
+        ) -> luarequire_WriteResult,
+    >,
+
+    // Provides the contents of the configuration file in the current context. This function is only called
+    // if is_config_present returns true. If this function pointer is set, get_alias must not be set. Opting
+    // in to this function pointer enables parsing configuration files internally.
+    pub get_config: Option<
+        unsafe extern "C-unwind" fn(
+            L: *mut lua_State,
+            ctx: *mut c_void,
+            buffer: *mut c_char,
+            buffer_size: usize,
+            size_out: *mut usize,
+        ) -> luarequire_WriteResult,
+    >,
+
+    // Executes the module and places the result on the stack. Returns the number of results placed on the
+    // stack.
+    // Returning -1 directs the requiring thread to yield. In this case, this thread should be resumed with
+    // the module result pushed onto its stack.
+    pub load: unsafe extern "C-unwind" fn(
+        L: *mut lua_State,
+        ctx: *mut c_void,
+        path: *const c_char,
+        chunkname: *const c_char,
+        loadname: *const c_char,
+    ) -> c_int,
+}
+
+// Populates function pointers in the given luarequire_Configuration.
+pub type luarequire_Configuration_init = unsafe extern "C-unwind" fn(config: *mut luarequire_Configuration);
+
+unsafe extern "C-unwind" {
+    // Initializes and pushes the require closure onto the stack without registration.
+    pub fn luarequire_pushrequire(
+        L: *mut lua_State,
+        config_init: luarequire_Configuration_init,
+        ctx: *mut c_void,
+    ) -> c_int;
+
+    // Initializes the require library and registers it globally.
+    pub fn luaopen_require(L: *mut lua_State, config_init: luarequire_Configuration_init, ctx: *mut c_void);
+
+    // Initializes and pushes a "proxyrequire" closure onto the stack.
+    //
+    // The closure takes two parameters: the string path to resolve and the chunkname of an existing
+    // module.
+    pub fn luarequire_pushproxyrequire(
+        L: *mut lua_State,
+        config_init: luarequire_Configuration_init,
+        ctx: *mut c_void,
+    ) -> c_int;
+
+    // Registers an aliased require path to a result.
+    //
+    // After registration, the given result will always be immediately returned when the given path is
+    // required.
+    // Expects the path and table to be passed as arguments on the stack.
+    pub fn luarequire_registermodule(L: *mut lua_State) -> c_int;
+
+    // Clears the entry associated with the given cache key from the require cache.
+    // Expects the cache key to be passed as an argument on the stack.
+    pub fn luarequire_clearcacheentry(L: *mut lua_State) -> c_int;
+
+    // Clears all entries from the require cache.
+    pub fn luarequire_clearcache(L: *mut lua_State) -> c_int;
+}

mlua-sys/src/luau/mod.rs

@@ -6,6 +6,7 @@ pub use lua::*;
 pub use luacode::*;
 pub use luacodegen::*;
 pub use lualib::*;
+pub use luarequire::*;
 
 pub mod compat;
 pub mod lauxlib;
@@ -13,3 +14,4 @@ pub mod lua;
 pub mod luacode;
 pub mod luacodegen;
 pub mod lualib;
+pub mod luarequire;

mlua_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mlua_derive"
-version = "0.10.1"
+version = "0.11.0"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
 edition = "2021"
 description = "Procedural macros for the mlua crate."

mlua_derive/src/lib.rs

@@ -103,7 +103,7 @@ pub fn chunk(input: TokenStream) -> TokenStream {
 
         struct InnerChunk<F: FnOnce(&Lua) -> Result<Table>>(Cell<Option<F>>);
 
-        impl<F> AsChunk<'static> for InnerChunk<F>
+        impl<F> AsChunk for InnerChunk<F>
         where
             F: FnOnce(&Lua) -> Result<Table>,
         {
@@ -120,7 +120,7 @@ pub fn chunk(input: TokenStream) -> TokenStream {
                 Some(ChunkMode::Text)
             }
 
-            fn source(self) -> IoResult<Cow<'static, [u8]>> {
+            fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>> {
                 Ok(Cow::Borrowed((#source).as_bytes()))
             }
         }
@@ -129,13 +129,13 @@ pub fn chunk(input: TokenStream) -> TokenStream {
             let globals = lua.globals();
             let env = lua.create_table()?;
             let meta = lua.create_table()?;
-            meta.raw_set("__index", globals.clone())?;
-            meta.raw_set("__newindex", globals)?;
+            meta.raw_set("__index", &globals)?;
+            meta.raw_set("__newindex", &globals)?;
 
             // Add captured variables
             #(#caps)*
 
-            env.set_metatable(Some(meta));
+            env.set_metatable(Some(meta))?;
             Ok(env)
         };
 

src/buffer.rs

@@ -1,6 +1,9 @@
-#[cfg(feature = "serialize")]
+use std::io;
+
+#[cfg(feature = "serde")]
 use serde::ser::{Serialize, Serializer};
 
+use crate::state::RawLua;
 use crate::types::ValueRef;
 
 /// A Luau buffer type.
@@ -16,16 +19,17 @@ pub struct Buffer(pub(crate) ValueRef);
 impl Buffer {
     /// Copies the buffer data into a new `Vec<u8>`.
     pub fn to_vec(&self) -> Vec<u8> {
-        unsafe { self.as_slice().to_vec() }
+        let lua = self.0.lua.lock();
+        self.as_slice(&lua).to_vec()
     }
 
     /// Returns the length of the buffer.
     pub fn len(&self) -> usize {
-        unsafe { self.as_slice().len() }
+        let lua = self.0.lua.lock();
+        self.as_slice(&lua).len()
     }
 
     /// Returns `true` if the buffer is empty.
-    #[doc(hidden)]
     pub fn is_empty(&self) -> bool {
         self.len() == 0
     }
@@ -35,7 +39,8 @@ impl Buffer {
     /// Offset is 0-based.
     #[track_caller]
     pub fn read_bytes<const N: usize>(&self, offset: usize) -> [u8; N] {
-        let data = unsafe { self.as_slice() };
+        let lua = self.0.lua.lock();
+        let data = self.as_slice(&lua);
         let mut bytes = [0u8; N];
         bytes.copy_from_slice(&data[offset..offset + N]);
         bytes
@@ -46,21 +51,36 @@ impl Buffer {
     /// Offset is 0-based.
     #[track_caller]
     pub fn write_bytes(&self, offset: usize, bytes: &[u8]) {
-        let data = unsafe {
-            let (buf, size) = self.as_raw_parts();
-            std::slice::from_raw_parts_mut(buf, size)
-        };
+        let lua = self.0.lua.lock();
+        let data = self.as_slice_mut(&lua);
         data[offset..offset + bytes.len()].copy_from_slice(bytes);
     }
 
-    pub(crate) unsafe fn as_slice(&self) -> &[u8] {
-        let (buf, size) = self.as_raw_parts();
-        std::slice::from_raw_parts(buf, size)
+    /// Returns an adaptor implementing [`io::Read`], [`io::Write`] and [`io::Seek`] over the
+    /// buffer.
+    ///
+    /// Buffer operations are infallible, none of the read/write functions will return a Err.
+    pub fn cursor(self) -> impl io::Read + io::Write + io::Seek {
+        BufferCursor(self, 0)
+    }
+
+    pub(crate) fn as_slice(&self, lua: &RawLua) -> &[u8] {
+        unsafe {
+            let (buf, size) = self.as_raw_parts(lua);
+            std::slice::from_raw_parts(buf, size)
+        }
+    }
+
+    #[allow(clippy::mut_from_ref)]
+    fn as_slice_mut(&self, lua: &RawLua) -> &mut [u8] {
+        unsafe {
+            let (buf, size) = self.as_raw_parts(lua);
+            std::slice::from_raw_parts_mut(buf, size)
+        }
     }
 
     #[cfg(feature = "luau")]
-    unsafe fn as_raw_parts(&self) -> (*mut u8, usize) {
-        let lua = self.0.lua.lock();
+    unsafe fn as_raw_parts(&self, lua: &RawLua) -> (*mut u8, usize) {
         let mut size = 0usize;
         let buf = ffi::lua_tobuffer(lua.ref_thread(), self.0.index, &mut size);
         mlua_assert!(!buf.is_null(), "invalid Luau buffer");
@@ -68,15 +88,76 @@ impl Buffer {
     }
 
     #[cfg(not(feature = "luau"))]
-    unsafe fn as_raw_parts(&self) -> (*mut u8, usize) {
+    unsafe fn as_raw_parts(&self, lua: &RawLua) -> (*mut u8, usize) {
         unreachable!()
     }
 }
 
-#[cfg(feature = "serialize")]
+struct BufferCursor(Buffer, usize);
+
+impl io::Read for BufferCursor {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let lua = self.0 .0.lua.lock();
+        let data = self.0.as_slice(&lua);
+        if self.1 == data.len() {
+            return Ok(0);
+        }
+        let len = buf.len().min(data.len() - self.1);
+        buf[..len].copy_from_slice(&data[self.1..self.1 + len]);
+        self.1 += len;
+        Ok(len)
+    }
+}
+
+impl io::Write for BufferCursor {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let lua = self.0 .0.lua.lock();
+        let data = self.0.as_slice_mut(&lua);
+        if self.1 == data.len() {
+            return Ok(0);
+        }
+        let len = buf.len().min(data.len() - self.1);
+        data[self.1..self.1 + len].copy_from_slice(&buf[..len]);
+        self.1 += len;
+        Ok(len)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl io::Seek for BufferCursor {
+    fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
+        let lua = self.0 .0.lua.lock();
+        let data = self.0.as_slice(&lua);
+        let new_offset = match pos {
+            io::SeekFrom::Start(offset) => offset as i64,
+            io::SeekFrom::End(offset) => data.len() as i64 + offset,
+            io::SeekFrom::Current(offset) => self.1 as i64 + offset,
+        };
+        if new_offset < 0 {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "invalid seek to a negative position",
+            ));
+        }
+        if new_offset as usize > data.len() {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "invalid seek to a position beyond the end of the buffer",
+            ));
+        }
+        self.1 = new_offset as usize;
+        Ok(self.1 as u64)
+    }
+}
+
+#[cfg(feature = "serde")]
 impl Serialize for Buffer {
     fn serialize<S: Serializer>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error> {
-        serializer.serialize_bytes(unsafe { self.as_slice() })
+        let lua = self.0.lua.lock();
+        serializer.serialize_bytes(self.as_slice(&lua))
     }
 }
 

src/chunk.rs

@@ -2,7 +2,6 @@ use std::borrow::Cow;
 use std::collections::HashMap;
 use std::ffi::CString;
 use std::io::Result as IoResult;
-use std::marker::PhantomData;
 use std::panic::Location;
 use std::path::{Path, PathBuf};
 use std::string::String as StdString;
@@ -17,7 +16,7 @@ use crate::value::Value;
 /// 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
-pub trait AsChunk<'a> {
+pub trait AsChunk {
     /// Returns optional chunk name
     ///
     /// See [`Chunk::set_name`] for possible name prefixes.
@@ -39,65 +38,100 @@ pub trait AsChunk<'a> {
     }
 
     /// Returns chunk data (can be text or binary)
-    fn source(self) -> IoResult<Cow<'a, [u8]>>;
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a;
 }
 
-impl<'a> AsChunk<'a> for &'a str {
-    fn source(self) -> IoResult<Cow<'a, [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<'a> AsChunk<'a> for &'a StdString {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+impl AsChunk for &str {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a,
+    {
         Ok(Cow::Borrowed(self.as_bytes()))
     }
 }
 
-impl<'a> AsChunk<'a> for &'a [u8] {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+impl AsChunk for StdString {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Owned(self.clone().into_bytes()))
+    }
+}
+
+impl AsChunk for &StdString {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a,
+    {
+        Ok(Cow::Borrowed(self.as_bytes()))
+    }
+}
+
+impl AsChunk for &[u8] {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a,
+    {
         Ok(Cow::Borrowed(self))
     }
 }
 
-impl AsChunk<'static> for Vec<u8> {
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
-        Ok(Cow::Owned(self))
+impl AsChunk for Vec<u8> {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Owned(self.clone()))
     }
 }
 
-impl<'a> AsChunk<'a> for &'a Vec<u8> {
-    fn source(self) -> IoResult<Cow<'a, [u8]>> {
-        Ok(Cow::Borrowed(self.as_ref()))
+impl AsChunk for &Vec<u8> {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a,
+    {
+        Ok(Cow::Borrowed(self))
     }
 }
 
-impl AsChunk<'static> for &Path {
+impl AsChunk for &Path {
     fn name(&self) -> Option<StdString> {
         Some(format!("@{}", self.display()))
     }
 
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>> {
         std::fs::read(self).map(Cow::Owned)
     }
 }
 
-impl AsChunk<'static> for PathBuf {
+impl AsChunk for PathBuf {
     fn name(&self) -> Option<StdString> {
         Some(format!("@{}", self.display()))
     }
 
-    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>> {
         std::fs::read(self).map(Cow::Owned)
     }
 }
 
+impl<C: AsChunk + ?Sized> AsChunk for Box<C> {
+    fn name(&self) -> Option<StdString> {
+        (**self).name()
+    }
+
+    fn environment(&self, lua: &Lua) -> Result<Option<Table>> {
+        (**self).environment(lua)
+    }
+
+    fn mode(&self) -> Option<ChunkMode> {
+        (**self).mode()
+    }
+
+    fn source<'a>(&self) -> IoResult<Cow<'a, [u8]>>
+    where
+        Self: 'a,
+    {
+        (**self).source()
+    }
+}
+
 /// Returned from [`Lua::load`] and is used to finalize loading and executing Lua main chunks.
 #[must_use = "`Chunk`s do nothing unless one of `exec`, `eval`, `call`, or `into_function` are called on them"]
 pub struct Chunk<'a> {
@@ -117,6 +151,49 @@ pub enum ChunkMode {
     Binary,
 }
 
+/// Represents a constant value that can be used by Luau compiler.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Clone, Debug)]
+pub enum CompileConstant {
+    Nil,
+    Boolean(bool),
+    Number(crate::Number),
+    Vector(crate::Vector),
+    String(StdString),
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl From<bool> for CompileConstant {
+    fn from(b: bool) -> Self {
+        CompileConstant::Boolean(b)
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl From<crate::Number> for CompileConstant {
+    fn from(n: crate::Number) -> Self {
+        CompileConstant::Number(n)
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl From<crate::Vector> for CompileConstant {
+    fn from(v: crate::Vector) -> Self {
+        CompileConstant::Vector(v)
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl From<&str> for CompileConstant {
+    fn from(s: &str) -> Self {
+        CompileConstant::String(s.to_owned())
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+type LibraryMemberConstantMap = HashMap<(StdString, StdString), CompileConstant>;
+
 /// Luau compiler
 #[cfg(any(feature = "luau", doc))]
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
@@ -126,11 +203,14 @@ pub struct Compiler {
     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>,
+    vector_lib: Option<StdString>,
+    vector_ctor: Option<StdString>,
+    vector_type: Option<StdString>,
+    mutable_globals: Vec<StdString>,
+    userdata_types: Vec<StdString>,
+    libraries_with_known_members: Vec<StdString>,
+    library_constants: Option<LibraryMemberConstantMap>,
+    disabled_builtins: Vec<StdString>,
 }
 
 #[cfg(any(feature = "luau", doc))]
@@ -155,6 +235,9 @@ impl Compiler {
             vector_type: None,
             mutable_globals: Vec::new(),
             userdata_types: Vec::new(),
+            libraries_with_known_members: Vec::new(),
+            library_constants: None,
+            disabled_builtins: Vec::new(),
         }
     }
 
@@ -187,6 +270,7 @@ impl Compiler {
     /// Possible values:
     /// * 0 - generate for native modules (default)
     /// * 1 - generate for all modules
+    #[must_use]
     pub const fn set_type_info_level(mut self, level: u8) -> Self {
         self.type_info_level = level;
         self
@@ -204,40 +288,103 @@ impl Compiler {
         self
     }
 
+    /// Sets alternative global builtin to construct vectors, in addition to default builtin
+    /// `vector.create`.
+    ///
+    /// To set the library and method name, use the `lib.ctor` format.
     #[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_ctor(mut self, ctor: impl Into<StdString>) -> Self {
+        let ctor = ctor.into();
+        let lib_ctor = ctor.split_once('.');
+        self.vector_lib = lib_ctor.as_ref().map(|&(lib, _)| lib.to_owned());
+        self.vector_ctor = (lib_ctor.as_ref())
+            .map(|&(_, ctor)| ctor.to_owned())
+            .or(Some(ctor));
         self
     }
 
+    /// Sets alternative vector type name for type tables, in addition to default type `vector`.
     #[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 {
+    pub fn set_vector_type(mut self, r#type: impl Into<StdString>) -> Self {
         self.vector_type = Some(r#type.into());
         self
     }
 
+    /// Adds a mutable global.
+    ///
+    /// It disables the import optimization for fields accessed through it.
+    #[must_use]
+    pub fn add_mutable_global(mut self, global: impl Into<StdString>) -> Self {
+        self.mutable_globals.push(global.into());
+        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;
+    pub fn set_mutable_globals<S: Into<StdString>>(mut self, globals: impl IntoIterator<Item = S>) -> Self {
+        self.mutable_globals = globals.into_iter().map(|s| s.into()).collect();
+        self
+    }
+
+    /// Adds a userdata type to the list that will be included in the type information.
+    #[must_use]
+    pub fn add_userdata_type(mut self, r#type: impl Into<StdString>) -> Self {
+        self.userdata_types.push(r#type.into());
         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;
+    pub fn set_userdata_types<S: Into<StdString>>(mut self, types: impl IntoIterator<Item = S>) -> Self {
+        self.userdata_types = types.into_iter().map(|s| s.into()).collect();
+        self
+    }
+
+    /// Adds a constant for a known library member.
+    ///
+    /// The constants are used by the compiler to optimize the generated bytecode.
+    /// Optimization level must be at least 2 for this to have any effect.
+    ///
+    /// The `name` is a string in the format `lib.member`, where `lib` is the library name
+    /// and `member` is the member (constant) name.
+    #[must_use]
+    pub fn add_library_constant(
+        mut self,
+        name: impl AsRef<str>,
+        r#const: impl Into<CompileConstant>,
+    ) -> Self {
+        let Some((lib, member)) = name.as_ref().split_once('.') else {
+            return self;
+        };
+        let (lib, member) = (lib.to_owned(), member.to_owned());
+
+        if !self.libraries_with_known_members.contains(&lib) {
+            self.libraries_with_known_members.push(lib.clone());
+        }
+        self.library_constants
+            .get_or_insert_with(HashMap::new)
+            .insert((lib, member), r#const.into());
+        self
+    }
+
+    /// Adds a builtin that should be disabled.
+    #[must_use]
+    pub fn add_disabled_builtin(mut self, builtin: impl Into<StdString>) -> Self {
+        self.disabled_builtins.push(builtin.into());
+        self
+    }
+
+    /// Sets a list of builtins that should be disabled.
+    #[must_use]
+    pub fn set_disabled_builtins<S: Into<StdString>>(
+        mut self,
+        builtins: impl IntoIterator<Item = S>,
+    ) -> Self {
+        self.disabled_builtins = builtins.into_iter().map(|s| s.into()).collect();
         self
     }
 
@@ -245,7 +392,9 @@ impl Compiler {
     ///
     /// Returns [`Error::SyntaxError`] if the source code is invalid.
     pub fn compile(&self, source: impl AsRef<[u8]>) -> Result<Vec<u8>> {
-        use std::os::raw::c_int;
+        use std::cell::RefCell;
+        use std::ffi::CStr;
+        use std::os::raw::{c_char, c_int};
         use std::ptr;
 
         let vector_lib = self.vector_lib.clone();
@@ -277,6 +426,44 @@ impl Compiler {
 
         vec2cstring_ptr!(mutable_globals, mutable_globals_ptr);
         vec2cstring_ptr!(userdata_types, userdata_types_ptr);
+        vec2cstring_ptr!(libraries_with_known_members, libraries_with_known_members_ptr);
+        vec2cstring_ptr!(disabled_builtins, disabled_builtins_ptr);
+
+        thread_local! {
+            static LIBRARY_MEMBER_CONSTANT_MAP: RefCell<LibraryMemberConstantMap> = Default::default();
+        }
+
+        #[cfg(feature = "luau")]
+        unsafe extern "C-unwind" fn library_member_constant_callback(
+            library: *const c_char,
+            member: *const c_char,
+            constant: *mut ffi::lua_CompileConstant,
+        ) {
+            let library = CStr::from_ptr(library).to_string_lossy();
+            let member = CStr::from_ptr(member).to_string_lossy();
+            LIBRARY_MEMBER_CONSTANT_MAP.with_borrow(|map| {
+                if let Some(cons) = map.get(&(library.to_string(), member.to_string())) {
+                    match cons {
+                        CompileConstant::Nil => ffi::luau_set_compile_constant_nil(constant),
+                        CompileConstant::Boolean(b) => {
+                            ffi::luau_set_compile_constant_boolean(constant, *b as c_int)
+                        }
+                        CompileConstant::Number(n) => ffi::luau_set_compile_constant_number(constant, *n),
+                        CompileConstant::Vector(v) => {
+                            #[cfg(not(feature = "luau-vector4"))]
+                            ffi::luau_set_compile_constant_vector(constant, v.x(), v.y(), v.z(), 0.0);
+                            #[cfg(feature = "luau-vector4")]
+                            ffi::luau_set_compile_constant_vector(constant, v.x(), v.y(), v.z(), v.w());
+                        }
+                        CompileConstant::String(s) => ffi::luau_set_compile_constant_string(
+                            constant,
+                            s.as_ptr() as *const c_char,
+                            s.len(),
+                        ),
+                    }
+                }
+            })
+        }
 
         let bytecode = unsafe {
             let mut options = ffi::lua_CompileOptions::default();
@@ -289,13 +476,21 @@ impl Compiler {
             options.vectorType = vector_type.map_or(ptr::null(), |s| s.as_ptr());
             options.mutableGlobals = mutable_globals_ptr;
             options.userdataTypes = userdata_types_ptr;
+            options.librariesWithKnownMembers = libraries_with_known_members_ptr;
+            if let Some(map) = self.library_constants.as_ref() {
+                if !self.libraries_with_known_members.is_empty() {
+                    LIBRARY_MEMBER_CONSTANT_MAP.with_borrow_mut(|gmap| *gmap = map.clone());
+                    options.libraryMemberConstantCallback = Some(library_member_constant_callback);
+                }
+            }
+            options.disabledBuiltins = disabled_builtins_ptr;
             ffi::luau_compile(source.as_ref(), options)
         };
 
         if bytecode.first() == Some(&0) {
             // The rest of the bytecode is the error message starting with `:`
             // See https://github.com/luau-lang/luau/blob/0.640/Compiler/src/Compiler.cpp#L4336
-            let message = String::from_utf8_lossy(&bytecode[2..]).to_string();
+            let message = StdString::from_utf8_lossy(&bytecode[2..]).into_owned();
             return Err(Error::SyntaxError {
                 incomplete_input: message.ends_with("<eof>"),
                 message,
@@ -318,7 +513,7 @@ impl Chunk<'_> {
     /// - `@` - file path (when truncation is needed, the end of the file path is kept, as this is
     ///   more useful for identifying the file)
     /// - `=` - custom chunk name (when truncation is needed, the beginning of the name is kept)
-    pub fn set_name(mut self, name: impl Into<String>) -> Self {
+    pub fn set_name(mut self, name: impl Into<StdString>) -> Self {
         self.name = name.into();
         self
     }
@@ -361,8 +556,6 @@ impl Chunk<'_> {
     /// Sets or overwrites a Luau compiler used for this chunk.
     ///
     /// See [`Compiler`] for details and possible options.
-    ///
-    /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     pub fn set_compiler(mut self, compiler: Compiler) -> Self {
@@ -381,8 +574,6 @@ impl Chunk<'_> {
     ///
     /// See [`exec`] for more details.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`exec`]: Chunk::exec
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
@@ -413,8 +604,6 @@ impl Chunk<'_> {
     ///
     /// See [`eval`] for more details.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`eval`]: Chunk::eval
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
@@ -442,8 +631,6 @@ impl Chunk<'_> {
     ///
     /// See [`call`] for more details.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`call`]: Chunk::call
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
@@ -503,7 +690,7 @@ impl Chunk<'_> {
         if let Ok(ref source) = self.source {
             if self.detect_mode() == ChunkMode::Text {
                 let lua = self.lua.lock();
-                if let Some(cache) = lua.app_data_ref_unguarded::<ChunksCache>() {
+                if let Some(cache) = lua.priv_app_data_ref::<ChunksCache>() {
                     if let Some(data) = cache.0.get(source.as_ref()) {
                         self.source = Ok(Cow::Owned(data.clone()));
                         self.mode = Some(ChunkMode::Binary);
@@ -520,12 +707,12 @@ impl Chunk<'_> {
             if let Ok(ref binary_source) = self.source {
                 if self.detect_mode() == ChunkMode::Binary {
                     let lua = self.lua.lock();
-                    if let Some(mut cache) = lua.app_data_mut_unguarded::<ChunksCache>() {
-                        cache.0.insert(text_source, binary_source.as_ref().to_vec());
+                    if let Some(mut cache) = lua.priv_app_data_mut::<ChunksCache>() {
+                        cache.0.insert(text_source, binary_source.to_vec());
                     } else {
                         let mut cache = ChunksCache(HashMap::new());
-                        cache.0.insert(text_source, binary_source.as_ref().to_vec());
-                        let _ = lua.try_set_app_data(cache);
+                        cache.0.insert(text_source, binary_source.to_vec());
+                        lua.set_priv_app_data(cache);
                     };
                 }
             }
@@ -558,24 +745,23 @@ impl Chunk<'_> {
     }
 
     fn detect_mode(&self) -> ChunkMode {
-        match (self.mode, &self.source) {
-            (Some(mode), _) => mode,
-            (None, Ok(source)) => {
-                #[cfg(not(feature = "luau"))]
-                if source.starts_with(ffi::LUA_SIGNATURE) {
-                    return ChunkMode::Binary;
-                }
-                #[cfg(feature = "luau")]
-                if *source.first().unwrap_or(&u8::MAX) < b'\n' {
-                    return ChunkMode::Binary;
-                }
-                ChunkMode::Text
-            }
-            (None, Err(_)) => ChunkMode::Text, // any value is fine
+        if let Some(mode) = self.mode {
+            return mode;
         }
+        if let Ok(source) = &self.source {
+            #[cfg(not(feature = "luau"))]
+            if source.starts_with(ffi::LUA_SIGNATURE) {
+                return ChunkMode::Binary;
+            }
+            #[cfg(feature = "luau")]
+            if *source.first().unwrap_or(&u8::MAX) < b'\n' {
+                return ChunkMode::Binary;
+            }
+        }
+        ChunkMode::Text
     }
 
-    fn convert_name(name: String) -> Result<CString> {
+    fn convert_name(name: StdString) -> Result<CString> {
         CString::new(name).map_err(|err| Error::runtime(format!("invalid name: {err}")))
     }
 
@@ -587,29 +773,27 @@ impl Chunk<'_> {
     }
 }
 
-struct WrappedChunk<'a, T: AsChunk<'a>> {
+struct WrappedChunk<T: AsChunk> {
     chunk: T,
     caller: &'static Location<'static>,
-    _marker: PhantomData<&'a T>,
 }
 
-impl<'a> Chunk<'a> {
+impl Chunk<'_> {
     /// Wraps a chunk of Lua code, returning an opaque type that implements [`IntoLua`] trait.
     ///
     /// The resulted `IntoLua` implementation will convert the chunk into a Lua function without
     /// executing it.
     #[doc(hidden)]
     #[track_caller]
-    pub fn wrap(chunk: impl AsChunk<'a> + 'a) -> impl IntoLua + 'a {
+    pub fn wrap(chunk: impl AsChunk) -> impl IntoLua {
         WrappedChunk {
             chunk,
             caller: Location::caller(),
-            _marker: PhantomData,
         }
     }
 }
 
-impl<'a, T: AsChunk<'a>> IntoLua for WrappedChunk<'a, T> {
+impl<T: AsChunk> IntoLua for WrappedChunk<T> {
     fn into_lua(self, lua: &Lua) -> Result<Value> {
         lua.load_with_location(self.chunk, self.caller)
             .into_function()

src/conversion.rs

@@ -645,7 +645,7 @@ impl FromLua for BString {
         match value {
             Value::String(s) => Ok((*s.as_bytes()).into()),
             #[cfg(feature = "luau")]
-            Value::Buffer(buf) => unsafe { Ok(buf.as_slice().into()) },
+            Value::Buffer(buf) => Ok(buf.to_vec().into()),
             _ => Ok((*lua
                 .coerce_string(value)?
                 .ok_or_else(|| Error::FromLuaConversionError {
@@ -808,15 +808,9 @@ macro_rules! lua_convert_int {
         impl IntoLua for $x {
             #[inline]
             fn into_lua(self, _: &Lua) -> Result<Value> {
-                cast(self)
+                Ok(cast(self)
                     .map(Value::Integer)
-                    .or_else(|| cast(self).map(Value::Number))
-                    // This is impossible error because conversion to Number never fails
-                    .ok_or_else(|| Error::ToLuaConversionError {
-                        from: stringify!($x).to_string(),
-                        to: "number",
-                        message: Some("out of range".to_owned()),
-                    })
+                    .unwrap_or_else(|| Value::Number(self as ffi::lua_Number)))
             }
 
             #[inline]
@@ -899,13 +893,7 @@ macro_rules! lua_convert_float {
         impl IntoLua for $x {
             #[inline]
             fn into_lua(self, _: &Lua) -> Result<Value> {
-                cast(self)
-                    .ok_or_else(|| Error::ToLuaConversionError {
-                        from: stringify!($x).to_string(),
-                        to: "number",
-                        message: Some("out of range".to_string()),
-                    })
-                    .map(Value::Number)
+                Ok(Value::Number(self as _))
             }
         }
 
@@ -914,33 +902,19 @@ macro_rules! lua_convert_float {
             fn from_lua(value: Value, lua: &Lua) -> Result<Self> {
                 let ty = value.type_name();
                 lua.coerce_number(value)?
+                    .map(|n| n as $x)
                     .ok_or_else(|| Error::FromLuaConversionError {
                         from: ty,
                         to: stringify!($x).to_string(),
                         message: Some("expected number or string coercible to number".to_string()),
                     })
-                    .and_then(|n| {
-                        cast(n).ok_or_else(|| Error::FromLuaConversionError {
-                            from: ty,
-                            to: stringify!($x).to_string(),
-                            message: Some("number out of range".to_string()),
-                        })
-                    })
             }
 
             unsafe fn from_stack(idx: c_int, lua: &RawLua) -> Result<Self> {
                 let state = lua.state();
                 let type_id = ffi::lua_type(state, idx);
                 if type_id == ffi::LUA_TNUMBER {
-                    let mut ok = 0;
-                    let i = ffi::lua_tonumberx(state, idx, &mut ok);
-                    if ok != 0 {
-                        return cast(i).ok_or_else(|| Error::FromLuaConversionError {
-                            from: "number",
-                            to: stringify!($x).to_string(),
-                            message: Some("out of range".to_owned()),
-                        });
-                    }
+                    return Ok(ffi::lua_tonumber(state, idx) as _);
                 }
                 // Fallback to default
                 Self::from_lua(lua.stack_value(idx, Some(type_id)), lua.lua())

src/debug.rs

@@ -1,66 +1,33 @@
 use std::borrow::Cow;
-use std::cell::UnsafeCell;
-use std::ops::Deref;
-#[cfg(not(feature = "luau"))]
-use std::ops::{BitOr, BitOrAssign};
 use std::os::raw::c_int;
 
-use ffi::lua_Debug;
+use ffi::{lua_Debug, lua_State};
 
+use crate::function::Function;
 use crate::state::RawLua;
-use crate::types::ReentrantMutexGuard;
-use crate::util::{linenumber_to_usize, ptr_to_lossy_str, ptr_to_str};
+use crate::util::{assert_stack, linenumber_to_usize, ptr_to_lossy_str, ptr_to_str, StackGuard};
 
 /// Contains information about currently executing Lua code.
 ///
-/// The `Debug` structure is provided as a parameter to the hook function set with
-/// [`Lua::set_hook`]. You may call the methods on this structure to retrieve information about the
-/// Lua code executing at the time that the hook function was called. Further information can be
-/// found in the Lua [documentation].
+/// You may call the methods on this structure to retrieve information about the Lua code executing
+/// at the specific level. Further information can be found in the Lua [documentation].
 ///
 /// [documentation]: https://www.lua.org/manual/5.4/manual.html#lua_Debug
-/// [`Lua::set_hook`]: crate::Lua::set_hook
 pub struct Debug<'a> {
-    lua: EitherLua<'a>,
-    ar: ActivationRecord,
-    #[cfg(feature = "luau")]
+    state: *mut lua_State,
+    lua: &'a RawLua,
+    #[cfg_attr(not(feature = "luau"), allow(unused))]
     level: c_int,
-}
-
-enum EitherLua<'a> {
-    Owned(ReentrantMutexGuard<'a, RawLua>),
-    #[cfg(not(feature = "luau"))]
-    Borrowed(&'a RawLua),
-}
-
-impl Deref for EitherLua<'_> {
-    type Target = RawLua;
-
-    fn deref(&self) -> &Self::Target {
-        match self {
-            EitherLua::Owned(guard) => guard,
-            #[cfg(not(feature = "luau"))]
-            EitherLua::Borrowed(lua) => lua,
-        }
-    }
+    ar: *mut lua_Debug,
 }
 
 impl<'a> Debug<'a> {
-    // We assume the lock is held when this function is called.
-    #[cfg(not(feature = "luau"))]
-    pub(crate) fn new(lua: &'a RawLua, ar: *mut lua_Debug) -> Self {
+    pub(crate) fn new(lua: &'a RawLua, level: c_int, ar: *mut lua_Debug) -> Self {
         Debug {
-            lua: EitherLua::Borrowed(lua),
-            ar: ActivationRecord::Borrowed(ar),
-        }
-    }
-
-    pub(crate) fn new_owned(guard: ReentrantMutexGuard<'a, RawLua>, _level: c_int, ar: lua_Debug) -> Self {
-        Debug {
-            lua: EitherLua::Owned(guard),
-            ar: ActivationRecord::Owned(UnsafeCell::new(ar)),
-            #[cfg(feature = "luau")]
-            level: _level,
+            state: lua.state(),
+            lua,
+            ar,
+            level,
         }
     }
 
@@ -74,7 +41,7 @@ impl<'a> Debug<'a> {
     #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub fn event(&self) -> DebugEvent {
         unsafe {
-            match (*self.ar.get()).event {
+            match (*self.ar).event {
                 ffi::LUA_HOOKCALL => DebugEvent::Call,
                 ffi::LUA_HOOKRET => DebugEvent::Ret,
                 ffi::LUA_HOOKTAILCALL => DebugEvent::TailCall,
@@ -85,24 +52,48 @@ impl<'a> Debug<'a> {
         }
     }
 
-    /// Corresponds to the `n` what mask.
-    pub fn names(&self) -> DebugNames {
+    /// Returns the function that is running at the given level.
+    ///
+    /// Corresponds to the `f` "what" mask.
+    pub fn function(&self) -> Function {
+        unsafe {
+            let _sg = StackGuard::new(self.state);
+            assert_stack(self.state, 1);
+
+            #[cfg(not(feature = "luau"))]
+            mlua_assert!(
+                ffi::lua_getinfo(self.state, cstr!("f"), self.ar) != 0,
+                "lua_getinfo failed with `f`"
+            );
+            #[cfg(feature = "luau")]
+            mlua_assert!(
+                ffi::lua_getinfo(self.state, self.level, cstr!("f"), self.ar) != 0,
+                "lua_getinfo failed with `f`"
+            );
+
+            ffi::lua_xmove(self.state, self.lua.ref_thread(), 1);
+            Function(self.lua.pop_ref_thread())
+        }
+    }
+
+    /// Corresponds to the `n` "what" mask.
+    pub fn names(&self) -> DebugNames<'_> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("n"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.state, cstr!("n"), self.ar) != 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.state, self.level, cstr!("n"), self.ar) != 0,
                 "lua_getinfo failed with `n`"
             );
 
             DebugNames {
-                name: ptr_to_lossy_str((*self.ar.get()).name),
+                name: ptr_to_lossy_str((*self.ar).name),
                 #[cfg(not(feature = "luau"))]
-                name_what: match ptr_to_str((*self.ar.get()).namewhat) {
+                name_what: match ptr_to_str((*self.ar).namewhat) {
                     Some("") => None,
                     val => val,
                 },
@@ -112,118 +103,110 @@ impl<'a> Debug<'a> {
         }
     }
 
-    /// Corresponds to the `S` what mask.
-    pub fn source(&self) -> DebugSource {
+    /// Corresponds to the `S` "what" mask.
+    pub fn source(&self) -> DebugSource<'_> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("S"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.state, cstr!("S"), self.ar) != 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.state, self.level, cstr!("s"), self.ar) != 0,
                 "lua_getinfo failed with `s`"
             );
 
             DebugSource {
-                source: ptr_to_lossy_str((*self.ar.get()).source),
+                source: ptr_to_lossy_str((*self.ar).source),
                 #[cfg(not(feature = "luau"))]
-                short_src: ptr_to_lossy_str((*self.ar.get()).short_src.as_ptr()),
+                short_src: ptr_to_lossy_str((*self.ar).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_lossy_str((*self.ar).short_src),
+                line_defined: linenumber_to_usize((*self.ar).linedefined),
                 #[cfg(not(feature = "luau"))]
-                last_line_defined: linenumber_to_usize((*self.ar.get()).lastlinedefined),
+                last_line_defined: linenumber_to_usize((*self.ar).lastlinedefined),
                 #[cfg(feature = "luau")]
                 last_line_defined: None,
-                what: ptr_to_str((*self.ar.get()).what).unwrap_or("main"),
+                what: ptr_to_str((*self.ar).what).unwrap_or("main"),
             }
         }
     }
 
-    /// Corresponds to the `l` what mask. Returns the current line.
+    #[doc(hidden)]
+    #[deprecated(note = "Use `current_line` instead")]
     pub fn curr_line(&self) -> i32 {
+        self.current_line().map(|n| n as i32).unwrap_or(-1)
+    }
+
+    /// Corresponds to the `l` "what" mask. Returns the current line.
+    pub fn current_line(&self) -> Option<usize> {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("l"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.state, cstr!("l"), self.ar) != 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.state, self.level, cstr!("l"), self.ar) != 0,
                 "lua_getinfo failed with `l`"
             );
 
-            (*self.ar.get()).currentline
+            linenumber_to_usize((*self.ar).currentline)
         }
     }
 
-    /// Corresponds to the `t` what mask. Returns true if the hook is in a function tail call, false
-    /// otherwise.
-    #[cfg(not(feature = "luau"))]
-    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
+    /// Corresponds to the `t` "what" mask. Returns true if the hook is in a function tail call,
+    /// false otherwise.
+    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua54", feature = "lua53", feature = "lua52")))
+    )]
     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.state, cstr!("t"), self.ar) != 0,
                 "lua_getinfo failed with `t`"
             );
-            (*self.ar.get()).currentline != 0
+            (*self.ar).istailcall != 0
         }
     }
 
-    /// Corresponds to the `u` what mask.
+    /// Corresponds to the `u` "what" mask.
     pub fn stack(&self) -> DebugStack {
         unsafe {
             #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), cstr!("u"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.state, cstr!("u"), self.ar) != 0,
                 "lua_getinfo failed with `u`"
             );
             #[cfg(feature = "luau")]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("au"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.state, self.level, cstr!("au"), self.ar) != 0,
                 "lua_getinfo failed with `au`"
             );
 
             #[cfg(not(feature = "luau"))]
             let stack = DebugStack {
-                num_ups: (*self.ar.get()).nups as _,
+                num_ups: (*self.ar).nups as _,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-                num_params: (*self.ar.get()).nparams as _,
+                num_params: (*self.ar).nparams as _,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-                is_vararg: (*self.ar.get()).isvararg != 0,
+                is_vararg: (*self.ar).isvararg != 0,
             };
             #[cfg(feature = "luau")]
             let stack = DebugStack {
-                num_ups: (*self.ar.get()).nupvals,
-                num_params: (*self.ar.get()).nparams,
-                is_vararg: (*self.ar.get()).isvararg != 0,
+                num_ups: (*self.ar).nupvals,
+                num_params: (*self.ar).nparams,
+                is_vararg: (*self.ar).isvararg != 0,
             };
             stack
         }
     }
 }
 
-enum ActivationRecord {
-    #[cfg(not(feature = "luau"))]
-    Borrowed(*mut lua_Debug),
-    Owned(UnsafeCell<lua_Debug>),
-}
-
-impl ActivationRecord {
-    #[inline]
-    fn get(&self) -> *mut lua_Debug {
-        match self {
-            #[cfg(not(feature = "luau"))]
-            ActivationRecord::Borrowed(x) => *x,
-            ActivationRecord::Owned(x) => x.get(),
-        }
-    }
-}
-
 /// Represents a specific event that triggered the hook.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum DebugEvent {
@@ -265,14 +248,18 @@ pub struct DebugStack {
     /// Number of upvalues.
     pub num_ups: u8,
     /// Number of parameters.
-    ///
-    /// Requires `feature = "lua54/lua53/lua52/luau"`
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau"))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau")))
+    )]
     pub num_params: u8,
     /// Whether the function is a vararg function.
-    ///
-    /// Requires `feature = "lua54/lua53/lua52/luau"`
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau"))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau")))
+    )]
     pub is_vararg: bool,
 }
 
@@ -378,7 +365,7 @@ impl HookTriggers {
 }
 
 #[cfg(not(feature = "luau"))]
-impl BitOr for HookTriggers {
+impl std::ops::BitOr for HookTriggers {
     type Output = Self;
 
     fn bitor(mut self, rhs: Self) -> Self::Output {
@@ -393,7 +380,7 @@ impl BitOr for HookTriggers {
 }
 
 #[cfg(not(feature = "luau"))]
-impl BitOrAssign for HookTriggers {
+impl std::ops::BitOrAssign for HookTriggers {
     fn bitor_assign(&mut self, rhs: Self) {
         *self = *self | rhs;
     }

src/error.rs

@@ -183,12 +183,12 @@ pub enum Error {
     /// and returned again.
     PreviouslyResumedPanic,
     /// Serialization error.
-    #[cfg(feature = "serialize")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+    #[cfg(feature = "serde")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
     SerializeError(StdString),
     /// Deserialization error.
-    #[cfg(feature = "serialize")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+    #[cfg(feature = "serde")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
     DeserializeError(StdString),
     /// A custom error.
     ///
@@ -309,11 +309,11 @@ impl fmt::Display for Error {
             Error::PreviouslyResumedPanic => {
                 write!(fmt, "previously resumed panic returned again")
             }
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Error::SerializeError(err) => {
                 write!(fmt, "serialize error: {err}")
             },
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Error::DeserializeError(err) => {
                 write!(fmt, "deserialize error: {err}")
             },
@@ -494,14 +494,14 @@ impl From<Utf8Error> for Error {
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl serde::ser::Error for Error {
     fn custom<T: fmt::Display>(msg: T) -> Self {
         Self::SerializeError(msg.to_string())
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl serde::de::Error for Error {
     fn custom<T: fmt::Display>(msg: T) -> Self {
         Self::DeserializeError(msg.to_string())

src/function.rs

@@ -14,9 +14,12 @@ use crate::value::Value;
 
 #[cfg(feature = "async")]
 use {
+    crate::thread::AsyncThread,
     crate::traits::LuaNativeAsyncFn,
     crate::types::AsyncCallback,
     std::future::{self, Future},
+    std::pin::{pin, Pin},
+    std::task::{Context, Poll},
 };
 
 /// Handle to an internal Lua function.
@@ -128,9 +131,8 @@ impl Function {
     /// Returns a future that, when polled, calls `self`, passing `args` as function arguments,
     /// and drives the execution.
     ///
-    /// Internally it wraps the function to an [`AsyncThread`].
-    ///
-    /// Requires `feature = "async"`
+    /// Internally it wraps the function to an [`AsyncThread`]. The returned type implements
+    /// `Future<Output = Result<R>>` and can be awaited.
     ///
     /// # Examples
     ///
@@ -155,19 +157,18 @@ impl Function {
     /// [`AsyncThread`]: crate::AsyncThread
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<R>(&self, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    pub fn call_async<R>(&self, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
         let lua = self.0.lua.lock();
-        let thread_res = unsafe {
-            lua.create_recycled_thread(self).map(|th| {
-                let mut th = th.into_async(args);
+        AsyncCallFuture(unsafe {
+            lua.create_recycled_thread(self).and_then(|th| {
+                let mut th = th.into_async(args)?;
                 th.set_recyclable(true);
-                th
+                Ok(th)
             })
-        };
-        async move { thread_res?.await }
+        })
     }
 
     /// Returns a function that, when called, calls `self`, passing `args` as the first set of
@@ -252,7 +253,7 @@ impl Function {
             "#,
         )
         .try_cache()
-        .set_name("__mlua_bind")
+        .set_name("=__mlua_bind")
         .call((self, args_wrapper))
     }
 
@@ -280,7 +281,7 @@ impl Function {
                 // 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,
+                    s if std::ffi::CStr::from_ptr(s as _) == c"_ENV" => break,
                     _ => ffi::lua_pop(state, 1),
                 }
             }
@@ -319,7 +320,7 @@ impl Function {
             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" => {
+                    s if std::ffi::CStr::from_ptr(s as _) == c"_ENV" => {
                         ffi::lua_pop(state, 1);
                         // Create an anonymous function with the new environment
                         let f_with_env = lua
@@ -430,12 +431,10 @@ impl Function {
     ///
     /// Recording of coverage information is controlled by [`Compiler::set_coverage_level`] option.
     ///
-    /// Requires `feature = "luau"`
-    ///
     /// [`Compiler::set_coverage_level`]: crate::chunk::Compiler::set_coverage_level
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    pub fn coverage<F>(&self, mut func: F)
+    pub fn coverage<F>(&self, func: F)
     where
         F: FnMut(CoverageInfo),
     {
@@ -455,13 +454,16 @@ impl Function {
             } else {
                 None
             };
-            let rust_callback = &mut *(data as *mut F);
-            rust_callback(CoverageInfo {
-                function,
-                line_defined,
-                depth,
-                hits: slice::from_raw_parts(hits, size).to_vec(),
-            });
+            let rust_callback = &*(data as *const RefCell<F>);
+            if let Ok(mut rust_callback) = rust_callback.try_borrow_mut() {
+                // Call the Rust callback with CoverageInfo
+                rust_callback(CoverageInfo {
+                    function,
+                    line_defined,
+                    depth,
+                    hits: slice::from_raw_parts(hits, size).to_vec(),
+                });
+            }
         }
 
         let lua = self.0.lua.lock();
@@ -471,7 +473,8 @@ impl Function {
             assert_stack(state, 1);
 
             lua.push_ref(&self.0);
-            let func_ptr = &mut func as *mut F as *mut c_void;
+            let func = RefCell::new(func);
+            let func_ptr = &func as *const RefCell<F> as *mut c_void;
             ffi::lua_getcoverage(state, -1, func_ptr, callback::<F>);
         }
     }
@@ -491,20 +494,26 @@ impl 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(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    pub fn deep_clone(&self) -> Self {
+    pub fn deep_clone(&self) -> Result<Self> {
         let lua = self.0.lua.lock();
-        let ref_thread = lua.ref_thread();
+        let state = lua.state();
         unsafe {
-            if ffi::lua_iscfunction(ref_thread, self.0.index) != 0 {
-                return self.clone();
+            let _sg = StackGuard::new(state);
+            check_stack(state, 2)?;
+
+            lua.push_ref(&self.0);
+            if ffi::lua_iscfunction(state, -1) != 0 {
+                return Ok(self.clone());
             }
 
-            ffi::lua_clonefunction(ref_thread, self.0.index);
-            Function(lua.pop_ref_thread())
+            if lua.unlikely_memory_error() {
+                ffi::lua_clonefunction(state, -1);
+            } else {
+                protect_lua!(state, 1, 1, fn(state) ffi::lua_clonefunction(state, -1))?;
+            }
+            Ok(Function(lua.pop_ref()))
         }
     }
 }
@@ -644,6 +653,30 @@ impl LuaType for Function {
     const TYPE_ID: c_int = ffi::LUA_TFUNCTION;
 }
 
+#[cfg(feature = "async")]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+pub struct AsyncCallFuture<R: FromLuaMulti>(Result<AsyncThread<R>>);
+
+#[cfg(feature = "async")]
+impl<R: FromLuaMulti> AsyncCallFuture<R> {
+    pub(crate) fn error(err: Error) -> Self {
+        AsyncCallFuture(Err(err))
+    }
+}
+
+#[cfg(feature = "async")]
+impl<R: FromLuaMulti> Future for AsyncCallFuture<R> {
+    type Output = Result<R>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
+        match &mut this.0 {
+            Ok(thread) => pin!(thread).poll(cx),
+            Err(err) => Poll::Ready(Err(err.clone())),
+        }
+    }
+}
+
 #[cfg(test)]
 mod assertions {
     use super::*;
@@ -652,4 +685,7 @@ mod assertions {
     static_assertions::assert_not_impl_any!(Function: Send);
     #[cfg(feature = "send")]
     static_assertions::assert_impl_all!(Function: Send, Sync);
+
+    #[cfg(all(feature = "async", feature = "send"))]
+    static_assertions::assert_impl_all!(AsyncCallFuture<()>: Send);
 }

src/lib.rs

@@ -35,7 +35,7 @@
 //! The [`Value`] enum and other types implement [`serde::Serialize`] trait to support serializing
 //! Lua values into Rust values.
 //!
-//! Requires `feature = "serialize"`.
+//! Requires `feature = "serde"`.
 //!
 //! # Async/await support
 //!
@@ -67,6 +67,7 @@
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![cfg_attr(not(send), allow(clippy::arc_with_non_send_sync))]
 #![allow(clippy::ptr_eq)]
+#![allow(unsafe_op_in_unsafe_fn)]
 
 #[macro_use]
 mod macros;
@@ -74,10 +75,10 @@ mod macros;
 mod buffer;
 mod chunk;
 mod conversion;
+mod debug;
 mod error;
 mod function;
-mod hook;
-#[cfg(feature = "luau")]
+#[cfg(any(feature = "luau", doc))]
 mod luau;
 mod memory;
 mod multi;
@@ -100,9 +101,9 @@ pub use bstr::BString;
 pub use ffi::{self, lua_CFunction, lua_State};
 
 pub use crate::chunk::{AsChunk, Chunk, ChunkMode};
+pub use crate::debug::{Debug, DebugEvent, DebugNames, DebugSource, DebugStack};
 pub use crate::error::{Error, ErrorContext, ExternalError, ExternalResult, Result};
 pub use crate::function::{Function, FunctionInfo};
-pub use crate::hook::{Debug, DebugEvent, DebugNames, DebugSource, DebugStack};
 pub use crate::multi::{MultiValue, Variadic};
 pub use crate::scope::Scope;
 pub use crate::state::{GCMode, Lua, LuaOptions, WeakLua};
@@ -123,22 +124,31 @@ pub use crate::userdata::{
 pub use crate::value::{Nil, Value};
 
 #[cfg(not(feature = "luau"))]
-pub use crate::hook::HookTriggers;
+pub use crate::debug::HookTriggers;
 
 #[cfg(any(feature = "luau", doc))]
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-pub use crate::{buffer::Buffer, chunk::Compiler, function::CoverageInfo, vector::Vector};
+pub use crate::{
+    buffer::Buffer,
+    chunk::{CompileConstant, Compiler},
+    function::CoverageInfo,
+    luau::{NavigateError, Require, TextRequirer},
+    vector::Vector,
+};
 
 #[cfg(feature = "async")]
 #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
 pub use crate::{thread::AsyncThread, traits::LuaNativeAsyncFn};
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 #[doc(inline)]
-pub use crate::serde::{de::Options as DeserializeOptions, ser::Options as SerializeOptions, LuaSerdeExt};
+pub use crate::{
+    serde::{de::Options as DeserializeOptions, ser::Options as SerializeOptions, LuaSerdeExt},
+    value::SerializableValue,
+};
 
-#[cfg(feature = "serialize")]
-#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 pub mod serde;
 
 #[cfg(feature = "mlua_derive")]

src/luau/mod.rs

@@ -1,16 +1,32 @@
 use std::ffi::CStr;
 use std::os::raw::c_int;
+use std::ptr;
 
+use crate::chunk::ChunkMode;
 use crate::error::Result;
-use crate::state::Lua;
+use crate::function::Function;
+use crate::state::{callback_error_ext, ExtraData, Lua};
+use crate::traits::{FromLuaMulti, IntoLua};
+use crate::types::MaybeSend;
+
+pub use require::{NavigateError, Require, TextRequirer};
 
 // Since Luau has some missing standard functions, we re-implement them here
 
 impl Lua {
+    /// Create a custom Luau `require` function using provided [`Require`] implementation to find
+    /// and load modules.
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn create_require_function<R: Require + MaybeSend + 'static>(&self, require: R) -> Result<Function> {
+        require::create_require_function(self, require)
+    }
+
     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("loadstring", self.create_c_function(lua_loadstring)?)?;
 
         // Set `_VERSION` global to include version number
         // The environment variable `LUAU_VERSION` set by the build script
@@ -18,11 +34,10 @@ impl Lua {
             globals.raw_set("_VERSION", format!("Luau {version}"))?;
         }
 
-        Ok(())
-    }
+        // Enable default `require` implementation
+        let require = self.create_require_function(require::TextRequirer::new())?;
+        self.globals().raw_set("require", require)?;
 
-    pub(crate) fn disable_c_modules(&self) -> Result<()> {
-        package::disable_dylibs(self);
         Ok(())
     }
 }
@@ -31,16 +46,17 @@ unsafe extern "C-unwind" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_
     let option = ffi::luaL_optstring(state, 1, cstr!("collect"));
     let option = CStr::from_ptr(option);
     let arg = ffi::luaL_optinteger(state, 2, 0);
+    let is_sandboxed = (*ExtraData::get(state)).sandboxed;
     match option.to_str() {
-        Ok("collect") => {
+        Ok("collect") if !is_sandboxed => {
             ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0);
             0
         }
-        Ok("stop") => {
+        Ok("stop") if !is_sandboxed => {
             ffi::lua_gc(state, ffi::LUA_GCSTOP, 0);
             0
         }
-        Ok("restart") => {
+        Ok("restart") if !is_sandboxed => {
             ffi::lua_gc(state, ffi::LUA_GCRESTART, 0);
             0
         }
@@ -50,12 +66,12 @@ unsafe extern "C-unwind" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_
             ffi::lua_pushnumber(state, kbytes + kbytes_rem / 1024.0);
             1
         }
-        Ok("step") => {
-            let res = ffi::lua_gc(state, ffi::LUA_GCSTEP, arg);
+        Ok("step") if !is_sandboxed => {
+            let res = ffi::lua_gc(state, ffi::LUA_GCSTEP, arg as _);
             ffi::lua_pushboolean(state, res);
             1
         }
-        Ok("isrunning") => {
+        Ok("isrunning") if !is_sandboxed => {
             let res = ffi::lua_gc(state, ffi::LUA_GCISRUNNING, 0);
             ffi::lua_pushboolean(state, res);
             1
@@ -64,6 +80,20 @@ unsafe extern "C-unwind" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_
     }
 }
 
-pub(crate) use package::register_package_module;
+unsafe extern "C-unwind" fn lua_loadstring(state: *mut ffi::lua_State) -> c_int {
+    callback_error_ext(state, ptr::null_mut(), false, move |extra, nargs| {
+        let rawlua = (*extra).raw_lua();
+        let (chunk, chunk_name) =
+            <(String, Option<String>)>::from_stack_args(nargs, 1, Some("loadstring"), rawlua)?;
+        let chunk_name = chunk_name.as_deref().unwrap_or("=(loadstring)");
+        (rawlua.lua())
+            .load(chunk)
+            .set_name(chunk_name)
+            .set_mode(ChunkMode::Text)
+            .into_function()?
+            .push_into_stack(rawlua)?;
+        Ok(1)
+    })
+}
 
-mod package;
+mod require;

src/luau/package.rs

@@ -1,271 +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::state::Lua;
-use crate::table::Table;
-use crate::traits::IntoLua;
-use crate::value::Value;
-
-#[cfg(unix)]
-use {libloading::Library, rustc_hash::FxHashMap};
-
-//
-// Luau package module
-//
-
-#[cfg(unix)]
-const TARGET_MLUA_LUAU_ABI_VERSION: u32 = 3;
-
-#[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 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
-    let package = lua.create_table()?;
-
-    // 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 = if let Ok(Some(loaded)) = lua.named_registry_value::<Option<Table>>("_LOADED") {
-        package.raw_set("loaded", &loaded)?;
-        loaded
-    } else {
-        let loaded = lua.create_table()?;
-        package.raw_set("loaded", &loaded)?;
-        lua.set_named_registry_value("_LOADED", &loaded)?;
-        loaded
-    };
-
-    // Set `package.loaders`
-    let loaders = lua.create_sequence_from([lua.create_function(lua_loader)?])?;
-    package.raw_set("loaders", &loaders)?;
-    #[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)?;
-    loaded.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 loaded = lua.named_registry_value::<Table>("_LOADED")?;
-        loaded.raw_get::<Table>("package")
-    }?;
-    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 loaded = lua.named_registry_value::<Table>("_LOADED")?;
-        loaded.raw_get::<Table>("package")
-    }?;
-    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/luau/require.rs

@@ -0,0 +1,688 @@
+use std::cell::RefCell;
+use std::collections::VecDeque;
+use std::ffi::CStr;
+use std::io::Result as IoResult;
+use std::ops::{Deref, DerefMut};
+use std::os::raw::{c_char, c_int, c_void};
+use std::path::{Component, Path, PathBuf};
+use std::result::Result as StdResult;
+use std::{env, fmt, fs, mem, ptr};
+
+use crate::error::{Error, Result};
+use crate::function::Function;
+use crate::state::{callback_error_ext, Lua};
+use crate::table::Table;
+use crate::types::MaybeSend;
+
+/// An error that can occur during navigation in the Luau `require-by-string` system.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Debug, Clone)]
+pub enum NavigateError {
+    Ambiguous,
+    NotFound,
+    Other(Error),
+}
+
+#[cfg(feature = "luau")]
+trait IntoNavigateResult {
+    fn into_nav_result(self) -> Result<ffi::luarequire_NavigateResult>;
+}
+
+#[cfg(feature = "luau")]
+impl IntoNavigateResult for StdResult<(), NavigateError> {
+    fn into_nav_result(self) -> Result<ffi::luarequire_NavigateResult> {
+        match self {
+            Ok(()) => Ok(ffi::luarequire_NavigateResult::Success),
+            Err(NavigateError::Ambiguous) => Ok(ffi::luarequire_NavigateResult::Ambiguous),
+            Err(NavigateError::NotFound) => Ok(ffi::luarequire_NavigateResult::NotFound),
+            Err(NavigateError::Other(err)) => Err(err),
+        }
+    }
+}
+
+impl From<Error> for NavigateError {
+    fn from(err: Error) -> Self {
+        NavigateError::Other(err)
+    }
+}
+
+#[cfg(feature = "luau")]
+type WriteResult = ffi::luarequire_WriteResult;
+
+/// A trait for handling modules loading and navigation in the Luau `require-by-string` system.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+pub trait Require {
+    /// Returns `true` if "require" is permitted for the given chunk name.
+    fn is_require_allowed(&self, chunk_name: &str) -> bool;
+
+    /// Resets the internal state to point at the requirer module.
+    fn reset(&mut self, chunk_name: &str) -> StdResult<(), NavigateError>;
+
+    /// Resets the internal state to point at an aliased module.
+    ///
+    /// This function received an exact path from a configuration file.
+    /// It's only called when an alias's path cannot be resolved relative to its
+    /// configuration file.
+    fn jump_to_alias(&mut self, path: &str) -> StdResult<(), NavigateError>;
+
+    // Navigate to parent directory
+    fn to_parent(&mut self) -> StdResult<(), NavigateError>;
+
+    /// Navigate to the given child directory.
+    fn to_child(&mut self, name: &str) -> StdResult<(), NavigateError>;
+
+    /// Returns whether the context is currently pointing at a module
+    fn has_module(&self) -> bool;
+
+    /// Provides a cache key representing the current module.
+    ///
+    /// This function is only called if `has_module` returns true.
+    fn cache_key(&self) -> String;
+
+    /// Returns whether a configuration is present in the current context.
+    fn has_config(&self) -> bool;
+
+    /// Returns the contents of the configuration file in the current context.
+    ///
+    /// This function is only called if `has_config` returns true.
+    fn config(&self) -> IoResult<Vec<u8>>;
+
+    /// Returns a loader function for the current module, that when called, loads the module
+    /// and returns the result.
+    ///
+    /// Loader can be sync or async.
+    /// This function is only called if `has_module` returns true.
+    fn loader(&self, lua: &Lua) -> Result<Function>;
+}
+
+impl fmt::Debug for dyn Require {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "<dyn Require>")
+    }
+}
+
+/// The standard implementation of Luau `require-by-string` navigation.
+#[derive(Default, Debug)]
+pub struct TextRequirer {
+    /// An absolute path to the current Luau module (not mapped to a physical file)
+    abs_path: PathBuf,
+    /// A relative path to the current Luau module (not mapped to a physical file)
+    rel_path: PathBuf,
+    /// A physical path to the current Luau module, which is a file or a directory with an
+    /// `init.lua(u)` file
+    resolved_path: Option<PathBuf>,
+}
+
+impl TextRequirer {
+    /// The prefix used for chunk names in the require system.
+    /// Only chunk names starting with this prefix are allowed to be used in `require`.
+    const CHUNK_PREFIX: &str = "@";
+
+    /// The file extensions that are considered valid for Luau modules.
+    const FILE_EXTENSIONS: &[&str] = &["luau", "lua"];
+
+    /// Creates a new `TextRequirer` instance.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    fn normalize_chunk_name(chunk_name: &str) -> &str {
+        if let Some((path, line)) = chunk_name.rsplit_once(':') {
+            if line.parse::<u32>().is_ok() {
+                return path;
+            }
+        }
+        chunk_name
+    }
+
+    // Normalizes the path by removing unnecessary components
+    fn normalize_path(path: &Path) -> PathBuf {
+        let mut components = VecDeque::new();
+
+        for comp in path.components() {
+            match comp {
+                Component::Prefix(..) | Component::RootDir => {
+                    components.push_back(comp);
+                }
+                Component::CurDir => {}
+                Component::ParentDir => {
+                    if matches!(components.back(), None | Some(Component::ParentDir)) {
+                        components.push_back(Component::ParentDir);
+                    } else if matches!(components.back(), Some(Component::Normal(..))) {
+                        components.pop_back();
+                    }
+                }
+                Component::Normal(..) => components.push_back(comp),
+            }
+        }
+
+        if matches!(components.front(), None | Some(Component::Normal(..))) {
+            components.push_front(Component::CurDir);
+        }
+
+        // Join the components back together
+        components.into_iter().collect()
+    }
+
+    /// Resolve a Luau module path to a physical file or directory.
+    ///
+    /// Empty directories without init files are considered valid as "intermediate" directories.
+    fn resolve_module(path: &Path) -> StdResult<Option<PathBuf>, NavigateError> {
+        let mut found_path = None;
+
+        if path.components().next_back() != Some(Component::Normal("init".as_ref())) {
+            let current_ext = (path.extension().and_then(|s| s.to_str()))
+                .map(|s| format!("{s}."))
+                .unwrap_or_default();
+            for ext in Self::FILE_EXTENSIONS {
+                let candidate = path.with_extension(format!("{current_ext}{ext}"));
+                if candidate.is_file() && found_path.replace(candidate).is_some() {
+                    return Err(NavigateError::Ambiguous);
+                }
+            }
+        }
+        if path.is_dir() {
+            for component in Self::FILE_EXTENSIONS.iter().map(|ext| format!("init.{ext}")) {
+                let candidate = path.join(component);
+                if candidate.is_file() && found_path.replace(candidate).is_some() {
+                    return Err(NavigateError::Ambiguous);
+                }
+            }
+
+            if found_path.is_none() {
+                // Directories without init files are considered valid "intermediate" path
+                return Ok(None);
+            }
+        }
+
+        Ok(Some(found_path.ok_or(NavigateError::NotFound)?))
+    }
+}
+
+impl Require for TextRequirer {
+    fn is_require_allowed(&self, chunk_name: &str) -> bool {
+        chunk_name.starts_with(Self::CHUNK_PREFIX)
+    }
+
+    fn reset(&mut self, chunk_name: &str) -> StdResult<(), NavigateError> {
+        if !chunk_name.starts_with(Self::CHUNK_PREFIX) {
+            return Err(NavigateError::NotFound);
+        }
+        let chunk_name = Self::normalize_chunk_name(&chunk_name[1..]);
+        let chunk_path = Self::normalize_path(chunk_name.as_ref());
+
+        if chunk_path.extension() == Some("rs".as_ref()) {
+            // Special case for Rust source files, reset to the current directory
+            let chunk_filename = chunk_path.file_name().unwrap();
+            let cwd = env::current_dir().map_err(|_| NavigateError::NotFound)?;
+            self.abs_path = Self::normalize_path(&cwd.join(chunk_filename));
+            self.rel_path = ([Component::CurDir, Component::Normal(chunk_filename)].into_iter()).collect();
+            self.resolved_path = None;
+
+            return Ok(());
+        }
+
+        if chunk_path.is_absolute() {
+            let resolved_path = Self::resolve_module(&chunk_path)?;
+            self.abs_path = chunk_path.clone();
+            self.rel_path = chunk_path;
+            self.resolved_path = resolved_path;
+        } else {
+            // Relative path
+            let cwd = env::current_dir().map_err(|_| NavigateError::NotFound)?;
+            let abs_path = Self::normalize_path(&cwd.join(&chunk_path));
+            let resolved_path = Self::resolve_module(&abs_path)?;
+            self.abs_path = abs_path;
+            self.rel_path = chunk_path;
+            self.resolved_path = resolved_path;
+        }
+
+        Ok(())
+    }
+
+    fn jump_to_alias(&mut self, path: &str) -> StdResult<(), NavigateError> {
+        let path = Self::normalize_path(path.as_ref());
+        let resolved_path = Self::resolve_module(&path)?;
+
+        self.abs_path = path.clone();
+        self.rel_path = path;
+        self.resolved_path = resolved_path;
+
+        Ok(())
+    }
+
+    fn to_parent(&mut self) -> StdResult<(), NavigateError> {
+        let mut abs_path = self.abs_path.clone();
+        if !abs_path.pop() {
+            // It's important to return `NotFound` if we reached the root, as it's a "recoverable" error if we
+            // cannot go beyond the root directory.
+            // Luau "require-by-string` has a special logic to search for config file to resolve aliases.
+            return Err(NavigateError::NotFound);
+        }
+        let mut rel_parent = self.rel_path.clone();
+        rel_parent.pop();
+        let resolved_path = Self::resolve_module(&abs_path)?;
+
+        self.abs_path = abs_path;
+        self.rel_path = Self::normalize_path(&rel_parent);
+        self.resolved_path = resolved_path;
+
+        Ok(())
+    }
+
+    fn to_child(&mut self, name: &str) -> StdResult<(), NavigateError> {
+        let abs_path = self.abs_path.join(name);
+        let rel_path = self.rel_path.join(name);
+        let resolved_path = Self::resolve_module(&abs_path)?;
+
+        self.abs_path = abs_path;
+        self.rel_path = rel_path;
+        self.resolved_path = resolved_path;
+
+        Ok(())
+    }
+
+    fn has_module(&self) -> bool {
+        (self.resolved_path.as_deref())
+            .map(Path::is_file)
+            .unwrap_or(false)
+    }
+
+    fn cache_key(&self) -> String {
+        self.resolved_path.as_deref().unwrap().display().to_string()
+    }
+
+    fn has_config(&self) -> bool {
+        self.abs_path.is_dir() && self.abs_path.join(".luaurc").is_file()
+    }
+
+    fn config(&self) -> IoResult<Vec<u8>> {
+        fs::read(self.abs_path.join(".luaurc"))
+    }
+
+    fn loader(&self, lua: &Lua) -> Result<Function> {
+        let name = format!("@{}", self.rel_path.display());
+        lua.load(self.resolved_path.as_deref().unwrap())
+            .set_name(name)
+            .into_function()
+    }
+}
+
+struct Context(Box<dyn Require>);
+
+impl Deref for Context {
+    type Target = dyn Require;
+
+    fn deref(&self) -> &Self::Target {
+        &*self.0
+    }
+}
+
+impl DerefMut for Context {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut *self.0
+    }
+}
+
+macro_rules! try_borrow {
+    ($state:expr, $ctx:expr) => {
+        match (*($ctx as *const RefCell<Context>)).try_borrow() {
+            Ok(ctx) => ctx,
+            Err(_) => ffi::luaL_error($state, cstr!("require context is already borrowed")),
+        }
+    };
+}
+
+macro_rules! try_borrow_mut {
+    ($state:expr, $ctx:expr) => {
+        match (*($ctx as *const RefCell<Context>)).try_borrow_mut() {
+            Ok(ctx) => ctx,
+            Err(_) => ffi::luaL_error($state, cstr!("require context is already borrowed")),
+        }
+    };
+}
+
+#[cfg(feature = "luau")]
+pub(super) unsafe extern "C-unwind" fn init_config(config: *mut ffi::luarequire_Configuration) {
+    if config.is_null() {
+        return;
+    }
+
+    unsafe extern "C-unwind" fn is_require_allowed(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        requirer_chunkname: *const c_char,
+    ) -> bool {
+        if requirer_chunkname.is_null() {
+            return false;
+        }
+
+        let this = try_borrow!(state, ctx);
+        let chunk_name = CStr::from_ptr(requirer_chunkname).to_string_lossy();
+        this.is_require_allowed(&chunk_name)
+    }
+
+    unsafe extern "C-unwind" fn reset(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        requirer_chunkname: *const c_char,
+    ) -> ffi::luarequire_NavigateResult {
+        let mut this = try_borrow_mut!(state, ctx);
+        let chunk_name = CStr::from_ptr(requirer_chunkname).to_string_lossy();
+        callback_error_ext(state, ptr::null_mut(), true, move |_, _| {
+            this.reset(&chunk_name).into_nav_result()
+        })
+    }
+
+    unsafe extern "C-unwind" fn jump_to_alias(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        path: *const c_char,
+    ) -> ffi::luarequire_NavigateResult {
+        let mut this = try_borrow_mut!(state, ctx);
+        let path = CStr::from_ptr(path).to_string_lossy();
+        callback_error_ext(state, ptr::null_mut(), true, move |_, _| {
+            this.jump_to_alias(&path).into_nav_result()
+        })
+    }
+
+    unsafe extern "C-unwind" fn to_parent(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+    ) -> ffi::luarequire_NavigateResult {
+        let mut this = try_borrow_mut!(state, ctx);
+        callback_error_ext(state, ptr::null_mut(), true, move |_, _| {
+            this.to_parent().into_nav_result()
+        })
+    }
+
+    unsafe extern "C-unwind" fn to_child(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        name: *const c_char,
+    ) -> ffi::luarequire_NavigateResult {
+        let mut this = try_borrow_mut!(state, ctx);
+        let name = CStr::from_ptr(name).to_string_lossy();
+        callback_error_ext(state, ptr::null_mut(), true, move |_, _| {
+            this.to_child(&name).into_nav_result()
+        })
+    }
+
+    unsafe extern "C-unwind" fn is_module_present(state: *mut ffi::lua_State, ctx: *mut c_void) -> bool {
+        let this = try_borrow!(state, ctx);
+        this.has_module()
+    }
+
+    unsafe extern "C-unwind" fn get_chunkname(
+        _state: *mut ffi::lua_State,
+        _ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> WriteResult {
+        write_to_buffer(buffer, buffer_size, size_out, &[])
+    }
+
+    unsafe extern "C-unwind" fn get_loadname(
+        _state: *mut ffi::lua_State,
+        _ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> WriteResult {
+        write_to_buffer(buffer, buffer_size, size_out, &[])
+    }
+
+    unsafe extern "C-unwind" fn get_cache_key(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> WriteResult {
+        let this = try_borrow!(state, ctx);
+        let cache_key = this.cache_key();
+        write_to_buffer(buffer, buffer_size, size_out, cache_key.as_bytes())
+    }
+
+    unsafe extern "C-unwind" fn is_config_present(state: *mut ffi::lua_State, ctx: *mut c_void) -> bool {
+        let this = try_borrow!(state, ctx);
+        this.has_config()
+    }
+
+    unsafe extern "C-unwind" fn get_config(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        buffer: *mut c_char,
+        buffer_size: usize,
+        size_out: *mut usize,
+    ) -> WriteResult {
+        let this = try_borrow!(state, ctx);
+        let config = callback_error_ext(state, ptr::null_mut(), true, move |_, _| Ok(this.config()?));
+        write_to_buffer(buffer, buffer_size, size_out, &config)
+    }
+
+    unsafe extern "C-unwind" fn load(
+        state: *mut ffi::lua_State,
+        ctx: *mut c_void,
+        _path: *const c_char,
+        _chunkname: *const c_char,
+        _loadname: *const c_char,
+    ) -> c_int {
+        let this = try_borrow!(state, ctx);
+        callback_error_ext(state, ptr::null_mut(), true, move |extra, _| {
+            let rawlua = (*extra).raw_lua();
+            let loader = this.loader(rawlua.lua())?;
+            rawlua.push(loader)?;
+            Ok(1)
+        })
+    }
+
+    (*config).is_require_allowed = is_require_allowed;
+    (*config).reset = reset;
+    (*config).jump_to_alias = jump_to_alias;
+    (*config).to_parent = to_parent;
+    (*config).to_child = to_child;
+    (*config).is_module_present = is_module_present;
+    (*config).get_chunkname = get_chunkname;
+    (*config).get_loadname = get_loadname;
+    (*config).get_cache_key = get_cache_key;
+    (*config).is_config_present = is_config_present;
+    (*config).get_alias = None;
+    (*config).get_config = Some(get_config);
+    (*config).load = load;
+}
+
+/// Helper function to write data to a buffer
+#[cfg(feature = "luau")]
+unsafe fn write_to_buffer(
+    buffer: *mut c_char,
+    buffer_size: usize,
+    size_out: *mut usize,
+    data: &[u8],
+) -> WriteResult {
+    // the buffer must be null terminated as it's a c++ `std::string` data() buffer
+    let is_null_terminated = data.last() == Some(&0);
+    *size_out = data.len() + if is_null_terminated { 0 } else { 1 };
+    if *size_out > buffer_size {
+        return WriteResult::BufferTooSmall;
+    }
+    ptr::copy_nonoverlapping(data.as_ptr(), buffer as *mut _, data.len());
+    if !is_null_terminated {
+        *buffer.add(data.len()) = 0;
+    }
+    WriteResult::Success
+}
+
+#[cfg(feature = "luau")]
+pub(super) fn create_require_function<R: Require + MaybeSend + 'static>(
+    lua: &Lua,
+    require: R,
+) -> Result<Function> {
+    unsafe extern "C-unwind" fn find_current_file(state: *mut ffi::lua_State) -> c_int {
+        let mut ar: ffi::lua_Debug = mem::zeroed();
+        for level in 2.. {
+            if ffi::lua_getinfo(state, level, cstr!("s"), &mut ar) == 0 {
+                ffi::luaL_error(state, cstr!("require is not supported in this context"));
+            }
+            if CStr::from_ptr(ar.what) != c"C" {
+                break;
+            }
+        }
+        ffi::lua_pushstring(state, ar.source);
+        1
+    }
+
+    unsafe extern "C-unwind" fn get_cache_key(state: *mut ffi::lua_State) -> c_int {
+        let ctx = ffi::lua_touserdata(state, ffi::lua_upvalueindex(1));
+        let ctx = try_borrow!(state, ctx);
+        let cache_key = ctx.cache_key();
+        ffi::lua_pushlstring(state, cache_key.as_ptr() as *const _, cache_key.len());
+        1
+    }
+
+    let (get_cache_key, find_current_file, proxyrequire, registered_modules, loader_cache) = unsafe {
+        lua.exec_raw::<(Function, Function, Function, Table, Table)>((), move |state| {
+            let context = Context(Box::new(require));
+            let context_ptr = ffi::lua_newuserdata_t(state, RefCell::new(context));
+            ffi::lua_pushcclosured(state, get_cache_key, cstr!("get_cache_key"), 1);
+            ffi::lua_pushcfunctiond(state, find_current_file, cstr!("find_current_file"));
+            ffi::luarequire_pushproxyrequire(state, init_config, context_ptr as *mut _);
+            ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, ffi::LUA_REGISTERED_MODULES_TABLE);
+            ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("__MLUA_LOADER_CACHE"));
+        })
+    }?;
+
+    unsafe extern "C-unwind" fn error(state: *mut ffi::lua_State) -> c_int {
+        ffi::luaL_where(state, 1);
+        ffi::lua_pushvalue(state, 1);
+        ffi::lua_concat(state, 2);
+        ffi::lua_error(state);
+    }
+
+    unsafe extern "C-unwind" fn r#type(state: *mut ffi::lua_State) -> c_int {
+        ffi::lua_pushstring(state, ffi::lua_typename(state, ffi::lua_type(state, 1)));
+        1
+    }
+
+    unsafe extern "C-unwind" fn to_lowercase(state: *mut ffi::lua_State) -> c_int {
+        let s = ffi::luaL_checkstring(state, 1);
+        let s = CStr::from_ptr(s);
+        if !s.to_bytes().iter().any(|&c| c.is_ascii_uppercase()) {
+            // If the string does not contain any uppercase ASCII letters, return it as is
+            return 1;
+        }
+        callback_error_ext(state, ptr::null_mut(), true, |extra, _| {
+            let s = (s.to_bytes().iter())
+                .map(|&c| c.to_ascii_lowercase())
+                .collect::<bstr::BString>();
+            (*extra).raw_lua().push(s).map(|_| 1)
+        })
+    }
+
+    let (error, r#type, to_lowercase) = unsafe {
+        lua.exec_raw::<(Function, Function, Function)>((), move |state| {
+            ffi::lua_pushcfunctiond(state, error, cstr!("error"));
+            ffi::lua_pushcfunctiond(state, r#type, cstr!("type"));
+            ffi::lua_pushcfunctiond(state, to_lowercase, cstr!("to_lowercase"));
+        })
+    }?;
+
+    // Prepare environment for the "require" function
+    let env = lua.create_table_with_capacity(0, 7)?;
+    env.raw_set("get_cache_key", get_cache_key)?;
+    env.raw_set("find_current_file", find_current_file)?;
+    env.raw_set("proxyrequire", proxyrequire)?;
+    env.raw_set("REGISTERED_MODULES", registered_modules)?;
+    env.raw_set("LOADER_CACHE", loader_cache)?;
+    env.raw_set("error", error)?;
+    env.raw_set("type", r#type)?;
+    env.raw_set("to_lowercase", to_lowercase)?;
+
+    lua.load(
+        r#"
+        local path = ...
+        if type(path) ~= "string" then
+            error("bad argument #1 to 'require' (string expected, got " .. type(path) .. ")")
+        end
+
+        -- Check if the module (path) is explicitly registered
+        local maybe_result = REGISTERED_MODULES[to_lowercase(path)]
+        if maybe_result ~= nil then
+            return maybe_result
+        end
+
+        local loader = proxyrequire(path, find_current_file())
+        local cache_key = get_cache_key()
+        -- Check if the loader result is already cached
+        local result = LOADER_CACHE[cache_key]
+        if result ~= nil then
+            return result
+        end
+
+        -- Call the loader function and cache the result
+        result = loader()
+        if result == nil then
+            result = true
+        end
+        LOADER_CACHE[cache_key] = result
+        return result
+        "#,
+    )
+    .try_cache()
+    .set_name("=__mlua_require")
+    .set_environment(env)
+    .into_function()
+}
+
+#[cfg(test)]
+mod tests {
+    use std::path::Path;
+
+    use super::TextRequirer;
+
+    #[test]
+    fn test_path_normalize() {
+        for (input, expected) in [
+            // Basic formatting checks
+            ("", "./"),
+            (".", "./"),
+            ("a/relative/path", "./a/relative/path"),
+            // Paths containing extraneous '.' and '/' symbols
+            ("./remove/extraneous/symbols/", "./remove/extraneous/symbols"),
+            ("./remove/extraneous//symbols", "./remove/extraneous/symbols"),
+            ("./remove/extraneous/symbols/.", "./remove/extraneous/symbols"),
+            ("./remove/extraneous/./symbols", "./remove/extraneous/symbols"),
+            ("../remove/extraneous/symbols/", "../remove/extraneous/symbols"),
+            ("../remove/extraneous//symbols", "../remove/extraneous/symbols"),
+            ("../remove/extraneous/symbols/.", "../remove/extraneous/symbols"),
+            ("../remove/extraneous/./symbols", "../remove/extraneous/symbols"),
+            ("/remove/extraneous/symbols/", "/remove/extraneous/symbols"),
+            ("/remove/extraneous//symbols", "/remove/extraneous/symbols"),
+            ("/remove/extraneous/symbols/.", "/remove/extraneous/symbols"),
+            ("/remove/extraneous/./symbols", "/remove/extraneous/symbols"),
+            // Paths containing '..'
+            ("./remove/me/..", "./remove"),
+            ("./remove/me/../", "./remove"),
+            ("../remove/me/..", "../remove"),
+            ("../remove/me/../", "../remove"),
+            ("/remove/me/..", "/remove"),
+            ("/remove/me/../", "/remove"),
+            ("./..", "../"),
+            ("./../", "../"),
+            ("../..", "../../"),
+            ("../../", "../../"),
+            // '..' disappears if path is absolute and component is non-erasable
+            ("/../", "/"),
+        ] {
+            let path = TextRequirer::normalize_path(input.as_ref());
+            assert_eq!(
+                &path,
+                expected.as_ref() as &Path,
+                "wrong normalization for {input}"
+            );
+        }
+    }
+}

src/memory.rs

@@ -97,7 +97,7 @@ impl MemoryState {
     }
 }
 
-unsafe extern "C-unwind" fn allocator(
+unsafe extern "C" fn allocator(
     extra: *mut c_void,
     ptr: *mut c_void,
     osize: usize,

src/multi.rs

@@ -297,6 +297,15 @@ impl<T: IntoLua> IntoLuaMulti for Variadic<T> {
     fn into_lua_multi(self, lua: &Lua) -> Result<MultiValue> {
         MultiValue::from_lua_iter(lua, self)
     }
+
+    unsafe fn push_into_stack_multi(self, lua: &RawLua) -> Result<c_int> {
+        let nresults = self.len() as i32;
+        check_stack(lua.state(), nresults + 1)?;
+        for value in self.0 {
+            value.push_into_stack(lua)?;
+        }
+        Ok(nresults)
+    }
 }
 
 impl<T: FromLua> FromLuaMulti for Variadic<T> {

src/prelude.rs

@@ -2,15 +2,16 @@
 
 #[doc(no_inline)]
 pub use crate::{
-    AnyUserData as LuaAnyUserData, Chunk as LuaChunk, Either as LuaEither, 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, LuaNativeFn,
-    LuaNativeFnMut, LuaOptions, MetaMethod as LuaMetaMethod, MultiValue as LuaMultiValue, Nil as LuaNil,
-    Number as LuaNumber, ObjectLike as LuaObjectLike, RegistryKey as LuaRegistryKey, Result as LuaResult,
-    StdLib as LuaStdLib, String as LuaString, Table as LuaTable, TablePairs as LuaTablePairs,
-    TableSequence as LuaTableSequence, Thread as LuaThread, ThreadStatus as LuaThreadStatus,
-    UserData as LuaUserData, UserDataFields as LuaUserDataFields, UserDataMetatable as LuaUserDataMetatable,
+    AnyUserData as LuaAnyUserData, BorrowedBytes as LuaBorrowedBytes, BorrowedStr as LuaBorrowedStr,
+    Chunk as LuaChunk, Either as LuaEither, 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, LuaNativeFn, LuaNativeFnMut, LuaOptions,
+    MetaMethod as LuaMetaMethod, MultiValue as LuaMultiValue, Nil as LuaNil, Number as LuaNumber,
+    ObjectLike as LuaObjectLike, RegistryKey as LuaRegistryKey, Result as LuaResult, StdLib as LuaStdLib,
+    String as LuaString, Table as LuaTable, 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, Value as LuaValue,
     Variadic as LuaVariadic, VmState as LuaVmState, WeakLua,
@@ -22,14 +23,19 @@ pub use crate::HookTriggers as LuaHookTriggers;
 
 #[cfg(feature = "luau")]
 #[doc(no_inline)]
-pub use crate::{CoverageInfo as LuaCoverageInfo, Vector as LuaVector};
+pub use crate::{
+    CompileConstant as LuaCompileConstant, CoverageInfo as LuaCoverageInfo,
+    NavigateError as LuaNavigateError, Require as LuaRequire, TextRequirer as LuaTextRequirer,
+    Vector as LuaVector,
+};
 
 #[cfg(feature = "async")]
 #[doc(no_inline)]
 pub use crate::{AsyncThread as LuaAsyncThread, LuaNativeAsyncFn};
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 #[doc(no_inline)]
 pub use crate::{
-    DeserializeOptions as LuaDeserializeOptions, LuaSerdeExt, SerializeOptions as LuaSerializeOptions,
+    DeserializeOptions as LuaDeserializeOptions, LuaSerdeExt, SerializableValue as LuaSerializableValue,
+    SerializeOptions as LuaSerializeOptions,
 };

src/scope.rs

@@ -8,9 +8,7 @@ use crate::state::{Lua, LuaGuard, RawLua};
 use crate::traits::{FromLuaMulti, IntoLuaMulti};
 use crate::types::{Callback, CallbackUpvalue, ScopedCallback, ValueRef};
 use crate::userdata::{AnyUserData, UserData, UserDataRegistry, UserDataStorage};
-use crate::util::{
-    self, assert_stack, check_stack, get_metatable_ptr, get_userdata, take_userdata, StackGuard,
-};
+use crate::util::{self, check_stack, get_metatable_ptr, get_userdata, take_userdata, StackGuard};
 
 /// Constructed by the [`Lua::scope`] method, allows temporarily creating Lua userdata and
 /// callbacks that are not required to be `Send` or `'static`.
@@ -284,22 +282,18 @@ impl<'scope, 'env: 'scope> Scope<'scope, 'env> {
     /// Shortens the lifetime of the userdata to the lifetime of the scope.
     fn seal_userdata<T: 'env>(&self, ud: &AnyUserData) {
         let destructor: DestructorCallback = Box::new(|rawlua, vref| unsafe {
-            let state = rawlua.state();
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 2);
-
             // Ensure that userdata is not destructed
-            match rawlua.push_userdata_ref(&vref) {
+            match rawlua.get_userdata_ref_type_id(&vref) {
                 Ok(Some(_)) => {}
                 Ok(None) => {
                     // Deregister metatable
-                    let mt_ptr = get_metatable_ptr(state, -1);
+                    let mt_ptr = get_metatable_ptr(rawlua.ref_thread(), vref.index);
                     rawlua.deregister_userdata_metatable(mt_ptr);
                 }
                 Err(_) => return vec![],
             }
 
-            let data = take_userdata::<UserDataStorage<T>>(state);
+            let data = take_userdata::<UserDataStorage<T>>(rawlua.ref_thread(), vref.index);
             vec![Box::new(move || drop(data))]
         });
         self.destructors.0.borrow_mut().push((ud.0.clone(), destructor));

src/serde/de.rs

@@ -15,11 +15,12 @@ use crate::userdata::AnyUserData;
 use crate::value::Value;
 
 /// A struct for deserializing Lua values into Rust values.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Deserializer {
     value: Value,
     options: Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
+    len: Option<usize>, // A length hint for sequences
 }
 
 /// A struct with options to change default deserializer behavior.
@@ -54,6 +55,19 @@ pub struct Options {
     ///
     /// Default: **false**
     pub encode_empty_tables_as_array: bool,
+
+    /// If true, enable detection of mixed tables.
+    ///
+    /// A mixed table is a table that has both array-like and map-like entries or several borders.
+    /// See [`The Length Operator`] documentation for details about borders.
+    ///
+    /// When this option is disabled, a table with a non-zero length (with one or more borders) will
+    /// be always encoded as an array.
+    ///
+    /// Default: **false**
+    ///
+    /// [`The Length Operator`]: https://www.lua.org/manual/5.4/manual.html#3.4.7
+    pub detect_mixed_tables: bool,
 }
 
 impl Default for Options {
@@ -70,6 +84,7 @@ impl Options {
             deny_recursive_tables: true,
             sort_keys: false,
             encode_empty_tables_as_array: false,
+            detect_mixed_tables: false,
         }
     }
 
@@ -108,6 +123,15 @@ impl Options {
         self.encode_empty_tables_as_array = enabled;
         self
     }
+
+    /// Sets [`detect_mixed_tables`] option.
+    ///
+    /// [`detect_mixed_tables`]: #structfield.detect_mixed_tables
+    #[must_use]
+    pub const fn detect_mixed_tables(mut self, enable: bool) -> Self {
+        self.detect_mixed_tables = enable;
+        self
+    }
 }
 
 impl Deserializer {
@@ -121,7 +145,7 @@ impl Deserializer {
         Deserializer {
             value,
             options,
-            visited: Rc::new(RefCell::new(FxHashSet::default())),
+            ..Default::default()
         }
     }
 
@@ -130,8 +154,14 @@ impl Deserializer {
             value,
             options,
             visited,
+            ..Default::default()
         }
     }
+
+    fn with_len(mut self, len: usize) -> Self {
+        self.len = Some(len);
+        self
+    }
 }
 
 impl<'de> serde::Deserializer<'de> for Deserializer {
@@ -155,17 +185,22 @@ impl<'de> serde::Deserializer<'de> for Deserializer {
                 Ok(s) => visitor.visit_str(&s),
                 Err(_) => visitor.visit_bytes(&s.as_bytes()),
             },
-            Value::Table(ref t) if t.raw_len() > 0 || t.is_array() => self.deserialize_seq(visitor),
-            Value::Table(ref t) if self.options.encode_empty_tables_as_array && t.is_empty() => {
-                self.deserialize_seq(visitor)
+            Value::Table(ref t) => {
+                if let Some(len) = t.encode_as_array(self.options) {
+                    self.with_len(len).deserialize_seq(visitor)
+                } else {
+                    self.deserialize_map(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::Buffer(buf) => visitor.visit_bytes(unsafe { buf.as_slice() }),
+            Value::Buffer(buf) => {
+                let lua = buf.0.lua.lock();
+                visitor.visit_bytes(buf.as_slice(&lua))
+            }
             Value::Function(_)
             | Value::Thread(_)
             | Value::UserData(_)
@@ -267,14 +302,14 @@ impl<'de> serde::Deserializer<'de> for Deserializer {
             Value::Table(t) => {
                 let _guard = RecursionGuard::new(&t, &self.visited);
 
-                let len = t.raw_len();
+                let len = self.len.unwrap_or_else(|| t.raw_len());
                 let mut deserializer = SeqDeserializer {
-                    seq: t.sequence_values(),
+                    seq: t.sequence_values().with_len(len),
                     options: self.options,
                     visited: self.visited,
                 };
                 let seq = visitor.visit_seq(&mut deserializer)?;
-                if deserializer.seq.count() == 0 {
+                if deserializer.seq.next().is_none() {
                     Ok(seq)
                 } else {
                     Err(de::Error::invalid_length(len, &"fewer elements in the table"))

src/serde/mod.rs

@@ -13,12 +13,10 @@ use crate::util::check_stack;
 use crate::value::Value;
 
 /// Trait for serializing/deserializing Lua values using Serde.
-#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 pub trait LuaSerdeExt: Sealed {
     /// A special value (lightuserdata) to encode/decode optional (none) values.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// # Example
     ///
     /// ```
@@ -42,8 +40,6 @@ pub trait LuaSerdeExt: Sealed {
     /// As result, encoded Array will contain only sequence part of the table, with the same length
     /// as the `#` operator on that table.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// # Example
     ///
     /// ```
@@ -71,8 +67,6 @@ pub trait LuaSerdeExt: Sealed {
 
     /// Converts `T` into a [`Value`] instance.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// [`Value`]: crate::Value
     ///
     /// # Example
@@ -104,8 +98,6 @@ pub trait LuaSerdeExt: Sealed {
 
     /// Converts `T` into a [`Value`] instance with options.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// # Example
     ///
     /// ```
@@ -129,8 +121,6 @@ pub trait LuaSerdeExt: Sealed {
 
     /// Deserializes a [`Value`] into any serde deserializable object.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// # Example
     ///
     /// ```
@@ -158,8 +148,6 @@ pub trait LuaSerdeExt: Sealed {
 
     /// Deserializes a [`Value`] into any serde deserializable object with options.
     ///
-    /// Requires `feature = "serialize"`
-    ///
     /// # Example
     ///
     /// ```

src/serde/ser.rs

@@ -256,7 +256,7 @@ impl<'a> ser::Serializer for Serializer<'a> {
     fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
         let table = self.lua.create_table_with_capacity(len.unwrap_or(0), 0)?;
         if self.options.set_array_metatable {
-            table.set_metatable(Some(self.lua.array_metatable()));
+            table.set_metatable(Some(self.lua.array_metatable()))?;
         }
         Ok(SerializeSeq::new(self.lua, table, self.options))
     }
@@ -529,8 +529,8 @@ impl ser::SerializeStruct for SerializeStruct<'_> {
     fn end(self) -> Result<Value> {
         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");
+            Some(value @ Value::String(_)) if self.options.detect_serde_json_arbitrary_precision => {
+                let number_s = value.to_string()?;
                 if number_s.contains(['.', 'e', 'E']) {
                     if let Ok(number) = number_s.parse().map(Value::Number) {
                         return Ok(number);

src/state/extra.rs

@@ -28,7 +28,7 @@ use super::{Lua, WeakLua};
 static EXTRA_REGISTRY_KEY: u8 = 0;
 
 const WRAPPED_FAILURE_POOL_DEFAULT_CAPACITY: usize = 64;
-const REF_STACK_RESERVE: c_int = 2;
+const REF_STACK_RESERVE: c_int = 3;
 
 /// Data associated with the Lua state.
 pub(crate) struct ExtraData {
@@ -44,8 +44,9 @@ pub(crate) struct ExtraData {
     // When Lua instance dropped, setting `None` would prevent collecting `RegistryKey`s
     pub(super) registry_unref_list: Arc<Mutex<Option<Vec<c_int>>>>,
 
-    // Container to store arbitrary data (extensions)
+    // Containers to store arbitrary data (extensions)
     pub(super) app_data: AppData,
+    pub(super) app_data_priv: AppData,
 
     pub(super) safe: bool,
     pub(super) libs: StdLib,
@@ -63,7 +64,7 @@ pub(crate) struct ExtraData {
     pub(super) wrapped_failure_top: usize,
     // Pool of `Thread`s (coroutines) for async execution
     #[cfg(feature = "async")]
-    pub(super) thread_pool: Vec<c_int>,
+    pub(super) thread_pool: Vec<crate::types::ValueRefIndex>,
 
     // Address of `WrappedFailure` metatable
     pub(super) wrapped_failure_mt_ptr: *const c_void,
@@ -75,14 +76,20 @@ pub(crate) struct ExtraData {
     #[cfg(not(feature = "luau"))]
     pub(super) hook_callback: Option<crate::types::HookCallback>,
     #[cfg(not(feature = "luau"))]
-    pub(super) hook_thread: *mut ffi::lua_State,
+    pub(super) hook_triggers: crate::debug::HookTriggers,
     #[cfg(feature = "lua54")]
     pub(super) warn_callback: Option<crate::types::WarnCallback>,
     #[cfg(feature = "luau")]
     pub(super) interrupt_callback: Option<crate::types::InterruptCallback>,
+    #[cfg(feature = "luau")]
+    pub(super) thread_creation_callback: Option<crate::types::ThreadCreationCallback>,
+    #[cfg(feature = "luau")]
+    pub(super) thread_collection_callback: Option<crate::types::ThreadCollectionCallback>,
 
     #[cfg(feature = "luau")]
-    pub(super) sandboxed: bool,
+    pub(crate) running_gc: bool,
+    #[cfg(feature = "luau")]
+    pub(crate) sandboxed: bool,
     #[cfg(feature = "luau")]
     pub(super) compiler: Option<Compiler>,
     #[cfg(feature = "luau-jit")]
@@ -153,6 +160,7 @@ impl ExtraData {
             last_checked_userdata_mt: (ptr::null(), None),
             registry_unref_list: Arc::new(Mutex::new(Some(Vec::new()))),
             app_data: AppData::default(),
+            app_data_priv: AppData::default(),
             safe: false,
             libs: StdLib::NONE,
             skip_memory_check: false,
@@ -171,17 +179,23 @@ impl ExtraData {
             #[cfg(not(feature = "luau"))]
             hook_callback: None,
             #[cfg(not(feature = "luau"))]
-            hook_thread: ptr::null_mut(),
+            hook_triggers: Default::default(),
             #[cfg(feature = "lua54")]
             warn_callback: None,
             #[cfg(feature = "luau")]
             interrupt_callback: None,
             #[cfg(feature = "luau")]
+            thread_creation_callback: None,
+            #[cfg(feature = "luau")]
+            thread_collection_callback: None,
+            #[cfg(feature = "luau")]
             sandboxed: false,
             #[cfg(feature = "luau")]
             compiler: None,
             #[cfg(feature = "luau-jit")]
             enable_jit: true,
+            #[cfg(feature = "luau")]
+            running_gc: false,
         }));
 
         // Store it in the registry
@@ -195,13 +209,10 @@ impl ExtraData {
             raw: XRc::clone(raw),
             collect_garbage: false,
         });
-        if self.owned {
-            XRc::decrement_strong_count(XRc::as_ptr(raw));
-        }
         self.weak.write(WeakLua(XRc::downgrade(raw)));
     }
 
-    pub(super) unsafe fn get(state: *mut ffi::lua_State) -> *mut Self {
+    pub(crate) unsafe fn get(state: *mut ffi::lua_State) -> *mut Self {
         #[cfg(feature = "luau")]
         if cfg!(not(feature = "module")) {
             // In the main app we can use `lua_callbacks` to access ExtraData
@@ -240,7 +251,7 @@ impl ExtraData {
     }
 
     #[inline(always)]
-    pub(super) unsafe fn raw_lua(&self) -> &RawLua {
+    pub(crate) unsafe fn raw_lua(&self) -> &RawLua {
         &*self.lua.assume_init_ref().raw.data_ptr()
     }
 
@@ -248,4 +259,32 @@ impl ExtraData {
     pub(super) unsafe fn weak(&self) -> &WeakLua {
         self.weak.assume_init_ref()
     }
+
+    /// Pops a reference from top of the auxiliary stack and move it to a first free slot.
+    pub(super) unsafe fn ref_stack_pop(&mut self) -> c_int {
+        if let Some(free) = self.ref_free.pop() {
+            ffi::lua_replace(self.ref_thread, free);
+            return free;
+        }
+
+        // Try to grow max stack size
+        if self.ref_stack_top >= self.ref_stack_size {
+            let mut inc = self.ref_stack_size; // Try to double stack size
+            while inc > 0 && ffi::lua_checkstack(self.ref_thread, inc + REF_STACK_RESERVE) == 0 {
+                inc /= 2;
+            }
+            if inc == 0 {
+                // Pop item on top of the stack to avoid stack leaking and successfully run destructors
+                // during unwinding.
+                ffi::lua_pop(self.ref_thread, 1);
+                let top = self.ref_stack_top;
+                // It is a user error to create too many references to exhaust the Lua max stack size
+                // for the ref thread.
+                panic!("cannot create a Lua reference, out of auxiliary stack space (used {top} slots)");
+            }
+            self.ref_stack_size += inc;
+        }
+        self.ref_stack_top += 1;
+        self.ref_stack_top
+    }
 }

src/state/raw.rs

@@ -1,18 +1,17 @@
 use std::any::TypeId;
 use std::cell::{Cell, UnsafeCell};
-use std::ffi::{CStr, CString};
+use std::ffi::CStr;
 use std::mem;
 use std::os::raw::{c_char, c_int, c_void};
 use std::panic::resume_unwind;
 use std::ptr::{self, NonNull};
-use std::result::Result as StdResult;
 use std::sync::Arc;
 
 use crate::chunk::ChunkMode;
 use crate::error::{Error, Result};
 use crate::function::Function;
 use crate::memory::{MemoryState, ALLOCATOR};
-use crate::state::util::{callback_error_ext, ref_stack_pop};
+use crate::state::util::callback_error_ext;
 use crate::stdlib::StdLib;
 use crate::string::String;
 use crate::table::Table;
@@ -29,8 +28,8 @@ use crate::userdata::{
 use crate::util::{
     assert_stack, check_stack, get_destructed_userdata_metatable, get_internal_userdata, get_main_state,
     get_metatable_ptr, get_userdata, init_error_registry, init_internal_metatable, pop_error,
-    push_internal_userdata, push_string, push_table, rawset_field, safe_pcall, safe_xpcall, short_type_name,
-    StackGuard, WrappedFailure,
+    push_internal_userdata, push_string, push_table, push_userdata, rawset_field, safe_pcall, safe_xpcall,
+    short_type_name, StackGuard, WrappedFailure,
 };
 use crate::value::{Nil, Value};
 
@@ -38,7 +37,10 @@ use super::extra::ExtraData;
 use super::{Lua, LuaOptions, WeakLua};
 
 #[cfg(not(feature = "luau"))]
-use crate::hook::{Debug, HookTriggers};
+use crate::{
+    debug::Debug,
+    types::{HookCallback, HookKind, VmState},
+};
 
 #[cfg(feature = "async")]
 use {
@@ -55,17 +57,25 @@ pub struct RawLua {
     pub(super) state: Cell<*mut ffi::lua_State>,
     pub(super) main_state: Option<NonNull<ffi::lua_State>>,
     pub(super) extra: XRc<UnsafeCell<ExtraData>>,
+    owned: bool,
 }
 
 impl Drop for RawLua {
     fn drop(&mut self) {
         unsafe {
-            if !(*self.extra.get()).owned {
+            if !self.owned {
                 return;
             }
 
             let mem_state = MemoryState::get(self.main_state());
 
+            #[cfg(feature = "luau")]
+            {
+                // Reset any callbacks
+                (*ffi::lua_callbacks(self.main_state())).interrupt = None;
+                (*ffi::lua_callbacks(self.main_state())).userthread = None;
+            }
+
             ffi::lua_close(self.main_state());
 
             // Deallocate `MemoryState`
@@ -110,7 +120,7 @@ impl RawLua {
         unsafe { (*self.extra.get()).ref_thread }
     }
 
-    pub(super) unsafe fn new(libs: StdLib, options: LuaOptions) -> XRc<ReentrantMutex<Self>> {
+    pub(super) unsafe fn new(libs: StdLib, options: &LuaOptions) -> XRc<ReentrantMutex<Self>> {
         let mem_state: *mut MemoryState = Box::into_raw(Box::default());
         let mut state = ffi::lua_newstate(ALLOCATOR, mem_state as *mut c_void);
         // If state is null then switch to Lua internal allocator
@@ -187,6 +197,8 @@ impl RawLua {
                 init_internal_metatable::<XRc<UnsafeCell<ExtraData>>>(state, None)?;
                 init_internal_metatable::<Callback>(state, None)?;
                 init_internal_metatable::<CallbackUpvalue>(state, None)?;
+                #[cfg(not(feature = "luau"))]
+                init_internal_metatable::<HookCallback>(state, None)?;
                 #[cfg(feature = "async")]
                 {
                     init_internal_metatable::<AsyncCallback>(state, None)?;
@@ -196,7 +208,7 @@ impl RawLua {
                 }
 
                 // Init serde metatables
-                #[cfg(feature = "serialize")]
+                #[cfg(feature = "serde")]
                 crate::serde::init_metatables(state)?;
 
                 Ok::<_, Error>(())
@@ -228,8 +240,17 @@ impl RawLua {
             // Make sure that we don't store current state as main state (if it's not available)
             main_state: get_main_state(state).and_then(NonNull::new),
             extra: XRc::clone(&extra),
+            owned,
         }));
         (*extra.get()).set_lua(&rawlua);
+        if owned {
+            // If Lua state is managed by us, then make internal `RawLua` reference "weak"
+            XRc::decrement_strong_count(XRc::as_ptr(&rawlua));
+        } else {
+            // If Lua state is not managed by us, then keep internal `RawLua` reference "strong"
+            // but `Extra` reference weak (it will be collected from registry at lua_close time)
+            XRc::decrement_strong_count(XRc::as_ptr(&extra));
+        }
 
         rawlua
     }
@@ -271,36 +292,41 @@ impl RawLua {
         let res = load_std_libs(self.main_state(), libs);
 
         // If `package` library loaded into a safe lua state then disable C modules
-        let curr_libs = (*self.extra.get()).libs;
-        if is_safe && (curr_libs ^ (curr_libs | libs)).contains(StdLib::PACKAGE) {
-            mlua_expect!(self.lua().disable_c_modules(), "Error during disabling C modules");
+        #[cfg(not(feature = "luau"))]
+        if is_safe {
+            let curr_libs = (*self.extra.get()).libs;
+            if (curr_libs ^ (curr_libs | libs)).contains(StdLib::PACKAGE) {
+                mlua_expect!(self.lua().disable_c_modules(), "Error disabling C modules");
+            }
         }
+        #[cfg(feature = "luau")]
+        let _ = is_safe;
         unsafe { (*self.extra.get()).libs |= libs };
 
         res
     }
 
-    /// See [`Lua::try_set_app_data`]
+    /// Private version of [`Lua::try_set_app_data`]
     #[inline]
-    pub(crate) fn try_set_app_data<T: MaybeSend + 'static>(&self, data: T) -> StdResult<Option<T>, T> {
+    pub(crate) fn set_priv_app_data<T: MaybeSend + 'static>(&self, data: T) -> Option<T> {
         let extra = unsafe { &*self.extra.get() };
-        extra.app_data.try_insert(data)
+        extra.app_data_priv.insert(data)
     }
 
-    /// See [`Lua::app_data_ref`]
+    /// Private version of [`Lua::app_data_ref`]
     #[track_caller]
     #[inline]
-    pub(crate) fn app_data_ref_unguarded<T: 'static>(&self) -> Option<AppDataRef<T>> {
+    pub(crate) fn priv_app_data_ref<T: 'static>(&self) -> Option<AppDataRef<'_, T>> {
         let extra = unsafe { &*self.extra.get() };
-        extra.app_data.borrow(None)
+        extra.app_data_priv.borrow(None)
     }
 
-    /// See [`Lua::app_data_mut`]
+    /// Private version of [`Lua::app_data_mut`]
     #[track_caller]
     #[inline]
-    pub(crate) fn app_data_mut_unguarded<T: 'static>(&self) -> Option<AppDataRefMut<T>> {
+    pub(crate) fn priv_app_data_mut<T: 'static>(&self) -> Option<AppDataRefMut<'_, T>> {
         let extra = unsafe { &*self.extra.get() };
-        extra.app_data.borrow_mut(None)
+        extra.app_data_priv.borrow_mut(None)
     }
 
     /// See [`Lua::create_registry_value`]
@@ -374,48 +400,29 @@ impl RawLua {
         status
     }
 
-    /// Sets a 'hook' function for a thread (coroutine).
+    /// Sets a hook for a thread (coroutine).
     #[cfg(not(feature = "luau"))]
-    pub(crate) unsafe fn set_thread_hook<F>(
+    pub(crate) unsafe fn set_thread_hook(
         &self,
-        state: *mut ffi::lua_State,
-        triggers: HookTriggers,
-        callback: F,
-    ) where
-        F: Fn(&Lua, Debug) -> Result<crate::VmState> + MaybeSend + 'static,
-    {
-        use crate::types::VmState;
-        use std::rc::Rc;
+        thread_state: *mut ffi::lua_State,
+        hook: HookKind,
+    ) -> Result<()> {
+        // Key to store hooks in the registry
+        const HOOKS_KEY: *const c_char = cstr!("__mlua_hooks");
 
-        unsafe extern "C-unwind" fn hook_proc(state: *mut ffi::lua_State, ar: *mut ffi::lua_Debug) {
-            let extra = ExtraData::get(state);
-            if (*extra).hook_thread != state {
-                // Hook was destined for a different thread, ignore
-                ffi::lua_sethook(state, None, 0, 0);
-                return;
-            }
-            let result = callback_error_ext(state, extra, move |extra, _| {
-                let hook_cb = (*extra).hook_callback.clone();
-                let hook_cb = mlua_expect!(hook_cb, "no hook callback set in hook_proc");
-                if Rc::strong_count(&hook_cb) > 2 {
-                    return Ok(VmState::Continue); // Don't allow recursion
-                }
-                let rawlua = (*extra).raw_lua();
-                let debug = Debug::new(rawlua, ar);
-                hook_cb((*extra).lua(), debug)
-            });
-            match result {
+        unsafe fn process_status(state: *mut ffi::lua_State, event: c_int, status: VmState) {
+            match status {
                 VmState::Continue => {}
                 VmState::Yield => {
                     // Only count and line events can yield
-                    if (*ar).event == ffi::LUA_HOOKCOUNT || (*ar).event == ffi::LUA_HOOKLINE {
+                    if event == ffi::LUA_HOOKCOUNT || event == ffi::LUA_HOOKLINE {
                         #[cfg(any(feature = "lua54", feature = "lua53"))]
                         if ffi::lua_isyieldable(state) != 0 {
                             ffi::lua_yield(state, 0);
                         }
                         #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
                         {
-                            ffi::lua_pushliteral(state, "attempt to yield from a hook");
+                            ffi::lua_pushliteral(state, c"attempt to yield from a hook");
                             ffi::lua_error(state);
                         }
                     }
@@ -423,9 +430,83 @@ impl RawLua {
             }
         }
 
-        (*self.extra.get()).hook_callback = Some(Rc::new(callback));
-        (*self.extra.get()).hook_thread = state; // Mark for what thread the hook is set
-        ffi::lua_sethook(state, Some(hook_proc), triggers.mask(), triggers.count());
+        unsafe extern "C-unwind" fn global_hook_proc(state: *mut ffi::lua_State, ar: *mut ffi::lua_Debug) {
+            let status = callback_error_ext(state, ptr::null_mut(), false, move |extra, _| {
+                match (*extra).hook_callback.clone() {
+                    Some(hook_callback) => {
+                        let rawlua = (*extra).raw_lua();
+                        let debug = Debug::new(rawlua, 0, ar);
+                        hook_callback((*extra).lua(), &debug)
+                    }
+                    None => {
+                        ffi::lua_sethook(state, None, 0, 0);
+                        Ok(VmState::Continue)
+                    }
+                }
+            });
+            process_status(state, (*ar).event, status);
+        }
+
+        unsafe extern "C-unwind" fn hook_proc(state: *mut ffi::lua_State, ar: *mut ffi::lua_Debug) {
+            let top = ffi::lua_gettop(state);
+            let mut hook_callback_ptr = ptr::null();
+            ffi::luaL_checkstack(state, 3, ptr::null());
+            if ffi::lua_getfield(state, ffi::LUA_REGISTRYINDEX, HOOKS_KEY) == ffi::LUA_TTABLE {
+                ffi::lua_pushthread(state);
+                if ffi::lua_rawget(state, -2) == ffi::LUA_TUSERDATA {
+                    hook_callback_ptr = get_internal_userdata::<HookCallback>(state, -1, ptr::null());
+                }
+            }
+            ffi::lua_settop(state, top);
+            if hook_callback_ptr.is_null() {
+                ffi::lua_sethook(state, None, 0, 0);
+                return;
+            }
+
+            let status = callback_error_ext(state, ptr::null_mut(), false, |extra, _| {
+                let rawlua = (*extra).raw_lua();
+                let debug = Debug::new(rawlua, 0, ar);
+                let hook_callback = (*hook_callback_ptr).clone();
+                hook_callback((*extra).lua(), &debug)
+            });
+            process_status(state, (*ar).event, status)
+        }
+
+        let (triggers, callback) = match hook {
+            HookKind::Global if (*self.extra.get()).hook_callback.is_none() => {
+                return Ok(());
+            }
+            HookKind::Global => {
+                let triggers = (*self.extra.get()).hook_triggers;
+                let (mask, count) = (triggers.mask(), triggers.count());
+                ffi::lua_sethook(thread_state, Some(global_hook_proc), mask, count);
+                return Ok(());
+            }
+            HookKind::Thread(triggers, callback) => (triggers, callback),
+        };
+
+        // Hooks for threads stored in the registry (in a weak table)
+        let state = self.state();
+        let _sg = StackGuard::new(state);
+        check_stack(state, 3)?;
+        protect_lua!(state, 0, 0, |state| {
+            if ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, HOOKS_KEY) == 0 {
+                // Table just created, initialize it
+                ffi::lua_pushliteral(state, c"k");
+                ffi::lua_setfield(state, -2, cstr!("__mode")); // hooktable.__mode = "k"
+                ffi::lua_pushvalue(state, -1);
+                ffi::lua_setmetatable(state, -2); // metatable(hooktable) = hooktable
+            }
+
+            ffi::lua_pushthread(thread_state);
+            ffi::lua_xmove(thread_state, state, 1); // key (thread)
+            let _ = push_internal_userdata(state, callback, false); // value (hook callback)
+            ffi::lua_rawset(state, -3); // hooktable[thread] = hook callback
+        })?;
+
+        ffi::lua_sethook(thread_state, Some(hook_proc), triggers.mask(), triggers.count());
+
+        Ok(())
     }
 
     /// See [`Lua::create_string`]
@@ -442,6 +523,20 @@ impl RawLua {
         Ok(String(self.pop_ref()))
     }
 
+    #[cfg(feature = "luau")]
+    pub(crate) unsafe fn create_buffer_with_capacity(&self, size: usize) -> Result<(*mut u8, crate::Buffer)> {
+        let state = self.state();
+        if self.unlikely_memory_error() {
+            let ptr = crate::util::push_buffer(state, size, false)?;
+            return Ok((ptr, crate::Buffer(self.pop_ref())));
+        }
+
+        let _sg = StackGuard::new(state);
+        check_stack(state, 3)?;
+        let ptr = crate::util::push_buffer(state, size, true)?;
+        Ok((ptr, crate::Buffer(self.pop_ref())))
+    }
+
     /// See [`Lua::create_table_with_capacity`]
     pub(crate) unsafe fn create_table_with_capacity(&self, narr: usize, nrec: usize) -> Result<Table> {
         let state = self.state();
@@ -456,6 +551,34 @@ impl RawLua {
         Ok(Table(self.pop_ref()))
     }
 
+    /// See [`Lua::create_table_from`]
+    pub(crate) unsafe fn create_table_from<I, K, V>(&self, iter: I) -> Result<Table>
+    where
+        I: IntoIterator<Item = (K, V)>,
+        K: IntoLua,
+        V: IntoLua,
+    {
+        let state = self.state();
+        let _sg = StackGuard::new(state);
+        check_stack(state, 6)?;
+
+        let iter = iter.into_iter();
+        let lower_bound = iter.size_hint().0;
+        let protect = !self.unlikely_memory_error();
+        push_table(state, 0, lower_bound, protect)?;
+        for (k, v) in iter {
+            self.push(k)?;
+            self.push(v)?;
+            if protect {
+                protect_lua!(state, 3, 1, fn(state) ffi::lua_rawset(state, -3))?;
+            } else {
+                ffi::lua_rawset(state, -3);
+            }
+        }
+
+        Ok(Table(self.pop_ref()))
+    }
+
     /// See [`Lua::create_sequence_from`]
     pub(crate) unsafe fn create_sequence_from<T, I>(&self, iter: I) -> Result<Table>
     where
@@ -492,11 +615,20 @@ impl RawLua {
         let _sg = StackGuard::new(state);
         check_stack(state, 3)?;
 
-        let thread_state = if self.unlikely_memory_error() {
+        let protect = !self.unlikely_memory_error();
+        #[cfg(feature = "luau")]
+        let protect = protect || (*self.extra.get()).thread_creation_callback.is_some();
+
+        let thread_state = if !protect {
             ffi::lua_newthread(state)
         } else {
             protect_lua!(state, 0, 1, |state| ffi::lua_newthread(state))?
         };
+
+        // Inherit global hook if set
+        #[cfg(not(feature = "luau"))]
+        self.set_thread_hook(thread_state, HookKind::Global)?;
+
         let thread = Thread(self.pop_ref(), thread_state);
         ffi::lua_xpush(self.ref_thread(), thread_state, func.0.index);
         Ok(thread)
@@ -506,7 +638,7 @@ impl RawLua {
     #[cfg(feature = "async")]
     pub(crate) unsafe fn create_recycled_thread(&self, func: &Function) -> Result<Thread> {
         if let Some(index) = (*self.extra.get()).thread_pool.pop() {
-            let thread_state = ffi::lua_tothread(self.ref_thread(), index);
+            let thread_state = ffi::lua_tothread(self.ref_thread(), *index.0);
             ffi::lua_xpush(self.ref_thread(), thread_state, func.0.index);
 
             #[cfg(feature = "luau")]
@@ -522,48 +654,14 @@ impl RawLua {
         self.create_thread(func)
     }
 
-    /// Resets thread (coroutine) and returns it to the pool for later use.
+    /// Returns the thread to the pool for later use.
     #[cfg(feature = "async")]
     pub(crate) unsafe fn recycle_thread(&self, thread: &mut Thread) {
-        let thread_state = thread.1;
         let extra = &mut *self.extra.get();
-        if extra.thread_pool.len() == extra.thread_pool.capacity() {
-            #[cfg(feature = "lua54")]
-            if ffi::lua_status(thread_state) != ffi::LUA_OK {
-                // Close all to-be-closed variables without returning thread to the pool
-                #[cfg(not(feature = "vendored"))]
-                ffi::lua_resetthread(thread_state);
-                #[cfg(feature = "vendored")]
-                ffi::lua_closethread(thread_state, self.state());
+        if extra.thread_pool.len() < extra.thread_pool.capacity() {
+            if let Some(index) = thread.0.index_count.take() {
+                extra.thread_pool.push(index);
             }
-            return;
-        }
-
-        let mut reset_ok = false;
-        if ffi::lua_status(thread_state) == ffi::LUA_OK {
-            if ffi::lua_gettop(thread_state) > 0 {
-                ffi::lua_settop(thread_state, 0);
-            }
-            reset_ok = true;
-        }
-
-        #[cfg(feature = "lua54")]
-        if !reset_ok {
-            #[cfg(not(feature = "vendored"))]
-            let status = ffi::lua_resetthread(thread_state);
-            #[cfg(feature = "vendored")]
-            let status = ffi::lua_closethread(thread_state, self.state());
-            reset_ok = status == ffi::LUA_OK;
-        }
-        #[cfg(feature = "luau")]
-        if !reset_ok {
-            ffi::lua_resetthread(thread_state);
-            reset_ok = true;
-        }
-
-        if reset_ok {
-            extra.thread_pool.push(thread.0.index);
-            thread.0.drop = false; // Prevent thread from being garbage collected
         }
     }
 
@@ -611,7 +709,7 @@ impl RawLua {
 
     /// Pops a value from the Lua stack.
     ///
-    /// Uses 2 stack spaces, does not call `checkstack`.
+    /// Uses up to 1 stack spaces, does not call `checkstack`.
     pub(crate) unsafe fn pop_value(&self) -> Value {
         let value = self.stack_value(-1, None);
         ffi::lua_pop(self.state(), 1);
@@ -620,7 +718,7 @@ impl RawLua {
 
     /// Returns value at given stack index without popping it.
     ///
-    /// Uses 2 stack spaces, does not call checkstack.
+    /// Uses up to 1 stack spaces, does not call `checkstack`.
     pub(crate) unsafe fn stack_value(&self, idx: c_int, type_hint: Option<c_int>) -> Value {
         let state = self.state();
         match type_hint.unwrap_or_else(|| ffi::lua_type(state, idx)) {
@@ -645,7 +743,7 @@ impl RawLua {
 
                 let n = ffi::lua_tonumber(state, idx);
                 match num_traits::cast(n) {
-                    Some(i) if (n - (i as Number)).abs() < Number::EPSILON => Value::Integer(i),
+                    Some(i) if n.to_bits() == (i as Number).to_bits() => Value::Integer(i),
                     _ => Value::Number(n),
                 }
             }
@@ -733,21 +831,14 @@ impl RawLua {
     #[inline]
     pub(crate) unsafe fn pop_ref(&self) -> ValueRef {
         ffi::lua_xmove(self.state(), self.ref_thread(), 1);
-        let index = ref_stack_pop(self.extra.get());
+        let index = (*self.extra.get()).ref_stack_pop();
         ValueRef::new(self, index)
     }
 
     // Same as `pop_ref` but assumes the value is already on the reference thread
     #[inline]
     pub(crate) unsafe fn pop_ref_thread(&self) -> ValueRef {
-        let index = ref_stack_pop(self.extra.get());
-        ValueRef::new(self, index)
-    }
-
-    #[inline]
-    pub(crate) unsafe fn clone_ref(&self, vref: &ValueRef) -> ValueRef {
-        ffi::lua_pushvalue(self.ref_thread(), vref.index);
-        let index = ref_stack_pop(self.extra.get());
+        let index = (*self.extra.get()).ref_stack_pop();
         ValueRef::new(self, index)
     }
 
@@ -837,7 +928,7 @@ impl RawLua {
         // We generate metatable first to make sure it *always* available when userdata pushed
         let mt_id = get_metatable_id()?;
         let protect = !self.unlikely_memory_error();
-        crate::util::push_userdata(state, data, protect)?;
+        push_userdata(state, data, protect)?;
         ffi::lua_rawgeti(state, ffi::LUA_REGISTRYINDEX, mt_id);
         ffi::lua_setmetatable(state, -2);
 
@@ -965,6 +1056,18 @@ impl RawLua {
             field_setters_index = Some(ffi::lua_absindex(state, -1));
         }
 
+        // Create methods namecall table
+        #[cfg_attr(not(feature = "luau"), allow(unused_mut))]
+        let mut methods_map = None;
+        #[cfg(feature = "luau")]
+        if registry.enable_namecall {
+            let map: &mut rustc_hash::FxHashMap<_, crate::types::CallbackPtr> =
+                methods_map.get_or_insert_with(Default::default);
+            for (k, m) in &registry.methods {
+                map.insert(k.as_bytes().to_vec(), &**m);
+            }
+        }
+
         let mut methods_index = None;
         let methods_nrec = registry.methods.len();
         #[cfg(feature = "async")]
@@ -1012,6 +1115,7 @@ impl RawLua {
             field_getters_index,
             field_setters_index,
             methods_index,
+            methods_map,
         )?;
 
         // Update stack guard to keep metatable after return
@@ -1100,7 +1204,7 @@ impl RawLua {
     pub(crate) fn create_callback(&self, func: Callback) -> Result<Function> {
         unsafe extern "C-unwind" fn call_callback(state: *mut ffi::lua_State) -> c_int {
             let upvalue = get_userdata::<CallbackUpvalue>(state, ffi::lua_upvalueindex(1));
-            callback_error_ext(state, (*upvalue).extra.get(), |extra, nargs| {
+            callback_error_ext(state, (*upvalue).extra.get(), true, |extra, nargs| {
                 // Lua ensures that `LUA_MINSTACK` stack spaces are available (after pushing arguments)
                 // The lock must be already held as the callback is executed
                 let rawlua = (*extra).raw_lua();
@@ -1147,13 +1251,13 @@ impl RawLua {
             // Async functions cannot be scoped and therefore destroyed,
             // so the first upvalue is always valid
             let upvalue = get_userdata::<AsyncCallbackUpvalue>(state, ffi::lua_upvalueindex(1));
-            callback_error_ext(state, (*upvalue).extra.get(), |extra, nargs| {
+            callback_error_ext(state, (*upvalue).extra.get(), true, |extra, nargs| {
                 // Lua ensures that `LUA_MINSTACK` stack spaces are available (after pushing arguments)
                 // The lock must be already held as the callback is executed
                 let rawlua = (*extra).raw_lua();
 
                 let func = &*(*upvalue).data;
-                let fut = func(rawlua, nargs);
+                let fut = Some(func(rawlua, nargs));
                 let extra = XRc::clone(&(*upvalue).extra);
                 let protect = !rawlua.unlikely_memory_error();
                 push_internal_userdata(state, AsyncPollUpvalue { data: fut, extra }, protect)?;
@@ -1171,20 +1275,34 @@ impl RawLua {
 
         unsafe extern "C-unwind" fn poll_future(state: *mut ffi::lua_State) -> c_int {
             let upvalue = get_userdata::<AsyncPollUpvalue>(state, ffi::lua_upvalueindex(1));
-            callback_error_ext(state, (*upvalue).extra.get(), |extra, _| {
+            callback_error_ext(state, (*upvalue).extra.get(), true, |extra, nargs| {
                 // Lua ensures that `LUA_MINSTACK` stack spaces are available (after pushing arguments)
                 // The lock must be already held as the future is polled
                 let rawlua = (*extra).raw_lua();
 
+                if nargs == 1 && ffi::lua_tolightuserdata(state, -1) == Lua::poll_terminate().0 {
+                    // Destroy the future and terminate the Lua thread
+                    (*upvalue).data.take();
+                    ffi::lua_pushinteger(state, -1);
+                    return Ok(1);
+                }
+
                 let fut = &mut (*upvalue).data;
                 let mut ctx = Context::from_waker(rawlua.waker());
-                match fut.as_mut().poll(&mut ctx) {
-                    Poll::Pending => {
+                match fut.as_mut().map(|fut| fut.as_mut().poll(&mut ctx)) {
+                    Some(Poll::Pending) => {
+                        let fut_nvals = ffi::lua_gettop(state);
+                        if fut_nvals >= 3 && ffi::lua_tolightuserdata(state, -3) == Lua::poll_yield().0 {
+                            // We have some values to yield
+                            ffi::lua_pushnil(state);
+                            ffi::lua_replace(state, -4);
+                            return Ok(3);
+                        }
                         ffi::lua_pushnil(state);
                         ffi::lua_pushlightuserdata(state, Lua::poll_pending().0);
                         Ok(2)
                     }
-                    Poll::Ready(nresults) => {
+                    Some(Poll::Ready(nresults)) => {
                         match nresults? {
                             nresults if nresults < 3 => {
                                 // Fast path for up to 2 results without creating a table
@@ -1202,6 +1320,7 @@ impl RawLua {
                             }
                         }
                     }
+                    None => Err(Error::CallbackDestructed),
                 }
             })
         }
@@ -1247,8 +1366,9 @@ impl RawLua {
         lua.load(
             r#"
             local poll = get_poll(...)
+            local nres, res, res2 = poll()
             while true do
-                local nres, res, res2 = poll()
+                -- Poll::Ready branch, `nres` is the number of results
                 if nres ~= nil then
                     if nres == 0 then
                         return
@@ -1256,45 +1376,60 @@ impl RawLua {
                         return res
                     elseif nres == 2 then
                         return res, res2
+                    elseif nres < 0 then
+                        -- Negative `nres` means that the future is terminated
+                        -- It must stay yielded and never be resumed again
+                        yield()
                     else
                         return unpack(res, nres)
                     end
                 end
-                yield(res) -- `res` is a "pending" value
+
+                -- Poll::Pending branch
+                if res2 == nil then
+                    -- `res` is a "pending" value
+                    -- `yield` can return a signal to drop the future that we should propagate
+                    -- to the poller
+                    nres, res, res2 = poll(yield(res))
+                elseif res2 == 0 then
+                    nres, res, res2 = poll(yield())
+                elseif res2 == 1 then
+                    nres, res, res2 = poll(yield(res))
+                else
+                    nres, res, res2 = poll(yield(unpack(res, res2)))
+                end
             end
             "#,
         )
         .try_cache()
-        .set_name("__mlua_async_poll")
+        .set_name("=__mlua_async_poll")
         .set_environment(env)
         .into_function()
     }
 
     #[cfg(feature = "async")]
     #[inline]
-    pub(crate) unsafe fn waker(&self) -> &Waker {
-        (*self.extra.get()).waker.as_ref()
+    pub(crate) fn waker(&self) -> &Waker {
+        unsafe { (*self.extra.get()).waker.as_ref() }
     }
 
     #[cfg(feature = "async")]
     #[inline]
-    pub(crate) unsafe fn set_waker(&self, waker: NonNull<Waker>) -> NonNull<Waker> {
-        mem::replace(&mut (*self.extra.get()).waker, waker)
+    pub(crate) fn set_waker(&self, waker: NonNull<Waker>) -> NonNull<Waker> {
+        unsafe { mem::replace(&mut (*self.extra.get()).waker, waker) }
     }
 }
 
 // Uses 3 stack spaces
 unsafe fn load_std_libs(state: *mut ffi::lua_State, libs: StdLib) -> Result<()> {
-    #[inline(always)]
-    pub unsafe fn requiref(
+    unsafe fn requiref(
         state: *mut ffi::lua_State,
-        modname: &str,
+        modname: *const c_char,
         openf: ffi::lua_CFunction,
         glb: c_int,
     ) -> Result<()> {
-        let modname = mlua_expect!(CString::new(modname), "modname contains nil byte");
-        protect_lua!(state, 0, 1, |state| {
-            ffi::luaL_requiref(state, modname.as_ptr() as *const c_char, openf, glb)
+        protect_lua!(state, 0, 0, |state| {
+            ffi::luaL_requiref(state, modname, openf, glb)
         })
     }
 
@@ -1325,36 +1460,30 @@ unsafe fn load_std_libs(state: *mut ffi::lua_State, libs: StdLib) -> Result<()>
     {
         if libs.contains(StdLib::COROUTINE) {
             requiref(state, ffi::LUA_COLIBNAME, ffi::luaopen_coroutine, 1)?;
-            ffi::lua_pop(state, 1);
         }
     }
 
     if libs.contains(StdLib::TABLE) {
         requiref(state, ffi::LUA_TABLIBNAME, ffi::luaopen_table, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     #[cfg(not(feature = "luau"))]
     if libs.contains(StdLib::IO) {
         requiref(state, ffi::LUA_IOLIBNAME, ffi::luaopen_io, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     if libs.contains(StdLib::OS) {
         requiref(state, ffi::LUA_OSLIBNAME, ffi::luaopen_os, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     if libs.contains(StdLib::STRING) {
         requiref(state, ffi::LUA_STRLIBNAME, ffi::luaopen_string, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
     {
         if libs.contains(StdLib::UTF8) {
             requiref(state, ffi::LUA_UTF8LIBNAME, ffi::luaopen_utf8, 1)?;
-            ffi::lua_pop(state, 1);
         }
     }
 
@@ -1362,7 +1491,6 @@ unsafe fn load_std_libs(state: *mut ffi::lua_State, libs: StdLib) -> Result<()>
     {
         if libs.contains(StdLib::BIT) {
             requiref(state, ffi::LUA_BITLIBNAME, ffi::luaopen_bit32, 1)?;
-            ffi::lua_pop(state, 1);
         }
     }
 
@@ -1370,53 +1498,40 @@ unsafe fn load_std_libs(state: *mut ffi::lua_State, libs: StdLib) -> Result<()>
     {
         if libs.contains(StdLib::BIT) {
             requiref(state, ffi::LUA_BITLIBNAME, ffi::luaopen_bit, 1)?;
-            ffi::lua_pop(state, 1);
         }
     }
 
     #[cfg(feature = "luau")]
     if libs.contains(StdLib::BUFFER) {
         requiref(state, ffi::LUA_BUFFERLIBNAME, ffi::luaopen_buffer, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     #[cfg(feature = "luau")]
     if libs.contains(StdLib::VECTOR) {
         requiref(state, ffi::LUA_VECLIBNAME, ffi::luaopen_vector, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     if libs.contains(StdLib::MATH) {
         requiref(state, ffi::LUA_MATHLIBNAME, ffi::luaopen_math, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     if libs.contains(StdLib::DEBUG) {
         requiref(state, ffi::LUA_DBLIBNAME, ffi::luaopen_debug, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     #[cfg(not(feature = "luau"))]
     if libs.contains(StdLib::PACKAGE) {
         requiref(state, ffi::LUA_LOADLIBNAME, ffi::luaopen_package, 1)?;
-        ffi::lua_pop(state, 1);
-    }
-    #[cfg(feature = "luau")]
-    if libs.contains(StdLib::PACKAGE) {
-        let lua = (*ExtraData::get(state)).lua();
-        crate::luau::register_package_module(lua)?;
     }
 
     #[cfg(feature = "luajit")]
     if libs.contains(StdLib::JIT) {
         requiref(state, ffi::LUA_JITLIBNAME, ffi::luaopen_jit, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     #[cfg(feature = "luajit")]
     if libs.contains(StdLib::FFI) {
         requiref(state, ffi::LUA_FFILIBNAME, ffi::luaopen_ffi, 1)?;
-        ffi::lua_pop(state, 1);
     }
 
     Ok(())

src/state/util.rs

@@ -24,9 +24,10 @@ impl Drop for StateGuard<'_> {
 
 // An optimized version of `callback_error` that does not allocate `WrappedFailure` userdata
 // and instead reuses unused values from previous calls (or allocates new).
-pub(super) unsafe fn callback_error_ext<F, R>(
+pub(crate) unsafe fn callback_error_ext<F, R>(
     state: *mut ffi::lua_State,
     mut extra: *mut ExtraData,
+    wrap_error: bool,
     f: F,
 ) -> R
 where
@@ -88,7 +89,7 @@ where
                 PreallocatedFailure::New(_) => {
                     ffi::lua_rotate(state, 1, -1);
                     ffi::lua_xmove(state, ref_thread, 1);
-                    let index = ref_stack_pop(extra);
+                    let index = (*extra).ref_stack_pop();
                     (*extra).wrapped_failure_pool.push(index);
                     (*extra).wrapped_failure_top += 1;
                 }
@@ -114,6 +115,13 @@ where
         Ok(Err(err)) => {
             let wrapped_error = prealloc_failure.r#use(state, extra);
 
+            if !wrap_error {
+                ptr::write(wrapped_error, WrappedFailure::Error(err));
+                get_internal_metatable::<WrappedFailure>(state);
+                ffi::lua_setmetatable(state, -2);
+                ffi::lua_error(state)
+            }
+
             // Build `CallbackError` with traceback
             let traceback = if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
                 ffi::luaL_traceback(state, state, ptr::null(), 0);
@@ -142,31 +150,3 @@ where
         }
     }
 }
-
-pub(super) unsafe fn ref_stack_pop(extra: *mut ExtraData) -> c_int {
-    let extra = &mut *extra;
-    if let Some(free) = extra.ref_free.pop() {
-        ffi::lua_replace(extra.ref_thread, free);
-        return free;
-    }
-
-    // Try to grow max stack size
-    if extra.ref_stack_top >= extra.ref_stack_size {
-        let mut inc = extra.ref_stack_size; // Try to double stack size
-        while inc > 0 && ffi::lua_checkstack(extra.ref_thread, inc) == 0 {
-            inc /= 2;
-        }
-        if inc == 0 {
-            // Pop item on top of the stack to avoid stack leaking and successfully run destructors
-            // during unwinding.
-            ffi::lua_pop(extra.ref_thread, 1);
-            let top = extra.ref_stack_top;
-            // It is a user error to create enough references to exhaust the Lua max stack size for
-            // the ref thread.
-            panic!("cannot create a Lua reference, out of auxiliary stack space (used {top} slots)");
-        }
-        extra.ref_stack_size += inc;
-    }
-    extra.ref_stack_top += 1;
-    extra.ref_stack_top
-}

src/stdlib.rs

@@ -6,9 +6,11 @@ pub struct StdLib(u32);
 
 impl StdLib {
     /// [`coroutine`](https://www.lua.org/manual/5.4/manual.html#6.2) library
-    ///
-    /// Requires `feature = "lua54/lua53/lua52/luau"`
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau"))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luau")))
+    )]
     pub const COROUTINE: StdLib = StdLib(1);
 
     /// [`table`](https://www.lua.org/manual/5.4/manual.html#6.6) library
@@ -26,21 +28,24 @@ impl StdLib {
     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"))]
+    #[cfg_attr(docsrs, doc(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))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua52", feature = "luajit", feature = "luau")))
+    )]
     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.org/library#buffer-library) library
@@ -54,15 +59,11 @@ impl StdLib {
     pub const VECTOR: StdLib = StdLib(1 << 10);
 
     /// [`jit`](http://luajit.org/ext_jit.html) library
-    ///
-    /// Requires `feature = "luajit"`
     #[cfg(any(feature = "luajit", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
     pub const JIT: StdLib = StdLib(1 << 11);
 
     /// (**unsafe**) [`ffi`](http://luajit.org/ext_ffi.html) library
-    ///
-    /// Requires `feature = "luajit"`
     #[cfg(any(feature = "luajit", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
     pub const FFI: StdLib = StdLib(1 << 30);

src/string.rs

@@ -11,7 +11,7 @@ use crate::traits::IntoLua;
 use crate::types::{LuaType, ValueRef};
 use crate::value::Value;
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use {
     serde::ser::{Serialize, Serializer},
     std::result::Result as StdResult,
@@ -43,7 +43,7 @@ impl String {
     /// # }
     /// ```
     #[inline]
-    pub fn to_str(&self) -> Result<BorrowedStr> {
+    pub fn to_str(&self) -> Result<BorrowedStr<'_>> {
         BorrowedStr::try_from(self)
     }
 
@@ -86,7 +86,7 @@ impl String {
 
     /// Get the bytes that make up this string.
     ///
-    /// The returned slice will not contain the terminating nul byte, but will contain any nul
+    /// The returned slice will not contain the terminating null byte, but will contain any null
     /// bytes embedded into the Lua string.
     ///
     /// # Examples
@@ -102,19 +102,19 @@ impl String {
     /// # }
     /// ```
     #[inline]
-    pub fn as_bytes(&self) -> BorrowedBytes {
+    pub fn as_bytes(&self) -> BorrowedBytes<'_> {
         BorrowedBytes::from(self)
     }
 
-    /// Get the bytes that make up this string, including the trailing nul byte.
-    pub fn as_bytes_with_nul(&self) -> BorrowedBytes {
+    /// Get the bytes that make up this string, including the trailing null byte.
+    pub fn as_bytes_with_nul(&self) -> BorrowedBytes<'_> {
         let BorrowedBytes { buf, borrow, _lua } = BorrowedBytes::from(self);
-        // Include the trailing nul byte (it's always present but excluded by default)
+        // Include the trailing null byte (it's always present but excluded by default)
         let buf = unsafe { slice::from_raw_parts((*buf).as_ptr(), (*buf).len() + 1) };
         BorrowedBytes { buf, borrow, _lua }
     }
 
-    // Does not return the terminating nul byte
+    // Does not return the terminating null byte
     unsafe fn to_slice(&self) -> (&[u8], Lua) {
         let lua = self.0.lua.upgrade();
         let slice = {
@@ -211,7 +211,7 @@ impl Hash for String {
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for String {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where

src/table.rs

@@ -6,16 +6,16 @@ use std::string::String as StdString;
 
 use crate::error::{Error, Result};
 use crate::function::Function;
-use crate::state::{LuaGuard, RawLua};
+use crate::state::{LuaGuard, RawLua, WeakLua};
 use crate::traits::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, ObjectLike};
 use crate::types::{Integer, LuaType, ValueRef};
 use crate::util::{assert_stack, check_stack, get_metatable_ptr, StackGuard};
 use crate::value::{Nil, Value};
 
 #[cfg(feature = "async")]
-use futures_util::future::{self, Either, Future};
+use crate::function::AsyncCallFuture;
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use {
     rustc_hash::FxHashSet,
     serde::ser::{Serialize, SerializeMap, SerializeSeq, Serializer},
@@ -211,7 +211,7 @@ impl Table {
     ///
     /// let always_equals_mt = lua.create_table()?;
     /// always_equals_mt.set("__eq", lua.create_function(|_, (_t1, _t2): (Table, Table)| Ok(true))?)?;
-    /// table2.set_metatable(Some(always_equals_mt));
+    /// table2.set_metatable(Some(always_equals_mt))?;
     ///
     /// assert!(table1.equals(&table1.clone())?);
     /// assert!(table1.equals(&table2)?);
@@ -416,14 +416,7 @@ impl Table {
 
                 lua.push_ref(&self.0);
 
-                // Clear array part
-                for i in 1..=ffi::lua_rawlen(state, -1) {
-                    ffi::lua_pushnil(state);
-                    ffi::lua_rawseti(state, -2, i as Integer);
-                }
-
-                // Clear hash part
-                // It must be safe as long as we don't use invalid keys
+                // This is safe as long as we don't assign new keys
                 ffi::lua_pushnil(state);
                 while ffi::lua_next(state, -2) != 0 {
                     ffi::lua_pop(state, 1); // pop value
@@ -487,52 +480,37 @@ impl Table {
     /// [`getmetatable`]: https://www.lua.org/manual/5.4/manual.html#pdf-getmetatable
     pub fn metatable(&self) -> Option<Table> {
         let lua = self.0.lua.lock();
-        let state = lua.state();
+        let ref_thread = lua.ref_thread();
         unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 2);
-
-            lua.push_ref(&self.0);
-            if ffi::lua_getmetatable(state, -1) == 0 {
+            if ffi::lua_getmetatable(ref_thread, self.0.index) == 0 {
                 None
             } else {
-                Some(Table(lua.pop_ref()))
+                Some(Table(lua.pop_ref_thread()))
             }
         }
     }
 
-    #[doc(hidden)]
-    #[deprecated(since = "0.10.0", note = "please use `metatable` instead")]
-    #[cfg(not(tarpaulin_include))]
-    pub fn get_metatable(&self) -> Option<Table> {
-        self.metatable()
-    }
-
     /// Sets or removes the metatable of this table.
     ///
     /// If `metatable` is `None`, the metatable is removed (if no metatable is set, this does
     /// nothing).
-    pub fn set_metatable(&self, metatable: Option<Table>) {
-        // Workaround to throw readonly error without returning Result
+    pub fn set_metatable(&self, metatable: Option<Table>) -> Result<()> {
         #[cfg(feature = "luau")]
         if self.is_readonly() {
-            panic!("attempt to modify a readonly table");
+            return Err(Error::runtime("attempt to modify a readonly table"));
         }
 
         let lua = self.0.lua.lock();
-        let state = lua.state();
+        let ref_thread = lua.ref_thread();
         unsafe {
-            let _sg = StackGuard::new(state);
-            assert_stack(state, 2);
-
-            lua.push_ref(&self.0);
-            if let Some(metatable) = metatable {
-                lua.push_ref(&metatable.0);
+            if let Some(metatable) = &metatable {
+                ffi::lua_pushvalue(ref_thread, metatable.0.index);
             } else {
-                ffi::lua_pushnil(state);
+                ffi::lua_pushnil(ref_thread);
             }
-            ffi::lua_setmetatable(state, -2);
+            ffi::lua_setmetatable(ref_thread, self.0.index);
         }
+        Ok(())
     }
 
     /// Returns true if the table has metatable attached.
@@ -544,8 +522,6 @@ impl Table {
     }
 
     /// Sets `readonly` attribute on the table.
-    ///
-    /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     pub fn set_readonly(&self, enabled: bool) {
@@ -561,8 +537,6 @@ impl Table {
     }
 
     /// Returns `readonly` attribute of the table.
-    ///
-    /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     pub fn is_readonly(&self) -> bool {
@@ -580,8 +554,6 @@ impl Table {
     /// - Fast-path for some built-in functions (fastcall).
     ///
     /// For `safeenv` environments, monkey patching or modifying values may not work as expected.
-    ///
-    /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     pub fn set_safeenv(&self, enabled: bool) {
@@ -626,7 +598,7 @@ impl Table {
     /// ```
     ///
     /// [Lua manual]: http://www.lua.org/manual/5.4/manual.html#pdf-next
-    pub fn pairs<K: FromLua, V: FromLua>(&self) -> TablePairs<K, V> {
+    pub fn pairs<K: FromLua, V: FromLua>(&self) -> TablePairs<'_, K, V> {
         TablePairs {
             guard: self.0.lua.lock(),
             table: self,
@@ -691,21 +663,30 @@ impl Table {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn sequence_values<V: FromLua>(&self) -> TableSequence<V> {
+    pub fn sequence_values<V: FromLua>(&self) -> TableSequence<'_, V> {
         TableSequence {
             guard: self.0.lua.lock(),
             table: self,
             index: 1,
+            len: None,
             _phantom: PhantomData,
         }
     }
 
     /// Iterates over the sequence part of the table, invoking the given closure on each value.
+    ///
+    /// This methods is similar to [`Table::sequence_values`], but optimized for performance.
     #[doc(hidden)]
-    pub fn for_each_value<V>(&self, mut f: impl FnMut(V) -> Result<()>) -> Result<()>
-    where
-        V: FromLua,
-    {
+    pub fn for_each_value<V: FromLua>(&self, f: impl FnMut(V) -> Result<()>) -> Result<()> {
+        self.for_each_value_by_len(None, f)
+    }
+
+    fn for_each_value_by_len<V: FromLua>(
+        &self,
+        len: impl Into<Option<usize>>,
+        mut f: impl FnMut(V) -> Result<()>,
+    ) -> Result<()> {
+        let len = len.into();
         let lua = self.0.lua.lock();
         let state = lua.state();
         unsafe {
@@ -713,9 +694,14 @@ impl Table {
             check_stack(state, 4)?;
 
             lua.push_ref(&self.0);
-            let len = ffi::lua_rawlen(state, -1);
-            for i in 1..=len {
-                ffi::lua_rawgeti(state, -1, i as _);
+            for i in 1.. {
+                if len.map(|len| i > len).unwrap_or(false) {
+                    break;
+                }
+                let t = ffi::lua_rawgeti(state, -1, i as _);
+                if len.is_none() && t == ffi::LUA_TNIL {
+                    break;
+                }
                 f(V::from_stack(-1, &lua)?)?;
                 ffi::lua_pop(state, 1);
             }
@@ -748,8 +734,9 @@ impl Table {
         Ok(())
     }
 
-    #[cfg(feature = "serialize")]
-    pub(crate) fn is_array(&self) -> bool {
+    /// Checks if the table has the array metatable attached.
+    #[cfg(feature = "serde")]
+    fn has_array_metatable(&self) -> bool {
         let lua = self.0.lua.lock();
         let state = lua.state();
         unsafe {
@@ -765,6 +752,70 @@ impl Table {
         }
     }
 
+    /// If the table is an array, returns the number of non-nil elements and max index.
+    ///
+    /// Returns `None` if the table is not an array.
+    ///
+    /// This operation has O(n) complexity.
+    #[cfg(feature = "serde")]
+    fn find_array_len(&self) -> Option<(usize, usize)> {
+        let lua = self.0.lua.lock();
+        let ref_thread = lua.ref_thread();
+        unsafe {
+            let _sg = StackGuard::new(ref_thread);
+
+            let (mut count, mut max_index) = (0, 0);
+            ffi::lua_pushnil(ref_thread);
+            while ffi::lua_next(ref_thread, self.0.index) != 0 {
+                if ffi::lua_type(ref_thread, -2) != ffi::LUA_TNUMBER {
+                    return None;
+                }
+
+                let k = ffi::lua_tonumber(ref_thread, -2);
+                if k.trunc() != k || k < 1.0 {
+                    return None;
+                }
+                max_index = std::cmp::max(max_index, k as usize);
+                count += 1;
+                ffi::lua_pop(ref_thread, 1);
+            }
+            Some((count, max_index))
+        }
+    }
+
+    /// Determines if the table should be encoded as an array or a map.
+    ///
+    /// The algorithm is the following:
+    /// 1. If `detect_mixed_tables` is enabled, iterate over all keys in the table checking is they
+    ///    all are positive integers. If non-array key is found, return `None` (encode as map).
+    ///    Otherwise check the sparsity of the array. Too sparse arrays are encoded as maps.
+    ///
+    /// 2. If `detect_mixed_tables` is disabled, check if the table has a positive length or has the
+    ///    array metatable. If so, encode as array. If the table is empty and
+    ///    `encode_empty_tables_as_array` is enabled, encode as array.
+    ///
+    /// Returns the length of the array if it should be encoded as an array.
+    #[cfg(feature = "serde")]
+    pub(crate) fn encode_as_array(&self, options: crate::serde::de::Options) -> Option<usize> {
+        if options.detect_mixed_tables {
+            if let Some((len, max_idx)) = self.find_array_len() {
+                // If the array is too sparse, serialize it as a map instead
+                if len < 10 || len * 2 >= max_idx {
+                    return Some(max_idx);
+                }
+            }
+        } else {
+            let len = self.raw_len();
+            if len > 0 || self.has_array_metatable() {
+                return Some(len);
+            }
+            if options.encode_empty_tables_as_array && self.is_empty() {
+                return Some(0);
+            }
+        }
+        None
+    }
+
     #[cfg(feature = "luau")]
     #[inline(always)]
     fn check_readonly_write(&self, lua: &RawLua) -> Result<()> {
@@ -905,16 +956,16 @@ impl ObjectLike for Table {
         R: FromLuaMulti,
     {
         // Convert table to a function and call via pcall that respects the `__call` metamethod.
-        Function(self.0.copy()).call(args)
+        Function(self.0.clone()).call(args)
     }
 
     #[cfg(feature = "async")]
     #[inline]
-    fn call_async<R>(&self, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async<R>(&self, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
-        Function(self.0.copy()).call_async(args)
+        Function(self.0.clone()).call_async(args)
     }
 
     #[inline]
@@ -926,7 +977,7 @@ impl ObjectLike for Table {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
@@ -946,35 +997,45 @@ impl ObjectLike for Table {
 
     #[cfg(feature = "async")]
     #[inline]
-    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
         match self.get(name) {
-            Ok(Value::Function(func)) => Either::Left(func.call_async(args)),
+            Ok(Value::Function(func)) => func.call_async(args),
             Ok(val) => {
                 let msg = format!("attempt to call a {} value (function '{name}')", val.type_name());
-                Either::Right(future::ready(Err(Error::RuntimeError(msg))))
+                AsyncCallFuture::error(Error::RuntimeError(msg))
             }
-            Err(err) => Either::Right(future::ready(Err(err))),
+            Err(err) => AsyncCallFuture::error(err),
         }
     }
 
     #[inline]
     fn to_string(&self) -> Result<StdString> {
-        Value::Table(Table(self.0.copy())).to_string()
+        Value::Table(Table(self.0.clone())).to_string()
+    }
+
+    #[inline]
+    fn to_value(&self) -> Value {
+        Value::Table(self.clone())
+    }
+
+    #[inline]
+    fn weak_lua(&self) -> &WeakLua {
+        &self.0.lua
     }
 }
 
 /// A wrapped [`Table`] with customized serialization behavior.
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 pub(crate) struct SerializableTable<'a> {
     table: &'a Table,
     options: crate::serde::de::Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for Table {
     #[inline]
     fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
@@ -982,7 +1043,7 @@ impl Serialize for Table {
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl<'a> SerializableTable<'a> {
     #[inline]
     pub(crate) fn new(
@@ -998,7 +1059,16 @@ impl<'a> SerializableTable<'a> {
     }
 }
 
-#[cfg(feature = "serialize")]
+impl<V> TableSequence<'_, V> {
+    /// Sets the length (hint) of the sequence.
+    #[cfg(feature = "serde")]
+    pub(crate) fn with_len(mut self, len: usize) -> Self {
+        self.len = Some(len);
+        self
+    }
+}
+
+#[cfg(feature = "serde")]
 impl Serialize for SerializableTable<'_> {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where
@@ -1019,14 +1089,10 @@ impl Serialize for SerializableTable<'_> {
         let _guard = RecursionGuard::new(self.table, visited);
 
         // Array
-        let len = self.table.raw_len();
-        if len > 0
-            || self.table.is_array()
-            || (self.options.encode_empty_tables_as_array && self.table.is_empty())
-        {
+        if let Some(len) = self.table.encode_as_array(self.options) {
             let mut seq = serializer.serialize_seq(Some(len))?;
             let mut serialize_err = None;
-            let res = self.table.for_each_value::<Value>(|value| {
+            let res = self.table.for_each_value_by_len::<Value>(len, |value| {
                 let skip = check_value_for_skip(&value, self.options, visited)
                     .map_err(|err| Error::SerializeError(err.to_string()))?;
                 if skip {
@@ -1150,13 +1216,11 @@ pub struct TableSequence<'a, V> {
     guard: LuaGuard,
     table: &'a Table,
     index: Integer,
+    len: Option<usize>,
     _phantom: PhantomData<V>,
 }
 
-impl<V> Iterator for TableSequence<'_, V>
-where
-    V: FromLua,
-{
+impl<V: FromLua> Iterator for TableSequence<'_, V> {
     type Item = Result<V>;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -1170,7 +1234,7 @@ where
 
             lua.push_ref(&self.table.0);
             match ffi::lua_rawgeti(state, -1, self.index) {
-                ffi::LUA_TNIL => None,
+                ffi::LUA_TNIL if self.index as usize > self.len.unwrap_or(0) => None,
                 _ => {
                     self.index += 1;
                     Some(V::from_stack(-1, lua))

src/thread.rs

@@ -10,8 +10,8 @@ use crate::util::{check_stack, error_traceback_thread, pop_error, StackGuard};
 
 #[cfg(not(feature = "luau"))]
 use crate::{
-    hook::{Debug, HookTriggers},
-    types::MaybeSend,
+    debug::{Debug, HookTriggers},
+    types::HookKind,
 };
 
 #[cfg(feature = "async")]
@@ -47,17 +47,24 @@ pub enum ThreadStatus {
 /// to the thread stack.
 #[derive(Clone, Copy)]
 enum ThreadStatusInner {
-    New,
+    New(c_int),
     Running,
-    Yielded,
+    Yielded(c_int),
     Finished,
     Error,
 }
 
 impl ThreadStatusInner {
+    #[cfg(feature = "async")]
     #[inline(always)]
     fn is_resumable(self) -> bool {
-        matches!(self, ThreadStatusInner::New | ThreadStatusInner::Yielded)
+        matches!(self, ThreadStatusInner::New(_) | ThreadStatusInner::Yielded(_))
+    }
+
+    #[cfg(feature = "async")]
+    #[inline(always)]
+    fn is_yielded(self) -> bool {
+        matches!(self, ThreadStatusInner::Yielded(_))
     }
 }
 
@@ -72,23 +79,22 @@ unsafe impl Sync for Thread {}
 
 /// Thread (coroutine) representation as an async [`Future`] or [`Stream`].
 ///
-/// Requires `feature = "async"`
-///
 /// [`Future`]: std::future::Future
 /// [`Stream`]: futures_util::stream::Stream
 #[cfg(feature = "async")]
 #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
 #[must_use = "futures do nothing unless you `.await` or poll them"]
-pub struct AsyncThread<A, R> {
+pub struct AsyncThread<R> {
     thread: Thread,
-    init_args: Option<A>,
-    ret: PhantomData<R>,
+    ret: PhantomData<fn() -> R>,
     recycle: bool,
 }
 
 impl Thread {
+    /// Returns reference to the Lua state that this thread is associated with.
+    #[doc(hidden)]
     #[inline(always)]
-    fn state(&self) -> *mut ffi::lua_State {
+    pub fn state(&self) -> *mut ffi::lua_State {
         self.1
     }
 
@@ -141,17 +147,58 @@ impl Thread {
         R: FromLuaMulti,
     {
         let lua = self.0.lua.lock();
-        if !self.status_inner(&lua).is_resumable() {
-            return Err(Error::CoroutineUnresumable);
-        }
+        let mut pushed_nargs = match self.status_inner(&lua) {
+            ThreadStatusInner::New(nargs) | ThreadStatusInner::Yielded(nargs) => nargs,
+            _ => return Err(Error::CoroutineUnresumable),
+        };
 
         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 nresults = self.resume_inner(&lua, args)?;
+            let nargs = args.push_into_stack_multi(&lua)?;
+            if nargs > 0 {
+                check_stack(thread_state, nargs)?;
+                ffi::lua_xmove(state, thread_state, nargs);
+                pushed_nargs += nargs;
+            }
+
+            let _thread_sg = StackGuard::with_top(thread_state, 0);
+            let (_, nresults) = self.resume_inner(&lua, pushed_nargs)?;
+            check_stack(state, nresults + 1)?;
+            ffi::lua_xmove(thread_state, state, nresults);
+
+            R::from_stack_multi(nresults, &lua)
+        }
+    }
+
+    /// Resumes execution of this thread, immediately raising an error.
+    ///
+    /// This is a Luau specific extension.
+    #[cfg(feature = "luau")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn resume_error<R>(&self, error: impl crate::IntoLua) -> Result<R>
+    where
+        R: FromLuaMulti,
+    {
+        let lua = self.0.lua.lock();
+        match self.status_inner(&lua) {
+            ThreadStatusInner::New(_) | ThreadStatusInner::Yielded(_) => {}
+            _ => return Err(Error::CoroutineUnresumable),
+        };
+
+        let state = lua.state();
+        let thread_state = self.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+
+            check_stack(state, 1)?;
+            error.push_into_stack(&lua)?;
+            ffi::lua_xmove(state, thread_state, 1);
+
+            let _thread_sg = StackGuard::with_top(thread_state, 0);
+            let (_, nresults) = self.resume_inner(&lua, ffi::LUA_RESUMEERROR)?;
             check_stack(state, nresults + 1)?;
             ffi::lua_xmove(thread_state, state, nresults);
 
@@ -162,35 +209,33 @@ impl Thread {
     /// Resumes execution of this thread.
     ///
     /// It's similar to `resume()` but leaves `nresults` values on the thread stack.
-    unsafe fn resume_inner(&self, lua: &RawLua, args: impl IntoLuaMulti) -> Result<c_int> {
+    unsafe fn resume_inner(&self, lua: &RawLua, nargs: c_int) -> Result<(ThreadStatusInner, c_int)> {
         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;
+        #[cfg(not(feature = "luau"))]
         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 {
+        #[cfg(feature = "luau")]
+        let ret = ffi::lua_resumex(thread_state, state, nargs, &mut nresults as *mut c_int);
+        match ret {
+            ffi::LUA_OK => Ok((ThreadStatusInner::Finished, nresults)),
+            ffi::LUA_YIELD => Ok((ThreadStatusInner::Yielded(0), nresults)),
+            ffi::LUA_ERRMEM => {
                 // Don't call error handler for memory errors
-                return Err(pop_error(thread_state, ret));
+                Err(pop_error(thread_state, ret))
+            }
+            _ => {
+                check_stack(state, 3)?;
+                protect_lua!(state, 0, 1, |state| error_traceback_thread(state, thread_state))?;
+                Err(pop_error(state, ret))
             }
-            check_stack(state, 3)?;
-            protect_lua!(state, 0, 1, |state| error_traceback_thread(state, thread_state))?;
-            return Err(pop_error(state, ret));
         }
-
-        Ok(nresults)
     }
 
     /// Gets the status of the thread.
     pub fn status(&self) -> ThreadStatus {
         match self.status_inner(&self.0.lua.lock()) {
-            ThreadStatusInner::New | ThreadStatusInner::Yielded => ThreadStatus::Resumable,
+            ThreadStatusInner::New(_) | ThreadStatusInner::Yielded(_) => ThreadStatus::Resumable,
             ThreadStatusInner::Running => ThreadStatus::Running,
             ThreadStatusInner::Finished => ThreadStatus::Finished,
             ThreadStatusInner::Error => ThreadStatus::Error,
@@ -205,9 +250,10 @@ impl Thread {
             return ThreadStatusInner::Running;
         }
         let status = unsafe { ffi::lua_status(thread_state) };
+        let top = unsafe { ffi::lua_gettop(thread_state) };
         match status {
-            ffi::LUA_YIELD => ThreadStatusInner::Yielded,
-            ffi::LUA_OK if unsafe { ffi::lua_gettop(thread_state) } > 0 => ThreadStatusInner::New,
+            ffi::LUA_YIELD => ThreadStatusInner::Yielded(top),
+            ffi::LUA_OK if top > 0 => ThreadStatusInner::New(top - 1),
             ffi::LUA_OK => ThreadStatusInner::Finished,
             _ => ThreadStatusInner::Error,
         }
@@ -216,16 +262,33 @@ impl Thread {
     /// 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`].
+    /// You can have multiple hooks for different threads.
+    ///
+    /// To remove a hook call [`Thread::remove_hook`].
+    ///
+    /// [`Lua::set_hook`]: crate::Lua::set_hook
     #[cfg(not(feature = "luau"))]
     #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
-    pub fn set_hook<F>(&self, triggers: HookTriggers, callback: F)
+    pub fn set_hook<F>(&self, triggers: HookTriggers, callback: F) -> Result<()>
     where
-        F: Fn(&crate::Lua, Debug) -> Result<crate::VmState> + MaybeSend + 'static,
+        F: Fn(&crate::Lua, &Debug) -> Result<crate::VmState> + crate::MaybeSend + 'static,
     {
         let lua = self.0.lua.lock();
         unsafe {
-            lua.set_thread_hook(self.state(), triggers, callback);
+            lua.set_thread_hook(
+                self.state(),
+                HookKind::Thread(triggers, crate::types::XRc::new(callback)),
+            )
+        }
+    }
+
+    /// Removes any hook function from this thread.
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
+    pub fn remove_hook(&self) {
+        let _lua = self.0.lua.lock();
+        unsafe {
+            ffi::lua_sethook(self.state(), None, 0, 0);
         }
     }
 
@@ -246,29 +309,10 @@ impl Thread {
     pub fn reset(&self, func: Function) -> Result<()> {
         let lua = self.0.lua.lock();
         let thread_state = self.state();
-        match self.status_inner(&lua) {
-            ThreadStatusInner::Running => return Err(Error::runtime("cannot reset a running thread")),
-            // Any Lua can reuse new or finished thread
-            ThreadStatusInner::New => unsafe { ffi::lua_settop(thread_state, 0) },
-            ThreadStatusInner::Finished => {}
-            #[cfg(not(any(feature = "lua54", feature = "luau")))]
-            _ => return Err(Error::runtime("cannot reset non-finished thread")),
-            #[cfg(any(feature = "lua54", feature = "luau"))]
-            _ => unsafe {
-                #[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());
-                #[cfg(feature = "lua54")]
-                if status != ffi::LUA_OK {
-                    return Err(pop_error(thread_state, status));
-                }
-                #[cfg(feature = "luau")]
-                ffi::lua_resetthread(thread_state);
-            },
-        }
-
         unsafe {
+            let status = self.status_inner(&lua);
+            self.reset_inner(status)?;
+
             // Push function to the top of the thread stack
             ffi::lua_xpush(lua.ref_thread(), thread_state, func.0.index);
 
@@ -283,9 +327,47 @@ impl Thread {
         }
     }
 
+    unsafe fn reset_inner(&self, status: ThreadStatusInner) -> Result<()> {
+        match status {
+            ThreadStatusInner::New(_) => {
+                // The thread is new, so we can just set the top to 0
+                ffi::lua_settop(self.state(), 0);
+                Ok(())
+            }
+            ThreadStatusInner::Running => Err(Error::runtime("cannot reset a running thread")),
+            ThreadStatusInner::Finished => Ok(()),
+            #[cfg(not(any(feature = "lua54", feature = "luau")))]
+            ThreadStatusInner::Yielded(_) | ThreadStatusInner::Error => {
+                Err(Error::runtime("cannot reset non-finished thread"))
+            }
+            #[cfg(any(feature = "lua54", feature = "luau"))]
+            ThreadStatusInner::Yielded(_) | ThreadStatusInner::Error => {
+                let thread_state = self.state();
+
+                #[cfg(all(feature = "lua54", not(feature = "vendored")))]
+                let status = ffi::lua_resetthread(thread_state);
+                #[cfg(all(feature = "lua54", feature = "vendored"))]
+                let status = {
+                    let lua = self.0.lua.lock();
+                    ffi::lua_closethread(thread_state, lua.state())
+                };
+                #[cfg(feature = "lua54")]
+                if status != ffi::LUA_OK {
+                    return Err(pop_error(thread_state, status));
+                }
+                #[cfg(feature = "luau")]
+                ffi::lua_resetthread(thread_state);
+
+                Ok(())
+            }
+        }
+    }
+
     /// Converts [`Thread`] to an [`AsyncThread`] which implements [`Future`] and [`Stream`] traits.
     ///
-    /// `args` are passed as arguments to the thread function for first call.
+    /// Only resumable threads can be converted to [`AsyncThread`].
+    ///
+    /// `args` are pushed to the thread stack and will be used when the thread is resumed.
     /// The object calls [`resume`] while polling and also allow to run Rust futures
     /// to completion using an executor.
     ///
@@ -293,8 +375,6 @@ impl Thread {
     /// values whereas [`Future`] version discards that values and poll until the final
     /// one (returned from the thread function).
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`Future`]: std::future::Future
     /// [`Stream`]: futures_util::stream::Stream
     /// [`resume`]: https://www.lua.org/manual/5.4/manual.html#lua_resume
@@ -318,7 +398,7 @@ impl Thread {
     ///     end)
     /// "#).eval()?;
     ///
-    /// let mut stream = thread.into_async::<i64>(1);
+    /// let mut stream = thread.into_async::<i64>(1)?;
     /// let mut sum = 0;
     /// while let Some(n) = stream.try_next().await? {
     ///     sum += n;
@@ -331,15 +411,31 @@ impl Thread {
     /// ```
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn into_async<R>(self, args: impl IntoLuaMulti) -> AsyncThread<impl IntoLuaMulti, R>
+    pub fn into_async<R>(self, args: impl IntoLuaMulti) -> Result<AsyncThread<R>>
     where
         R: FromLuaMulti,
     {
-        AsyncThread {
-            thread: self,
-            init_args: Some(args),
-            ret: PhantomData,
-            recycle: false,
+        let lua = self.0.lua.lock();
+        if !self.status_inner(&lua).is_resumable() {
+            return Err(Error::CoroutineUnresumable);
+        }
+
+        let state = lua.state();
+        let thread_state = self.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+
+            let nargs = args.push_into_stack_multi(&lua)?;
+            if nargs > 0 {
+                check_stack(thread_state, nargs)?;
+                ffi::lua_xmove(state, thread_state, nargs);
+            }
+
+            Ok(AsyncThread {
+                thread: self,
+                ret: PhantomData,
+                recycle: false,
+            })
         }
     }
 
@@ -376,11 +472,8 @@ impl Thread {
     /// # #[cfg(not(feature = "luau"))]
     /// # fn main() { }
     /// ```
-    ///
-    /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    #[doc(hidden)]
     pub fn sandbox(&self) -> Result<()> {
         let lua = self.0.lua.lock();
         let state = lua.state();
@@ -420,7 +513,7 @@ impl LuaType for Thread {
 }
 
 #[cfg(feature = "async")]
-impl<A, R> AsyncThread<A, R> {
+impl<R> AsyncThread<R> {
     #[inline(always)]
     pub(crate) fn set_recyclable(&mut self, recyclable: bool) {
         self.recycle = recyclable;
@@ -428,26 +521,41 @@ impl<A, R> AsyncThread<A, R> {
 }
 
 #[cfg(feature = "async")]
-impl<A, R> Drop for AsyncThread<A, R> {
+impl<R> Drop for AsyncThread<R> {
     fn drop(&mut self) {
         if self.recycle {
             if let Some(lua) = self.thread.0.lua.try_lock() {
-                // For Lua 5.4 this also closes all pending to-be-closed variables
-                unsafe { lua.recycle_thread(&mut self.thread) };
+                unsafe {
+                    let mut status = self.thread.status_inner(&lua);
+                    if matches!(status, ThreadStatusInner::Yielded(0)) {
+                        // The thread is dropped while yielded, resume it with the "terminate" signal
+                        ffi::lua_pushlightuserdata(self.thread.1, crate::Lua::poll_terminate().0);
+                        if let Ok((new_status, _)) = self.thread.resume_inner(&lua, 1) {
+                            // `new_status` should always be `ThreadStatusInner::Yielded(0)`
+                            status = new_status;
+                        }
+                    }
+
+                    // For Lua 5.4 this also closes all pending to-be-closed variables
+                    if self.thread.reset_inner(status).is_ok() {
+                        lua.recycle_thread(&mut self.thread);
+                    }
+                }
             }
         }
     }
 }
 
 #[cfg(feature = "async")]
-impl<A: IntoLuaMulti, R: FromLuaMulti> Stream for AsyncThread<A, R> {
+impl<R: FromLuaMulti> Stream for AsyncThread<R> {
     type Item = Result<R>;
 
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let lua = self.thread.0.lua.lock();
-        if !self.thread.status_inner(&lua).is_resumable() {
-            return Poll::Ready(None);
-        }
+        let nargs = match self.thread.status_inner(&lua) {
+            ThreadStatusInner::New(nargs) | ThreadStatusInner::Yielded(nargs) => nargs,
+            _ => return Poll::Ready(None),
+        };
 
         let state = lua.state();
         let thread_state = self.thread.state();
@@ -456,36 +564,34 @@ impl<A: IntoLuaMulti, R: FromLuaMulti> Stream for AsyncThread<A, R> {
             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(&lua, args)?
-            } else {
-                this.thread.resume_inner(&lua, ())?
-            };
+            let (status, nresults) = (self.thread).resume_inner(&lua, nargs)?;
 
-            if nresults == 1 && is_poll_pending(thread_state) {
-                return Poll::Pending;
+            if status.is_yielded() {
+                if nresults == 1 && is_poll_pending(thread_state) {
+                    return Poll::Pending;
+                }
+                // Continue polling
+                cx.waker().wake_by_ref();
             }
 
             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)))
         }
     }
 }
 
 #[cfg(feature = "async")]
-impl<A: IntoLuaMulti, R: FromLuaMulti> Future for AsyncThread<A, R> {
+impl<R: FromLuaMulti> Future for AsyncThread<R> {
     type Output = Result<R>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let lua = self.thread.0.lua.lock();
-        if !self.thread.status_inner(&lua).is_resumable() {
-            return Poll::Ready(Err(Error::CoroutineUnresumable));
-        }
+        let nargs = match self.thread.status_inner(&lua) {
+            ThreadStatusInner::New(nargs) | ThreadStatusInner::Yielded(nargs) => nargs,
+            _ => return Poll::Ready(Err(Error::CoroutineUnresumable)),
+        };
 
         let state = lua.state();
         let thread_state = self.thread.state();
@@ -494,21 +600,13 @@ impl<A: IntoLuaMulti, R: FromLuaMulti> Future for AsyncThread<A, R> {
             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(&lua, args)?
-            } else {
-                this.thread.resume_inner(&lua, ())?
-            };
+            let (status, nresults) = self.thread.resume_inner(&lua, nargs)?;
 
-            if nresults == 1 && is_poll_pending(thread_state) {
-                return Poll::Pending;
-            }
-
-            if ffi::lua_status(thread_state) == ffi::LUA_YIELD {
-                // Ignore value returned via yield()
-                cx.waker().wake_by_ref();
+            if status.is_yielded() {
+                if !(nresults == 1 && is_poll_pending(thread_state)) {
+                    // Ignore values returned via yield()
+                    cx.waker().wake_by_ref();
+                }
                 return Poll::Pending;
             }
 
@@ -537,7 +635,7 @@ struct WakerGuard<'lua, 'a> {
 impl<'lua, 'a> WakerGuard<'lua, 'a> {
     #[inline]
     pub fn new(lua: &'lua RawLua, waker: &'a Waker) -> Result<WakerGuard<'lua, 'a>> {
-        let prev = unsafe { lua.set_waker(NonNull::from(waker)) };
+        let prev = lua.set_waker(NonNull::from(waker));
         Ok(WakerGuard {
             lua,
             prev,
@@ -549,7 +647,7 @@ impl<'lua, 'a> WakerGuard<'lua, 'a> {
 #[cfg(feature = "async")]
 impl Drop for WakerGuard<'_, '_> {
     fn drop(&mut self) {
-        unsafe { self.lua.set_waker(self.prev) };
+        self.lua.set_waker(self.prev);
     }
 }
 
@@ -562,7 +660,7 @@ mod assertions {
     #[cfg(feature = "send")]
     static_assertions::assert_impl_all!(Thread: Send, Sync);
     #[cfg(all(feature = "async", not(feature = "send")))]
-    static_assertions::assert_not_impl_any!(AsyncThread<(), ()>: Send);
+    static_assertions::assert_not_impl_any!(AsyncThread<()>: Send);
     #[cfg(all(feature = "async", feature = "send"))]
-    static_assertions::assert_impl_all!(AsyncThread<(), ()>: Send, Sync);
+    static_assertions::assert_impl_all!(AsyncThread<()>: Send, Sync);
 }

src/traits.rs

@@ -5,13 +5,13 @@ use std::sync::Arc;
 use crate::error::{Error, Result};
 use crate::multi::MultiValue;
 use crate::private::Sealed;
-use crate::state::{Lua, RawLua};
+use crate::state::{Lua, RawLua, WeakLua};
 use crate::types::MaybeSend;
-use crate::util::{check_stack, short_type_name};
+use crate::util::{check_stack, parse_lookup_path, short_type_name};
 use crate::value::Value;
 
 #[cfg(feature = "async")]
-use std::future::Future;
+use {crate::function::AsyncCallFuture, std::future::Future};
 
 /// Trait for types convertible to [`Value`].
 pub trait IntoLua: Sized {
@@ -162,7 +162,7 @@ pub trait ObjectLike: Sealed {
     /// arguments.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<R>(&self, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async<R>(&self, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti;
 
@@ -175,12 +175,10 @@ pub trait ObjectLike: Sealed {
     /// Gets the function associated to key `name` from the object and asynchronously calls it,
     /// passing the object itself along with `args` as function arguments.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti;
 
@@ -195,19 +193,57 @@ pub trait ObjectLike: Sealed {
     /// Gets the function associated to key `name` from the object and asynchronously calls it,
     /// passing `args` as function arguments.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti;
 
+    /// Look up a value by a path of keys.
+    ///
+    /// The syntax is similar to accessing nested tables in Lua, with additional support for
+    /// `?` operator to perform safe navigation.
+    ///
+    /// For example, the path `a[1].c` is equivalent to `table.a[1].c` in Lua.
+    /// With `?` operator, `a[1]?.c` is equivalent to `table.a[1] and table.a[1].c or nil` in Lua.
+    ///
+    /// Bracket notation rules:
+    /// - `[123]` - integer keys
+    /// - `["string key"]` or `['string key']` - string keys (must be quoted)
+    /// - String keys support escape sequences: `\"`, `\'`, `\\`
+    fn get_path<V: FromLua>(&self, path: &str) -> Result<V> {
+        let mut current = self.to_value();
+        for (key, safe_nil) in parse_lookup_path(path)? {
+            current = match current {
+                Value::Table(table) => table.get::<Value>(key),
+                Value::UserData(ud) => ud.get::<Value>(key),
+                _ => {
+                    let type_name = current.type_name();
+                    let err = format!("attempt to index a {type_name} value with key '{key}'");
+                    Err(Error::runtime(err))
+                }
+            }?;
+            if safe_nil && (current == Value::Nil || current == Value::NULL) {
+                break;
+            }
+        }
+
+        let lua = self.weak_lua().lock();
+        V::from_lua(current, lua.lua())
+    }
+
     /// Converts the object to a string in a human-readable format.
     ///
     /// This might invoke the `__tostring` metamethod.
     fn to_string(&self) -> Result<StdString>;
+
+    /// Converts the object to a Lua value.
+    fn to_value(&self) -> Value;
+
+    /// Gets a reference to the associated Lua state.
+    #[doc(hidden)]
+    fn weak_lua(&self) -> &WeakLua;
 }
 
 /// A trait for types that can be used as Lua functions.

src/types.rs

@@ -1,10 +1,9 @@
 use std::cell::UnsafeCell;
 use std::os::raw::{c_int, c_void};
-use std::rc::Rc;
 
-use crate::error::Result;
 #[cfg(not(feature = "luau"))]
-use crate::hook::Debug;
+use crate::debug::{Debug, HookTriggers};
+use crate::error::Result;
 use crate::state::{ExtraData, Lua, RawLua};
 
 // Re-export mutex wrappers
@@ -21,6 +20,9 @@ pub use either::Either;
 pub use registry_key::RegistryKey;
 pub(crate) use value_ref::ValueRef;
 
+#[cfg(feature = "async")]
+pub(crate) use value_ref::ValueRefIndex;
+
 /// Type of Lua integer numbers.
 pub type Integer = ffi::lua_Integer;
 /// Type of Lua floating point numbers.
@@ -36,10 +38,13 @@ unsafe impl Send for LightUserData {}
 unsafe impl Sync for LightUserData {}
 
 #[cfg(feature = "send")]
-pub(crate) type Callback = Box<dyn Fn(&RawLua, c_int) -> Result<c_int> + Send + 'static>;
+type CallbackFn<'a> = dyn Fn(&RawLua, c_int) -> Result<c_int> + Send + 'a;
 
 #[cfg(not(feature = "send"))]
-pub(crate) type Callback = Box<dyn Fn(&RawLua, c_int) -> Result<c_int> + 'static>;
+type CallbackFn<'a> = dyn Fn(&RawLua, c_int) -> Result<c_int> + 'a;
+
+pub(crate) type Callback = Box<CallbackFn<'static>>;
+pub(crate) type CallbackPtr = *const CallbackFn<'static>;
 
 pub(crate) type ScopedCallback<'s> = Box<dyn Fn(&RawLua, c_int) -> Result<c_int> + 's>;
 
@@ -62,7 +67,7 @@ pub(crate) type AsyncCallback =
 pub(crate) type AsyncCallbackUpvalue = Upvalue<AsyncCallback>;
 
 #[cfg(feature = "async")]
-pub(crate) type AsyncPollUpvalue = Upvalue<BoxFuture<'static, Result<c_int>>>;
+pub(crate) type AsyncPollUpvalue = Upvalue<Option<BoxFuture<'static, Result<c_int>>>>;
 
 /// Type to set next Lua VM action after executing interrupt or hook function.
 pub enum VmState {
@@ -73,17 +78,35 @@ pub enum VmState {
     Yield,
 }
 
+#[cfg(not(feature = "luau"))]
+pub(crate) enum HookKind {
+    Global,
+    Thread(HookTriggers, HookCallback),
+}
+
 #[cfg(all(feature = "send", not(feature = "luau")))]
-pub(crate) type HookCallback = Rc<dyn Fn(&Lua, Debug) -> Result<VmState> + Send>;
+pub(crate) type HookCallback = XRc<dyn Fn(&Lua, &Debug) -> Result<VmState> + Send>;
 
 #[cfg(all(not(feature = "send"), not(feature = "luau")))]
-pub(crate) type HookCallback = Rc<dyn Fn(&Lua, Debug) -> Result<VmState>>;
+pub(crate) type HookCallback = XRc<dyn Fn(&Lua, &Debug) -> Result<VmState>>;
 
 #[cfg(all(feature = "send", feature = "luau"))]
-pub(crate) type InterruptCallback = Rc<dyn Fn(&Lua) -> Result<VmState> + Send>;
+pub(crate) type InterruptCallback = XRc<dyn Fn(&Lua) -> Result<VmState> + Send>;
 
 #[cfg(all(not(feature = "send"), feature = "luau"))]
-pub(crate) type InterruptCallback = Rc<dyn Fn(&Lua) -> Result<VmState>>;
+pub(crate) type InterruptCallback = XRc<dyn Fn(&Lua) -> Result<VmState>>;
+
+#[cfg(all(feature = "send", feature = "luau"))]
+pub(crate) type ThreadCreationCallback = XRc<dyn Fn(&Lua, crate::Thread) -> Result<()> + Send>;
+
+#[cfg(all(not(feature = "send"), feature = "luau"))]
+pub(crate) type ThreadCreationCallback = XRc<dyn Fn(&Lua, crate::Thread) -> Result<()>>;
+
+#[cfg(all(feature = "send", feature = "luau"))]
+pub(crate) type ThreadCollectionCallback = XRc<dyn Fn(crate::LightUserData) + Send>;
+
+#[cfg(all(not(feature = "send"), feature = "luau"))]
+pub(crate) type ThreadCollectionCallback = XRc<dyn Fn(crate::LightUserData)>;
 
 #[cfg(all(feature = "send", feature = "lua54"))]
 pub(crate) type WarnCallback = XRc<dyn Fn(&Lua, &str, bool) -> Result<()> + Send>;

src/types/app_data.rs

@@ -43,7 +43,7 @@ impl AppData {
 
     #[inline]
     #[track_caller]
-    pub(crate) fn borrow<T: 'static>(&self, guard: Option<LuaGuard>) -> Option<AppDataRef<T>> {
+    pub(crate) fn borrow<T: 'static>(&self, guard: Option<LuaGuard>) -> Option<AppDataRef<'_, T>> {
         match self.try_borrow(guard) {
             Ok(data) => data,
             Err(err) => panic!("already mutably borrowed: {err:?}"),
@@ -53,7 +53,7 @@ impl AppData {
     pub(crate) fn try_borrow<T: 'static>(
         &self,
         guard: Option<LuaGuard>,
-    ) -> Result<Option<AppDataRef<T>>, BorrowError> {
+    ) -> Result<Option<AppDataRef<'_, T>>, BorrowError> {
         let data = unsafe { &*self.container.get() }
             .get(&TypeId::of::<T>())
             .map(|c| c.try_borrow())
@@ -74,7 +74,7 @@ impl AppData {
 
     #[inline]
     #[track_caller]
-    pub(crate) fn borrow_mut<T: 'static>(&self, guard: Option<LuaGuard>) -> Option<AppDataRefMut<T>> {
+    pub(crate) fn borrow_mut<T: 'static>(&self, guard: Option<LuaGuard>) -> Option<AppDataRefMut<'_, T>> {
         match self.try_borrow_mut(guard) {
             Ok(data) => data,
             Err(err) => panic!("already borrowed: {err:?}"),
@@ -84,7 +84,7 @@ impl AppData {
     pub(crate) fn try_borrow_mut<T: 'static>(
         &self,
         guard: Option<LuaGuard>,
-    ) -> Result<Option<AppDataRefMut<T>>, BorrowMutError> {
+    ) -> Result<Option<AppDataRefMut<'_, T>>, BorrowMutError> {
         let data = unsafe { &*self.container.get() }
             .get(&TypeId::of::<T>())
             .map(|c| c.try_borrow_mut())

src/types/sync.rs

@@ -31,7 +31,7 @@ mod inner {
         }
 
         #[inline(always)]
-        pub(crate) fn lock(&self) -> ReentrantMutexGuard<T> {
+        pub(crate) fn lock(&self) -> ReentrantMutexGuard<'_, T> {
             ReentrantMutexGuard(&self.0)
         }
 

src/types/value_ref.rs

@@ -1,22 +1,39 @@
 use std::fmt;
 use std::os::raw::{c_int, c_void};
 
+use super::XRc;
 use crate::state::{RawLua, WeakLua};
 
 /// A reference to a Lua (complex) value stored in the Lua auxiliary thread.
+#[derive(Clone)]
 pub struct ValueRef {
     pub(crate) lua: WeakLua,
+    // Keep index separate to avoid additional indirection when accessing it.
     pub(crate) index: c_int,
-    pub(crate) drop: bool,
+    // If `index_count` is `None`, the value does not need to be destroyed.
+    pub(crate) index_count: Option<ValueRefIndex>,
+}
+
+/// A reference to a Lua value index in the auxiliary thread.
+/// It's cheap to clone and can be used to track the number of references to a value.
+#[derive(Clone)]
+pub(crate) struct ValueRefIndex(pub(crate) XRc<c_int>);
+
+impl From<c_int> for ValueRefIndex {
+    #[inline]
+    fn from(index: c_int) -> Self {
+        ValueRefIndex(XRc::new(index))
+    }
 }
 
 impl ValueRef {
     #[inline]
-    pub(crate) fn new(lua: &RawLua, index: c_int) -> Self {
+    pub(crate) fn new(lua: &RawLua, index: impl Into<ValueRefIndex>) -> Self {
+        let index = index.into();
         ValueRef {
             lua: lua.weak().clone(),
-            index,
-            drop: true,
+            index: *index.0,
+            index_count: Some(index),
         }
     }
 
@@ -25,16 +42,6 @@ impl ValueRef {
         let lua = self.lua.lock();
         unsafe { ffi::lua_topointer(lua.ref_thread(), self.index) }
     }
-
-    /// Returns a copy of the value, which is valid as long as the original value is held.
-    #[inline]
-    pub(crate) fn copy(&self) -> Self {
-        ValueRef {
-            lua: self.lua.clone(),
-            index: self.index,
-            drop: false,
-        }
-    }
 }
 
 impl fmt::Debug for ValueRef {
@@ -43,17 +50,15 @@ impl fmt::Debug for ValueRef {
     }
 }
 
-impl Clone for ValueRef {
-    fn clone(&self) -> Self {
-        unsafe { self.lua.lock().clone_ref(self) }
-    }
-}
-
 impl Drop for ValueRef {
     fn drop(&mut self) {
-        if self.drop {
-            if let Some(lua) = self.lua.try_lock() {
-                unsafe { lua.drop_ref(self) };
+        if let Some(ValueRefIndex(index)) = self.index_count.take() {
+            // It's guaranteed that the inner value returns exactly once.
+            // This means in particular that the value is not dropped.
+            if XRc::into_inner(index).is_some() {
+                if let Some(lua) = self.lua.try_lock() {
+                    unsafe { lua.drop_ref(self) };
+                }
             }
         }
     }

src/userdata.rs

@@ -18,7 +18,7 @@ use crate::value::Value;
 #[cfg(feature = "async")]
 use std::future::Future;
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use {
     serde::ser::{self, Serialize, Serializer},
     std::result::Result as StdResult,
@@ -56,30 +56,32 @@ pub enum MetaMethod {
     /// The unary minus (`-`) operator.
     Unm,
     /// The floor division (//) operator.
-    /// Requires `feature = "lua54/lua53/luau"`
     #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))))]
     IDiv,
     /// The bitwise AND (&) operator.
-    /// Requires `feature = "lua54/lua53"`
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     BAnd,
     /// The bitwise OR (|) operator.
-    /// Requires `feature = "lua54/lua53"`
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     BOr,
     /// The bitwise XOR (binary ~) operator.
-    /// Requires `feature = "lua54/lua53"`
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     BXor,
     /// The bitwise NOT (unary ~) operator.
-    /// Requires `feature = "lua54/lua53"`
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     BNot,
     /// The bitwise left shift (<<) operator.
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     Shl,
     /// The bitwise right shift (>>) operator.
     #[cfg(any(feature = "lua54", feature = "lua53"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "lua53"))))]
     Shr,
     /// The string concatenation operator `..`.
     Concat,
@@ -104,16 +106,16 @@ pub enum MetaMethod {
     /// The `__pairs` metamethod.
     ///
     /// This is not an operator, but it will be called by the built-in `pairs` function.
-    ///
-    /// Requires `feature = "lua54/lua53/lua52"`
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luajit52",))]
+    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luajit52"))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luajit52")))
+    )]
     Pairs,
     /// The `__ipairs` metamethod.
     ///
     /// This is not an operator, but it will be called by the built-in [`ipairs`] function.
     ///
-    /// Requires `feature = "lua52"`
-    ///
     /// [`ipairs`]: https://www.lua.org/manual/5.2/manual.html#pdf-ipairs
     #[cfg(any(feature = "lua52", feature = "luajit52", doc))]
     #[cfg_attr(docsrs, doc(cfg(any(feature = "lua52", feature = "luajit52"))))]
@@ -122,8 +124,6 @@ pub enum MetaMethod {
     ///
     /// Executed before the iteration begins, and should return an iterator function like `next`
     /// (or a custom one).
-    ///
-    /// Requires `feature = "lua"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
     Iter,
@@ -134,8 +134,6 @@ pub enum MetaMethod {
     /// More information about to-be-closed variables can be found in the Lua 5.4
     /// [documentation][lua_doc].
     ///
-    /// Requires `feature = "lua54"`
-    ///
     /// [lua_doc]: https://www.lua.org/manual/5.4/manual.html#3.3.8
     #[cfg(feature = "lua54")]
     #[cfg_attr(docsrs, doc(cfg(feature = "lua54")))]
@@ -221,9 +219,7 @@ impl MetaMethod {
     pub(crate) const fn as_cstr(self) -> &'static CStr {
         match self {
             #[rustfmt::skip]
-            MetaMethod::Type => unsafe {
-                CStr::from_bytes_with_nul_unchecked(if cfg!(feature = "luau") { b"__type\0" } else { b"__name\0" })
-            },
+            MetaMethod::Type => if cfg!(feature = "luau") { c"__type" } else { c"__name" },
             _ => unreachable!(),
         }
     }
@@ -244,6 +240,13 @@ impl AsRef<str> for MetaMethod {
     }
 }
 
+impl From<MetaMethod> for StdString {
+    #[inline]
+    fn from(method: MetaMethod) -> Self {
+        method.name().to_owned()
+    }
+}
+
 /// Method registry for [`UserData`] implementors.
 pub trait UserDataMethods<T> {
     /// Add a regular method which accepts a `&T` as the first parameter.
@@ -253,7 +256,7 @@ pub trait UserDataMethods<T> {
     ///
     /// If `add_meta_method` is used to set the `__index` metamethod, the `__index` metamethod will
     /// be used as a fall-back if no regular method is found.
-    fn add_method<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_method<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -264,7 +267,7 @@ pub trait UserDataMethods<T> {
     /// Refer to [`add_method`] for more information about the implementation.
     ///
     /// [`add_method`]: UserDataMethods::add_method
-    fn add_method_mut<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_method_mut<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -274,12 +277,10 @@ pub trait UserDataMethods<T> {
     ///
     /// Refer to [`add_method`] for more information about the implementation.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_method`]: UserDataMethods::add_method
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_method<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_method<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRef<T>, A) -> MR + MaybeSend + 'static,
@@ -291,12 +292,10 @@ pub trait UserDataMethods<T> {
     ///
     /// Refer to [`add_method`] for more information about the implementation.
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_method`]: UserDataMethods::add_method
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_method_mut<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_method_mut<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRefMut<T>, A) -> MR + MaybeSend + 'static,
@@ -309,7 +308,7 @@ pub trait UserDataMethods<T> {
     /// The first argument will be a [`AnyUserData`] of type `T` if the method is called with Lua
     /// method syntax: `my_userdata:my_method(arg1, arg2)`, or it is passed in as the first
     /// argument: `my_userdata.my_method(my_userdata, arg1, arg2)`.
-    fn add_function<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_function<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -320,7 +319,7 @@ pub trait UserDataMethods<T> {
     /// This is a version of [`add_function`] that accepts a `FnMut` argument.
     ///
     /// [`add_function`]: UserDataMethods::add_function
-    fn add_function_mut<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_function_mut<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: FnMut(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -331,12 +330,10 @@ pub trait UserDataMethods<T> {
     ///
     /// This is an async version of [`add_function`].
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_function`]: UserDataMethods::add_function
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_function<F, A, FR, R>(&mut self, name: impl ToString, function: F)
+    fn add_async_function<F, A, FR, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(Lua, A) -> FR + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -351,7 +348,7 @@ pub trait UserDataMethods<T> {
     /// side has a metatable. To prevent this, use [`add_meta_function`].
     ///
     /// [`add_meta_function`]: UserDataMethods::add_meta_function
-    fn add_meta_method<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_meta_method<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -365,7 +362,7 @@ pub trait UserDataMethods<T> {
     /// side has a metatable. To prevent this, use [`add_meta_function`].
     ///
     /// [`add_meta_function`]: UserDataMethods::add_meta_function
-    fn add_meta_method_mut<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_meta_method_mut<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -375,12 +372,13 @@ pub trait UserDataMethods<T> {
     ///
     /// This is an async version of [`add_meta_method`].
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_meta_method`]: UserDataMethods::add_meta_method
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau")))))
+    )]
+    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRef<T>, A) -> MR + MaybeSend + 'static,
@@ -393,12 +391,10 @@ pub trait UserDataMethods<T> {
     ///
     /// This is an async version of [`add_meta_method_mut`].
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_meta_method_mut`]: UserDataMethods::add_meta_method_mut
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_meta_method_mut<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_meta_method_mut<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRefMut<T>, A) -> MR + MaybeSend + 'static,
@@ -411,7 +407,7 @@ pub trait UserDataMethods<T> {
     /// Metamethods for binary operators can be triggered if either the left or right argument to
     /// the binary operator has a metatable, so the first argument here is not necessarily a
     /// userdata of type `T`.
-    fn add_meta_function<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_meta_function<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -422,7 +418,7 @@ pub trait UserDataMethods<T> {
     /// This is a version of [`add_meta_function`] that accepts a `FnMut` argument.
     ///
     /// [`add_meta_function`]: UserDataMethods::add_meta_function
-    fn add_meta_function_mut<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_meta_function_mut<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: FnMut(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -432,12 +428,13 @@ pub trait UserDataMethods<T> {
     ///
     /// This is an async version of [`add_meta_function`].
     ///
-    /// Requires `feature = "async"`
-    ///
     /// [`add_meta_function`]: UserDataMethods::add_meta_function
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_meta_function<F, A, FR, R>(&mut self, name: impl ToString, function: F)
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau")))))
+    )]
+    fn add_async_meta_function<F, A, FR, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(Lua, A) -> FR + MaybeSend + 'static,
         A: FromLuaMulti,
@@ -456,7 +453,7 @@ pub trait UserDataFields<T> {
     ///
     /// If `add_meta_method` is used to set the `__index` metamethod, it will
     /// be used as a fall-back if no regular field or method are found.
-    fn add_field<V>(&mut self, name: impl ToString, value: V)
+    fn add_field<V>(&mut self, name: impl Into<StdString>, value: V)
     where
         V: IntoLua + 'static;
 
@@ -467,7 +464,7 @@ pub trait UserDataFields<T> {
     ///
     /// If `add_meta_method` is used to set the `__index` metamethod, the `__index` metamethod will
     /// be used as a fall-back if no regular field or method are found.
-    fn add_field_method_get<M, R>(&mut self, name: impl ToString, method: M)
+    fn add_field_method_get<M, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T) -> Result<R> + MaybeSend + 'static,
         R: IntoLua;
@@ -480,21 +477,21 @@ pub trait UserDataFields<T> {
     ///
     /// If `add_meta_method` is used to set the `__newindex` metamethod, the `__newindex` metamethod
     /// will be used as a fall-back if no regular field is found.
-    fn add_field_method_set<M, A>(&mut self, name: impl ToString, method: M)
+    fn add_field_method_set<M, A>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<()> + MaybeSend + 'static,
         A: FromLua;
 
     /// Add a regular field getter as a function which accepts a generic [`AnyUserData`] of type `T`
     /// argument.
-    fn add_field_function_get<F, R>(&mut self, name: impl ToString, function: F)
+    fn add_field_function_get<F, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, AnyUserData) -> Result<R> + MaybeSend + 'static,
         R: IntoLua;
 
     /// Add a regular field setter as a function which accepts a generic [`AnyUserData`] of type `T`
     /// first argument.
-    fn add_field_function_set<F, A>(&mut self, name: impl ToString, function: F)
+    fn add_field_function_set<F, A>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: FnMut(&Lua, AnyUserData, A) -> Result<()> + MaybeSend + 'static,
         A: FromLua;
@@ -507,7 +504,7 @@ pub trait UserDataFields<T> {
     ///
     /// `mlua` will trigger an error on an attempt to define a protected metamethod,
     /// like `__gc` or `__metatable`.
-    fn add_meta_field<V>(&mut self, name: impl ToString, value: V)
+    fn add_meta_field<V>(&mut self, name: impl Into<StdString>, value: V)
     where
         V: IntoLua + 'static;
 
@@ -519,7 +516,7 @@ pub trait UserDataFields<T> {
     ///
     /// `mlua` will trigger an error on an attempt to define a protected metamethod,
     /// like `__gc` or `__metatable`.
-    fn add_meta_field_with<F, R>(&mut self, name: impl ToString, f: F)
+    fn add_meta_field_with<F, R>(&mut self, name: impl Into<StdString>, f: F)
     where
         F: FnOnce(&Lua) -> Result<R> + 'static,
         R: IntoLua;
@@ -693,22 +690,16 @@ impl AnyUserData {
     /// Keeps associated user values unchanged (they will be collected by Lua's GC).
     pub fn take<T: 'static>(&self) -> Result<T> {
         let lua = self.0.lua.lock();
-        let state = lua.state();
-        unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, 2)?;
-
-            let type_id = lua.push_userdata_ref(&self.0)?;
-            match type_id {
-                Some(type_id) if type_id == TypeId::of::<T>() => {
-                    if (*get_userdata::<UserDataStorage<T>>(state, -1)).has_exclusive_access() {
-                        take_userdata::<UserDataStorage<T>>(state).into_inner()
-                    } else {
-                        Err(Error::UserDataBorrowMutError)
-                    }
+        match lua.get_userdata_ref_type_id(&self.0)? {
+            Some(type_id) if type_id == TypeId::of::<T>() => unsafe {
+                let ref_thread = lua.ref_thread();
+                if (*get_userdata::<UserDataStorage<T>>(ref_thread, self.0.index)).has_exclusive_access() {
+                    take_userdata::<UserDataStorage<T>>(ref_thread, self.0.index).into_inner()
+                } else {
+                    Err(Error::UserDataBorrowMutError)
                 }
-                _ => Err(Error::UserDataTypeMismatch),
-            }
+            },
+            _ => Err(Error::UserDataTypeMismatch),
         }
     }
 
@@ -897,22 +888,17 @@ impl AnyUserData {
         self.raw_metatable().map(UserDataMetatable)
     }
 
-    #[doc(hidden)]
-    #[deprecated(since = "0.10.0", note = "please use `metatable` instead")]
-    pub fn get_metatable(&self) -> Result<UserDataMetatable> {
-        self.metatable()
-    }
-
+    /// Returns a raw metatable of this [`AnyUserData`].
     fn raw_metatable(&self) -> Result<Table> {
         let lua = self.0.lua.lock();
-        let state = lua.state();
+        let ref_thread = lua.ref_thread();
         unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, 3)?;
+            // Check that userdata is registered and not destructed
+            // All registered userdata types have a non-empty metatable
+            let _type_id = lua.get_userdata_ref_type_id(&self.0)?;
 
-            lua.push_userdata_ref(&self.0)?;
-            ffi::lua_getmetatable(state, -1); // Checked that non-empty on the previous call
-            Ok(Table(lua.pop_ref()))
+            ffi::lua_getmetatable(ref_thread, self.0.index);
+            Ok(Table(lua.pop_ref_thread()))
         }
     }
 
@@ -979,7 +965,7 @@ impl AnyUserData {
 
     /// Returns `true` if this [`AnyUserData`] is serializable (e.g. was created using
     /// [`Lua::create_ser_userdata`]).
-    #[cfg(feature = "serialize")]
+    #[cfg(feature = "serde")]
     pub(crate) fn is_serializable(&self) -> bool {
         let lua = self.0.lua.lock();
         let is_serializable = || unsafe {
@@ -1030,7 +1016,7 @@ impl UserDataMetatable {
     /// The pairs are wrapped in a [`Result`], since they are lazily converted to `V` type.
     ///
     /// [`Result`]: crate::Result
-    pub fn pairs<V: FromLua>(&self) -> UserDataMetatablePairs<V> {
+    pub fn pairs<V: FromLua>(&self) -> UserDataMetatablePairs<'_, V> {
         UserDataMetatablePairs(self.0.pairs())
     }
 }
@@ -1063,7 +1049,7 @@ where
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for AnyUserData {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where
@@ -1094,8 +1080,8 @@ impl AnyUserData {
     /// [`IntoLua`] trait.
     ///
     /// This function uses [`Lua::create_ser_any_userdata`] under the hood.
-    #[cfg(feature = "serialize")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+    #[cfg(feature = "serde")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
     pub fn wrap_ser<T: Serialize + MaybeSend + 'static>(data: T) -> impl IntoLua {
         WrappedUserdata(move |lua| lua.create_ser_any_userdata(data))
     }

src/userdata/cell.rs

@@ -1,6 +1,6 @@
 use std::cell::{RefCell, UnsafeCell};
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use serde::ser::{Serialize, Serializer};
 
 use crate::error::{Error, Result};
@@ -9,10 +9,10 @@ use crate::types::XRc;
 use super::lock::{RawLock, UserDataLock};
 use super::r#ref::{UserDataRef, UserDataRefMut};
 
-#[cfg(all(feature = "serialize", not(feature = "send")))]
+#[cfg(all(feature = "serde", not(feature = "send")))]
 type DynSerialize = dyn erased_serde::Serialize;
 
-#[cfg(all(feature = "serialize", feature = "send"))]
+#[cfg(all(feature = "serde", feature = "send"))]
 type DynSerialize = dyn erased_serde::Serialize + Send;
 
 pub(crate) enum UserDataStorage<T> {
@@ -24,7 +24,7 @@ pub(crate) enum UserDataStorage<T> {
 // It's stored inside a Lua VM and protected by the outer `ReentrantMutex`.
 pub(crate) enum UserDataVariant<T> {
     Default(XRc<UserDataCell<T>>),
-    #[cfg(feature = "serialize")]
+    #[cfg(feature = "serde")]
     Serializable(XRc<UserDataCell<Box<DynSerialize>>>, bool), // bool is `is_sync`
 }
 
@@ -33,7 +33,7 @@ impl<T> Clone for UserDataVariant<T> {
     fn clone(&self) -> Self {
         match self {
             Self::Default(inner) => Self::Default(XRc::clone(inner)),
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Self::Serializable(inner, is_sync) => Self::Serializable(XRc::clone(inner), *is_sync),
         }
     }
@@ -79,7 +79,7 @@ impl<T> UserDataVariant<T> {
         }
         Ok(match self {
             Self::Default(inner) => XRc::into_inner(inner).unwrap().value.into_inner(),
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Self::Serializable(inner, _) => unsafe {
                 let raw = Box::into_raw(XRc::into_inner(inner).unwrap().value.into_inner());
                 *Box::from_raw(raw as *mut T)
@@ -91,7 +91,7 @@ impl<T> UserDataVariant<T> {
     fn strong_count(&self) -> usize {
         match self {
             Self::Default(inner) => XRc::strong_count(inner),
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Self::Serializable(inner, _) => XRc::strong_count(inner),
         }
     }
@@ -100,7 +100,7 @@ impl<T> UserDataVariant<T> {
     pub(super) fn raw_lock(&self) -> &RawLock {
         match self {
             Self::Default(inner) => &inner.raw_lock,
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Self::Serializable(inner, _) => &inner.raw_lock,
         }
     }
@@ -109,13 +109,13 @@ impl<T> UserDataVariant<T> {
     pub(super) fn as_ptr(&self) -> *mut T {
         match self {
             Self::Default(inner) => inner.value.get(),
-            #[cfg(feature = "serialize")]
+            #[cfg(feature = "serde")]
             Self::Serializable(inner, _) => unsafe { &mut **(inner.value.get() as *mut Box<T>) },
         }
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for UserDataStorage<()> {
     fn serialize<S: Serializer>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error> {
         match self {
@@ -197,7 +197,7 @@ impl<T: 'static> UserDataStorage<T> {
         Self::Scoped(ScopedUserDataVariant::RefMut(RefCell::new(data)))
     }
 
-    #[cfg(feature = "serialize")]
+    #[cfg(feature = "serde")]
     #[inline(always)]
     pub(crate) fn new_ser(data: T) -> Self
     where
@@ -209,7 +209,7 @@ impl<T: 'static> UserDataStorage<T> {
         Self::Owned(variant)
     }
 
-    #[cfg(feature = "serialize")]
+    #[cfg(feature = "serde")]
     #[inline(always)]
     pub(crate) fn is_serializable(&self) -> bool {
         matches!(self, Self::Owned(UserDataVariant::Serializable(..)))

src/userdata/object.rs

@@ -1,6 +1,7 @@
 use std::string::String as StdString;
 
 use crate::error::{Error, Result};
+use crate::state::WeakLua;
 use crate::table::Table;
 use crate::traits::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, ObjectLike};
 use crate::userdata::AnyUserData;
@@ -8,21 +9,21 @@ use crate::value::Value;
 use crate::Function;
 
 #[cfg(feature = "async")]
-use futures_util::future::{self, Either, Future};
+use crate::function::AsyncCallFuture;
 
 impl ObjectLike for AnyUserData {
     #[inline]
     fn get<V: FromLua>(&self, key: impl IntoLua) -> Result<V> {
         // `lua_gettable` method used under the hood can work with any Lua value
         // that has `__index` metamethod
-        Table(self.0.copy()).get_protected(key)
+        Table(self.0.clone()).get_protected(key)
     }
 
     #[inline]
     fn set(&self, key: impl IntoLua, value: impl IntoLua) -> Result<()> {
         // `lua_settable` method used under the hood can work with any Lua value
         // that has `__newindex` metamethod
-        Table(self.0.copy()).set_protected(key, value)
+        Table(self.0.clone()).set_protected(key, value)
     }
 
     #[inline]
@@ -30,16 +31,16 @@ impl ObjectLike for AnyUserData {
     where
         R: FromLuaMulti,
     {
-        Function(self.0.copy()).call(args)
+        Function(self.0.clone()).call(args)
     }
 
     #[cfg(feature = "async")]
     #[inline]
-    fn call_async<R>(&self, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async<R>(&self, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
-        Function(self.0.copy()).call_async(args)
+        Function(self.0.clone()).call_async(args)
     }
 
     #[inline]
@@ -51,7 +52,7 @@ impl ObjectLike for AnyUserData {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_method<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
@@ -72,22 +73,32 @@ impl ObjectLike for AnyUserData {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> impl Future<Output = Result<R>>
+    fn call_async_function<R>(&self, name: &str, args: impl IntoLuaMulti) -> AsyncCallFuture<R>
     where
         R: FromLuaMulti,
     {
         match self.get(name) {
-            Ok(Value::Function(func)) => Either::Left(func.call_async(args)),
+            Ok(Value::Function(func)) => func.call_async(args),
             Ok(val) => {
                 let msg = format!("attempt to call a {} value (function '{name}')", val.type_name());
-                Either::Right(future::ready(Err(Error::RuntimeError(msg))))
+                AsyncCallFuture::error(Error::RuntimeError(msg))
             }
-            Err(err) => Either::Right(future::ready(Err(err))),
+            Err(err) => AsyncCallFuture::error(err),
         }
     }
 
     #[inline]
     fn to_string(&self) -> Result<StdString> {
-        Value::UserData(AnyUserData(self.0.copy())).to_string()
+        Value::UserData(self.clone()).to_string()
+    }
+
+    #[inline]
+    fn to_value(&self) -> Value {
+        Value::UserData(self.clone())
+    }
+
+    #[inline]
+    fn weak_lua(&self) -> &WeakLua {
+        &self.0.lua
     }
 }

src/userdata/ref.rs

@@ -1,4 +1,4 @@
-use std::any::TypeId;
+use std::any::{type_name, TypeId};
 use std::ops::{Deref, DerefMut};
 use std::os::raw::c_int;
 use std::{fmt, mem};
@@ -7,7 +7,7 @@ use crate::error::{Error, Result};
 use crate::state::{Lua, RawLua};
 use crate::traits::FromLua;
 use crate::userdata::AnyUserData;
-use crate::util::{get_userdata, short_type_name};
+use crate::util::get_userdata;
 use crate::value::Value;
 
 use super::cell::{UserDataStorage, UserDataVariant};
@@ -63,7 +63,7 @@ impl<T> TryFrom<UserDataVariant<T>> for UserDataRef<T> {
 
     #[inline]
     fn try_from(variant: UserDataVariant<T>) -> Result<Self> {
-        let guard = if !cfg!(feature = "send") || is_sync::<T>() {
+        let guard = if cfg!(not(feature = "send")) || is_sync::<T>() {
             variant.raw_lock().try_lock_shared_guarded()
         } else {
             variant.raw_lock().try_lock_exclusive_guarded()
@@ -449,7 +449,7 @@ fn try_value_to_userdata<T>(value: Value) -> Result<AnyUserData> {
         _ => Err(Error::FromLuaConversionError {
             from: value.type_name(),
             to: "userdata".to_string(),
-            message: Some(format!("expected userdata of type {}", short_type_name::<T>())),
+            message: Some(format!("expected userdata of type {}", type_name::<T>())),
         }),
     }
 }

src/userdata/registry.rs

@@ -56,6 +56,9 @@ pub(crate) struct RawUserDataRegistry {
     pub(crate) destructor: ffi::lua_CFunction,
     pub(crate) type_id: Option<TypeId>,
     pub(crate) type_name: StdString,
+
+    #[cfg(feature = "luau")]
+    pub(crate) enable_namecall: bool,
 }
 
 impl UserDataType {
@@ -100,6 +103,8 @@ impl<T> UserDataRegistry<T> {
             destructor: super::util::destroy_userdata_storage::<T>,
             type_id: r#type.type_id(),
             type_name: short_type_name::<T>(),
+            #[cfg(feature = "luau")]
+            enable_namecall: false,
         };
 
         UserDataRegistry {
@@ -110,6 +115,23 @@ impl<T> UserDataRegistry<T> {
         }
     }
 
+    /// Enables support for the namecall optimization in Luau.
+    ///
+    /// This enables methods resolution optimization in Luau for complex userdata types with methods
+    /// and field getters. When enabled, Luau will use a faster lookup path for method calls when a
+    /// specific syntax is used (e.g. `obj:method()`.
+    ///
+    /// This optimization does not play well with async methods, custom `__index` metamethod and
+    /// field getters as functions. So, it is disabled by default.
+    ///
+    /// Use with caution.
+    #[doc(hidden)]
+    #[cfg(feature = "luau")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn enable_namecall(&mut self) {
+        self.raw.enable_namecall = true;
+    }
+
     fn box_method<M, A, R>(&self, name: &str, method: M) -> Callback
     where
         M: Fn(&Lua, &T, A) -> Result<R> + MaybeSend + 'static,
@@ -365,101 +387,101 @@ fn get_function_name<T>(name: &str) -> StdString {
 }
 
 impl<T> UserDataFields<T> for UserDataRegistry<T> {
-    fn add_field<V>(&mut self, name: impl ToString, value: V)
+    fn add_field<V>(&mut self, name: impl Into<StdString>, value: V)
     where
         V: IntoLua + 'static,
     {
-        let name = name.to_string();
+        let name = name.into();
         self.raw.fields.push((name, value.into_lua(self.lua.lua())));
     }
 
-    fn add_field_method_get<M, R>(&mut self, name: impl ToString, method: M)
+    fn add_field_method_get<M, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T) -> Result<R> + MaybeSend + 'static,
         R: IntoLua,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method(&name, move |lua, data, ()| method(lua, data));
         self.raw.field_getters.push((name, callback));
     }
 
-    fn add_field_method_set<M, A>(&mut self, name: impl ToString, method: M)
+    fn add_field_method_set<M, A>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<()> + MaybeSend + 'static,
         A: FromLua,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method_mut(&name, method);
         self.raw.field_setters.push((name, callback));
     }
 
-    fn add_field_function_get<F, R>(&mut self, name: impl ToString, function: F)
+    fn add_field_function_get<F, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, AnyUserData) -> Result<R> + MaybeSend + 'static,
         R: IntoLua,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function(&name, function);
         self.raw.field_getters.push((name, callback));
     }
 
-    fn add_field_function_set<F, A>(&mut self, name: impl ToString, mut function: F)
+    fn add_field_function_set<F, A>(&mut self, name: impl Into<StdString>, mut function: F)
     where
         F: FnMut(&Lua, AnyUserData, A) -> Result<()> + MaybeSend + 'static,
         A: FromLua,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function_mut(&name, move |lua, (data, val)| function(lua, data, val));
         self.raw.field_setters.push((name, callback));
     }
 
-    fn add_meta_field<V>(&mut self, name: impl ToString, value: V)
+    fn add_meta_field<V>(&mut self, name: impl Into<StdString>, value: V)
     where
         V: IntoLua + 'static,
     {
         let lua = self.lua.lua();
-        let name = name.to_string();
+        let name = name.into();
         let field = Self::check_meta_field(lua, &name, value).and_then(|v| v.into_lua(lua));
         self.raw.meta_fields.push((name, field));
     }
 
-    fn add_meta_field_with<F, R>(&mut self, name: impl ToString, f: F)
+    fn add_meta_field_with<F, R>(&mut self, name: impl Into<StdString>, f: F)
     where
         F: FnOnce(&Lua) -> Result<R> + 'static,
         R: IntoLua,
     {
         let lua = self.lua.lua();
-        let name = name.to_string();
+        let name = name.into();
         let field = f(lua).and_then(|v| Self::check_meta_field(lua, &name, v).and_then(|v| v.into_lua(lua)));
         self.raw.meta_fields.push((name, field));
     }
 }
 
 impl<T> UserDataMethods<T> for UserDataRegistry<T> {
-    fn add_method<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_method<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method(&name, method);
         self.raw.methods.push((name, callback));
     }
 
-    fn add_method_mut<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_method_mut<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method_mut(&name, method);
         self.raw.methods.push((name, callback));
     }
 
     #[cfg(feature = "async")]
-    fn add_async_method<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_method<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRef<T>, A) -> MR + MaybeSend + 'static,
@@ -467,13 +489,13 @@ impl<T> UserDataMethods<T> for UserDataRegistry<T> {
         MR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_method(&name, method);
         self.raw.async_methods.push((name, callback));
     }
 
     #[cfg(feature = "async")]
-    fn add_async_method_mut<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_method_mut<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRefMut<T>, A) -> MR + MaybeSend + 'static,
@@ -481,70 +503,70 @@ impl<T> UserDataMethods<T> for UserDataRegistry<T> {
         MR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_method_mut(&name, method);
         self.raw.async_methods.push((name, callback));
     }
 
-    fn add_function<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_function<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function(&name, function);
         self.raw.methods.push((name, callback));
     }
 
-    fn add_function_mut<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_function_mut<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: FnMut(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function_mut(&name, function);
         self.raw.methods.push((name, callback));
     }
 
     #[cfg(feature = "async")]
-    fn add_async_function<F, A, FR, R>(&mut self, name: impl ToString, function: F)
+    fn add_async_function<F, A, FR, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(Lua, A) -> FR + MaybeSend + 'static,
         A: FromLuaMulti,
         FR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_function(&name, function);
         self.raw.async_methods.push((name, callback));
     }
 
-    fn add_meta_method<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_meta_method<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: Fn(&Lua, &T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method(&name, method);
         self.raw.meta_methods.push((name, callback));
     }
 
-    fn add_meta_method_mut<M, A, R>(&mut self, name: impl ToString, method: M)
+    fn add_meta_method_mut<M, A, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         M: FnMut(&Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_method_mut(&name, method);
         self.raw.meta_methods.push((name, callback));
     }
 
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRef<T>, A) -> MR + MaybeSend + 'static,
@@ -552,13 +574,13 @@ impl<T> UserDataMethods<T> for UserDataRegistry<T> {
         MR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_method(&name, method);
         self.raw.async_meta_methods.push((name, callback));
     }
 
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    fn add_async_meta_method_mut<M, A, MR, R>(&mut self, name: impl ToString, method: M)
+    fn add_async_meta_method_mut<M, A, MR, R>(&mut self, name: impl Into<StdString>, method: M)
     where
         T: 'static,
         M: Fn(Lua, UserDataRefMut<T>, A) -> MR + MaybeSend + 'static,
@@ -566,42 +588,42 @@ impl<T> UserDataMethods<T> for UserDataRegistry<T> {
         MR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_method_mut(&name, method);
         self.raw.async_meta_methods.push((name, callback));
     }
 
-    fn add_meta_function<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_meta_function<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function(&name, function);
         self.raw.meta_methods.push((name, callback));
     }
 
-    fn add_meta_function_mut<F, A, R>(&mut self, name: impl ToString, function: F)
+    fn add_meta_function_mut<F, A, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: FnMut(&Lua, A) -> Result<R> + MaybeSend + 'static,
         A: FromLuaMulti,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_function_mut(&name, function);
         self.raw.meta_methods.push((name, callback));
     }
 
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    fn add_async_meta_function<F, A, FR, R>(&mut self, name: impl ToString, function: F)
+    fn add_async_meta_function<F, A, FR, R>(&mut self, name: impl Into<StdString>, function: F)
     where
         F: Fn(Lua, A) -> FR + MaybeSend + 'static,
         A: FromLuaMulti,
         FR: Future<Output = Result<R>> + MaybeSend + 'static,
         R: IntoLuaMulti,
     {
-        let name = name.to_string();
+        let name = name.into();
         let callback = self.box_async_function(&name, function);
         self.raw.async_meta_methods.push((name, callback));
     }

src/userdata/util.rs

@@ -4,8 +4,11 @@ use std::marker::PhantomData;
 use std::os::raw::c_int;
 use std::ptr;
 
+use rustc_hash::FxHashMap;
+
 use super::UserDataStorage;
 use crate::error::{Error, Result};
+use crate::types::CallbackPtr;
 use crate::util::{get_userdata, rawget_field, rawset_field, take_userdata};
 
 // This is a trick to check if a type is `Sync` or not.
@@ -244,6 +247,7 @@ pub(crate) unsafe fn init_userdata_metatable(
     field_getters: Option<c_int>,
     field_setters: Option<c_int>,
     methods: Option<c_int>,
+    _methods_map: Option<FxHashMap<Vec<u8>, CallbackPtr>>, // Used only in Luau for `__namecall`
 ) -> Result<()> {
     if field_getters.is_some() || methods.is_some() {
         // Push `__index` generator function
@@ -267,6 +271,13 @@ pub(crate) unsafe fn init_userdata_metatable(
         }
 
         rawset_field(state, metatable, "__index")?;
+
+        #[cfg(feature = "luau")]
+        if let Some(methods_map) = _methods_map {
+            // In Luau we can speedup method calls by providing a dedicated `__namecall` metamethod
+            push_userdata_metatable_namecall(state, methods_map)?;
+            rawset_field(state, metatable, "__namecall")?;
+        }
     }
 
     if let Some(field_setters) = field_setters {
@@ -425,6 +436,36 @@ unsafe fn init_userdata_metatable_newindex(state: *mut ffi::lua_State) -> Result
     })
 }
 
+#[cfg(feature = "luau")]
+unsafe fn push_userdata_metatable_namecall(
+    state: *mut ffi::lua_State,
+    methods_map: FxHashMap<Vec<u8>, CallbackPtr>,
+) -> Result<()> {
+    unsafe extern "C-unwind" fn namecall(state: *mut ffi::lua_State) -> c_int {
+        let name = ffi::lua_namecallatom(state, ptr::null_mut());
+        if name.is_null() {
+            ffi::luaL_error(state, cstr!("attempt to call an unknown method"));
+        }
+        let name_cs = std::ffi::CStr::from_ptr(name);
+        let methods_map = get_userdata::<FxHashMap<Vec<u8>, CallbackPtr>>(state, ffi::lua_upvalueindex(1));
+        let callback_ptr = match (*methods_map).get(name_cs.to_bytes()) {
+            Some(ptr) => *ptr,
+            #[rustfmt::skip]
+            None => ffi::luaL_error(state, cstr!("attempt to call an unknown method '%s'"), name),
+        };
+        crate::state::callback_error_ext(state, ptr::null_mut(), true, |extra, nargs| {
+            let rawlua = (*extra).raw_lua();
+            (*callback_ptr)(rawlua, nargs)
+        })
+    }
+
+    // Automatic destructor is provided for any Luau userdata
+    crate::util::push_userdata(state, methods_map, true)?;
+    protect_lua!(state, 1, 1, |state| {
+        ffi::lua_pushcclosured(state, namecall, cstr!("__namecall"), 1);
+    })
+}
+
 // This method is called by Lua GC when it's time to collect the userdata.
 //
 // This method is usually used to collect internal userdata.
@@ -437,17 +478,27 @@ pub(crate) unsafe extern "C-unwind" fn collect_userdata<T>(state: *mut ffi::lua_
 
 // This method is called by Luau GC when it's time to collect the userdata.
 #[cfg(feature = "luau")]
-pub(crate) unsafe extern "C-unwind" fn collect_userdata<T>(ud: *mut std::os::raw::c_void) {
+pub(crate) unsafe extern "C" fn collect_userdata<T>(
+    state: *mut ffi::lua_State,
+    ud: *mut std::os::raw::c_void,
+) {
+    // Almost none Lua operations are allowed when destructor is running,
+    // so we need to set a flag to prevent calling any Lua functions
+    let extra = (*ffi::lua_callbacks(state)).userdata as *mut crate::state::ExtraData;
+    (*extra).running_gc = true;
+    // Luau does not support _any_ panics in destructors (they are declared as "C", NOT as "C-unwind"),
+    // so any panics will trigger `abort()`.
     ptr::drop_in_place(ud as *mut T);
+    (*extra).running_gc = false;
 }
 
 // This method can be called by user or Lua GC to destroy the userdata.
 // It checks if the userdata is safe to destroy and sets the "destroyed" metatable
 // to prevent further GC collection.
 pub(super) unsafe extern "C-unwind" fn destroy_userdata_storage<T>(state: *mut ffi::lua_State) -> c_int {
-    let ud = get_userdata::<UserDataStorage<T>>(state, -1);
+    let ud = get_userdata::<UserDataStorage<T>>(state, 1);
     if (*ud).is_safe_to_destroy() {
-        take_userdata::<UserDataStorage<T>>(state);
+        take_userdata::<UserDataStorage<T>>(state, 1);
         ffi::lua_pushboolean(state, 1);
     } else {
         ffi::lua_pushboolean(state, 0);

src/util/error.rs

@@ -315,7 +315,7 @@ pub(crate) unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<(
                     let _ = write!(&mut (*err_buf), "{error}");
                     Ok(err_buf)
                 }
-                Some(WrappedFailure::Panic(Some(ref panic))) => {
+                Some(WrappedFailure::Panic(Some(panic))) => {
                     let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
                     ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
                     let err_buf = ffi::lua_touserdata(state, -1) as *mut String;
@@ -349,7 +349,11 @@ pub(crate) unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<(
         state,
         Some(|state| {
             ffi::lua_pushcfunction(state, error_tostring);
-            rawset_field(state, -2, "__tostring")
+            ffi::lua_setfield(state, -2, cstr!("__tostring"));
+
+            // This is mostly for Luau typeof() function
+            ffi::lua_pushstring(state, cstr!("error"));
+            ffi::lua_setfield(state, -2, cstr!("__type"));
         }),
     )?;
 
@@ -398,6 +402,8 @@ pub(crate) unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<(
         "__ipairs",
         #[cfg(feature = "luau")]
         "__iter",
+        #[cfg(feature = "luau")]
+        "__namecall",
         #[cfg(feature = "lua54")]
         "__close",
     ] {

src/util/mod.rs

@@ -9,6 +9,7 @@ pub(crate) use error::{
     error_traceback, error_traceback_thread, init_error_registry, pop_error, protect_lua_call,
     protect_lua_closure, WrappedFailure,
 };
+pub(crate) use path::parse_path as parse_lookup_path;
 pub(crate) use short_names::short_type_name;
 pub(crate) use types::TypeKey;
 pub(crate) use userdata::{
@@ -88,7 +89,7 @@ impl Drop for StackGuard {
 #[inline(always)]
 pub(crate) unsafe fn push_string(state: *mut ffi::lua_State, s: &[u8], protect: bool) -> Result<()> {
     // Always use protected mode if the string is too long
-    if protect || s.len() > (1 << 30) {
+    if protect || s.len() >= const { 1 << 30 } {
         protect_lua!(state, 0, 1, |state| {
             ffi::lua_pushlstring(state, s.as_ptr() as *const c_char, s.len());
         })
@@ -101,15 +102,13 @@ pub(crate) unsafe fn push_string(state: *mut ffi::lua_State, s: &[u8], protect:
 // Uses 3 stack spaces (when protect), does not call checkstack.
 #[cfg(feature = "luau")]
 #[inline(always)]
-pub(crate) 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()))?
+pub(crate) unsafe fn push_buffer(state: *mut ffi::lua_State, size: usize, protect: bool) -> Result<*mut u8> {
+    let data = if protect || size > const { 1024 * 1024 * 1024 } {
+        protect_lua!(state, 0, 1, |state| ffi::lua_newbuffer(state, size))?
     } else {
-        ffi::lua_newbuffer(state, b.len())
+        ffi::lua_newbuffer(state, size)
     };
-    let buf = slice::from_raw_parts_mut(data as *mut u8, b.len());
-    buf.copy_from_slice(b);
-    Ok(())
+    Ok(data as *mut u8)
 }
 
 // Uses 3 stack spaces, does not call checkstack.
@@ -122,7 +121,7 @@ pub(crate) unsafe fn push_table(
 ) -> 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 {
+    if protect || narr >= const { 1 << 26 } || nrec >= const { 1 << 26 } {
         protect_lua!(state, 0, 1, |state| ffi::lua_createtable(state, narr, nrec))
     } else {
         ffi::lua_createtable(state, narr, nrec);
@@ -329,6 +328,7 @@ pub(crate) fn linenumber_to_usize(n: c_int) -> Option<usize> {
 }
 
 mod error;
+mod path;
 mod short_names;
 mod types;
 mod userdata;

src/util/path.rs

@@ -0,0 +1,255 @@
+use std::borrow::Cow;
+use std::fmt;
+use std::iter::Peekable;
+use std::str::CharIndices;
+
+use crate::error::{Error, Result};
+use crate::state::Lua;
+use crate::traits::IntoLua;
+use crate::types::Integer;
+use crate::value::Value;
+
+#[derive(Debug)]
+pub(crate) enum PathKey<'a> {
+    Str(Cow<'a, str>),
+    Int(Integer),
+}
+
+impl fmt::Display for PathKey<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            PathKey::Str(s) => write!(f, "{}", s),
+            PathKey::Int(i) => write!(f, "{}", i),
+        }
+    }
+}
+
+impl IntoLua for PathKey<'_> {
+    fn into_lua(self, lua: &Lua) -> Result<Value> {
+        match self {
+            PathKey::Str(s) => Ok(Value::String(lua.create_string(s.as_ref())?)),
+            PathKey::Int(i) => Ok(Value::Integer(i)),
+        }
+    }
+}
+
+// Parses a path like `a.b[3]?.c["d"]` into segments of `(key, safe_nil)`.
+pub(crate) fn parse_path<'a>(path: &'a str) -> Result<Vec<(PathKey<'a>, bool)>> {
+    fn read_ident<'a>(path: &'a str, chars: &mut Peekable<CharIndices<'a>>) -> (Cow<'a, str>, bool) {
+        let mut safe_nil = false;
+        let start = chars.peek().map(|&(i, _)| i).unwrap_or(path.len());
+        let mut end = start;
+        while let Some(&(pos, c)) = chars.peek() {
+            if c == '.' || c == '?' || c.is_ascii_whitespace() || c == '[' {
+                if c == '?' {
+                    safe_nil = true;
+                    chars.next(); // consume '?'
+                }
+                break;
+            }
+            end = pos + c.len_utf8();
+            chars.next();
+        }
+        (Cow::Borrowed(&path[start..end]), safe_nil)
+    }
+
+    let mut segments = Vec::new();
+    let mut chars = path.char_indices().peekable();
+    while let Some(&(pos, next)) = chars.peek() {
+        match next {
+            '.' => {
+                // Dot notation: identifier
+                chars.next();
+                let (key, safe_nil) = read_ident(path, &mut chars);
+                if key.is_empty() {
+                    return Err(Error::runtime(format!("empty key in path at position {pos}")));
+                }
+                segments.push((PathKey::Str(key), safe_nil));
+            }
+            '[' => {
+                // Bracket notation: either integer or quoted string
+                chars.next();
+                let key = match chars.peek() {
+                    Some(&(pos, c @ '0'..='9' | c @ '-')) => {
+                        // Integer key
+                        let negative = c == '-';
+                        if negative {
+                            chars.next(); // consume '-'
+                        }
+                        let mut num: Option<Integer> = None;
+                        while let Some(&(_, c @ '0'..='9')) = chars.peek() {
+                            let new_num = num
+                                .unwrap_or(0)
+                                .checked_mul(10)
+                                .and_then(|n| n.checked_add((c as u8 - b'0') as Integer))
+                                .ok_or_else(|| {
+                                    Error::runtime(format!("integer overflow in path at position {pos}"))
+                                })?;
+                            num = Some(new_num);
+                            chars.next(); // consume digit
+                        }
+                        match num {
+                            Some(n) if negative => PathKey::Int(-n),
+                            Some(n) => PathKey::Int(n),
+                            None => {
+                                let err = format!("invalid integer in path at position {pos}");
+                                return Err(Error::runtime(err));
+                            }
+                        }
+                    }
+                    Some((_, '\'' | '"')) => {
+                        // Quoted string
+                        PathKey::Str(unquote_string(path, &mut chars)?)
+                    }
+                    Some((_, ']')) => {
+                        return Err(Error::runtime(format!("empty key in path at position {pos}")));
+                    }
+                    Some((pos, c)) => {
+                        let err = format!("unexpected character '{c}' in path at position {pos}");
+                        return Err(Error::runtime(err));
+                    }
+                    None => {
+                        return Err(Error::runtime("unexpected end of path"));
+                    }
+                };
+                // Expect closing bracket
+                let mut safe_nil = false;
+                match chars.next() {
+                    Some((_, ']')) => {
+                        // Check for optional safe-nil operator
+                        if let Some(&(_, '?')) = chars.peek() {
+                            safe_nil = true;
+                            chars.next(); // consume '?'
+                        }
+                    }
+                    Some((pos, c)) => {
+                        let err = format!("expected ']' in path at position {pos}, found '{c}'");
+                        return Err(Error::runtime(err));
+                    }
+                    None => {
+                        return Err(Error::runtime("unexpected end of path"));
+                    }
+                }
+                segments.push((key, safe_nil));
+            }
+            c if c.is_ascii_whitespace() => {
+                chars.next(); // Skip whitespace
+            }
+            _ if segments.is_empty() => {
+                // First segment without dot/bracket notation
+                let (key_cow, safe_nil) = read_ident(path, &mut chars);
+                if key_cow.is_empty() {
+                    return Err(Error::runtime(format!("empty key in path at position {pos}")));
+                }
+                segments.push((PathKey::Str(key_cow), safe_nil));
+            }
+            c => {
+                let err = format!("unexpected character '{c}' in path at position {pos}");
+                return Err(Error::runtime(err));
+            }
+        }
+    }
+    Ok(segments)
+}
+
+fn unquote_string<'a>(path: &'a str, chars: &mut Peekable<CharIndices<'a>>) -> Result<Cow<'a, str>> {
+    let (start_pos, first_quote) = chars.next().unwrap();
+    let mut result = String::new();
+    loop {
+        match chars.next() {
+            Some((pos, '\\')) => {
+                if result.is_empty() {
+                    // First escape found, copy everything up to this point
+                    result.push_str(&path[start_pos + 1..pos]);
+                }
+                match chars.next() {
+                    Some((_, '\\')) => result.push('\\'),
+                    Some((_, '"')) => result.push('"'),
+                    Some((_, '\'')) => result.push('\''),
+                    Some((_, other)) => {
+                        result.push('\\');
+                        result.push(other);
+                    }
+                    None => continue, // will be handled by outer loop
+                }
+            }
+            Some((pos, c)) if c == first_quote => {
+                if !result.is_empty() {
+                    return Ok(Cow::Owned(result));
+                }
+                // No escapes, return borrowed slice
+                return Ok(Cow::Borrowed(&path[start_pos + 1..pos]));
+            }
+            Some((_, c)) => {
+                if !result.is_empty() {
+                    result.push(c);
+                }
+                // If no escapes yet, continue tracking for potential borrowed slice
+            }
+            None => {
+                let err = format!("unexpected end of string at position {start_pos}");
+                return Err(Error::runtime(err));
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{parse_path, PathKey};
+
+    #[test]
+    fn test_parse_path() {
+        // Test valid paths
+        let path = parse_path("a.b[3]?.c['d']").unwrap();
+        assert_eq!(path.len(), 5);
+        assert!(matches!(path[0], (PathKey::Str(ref s), false) if s == "a"));
+        assert!(matches!(path[1], (PathKey::Str(ref s), false) if s == "b"));
+        assert!(matches!(path[2], (PathKey::Int(3), true)));
+        assert!(matches!(path[3], (PathKey::Str(ref s), false) if s == "c"));
+        assert!(matches!(path[4], (PathKey::Str(ref s), false) if s == "d"));
+
+        // Test empty path
+        let path = parse_path("").unwrap();
+        assert_eq!(path.len(), 0);
+        let path = parse_path("   ").unwrap();
+        assert_eq!(path.len(), 0);
+
+        // Test invalid dot syntax
+        let err = parse_path("a..b").unwrap_err().to_string();
+        assert_eq!(err, "runtime error: empty key in path at position 1");
+        let err = parse_path("a.b.").unwrap_err().to_string();
+        assert_eq!(err, "runtime error: empty key in path at position 3");
+
+        // Test invalid bracket syntax
+        let err = parse_path("a[unclosed").unwrap_err().to_string();
+        assert_eq!(
+            err,
+            "runtime error: unexpected character 'u' in path at position 2"
+        );
+        let err = parse_path("a[]").unwrap_err().to_string();
+        assert_eq!(err, "runtime error: empty key in path at position 1");
+        let err = parse_path(r#"a["unclosed"#).unwrap_err().to_string();
+        assert_eq!(err, "runtime error: unexpected end of string at position 2");
+        let err = parse_path(r#"a["#).unwrap_err().to_string();
+        assert_eq!(err, "runtime error: unexpected end of path");
+        let err = parse_path(r#"a[123"#).unwrap_err().to_string();
+        assert_eq!(err, "runtime error: unexpected end of path");
+        let err = parse_path(r#"a['bla'123"#).unwrap_err().to_string();
+        assert_eq!(
+            err,
+            "runtime error: expected ']' in path at position 7, found '1'"
+        );
+        let err = parse_path(r#"a["bla"]x"#).unwrap_err().to_string();
+        assert_eq!(
+            err,
+            "runtime error: unexpected character 'x' in path at position 8"
+        );
+
+        // Test bad integers
+        let err = parse_path("a[99999999999999999999]").unwrap_err().to_string();
+        assert_eq!(err, "runtime error: integer overflow in path at position 2");
+        let err = parse_path("a[-]").unwrap_err().to_string();
+        assert_eq!(err, "runtime error: invalid integer in path at position 2");
+    }
+}

src/util/short_names.rs

@@ -1,6 +1,6 @@
-//! Mostly copied from [bevy_utils]
+//! Inspired by bevy's [disqualified]
 //!
-//! [bevy_utils]: https://github.com/bevyengine/bevy/blob/main/crates/bevy_utils/src/short_names.rs
+//! [disqualified]: https://github.com/bevyengine/disqualified/blob/main/src/short_name.rs
 
 use std::any::type_name;
 
@@ -23,8 +23,7 @@ pub(crate) fn short_type_name<T: ?Sized>() -> String {
     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
+        // 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))
         {
@@ -32,11 +31,16 @@ pub(crate) fn short_type_name<T: ?Sized>() -> String {
             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);
+            parsed_name += special_character;
+
+            // Remove lifetimes like <'_> or <'_, '_, ...>
+            if parsed_name.ends_with("<'_>") || parsed_name.ends_with("<'_, ") {
+                _ = parsed_name.split_off(parsed_name.len() - 4);
+            }
 
             match special_character {
                 ">" | ")" | "]" if rest_of_string[special_character_index + 1..].starts_with("::") => {
-                    parsed_name.push_str("::");
+                    parsed_name += "::";
                     // Move the index past the "::"
                     index += special_character_index + 3;
                 }
@@ -53,14 +57,18 @@ pub(crate) fn short_type_name<T: ?Sized>() -> String {
 }
 
 #[inline(always)]
-fn collapse_type_name(string: &str) -> &str {
-    string.rsplit("::").next().unwrap()
+fn collapse_type_name(segment: &str) -> &str {
+    segment.rsplit("::").next().unwrap()
 }
 
 #[cfg(test)]
 mod tests {
     use super::short_type_name;
     use std::collections::HashMap;
+    use std::marker::PhantomData;
+
+    struct MyData<'a, 'b>(PhantomData<&'a &'b ()>);
+    struct MyDataT<'a, T>(PhantomData<&'a T>);
 
     #[test]
     fn tests() {
@@ -73,5 +81,7 @@ mod tests {
             "HashMap<String, Option<[i32; 3]>>"
         );
         assert_eq!(short_type_name::<dyn Fn(i32) -> i32>(), "dyn Fn(i32) -> i32");
+        assert_eq!(short_type_name::<MyDataT<&str>>(), "MyDataT<&str>");
+        assert_eq!(short_type_name::<(&MyData, [MyData])>(), "(MyData, [MyData])");
     }
 }

src/util/types.rs

@@ -10,73 +10,71 @@ pub(crate) trait TypeKey: Any {
     fn type_key() -> *const c_void;
 }
 
-static STRING_TYPE_KEY: u8 = 0;
-
 impl TypeKey for String {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static STRING_TYPE_KEY: u8 = 0;
         &STRING_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-static CALLBACK_TYPE_KEY: u8 = 0;
-
 impl TypeKey for Callback {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static CALLBACK_TYPE_KEY: u8 = 0;
         &CALLBACK_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-static CALLBACK_UPVALUE_TYPE_KEY: u8 = 0;
-
 impl TypeKey for CallbackUpvalue {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static CALLBACK_UPVALUE_TYPE_KEY: u8 = 0;
         &CALLBACK_UPVALUE_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-#[cfg(feature = "async")]
-static ASYNC_CALLBACK_TYPE_KEY: u8 = 0;
+#[cfg(not(feature = "luau"))]
+impl TypeKey for crate::types::HookCallback {
+    #[inline(always)]
+    fn type_key() -> *const c_void {
+        static HOOK_CALLBACK_TYPE_KEY: u8 = 0;
+        &HOOK_CALLBACK_TYPE_KEY as *const u8 as *const c_void
+    }
+}
 
 #[cfg(feature = "async")]
 impl TypeKey for AsyncCallback {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static ASYNC_CALLBACK_TYPE_KEY: u8 = 0;
         &ASYNC_CALLBACK_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-#[cfg(feature = "async")]
-static ASYNC_CALLBACK_UPVALUE_TYPE_KEY: u8 = 0;
-
 #[cfg(feature = "async")]
 impl TypeKey for AsyncCallbackUpvalue {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static ASYNC_CALLBACK_UPVALUE_TYPE_KEY: u8 = 0;
         &ASYNC_CALLBACK_UPVALUE_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-#[cfg(feature = "async")]
-static ASYNC_POLL_UPVALUE_TYPE_KEY: u8 = 0;
-
 #[cfg(feature = "async")]
 impl TypeKey for AsyncPollUpvalue {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static ASYNC_POLL_UPVALUE_TYPE_KEY: u8 = 0;
         &ASYNC_POLL_UPVALUE_TYPE_KEY as *const u8 as *const c_void
     }
 }
 
-#[cfg(feature = "async")]
-static WAKER_TYPE_KEY: u8 = 0;
-
 #[cfg(feature = "async")]
 impl TypeKey for Option<std::task::Waker> {
     #[inline(always)]
     fn type_key() -> *const c_void {
+        static WAKER_TYPE_KEY: u8 = 0;
         &WAKER_TYPE_KEY as *const u8 as *const c_void
     }
 }

src/util/userdata.rs

@@ -15,20 +15,23 @@ pub(crate) unsafe fn push_internal_userdata<T: TypeKey>(
     #[cfg(not(feature = "luau"))]
     let ud_ptr = if protect {
         protect_lua!(state, 0, 1, move |state| {
-            ffi::lua_newuserdata(state, const { mem::size_of::<T>() }) as *mut T
+            let ud_ptr = ffi::lua_newuserdata(state, const { mem::size_of::<T>() }) as *mut T;
+            ptr::write(ud_ptr, t);
+            ud_ptr
         })?
     } else {
-        ffi::lua_newuserdata(state, const { mem::size_of::<T>() }) as *mut T
+        let ud_ptr = ffi::lua_newuserdata(state, const { mem::size_of::<T>() }) as *mut T;
+        ptr::write(ud_ptr, t);
+        ud_ptr
     };
 
     #[cfg(feature = "luau")]
     let ud_ptr = if protect {
-        protect_lua!(state, 0, 1, move |state| ffi::lua_newuserdata_t::<T>(state))?
+        protect_lua!(state, 0, 1, move |state| ffi::lua_newuserdata_t::<T>(state, t))?
     } else {
-        ffi::lua_newuserdata_t::<T>(state)
+        ffi::lua_newuserdata_t::<T>(state, t)
     };
 
-    ptr::write(ud_ptr, t);
     get_internal_metatable::<T>(state);
     ffi::lua_setmetatable(state, -2);
     Ok(ud_ptr)
@@ -44,7 +47,7 @@ pub(crate) unsafe fn get_internal_metatable<T: TypeKey>(state: *mut ffi::lua_Sta
 // Uses 6 stack spaces and calls checkstack.
 pub(crate) unsafe fn init_internal_metatable<T: TypeKey>(
     state: *mut ffi::lua_State,
-    customize_fn: Option<fn(*mut ffi::lua_State) -> Result<()>>,
+    customize_fn: Option<fn(*mut ffi::lua_State)>,
 ) -> Result<()> {
     check_stack(state, 6)?;
 
@@ -59,18 +62,18 @@ pub(crate) unsafe fn init_internal_metatable<T: TypeKey>(
     ffi::lua_pushboolean(state, 0);
     rawset_field(state, -2, "__metatable")?;
 
-    if let Some(f) = customize_fn {
-        f(state)?;
-    }
-
     protect_lua!(state, 1, 0, |state| {
+        if let Some(f) = customize_fn {
+            f(state);
+        }
+
         ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, T::type_key());
     })?;
 
     Ok(())
 }
 
-// Uses 2 stack spaces, does not call checkstack
+// Uses up to 1 stack space, does not call `checkstack`
 pub(crate) unsafe fn get_internal_userdata<T: TypeKey>(
     state: *mut ffi::lua_State,
     index: c_int,
@@ -138,24 +141,27 @@ pub(crate) unsafe fn get_userdata<T>(state: *mut ffi::lua_State, index: c_int) -
     ud
 }
 
-// Pops the userdata off of the top of the stack and returns it to rust, invalidating the lua
-// userdata and gives it the special "destructed" userdata metatable. Userdata must not have been
-// previously invalidated, and this method does not check for this.
-// Uses 1 extra stack space and does not call checkstack.
-pub(crate) unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
-    // We set the metatable of userdata on __gc to a special table with no __gc method and with
-    // metamethods that trigger an error on access. We do this so that it will not be double
-    // dropped, and also so that it cannot be used or identified as any particular userdata type
-    // after the first call to __gc.
+/// Unwraps `T` from the Lua userdata and invalidating it by setting the special "destructed"
+/// metatable.
+///
+/// This method does not check that userdata is of type `T` and was not previously invalidated.
+///
+/// Uses 1 extra stack space, does not call checkstack.
+pub(crate) unsafe fn take_userdata<T>(state: *mut ffi::lua_State, idx: c_int) -> T {
+    #[rustfmt::skip]
+    let idx = if idx < 0 { ffi::lua_absindex(state, idx) } else { idx };
+
+    // Update the metatable of this userdata to a special one with no `__gc` method and with
+    // metamethods that trigger an error on access.
+    // We do this so that it will not be double dropped or used after being dropped.
     get_destructed_userdata_metatable(state);
-    ffi::lua_setmetatable(state, -2);
-    let ud = get_userdata::<T>(state, -1);
+    ffi::lua_setmetatable(state, idx);
+    let ud = get_userdata::<T>(state, idx);
 
     // Update userdata tag to disable destructor and mark as destructed
     #[cfg(feature = "luau")]
-    ffi::lua_setuserdatatag(state, -1, 1);
+    ffi::lua_setuserdatatag(state, idx, 1);
 
-    ffi::lua_pop(state, 1);
     ptr::read(ud)
 }
 

src/value.rs

@@ -15,7 +15,7 @@ use crate::types::{Integer, LightUserData, Number, ValueRef};
 use crate::userdata::AnyUserData;
 use crate::util::{check_stack, StackGuard};
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use {
     crate::table::SerializableTable,
     rustc_hash::FxHashSet,
@@ -28,9 +28,10 @@ use {
 /// The non-primitive variants (eg. string/table/function/thread/userdata) 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(Clone, Default)]
 pub enum Value {
     /// The Lua value `nil`.
+    #[default]
     Nil,
     /// The Lua value `true` or `false`.
     Boolean(bool),
@@ -272,7 +273,10 @@ impl Value {
     /// 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)
+        #[cfg(target_pointer_width = "64")]
+        return self.as_integer();
+        #[cfg(not(target_pointer_width = "64"))]
+        return self.as_integer().map(i64::from);
     }
 
     /// Cast the value to `u64`.
@@ -353,14 +357,22 @@ impl Value {
     ///
     /// If the value is a Lua [`String`], try to convert it to [`BorrowedStr`] or return `None`
     /// otherwise.
+    #[deprecated(
+        since = "0.11.0",
+        note = "This method does not follow Rust naming convention. Use `as_string().and_then(|s| s.to_str().ok())` instead."
+    )]
     #[inline]
-    pub fn as_str(&self) -> Option<BorrowedStr> {
+    pub fn as_str(&self) -> Option<BorrowedStr<'_>> {
         self.as_string().and_then(|s| s.to_str().ok())
     }
 
     /// Cast the value to [`StdString`].
     ///
     /// If the value is a Lua [`String`], converts it to [`StdString`] or returns `None` otherwise.
+    #[deprecated(
+        since = "0.11.0",
+        note = "This method does not follow Rust naming convention. Use `as_string().map(|s| s.to_string_lossy())` instead."
+    )]
     #[inline]
     pub fn as_string_lossy(&self) -> Option<StdString> {
         self.as_string().map(|s| s.to_string_lossy())
@@ -478,10 +490,9 @@ impl Value {
     /// 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 {
+    #[cfg(feature = "serde")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+    pub fn to_serializable(&self) -> SerializableValue<'_> {
         SerializableValue::new(self, Default::default(), None)
     }
 
@@ -569,12 +580,6 @@ impl Value {
     }
 }
 
-impl Default for Value {
-    fn default() -> Self {
-        Self::Nil
-    }
-}
-
 impl fmt::Debug for Value {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         if fmt.alternate() {
@@ -627,8 +632,8 @@ impl PartialEq for Value {
 }
 
 /// A wrapped [`Value`] with customized serialization behavior.
-#[cfg(feature = "serialize")]
-#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 pub struct SerializableValue<'a> {
     value: &'a Value,
     options: crate::serde::de::Options,
@@ -636,7 +641,7 @@ pub struct SerializableValue<'a> {
     visited: Option<Rc<RefCell<FxHashSet<*const c_void>>>>,
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for Value {
     #[inline]
     fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
@@ -644,7 +649,7 @@ impl Serialize for Value {
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl<'a> SerializableValue<'a> {
     #[inline]
     pub(crate) fn new(
@@ -673,7 +678,7 @@ impl<'a> SerializableValue<'a> {
     ///
     /// Default: **true**
     #[must_use]
-    pub const fn deny_unsupported_types(mut self, enabled: bool) -> Self {
+    pub fn deny_unsupported_types(mut self, enabled: bool) -> Self {
         self.options.deny_unsupported_types = enabled;
         self
     }
@@ -684,7 +689,7 @@ impl<'a> SerializableValue<'a> {
     ///
     /// Default: **true**
     #[must_use]
-    pub const fn deny_recursive_tables(mut self, enabled: bool) -> Self {
+    pub fn deny_recursive_tables(mut self, enabled: bool) -> Self {
         self.options.deny_recursive_tables = enabled;
         self
     }
@@ -693,7 +698,7 @@ impl<'a> SerializableValue<'a> {
     ///
     /// Default: **false**
     #[must_use]
-    pub const fn sort_keys(mut self, enabled: bool) -> Self {
+    pub fn sort_keys(mut self, enabled: bool) -> Self {
         self.options.sort_keys = enabled;
         self
     }
@@ -702,13 +707,24 @@ impl<'a> SerializableValue<'a> {
     ///
     /// Default: **false**
     #[must_use]
-    pub const fn encode_empty_tables_as_array(mut self, enabled: bool) -> Self {
+    pub fn encode_empty_tables_as_array(mut self, enabled: bool) -> Self {
         self.options.encode_empty_tables_as_array = enabled;
         self
     }
+
+    /// If true, enable detection of mixed tables.
+    ///
+    /// A mixed table is a table that has both array-like and map-like entries or several borders.
+    ///
+    /// Default: **false**
+    #[must_use]
+    pub fn detect_mixed_tables(mut self, enabled: bool) -> Self {
+        self.options.detect_mixed_tables = enabled;
+        self
+    }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for SerializableValue<'_> {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where

src/vector.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
 
 /// A Luau vector type.
@@ -38,7 +38,6 @@ impl Vector {
     }
 
     /// Creates a new vector with all components set to `0.0`.
-    #[doc(hidden)]
     pub const fn zero() -> Self {
         Self([0.0; Self::SIZE])
     }
@@ -66,7 +65,7 @@ impl Vector {
     }
 }
 
-#[cfg(feature = "serialize")]
+#[cfg(feature = "serde")]
 impl Serialize for Vector {
     fn serialize<S: Serializer>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error> {
         let mut ts = serializer.serialize_tuple_struct("Vector", Self::SIZE)?;

tarpaulin.toml

@@ -1,23 +1,23 @@
 [lua54]
-features = "lua54,vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+features = "lua54,vendored,async,send,serde,macros,anyhow,userdata-wrappers"
 
 [lua54_non_send]
-features = "lua54,vendored,async,serialize,macros,anyhow,userdata-wrappers"
+features = "lua54,vendored,async,serde,macros,anyhow,userdata-wrappers"
 
 [lua54_with_memory_limit]
-features = "lua54,vendored,async,send,serialize,macros,anyhow,userdata-wrappers"
+features = "lua54,vendored,async,send,serde,macros,anyhow,userdata-wrappers"
 rustflags = "--cfg force_memory_limit"
 
 [lua51]
-features = "lua51,vendored,async,send,serialize,macros"
+features = "lua51,vendored,async,send,serde,macros"
 
 [lua51_with_memory_limit]
-features = "lua51,vendored,async,send,serialize,macros"
+features = "lua51,vendored,async,send,serde,macros"
 rustflags = "--cfg force_memory_limit"
 
 [luau]
-features = "luau,async,send,serialize,macros"
+features = "luau,async,send,serde,macros"
 
 [luau_with_memory_limit]
-features = "luau,async,send,serialize,macros"
+features = "luau,async,send,serde,macros"
 rustflags = "--cfg force_memory_limit"

tests/async.rs

@@ -8,8 +8,8 @@ use futures_util::stream::TryStreamExt;
 use tokio::sync::Mutex;
 
 use mlua::{
-    Error, Function, Lua, LuaOptions, MultiValue, ObjectLike, Result, StdLib, Table, UserData,
-    UserDataMethods, Value,
+    Error, Function, Lua, LuaOptions, MultiValue, ObjectLike, Result, StdLib, Table, ThreadStatus, UserData,
+    UserDataMethods, UserDataRef, Value,
 };
 
 #[cfg(not(target_arch = "wasm32"))]
@@ -273,7 +273,7 @@ async fn test_async_lua54_to_be_closed() -> Result<()> {
 
     // Don't close by default when awaiting async threads
     let co = lua.create_thread(f.clone())?;
-    let _ = co.clone().into_async::<()>(()).await;
+    let _ = co.clone().into_async::<()>(())?.await;
     assert_eq!(globals.get::<usize>("close_count")?, 1);
     let _ = co.reset(f);
     assert_eq!(globals.get::<usize>("close_count")?, 2);
@@ -300,7 +300,7 @@ async fn test_async_thread_stream() -> Result<()> {
         .eval()?,
     )?;
 
-    let mut stream = thread.into_async::<i64>(1);
+    let mut stream = thread.into_async::<i64>(1)?;
     let mut sum = 0;
     while let Some(n) = stream.try_next().await? {
         sum += n;
@@ -325,7 +325,7 @@ async fn test_async_thread() -> Result<()> {
         }
     })?;
 
-    let res: String = lua.create_thread(f)?.into_async(()).await?;
+    let res: String = lua.create_thread(f)?.into_async(())?.await?;
 
     assert_eq!(res, "done");
 
@@ -386,7 +386,7 @@ async fn test_async_table_object_like() -> Result<()> {
             table.get::<i64>("val")
         })?,
     )?;
-    table.set_metatable(Some(metatable));
+    table.set_metatable(Some(metatable))?;
     assert_eq!(table.call_async::<i64>(()).await.unwrap(), 15);
 
     match table.call_async_method::<()>("non_existent", ()).await {
@@ -547,6 +547,7 @@ async fn test_async_thread_error() -> Result<()> {
 
 #[tokio::test]
 async fn test_async_terminate() -> Result<()> {
+    // Future captures `Lua` instance and dropped all together
     let mutex = Arc::new(Mutex::new(0u32));
     {
         let lua = Lua::new();
@@ -565,5 +566,136 @@ async fn test_async_terminate() -> Result<()> {
     }
     assert!(mutex.try_lock().is_ok());
 
+    // Future is dropped, but `Lua` instance is still alive
+    let lua = Lua::new();
+    let func = lua.create_async_function(move |_, mutex: UserDataRef<Arc<Mutex<u32>>>| async move {
+        let _guard = mutex.lock().await;
+        sleep_ms(100).await;
+        Ok(())
+    })?;
+    let mutex2 = lua.create_any_userdata(mutex.clone())?;
+    let _ = tokio::time::timeout(Duration::from_millis(30), func.call_async::<()>(mutex2)).await;
+    assert!(mutex.try_lock().is_ok());
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_async_task() -> Result<()> {
+    let lua = Lua::new();
+
+    let delay = lua.create_function(|lua, (secs, f, args): (f32, Function, MultiValue)| {
+        let thread = lua.create_thread(f)?;
+        let thread2 = thread.clone().into_async::<()>(args)?;
+        tokio::task::spawn_local(async move {
+            tokio::time::sleep(Duration::from_secs_f32(secs)).await;
+            _ = thread2.await;
+        });
+        Ok(thread)
+    })?;
+
+    lua.globals().set("delay", delay)?;
+    let local = tokio::task::LocalSet::new();
+    local
+        .run_until(async {
+            _ = lua
+                .load("delay(0.1, function(msg) global_msg = msg end, 'done')")
+                .exec_async()
+                .await;
+        })
+        .await;
+    local.await;
+    assert_eq!(lua.globals().get::<String>("global_msg")?, "done");
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_async_task_abort() -> Result<()> {
+    let lua = Lua::new();
+
+    let sleep = lua.create_async_function(move |_lua, n: u64| async move {
+        sleep_ms(n).await;
+        Ok(())
+    })?;
+    lua.globals().set("sleep", sleep)?;
+
+    let local = tokio::task::LocalSet::new();
+    local
+        .run_until(async {
+            let lua2 = lua.clone();
+            let jh = tokio::task::spawn_local(async move {
+                lua2.load("sleep(200) result = 'done'")
+                    .exec_async()
+                    .await
+                    .unwrap();
+            });
+            sleep_ms(100).await; // Wait for the task to start
+            jh.abort();
+        })
+        .await;
+    local.await;
+    assert_eq!(lua.globals().get::<Value>("result")?, Value::Nil);
+
+    Ok(())
+}
+
+#[tokio::test]
+#[cfg(not(feature = "luau"))]
+async fn test_async_hook() -> Result<()> {
+    use std::sync::atomic::{AtomicBool, Ordering};
+
+    let lua = Lua::new();
+
+    static HOOK_CALLED: AtomicBool = AtomicBool::new(false);
+    lua.set_global_hook(mlua::HookTriggers::new().every_line(), move |_, _| {
+        if !HOOK_CALLED.swap(true, Ordering::Relaxed) {
+            #[cfg(any(feature = "lu53", feature = "lua54"))]
+            return Ok(mlua::VmState::Yield);
+        }
+        Ok(mlua::VmState::Continue)
+    })?;
+
+    let sleep = lua.create_async_function(move |_lua, n: u64| async move {
+        sleep_ms(n).await;
+        Ok(())
+    })?;
+    lua.globals().set("sleep", sleep)?;
+
+    lua.load(r"sleep(100)").exec_async().await?;
+    assert!(HOOK_CALLED.load(Ordering::Relaxed));
+
+    Ok(())
+}
+
+#[test]
+fn test_async_yield_with() -> Result<()> {
+    let lua = Lua::new();
+
+    let func = lua.create_async_function(|lua, (mut a, mut b): (i32, i32)| async move {
+        let zero = lua.yield_with::<MultiValue>(()).await?;
+        assert!(zero.is_empty());
+        let one = lua.yield_with::<MultiValue>(a + b).await?;
+        assert_eq!(one.len(), 1);
+
+        for _ in 0..3 {
+            (a, b) = lua.yield_with((a + b, a * b)).await?;
+        }
+        Ok((0, 0))
+    })?;
+
+    let thread = lua.create_thread(func)?;
+
+    let zero = thread.resume::<MultiValue>((2, 3))?; // function arguments
+    assert!(zero.is_empty());
+    let one = thread.resume::<i32>(())?; // value of "zero" is passed here
+    assert_eq!(one, 5);
+
+    assert_eq!(thread.resume::<(i32, i32)>(1)?, (5, 6)); // value of "one" is passed here
+    assert_eq!(thread.resume::<(i32, i32)>((10, 11))?, (21, 110));
+    assert_eq!(thread.resume::<(i32, i32)>((11, 12))?, (23, 132));
+    assert_eq!(thread.resume::<(i32, i32)>((12, 13))?, (0, 0));
+    assert_eq!(thread.status(), ThreadStatus::Finished);
+
     Ok(())
 }

tests/buffer.rs

@@ -1,5 +1,7 @@
 #![cfg(feature = "luau")]
 
+use std::io::{Read, Seek, SeekFrom, Write};
+
 use mlua::{Lua, Result, Value};
 
 #[test]
@@ -41,7 +43,7 @@ fn test_buffer() -> Result<()> {
 }
 
 #[test]
-#[should_panic(expected = "range end index 14 out of range for slice of length 13")]
+#[should_panic(expected = "out of range for slice of length 13")]
 fn test_buffer_out_of_bounds_read() {
     let lua = Lua::new();
     let buf = lua.create_buffer(b"hello, world!").unwrap();
@@ -49,9 +51,73 @@ fn test_buffer_out_of_bounds_read() {
 }
 
 #[test]
-#[should_panic(expected = "range end index 16 out of range for slice of length 13")]
+#[should_panic(expected = "out of range for slice of length 13")]
 fn test_buffer_out_of_bounds_write() {
     let lua = Lua::new();
     let buf = lua.create_buffer(b"hello, world!").unwrap();
     buf.write_bytes(14, b"!!");
 }
+
+#[test]
+fn create_large_buffer() {
+    let lua = Lua::new();
+    let err = lua.create_buffer_with_capacity(1_073_741_824 + 1).unwrap_err(); // 1GB
+    assert!(err.to_string().contains("memory allocation error"));
+
+    // Normal buffer is okay
+    let buf = lua.create_buffer_with_capacity(1024 * 1024).unwrap();
+    assert_eq!(buf.len(), 1024 * 1024);
+}
+
+#[test]
+fn test_buffer_cursor() -> Result<()> {
+    let lua = Lua::new();
+    let mut cursor = lua.create_buffer(b"hello, world")?.cursor();
+
+    let mut data = Vec::new();
+    cursor.read_to_end(&mut data)?;
+    assert_eq!(data, b"hello, world");
+
+    // No more data to read
+    let mut one = [0u8; 1];
+    assert_eq!(cursor.read(&mut one)?, 0);
+
+    // Seek to start
+    cursor.seek(SeekFrom::Start(0))?;
+    cursor.read_exact(&mut one)?;
+    assert_eq!(one, [b'h']);
+
+    // Seek to end -5
+    cursor.seek(SeekFrom::End(-5))?;
+    let mut five = [0u8; 5];
+    cursor.read_exact(&mut five)?;
+    assert_eq!(&five, b"world");
+
+    // Seek to current -1
+    cursor.seek(SeekFrom::Current(-1))?;
+    cursor.read_exact(&mut one)?;
+    assert_eq!(one, [b'd']);
+
+    // Invalid seek
+    assert!(cursor.seek(SeekFrom::Current(-100)).is_err());
+    assert!(cursor.seek(SeekFrom::End(1)).is_err());
+
+    // Write data
+    let buf = lua.create_buffer_with_capacity(100)?;
+    cursor = buf.clone().cursor();
+
+    cursor.write_all(b"hello, ...")?;
+    cursor.seek(SeekFrom::Current(-3))?;
+    cursor.write_all(b"Rust!")?;
+
+    assert_eq!(&buf.read_bytes::<12>(0), b"hello, Rust!");
+
+    // Writing beyond the end of the buffer does nothing
+    cursor.seek(SeekFrom::End(0))?;
+    assert_eq!(cursor.write(b".")?, 0);
+
+    // Flush is no-op
+    cursor.flush()?;
+
+    Ok(())
+}

tests/chunk.rs

@@ -7,7 +7,7 @@ fn test_chunk_methods() -> Result<()> {
     let lua = Lua::new();
 
     #[cfg(unix)]
-    assert!(lua.load("return 123").name().contains("tests/chunk.rs"));
+    assert!(lua.load("return 123").name().starts_with("@tests/chunk.rs"));
     let chunk2 = lua.load("return 123").set_name("@new_name");
     assert_eq!(chunk2.name(), "@new_name");
 
@@ -114,20 +114,18 @@ fn test_chunk_macro() -> Result<()> {
 #[cfg(feature = "luau")]
 #[test]
 fn test_compiler() -> Result<()> {
-    use std::vec;
-
     let compiler = mlua::Compiler::new()
         .set_optimization_level(2)
         .set_debug_level(2)
         .set_type_info_level(1)
         .set_coverage_level(2)
-        .set_vector_lib("vector")
-        .set_vector_ctor("new")
+        .set_vector_ctor("vector.new")
         .set_vector_type("vector")
-        .set_mutable_globals(vec!["mutable_global".into()])
-        .set_userdata_types(vec!["MyUserdata".into()]);
+        .set_mutable_globals(["mutable_global"])
+        .set_userdata_types(["MyUserdata"])
+        .set_disabled_builtins(["tostring"]);
 
-    assert!(compiler.compile("return vector.new(1, 2, 3)").is_ok());
+    assert!(compiler.compile("return tostring(vector.new(1, 2, 3))").is_ok());
 
     // Error
     match compiler.compile("%") {
@@ -140,6 +138,30 @@ fn test_compiler() -> Result<()> {
     Ok(())
 }
 
+#[cfg(feature = "luau")]
+#[test]
+fn test_compiler_library_constants() {
+    use mlua::{Compiler, Vector};
+
+    let compiler = Compiler::new()
+        .set_optimization_level(2)
+        .add_library_constant("mylib.const_bool", true)
+        .add_library_constant("mylib.const_num", 123.0)
+        .add_library_constant("mylib.const_vec", Vector::zero())
+        .add_library_constant("mylib.const_str", "value1");
+
+    let lua = Lua::new();
+    lua.set_compiler(compiler);
+    let const_bool = lua.load("return mylib.const_bool").eval::<bool>().unwrap();
+    assert_eq!(const_bool, true);
+    let const_num = lua.load("return mylib.const_num").eval::<f64>().unwrap();
+    assert_eq!(const_num, 123.0);
+    let const_vec = lua.load("return mylib.const_vec").eval::<Vector>().unwrap();
+    assert_eq!(const_vec, Vector::zero());
+    let const_str = lua.load("return mylib.const_str").eval::<String>();
+    assert_eq!(const_str.unwrap(), "value1");
+}
+
 #[test]
 fn test_chunk_wrap() -> Result<()> {
     let lua = Lua::new();

tests/conversion.rs

@@ -1,6 +1,6 @@
 use std::borrow::Cow;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
-use std::ffi::{CStr, CString, OsString};
+use std::ffi::{CString, OsString};
 use std::path::PathBuf;
 
 use bstr::BString;
@@ -267,7 +267,7 @@ fn test_registry_value_into_lua() -> Result<()> {
     let r = lua.create_registry_value(&s)?;
     let value1 = lua.pack(&r)?;
     let value2 = lua.pack(r)?;
-    assert_eq!(value1.as_str().as_deref(), Some("hello, world"));
+    assert_eq!(value1.to_string()?, "hello, world");
     assert_eq!(value1.to_pointer(), value2.to_pointer());
 
     // Push into stack
@@ -450,8 +450,8 @@ fn test_conv_cstring() -> Result<()> {
     let s2: CString = lua.globals().get("s")?;
     assert_eq!(s, s2);
 
-    let cs = CStr::from_bytes_with_nul(b"hello\0").unwrap();
-    lua.globals().set("cs", cs)?;
+    let cs = c"hello";
+    lua.globals().set("cs", c"hello")?;
     let cs2: CString = lua.globals().get("cs")?;
     assert_eq!(cs, cs2.as_c_str());
 
@@ -560,11 +560,11 @@ fn test_osstring_into_from_lua() -> Result<()> {
 
     let v = lua.pack(s.as_os_str())?;
     assert!(v.is_string());
-    assert_eq!(v.as_str().unwrap(), "hello, world");
+    assert_eq!(v.as_string().unwrap(), "hello, world");
 
     let v = lua.pack(s)?;
     assert!(v.is_string());
-    assert_eq!(v.as_str().unwrap(), "hello, world");
+    assert_eq!(v.as_string().unwrap(), "hello, world");
 
     let s = lua.create_string("hello, world")?;
     let bstr = lua.unpack::<OsString>(Value::String(s))?;
@@ -588,11 +588,11 @@ fn test_pathbuf_into_from_lua() -> Result<()> {
 
     let v = lua.pack(pb.as_path())?;
     assert!(v.is_string());
-    assert_eq!(v.as_str().unwrap(), pb_str);
+    assert_eq!(v.to_string().unwrap(), pb_str);
 
     let v = lua.pack(pb.clone())?;
     assert!(v.is_string());
-    assert_eq!(v.as_str().unwrap(), pb_str);
+    assert_eq!(v.to_string().unwrap(), pb_str);
 
     let s = lua.create_string(pb_str)?;
     let bstr = lua.unpack::<PathBuf>(Value::String(s))?;
@@ -724,7 +724,7 @@ fn test_char_into_lua() -> Result<()> {
 
     let v = '🦀';
     let v2 = v.into_lua(&lua)?;
-    assert_eq!(Some(v.to_string()), v2.as_string_lossy());
+    assert_eq!(*v2.as_string().unwrap(), v.to_string());
 
     Ok(())
 }

tests/function.rs

@@ -306,7 +306,7 @@ fn test_function_deep_clone() -> Result<()> {
 
     lua.globals().set("a", 1)?;
     let func1 = lua.load("a += 1; return a").into_function()?;
-    let func2 = func1.deep_clone();
+    let func2 = func1.deep_clone()?;
 
     assert_ne!(func1.to_pointer(), func2.to_pointer());
     assert_eq!(func1.call::<i32>(())?, 2);
@@ -314,7 +314,7 @@ fn test_function_deep_clone() -> Result<()> {
 
     // Check that for Rust functions deep_clone is just a clone
     let rust_func = lua.create_function(|_, ()| Ok(42))?;
-    let rust_func2 = rust_func.deep_clone();
+    let rust_func2 = rust_func.deep_clone()?;
     assert_eq!(rust_func.to_pointer(), rust_func2.to_pointer());
 
     Ok(())

tests/hooks.rs

@@ -1,6 +1,5 @@
 #![cfg(not(feature = "luau"))]
 
-use std::ops::Deref;
 use std::sync::atomic::{AtomicI64, Ordering};
 use std::sync::{Arc, Mutex};
 
@@ -25,9 +24,9 @@ fn test_line_counts() -> Result<()> {
     let lua = Lua::new();
     lua.set_hook(HookTriggers::EVERY_LINE, move |_lua, debug| {
         assert_eq!(debug.event(), DebugEvent::Line);
-        hook_output.lock().unwrap().push(debug.curr_line());
+        hook_output.lock().unwrap().push(debug.current_line().unwrap());
         Ok(VmState::Continue)
-    });
+    })?;
     lua.load(
         r#"
             local x = 2 + 3
@@ -62,7 +61,7 @@ fn test_function_calls() -> Result<()> {
         let name = names.name.map(|s| s.into_owned());
         hook_output.lock().unwrap().push((name, source.what));
         Ok(VmState::Continue)
-    });
+    })?;
 
     lua.load(
         r#"
@@ -101,17 +100,13 @@ fn test_error_within_hook() -> Result<()> {
 
     lua.set_hook(HookTriggers::EVERY_LINE, |_lua, _debug| {
         Err(Error::runtime("Something happened in there!"))
-    });
+    })?;
 
     let err = lua.load("x = 1").exec().expect_err("panic didn't propagate");
-
     match err {
-        Error::CallbackError { cause, .. } => match cause.deref() {
-            Error::RuntimeError(s) => assert_eq!(s, "Something happened in there!"),
-            _ => panic!("wrong callback error kind caught"),
-        },
-        _ => panic!("wrong error kind caught"),
-    };
+        Error::RuntimeError(msg) => assert_eq!(msg, "Something happened in there!"),
+        err => panic!("expected `RuntimeError` with a specific message, got {err:?}"),
+    }
 
     Ok(())
 }
@@ -135,7 +130,7 @@ fn test_limit_execution_instructions() -> Result<()> {
                 Ok(VmState::Continue)
             }
         },
-    );
+    )?;
 
     lua.globals().set("x", Value::Integer(0))?;
     let _ = lua
@@ -158,7 +153,7 @@ fn test_hook_removal() -> Result<()> {
 
     lua.set_hook(HookTriggers::new().every_nth_instruction(1), |_lua, _debug| {
         Err(Error::runtime("this hook should've been removed by this time"))
-    });
+    })?;
 
     assert!(lua.load("local x = 1").exec().is_err());
     lua.remove_hook();
@@ -205,10 +200,10 @@ fn test_hook_swap_within_hook() -> Result<()> {
                             });
                             Ok(VmState::Continue)
                         })
-                });
+                })?;
                 Ok(VmState::Continue)
             })
-    });
+    })?;
 
     TL_LUA.with(|tl| {
         let tl = tl.borrow();
@@ -245,9 +240,9 @@ fn test_hook_threads() -> Result<()> {
     let hook_output = output.clone();
     co.set_hook(HookTriggers::EVERY_LINE, move |_lua, debug| {
         assert_eq!(debug.event(), DebugEvent::Line);
-        hook_output.lock().unwrap().push(debug.curr_line());
+        hook_output.lock().unwrap().push(debug.current_line().unwrap());
         Ok(VmState::Continue)
-    });
+    })?;
 
     co.resume::<()>(())?;
     lua.remove_hook();
@@ -277,7 +272,7 @@ fn test_hook_yield() -> Result<()> {
         .into_function()?;
     let co = lua.create_thread(func)?;
 
-    co.set_hook(HookTriggers::EVERY_LINE, move |_lua, _debug| Ok(VmState::Yield));
+    co.set_hook(HookTriggers::EVERY_LINE, move |_lua, _debug| Ok(VmState::Yield))?;
 
     #[cfg(any(feature = "lua54", feature = "lua53"))]
     {
@@ -297,3 +292,36 @@ fn test_hook_yield() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn test_global_hook() -> Result<()> {
+    let lua = Lua::new();
+
+    let counter = Arc::new(AtomicI64::new(0));
+    let hook_counter = counter.clone();
+    lua.set_global_hook(HookTriggers::EVERY_LINE, move |_lua, debug| {
+        assert_eq!(debug.event(), DebugEvent::Line);
+        hook_counter.fetch_add(1, Ordering::Relaxed);
+        Ok(VmState::Continue)
+    })?;
+
+    let thread = lua.create_thread(
+        lua.load(
+            r#"
+            local x = 2 + 3
+            local y = x * 63
+            coroutine.yield()
+            local z = string.len(x..", "..y)
+        "#,
+        )
+        .into_function()?,
+    )?;
+
+    thread.resume::<()>(()).unwrap();
+    lua.remove_global_hook();
+    thread.resume::<()>(()).unwrap();
+    assert_eq!(thread.status(), ThreadStatus::Finished);
+    assert_eq!(counter.load(Ordering::Relaxed), 3);
+
+    Ok(())
+}

tests/luau.rs

@@ -1,12 +1,14 @@
 #![cfg(feature = "luau")]
 
+use std::cell::Cell;
 use std::fmt::Debug;
-use std::fs;
-use std::panic::{catch_unwind, AssertUnwindSafe};
-use std::sync::atomic::{AtomicU64, Ordering};
+use std::os::raw::c_void;
+use std::sync::atomic::{AtomicBool, AtomicPtr, AtomicU64, Ordering};
 use std::sync::Arc;
 
-use mlua::{Compiler, Error, Lua, LuaOptions, Result, StdLib, Table, ThreadStatus, Value, Vector, VmState};
+use mlua::{
+    Compiler, Error, Function, Lua, LuaOptions, Result, StdLib, Table, ThreadStatus, Value, Vector, VmState,
+};
 
 #[test]
 fn test_version() -> Result<()> {
@@ -15,83 +17,6 @@ fn test_version() -> Result<()> {
     Ok(())
 }
 
-#[test]
-fn test_require() -> Result<()> {
-    // Ensure that require() is not available if package module is not loaded
-    let mut lua = Lua::new_with(StdLib::NONE, LuaOptions::default())?;
-    assert!(lua.globals().get::<Option<Value>>("require")?.is_none());
-    assert!(lua.globals().get::<Option<Value>>("package")?.is_none());
-
-    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(());
-    }
-
-    lua = Lua::new();
-
-    // Check that require() can load stdlib modules (including `package`)
-    lua.load(
-        r#"
-        local math = require("math")
-        assert(math == _G.math, "math module does not match _G.math")
-        local package = require("package")
-        assert(package == _G.package, "package module does not match _G.package")
-    "#,
-    )
-    .exec()?;
-
-    let temp_dir = tempfile::tempdir().unwrap();
-    fs::write(
-        temp_dir.path().join("module.luau"),
-        r#"
-        counter = (counter or 0) + 1
-        return {
-            counter = counter,
-            error = function() error("test") end,
-        }
-    "#,
-    )?;
-
-    lua.globals()
-        .get::<Table>("package")?
-        .set("path", temp_dir.path().join("?.luau").to_string_lossy())?;
-
-    lua.load(
-        r#"
-        local module = require("module")
-        assert(module.counter == 1)
-        module = require("module")
-        assert(module.counter == 1)
-
-        local ok, err = pcall(module.error)
-        assert(not ok and string.find(err, "module.luau") ~= nil)
-    "#,
-    )
-    .exec()?;
-
-    // Require non-existent module
-    match lua.load("require('non-existent')").exec() {
-        Err(Error::RuntimeError(e)) if e.contains("module 'non-existent' not found") => {}
-        r => panic!("expected RuntimeError(...) with a specific message, got {r:?}"),
-    }
-
-    // Require binary module in safe mode
-    lua.globals()
-        .get::<Table>("package")?
-        .set("cpath", temp_dir.path().join("?.so").to_string_lossy())?;
-    fs::write(temp_dir.path().join("dylib.so"), "")?;
-    match lua.load("require('dylib')").exec() {
-        Err(Error::RuntimeError(e)) if cfg!(unix) && e.contains("module 'dylib' not found") => {
-            assert!(e.contains("dynamic libraries are disabled in safe mode"))
-        }
-        Err(Error::RuntimeError(e)) if e.contains("module 'dylib' not found") => {}
-        r => panic!("expected RuntimeError(...) with a specific message, got {r:?}"),
-    }
-
-    Ok(())
-}
-
 #[cfg(not(feature = "luau-vector4"))]
 #[test]
 fn test_vectors() -> Result<()> {
@@ -194,11 +119,13 @@ fn test_vector_metatable() -> Result<()> {
     "#,
         )
         .eval::<Table>()?;
-    vector_mt.set_metatable(Some(vector_mt.clone()));
+    vector_mt.set_metatable(Some(vector_mt.clone()))?;
     lua.set_type_metatable::<Vector>(Some(vector_mt.clone()));
     lua.globals().set("Vector3", vector_mt)?;
 
-    let compiler = Compiler::new().set_vector_lib("Vector3").set_vector_ctor("new");
+    let compiler = Compiler::new()
+        .set_vector_ctor("Vector3.new")
+        .set_vector_type("Vector3");
 
     // Test vector methods (fastcall)
     lua.load(
@@ -241,9 +168,9 @@ fn test_readonly_table() -> Result<()> {
     check_readonly_error(t.raw_pop::<Value>());
 
     // Special case
-    match catch_unwind(AssertUnwindSafe(|| t.set_metatable(None))) {
-        Ok(_) => panic!("expected panic, got nothing"),
-        Err(_) => {}
+    match t.set_metatable(None) {
+        Err(Error::RuntimeError(e)) if e.contains("attempt to modify a readonly table") => {}
+        r => panic!("expected RuntimeError(...) with a specific message, got {r:?}"),
     }
 
     Ok(())
@@ -270,6 +197,14 @@ fn test_sandbox() -> Result<()> {
     co.sandbox()?;
     assert_eq!(co.resume::<Option<i32>>(())?, Some(123));
 
+    // collectgarbage should be restricted in sandboxed mode
+    let collectgarbage = lua.globals().get::<Function>("collectgarbage")?;
+    for arg in ["collect", "stop", "restart", "step", "isrunning"] {
+        let err = collectgarbage.call::<()>(arg).err().unwrap().to_string();
+        assert!(err.contains("collectgarbage called with invalid option"));
+    }
+    assert!(collectgarbage.call::<u64>("count").unwrap() > 0);
+
     lua.sandbox(false)?;
 
     // Previously set variable `global` should be cleared now
@@ -279,6 +214,11 @@ fn test_sandbox() -> Result<()> {
     let table = lua.globals().get::<Table>("table")?;
     table.set("test", "test")?;
 
+    // collectgarbage should work now
+    for arg in ["collect", "stop", "restart", "count", "step", "isrunning"] {
+        collectgarbage.call::<()>(arg).unwrap();
+    }
+
     Ok(())
 }
 
@@ -390,16 +330,22 @@ fn test_interrupts() -> Result<()> {
     assert_eq!(yield_count.load(Ordering::Relaxed), 7);
     assert_eq!(co.status(), ThreadStatus::Finished);
 
+    // Test no yielding at non-yieldable points
+    yield_count.store(0, Ordering::Relaxed);
+    let co = lua.create_thread(lua.create_function(|lua, arg: Value| {
+        (lua.load("return (function(x) return x end)(...)")).call::<Value>(arg)
+    })?)?;
+    let res = co.resume::<String>("abc")?;
+    assert_eq!(res, "abc".to_string());
+    assert_eq!(yield_count.load(Ordering::Relaxed), 3);
+
     //
     // Test errors in interrupts
     //
     lua.set_interrupt(|_| Err(Error::runtime("error from interrupt")));
     match f.call::<()>(()) {
-        Err(Error::CallbackError { cause, .. }) => match *cause {
-            Error::RuntimeError(ref m) if m == "error from interrupt" => {}
-            ref e => panic!("expected RuntimeError with a specific message, got {:?}", e),
-        },
-        r => panic!("expected CallbackError, got {:?}", r),
+        Err(Error::RuntimeError(ref msg)) => assert_eq!(msg, "error from interrupt"),
+        res => panic!("expected `RuntimeError` with a specific message, got {res:?}"),
     }
 
     lua.remove_interrupt();
@@ -412,3 +358,117 @@ fn test_fflags() {
     // We cannot really on any particular feature flag to be present
     assert!(Lua::set_fflag("UnknownFlag", true).is_err());
 }
+
+#[test]
+fn test_thread_events() -> Result<()> {
+    let lua = Lua::new();
+
+    let count = Arc::new(AtomicU64::new(0));
+    let thread_data: Arc<(AtomicPtr<c_void>, AtomicBool)> = Arc::new(Default::default());
+
+    let (count2, thread_data2) = (count.clone(), thread_data.clone());
+    lua.set_thread_creation_callback(move |_, thread| {
+        count2.fetch_add(1, Ordering::Relaxed);
+        (thread_data2.0).store(thread.to_pointer() as *mut _, Ordering::Relaxed);
+        thread_data2.1.store(false, Ordering::Relaxed);
+        Ok(())
+    });
+    let (count3, thread_data3) = (count.clone(), thread_data.clone());
+    lua.set_thread_collection_callback(move |thread_ptr| {
+        count3.fetch_add(1, Ordering::Relaxed);
+        if thread_data3.0.load(Ordering::Relaxed) == thread_ptr.0 {
+            thread_data3.1.store(true, Ordering::Relaxed);
+        }
+    });
+
+    let t = lua.create_thread(lua.load("return 123").into_function()?)?;
+    assert_eq!(count.load(Ordering::Relaxed), 1);
+    let t_ptr = t.to_pointer();
+    assert_eq!(t_ptr, thread_data.0.load(Ordering::Relaxed));
+    assert!(!thread_data.1.load(Ordering::Relaxed));
+
+    // Thead will be destroyed after GC cycle
+    drop(t);
+    lua.gc_collect()?;
+    assert_eq!(count.load(Ordering::Relaxed), 2);
+    assert_eq!(t_ptr, thread_data.0.load(Ordering::Relaxed));
+    assert!(thread_data.1.load(Ordering::Relaxed));
+
+    // Check that recursion is not allowed
+    let count4 = count.clone();
+    lua.set_thread_creation_callback(move |lua, _value| {
+        count4.fetch_add(1, Ordering::Relaxed);
+        let _ = lua.create_thread(lua.load("return 123").into_function().unwrap())?;
+        Ok(())
+    });
+    let t = lua.create_thread(lua.load("return 123").into_function()?)?;
+    assert_eq!(count.load(Ordering::Relaxed), 3);
+
+    lua.remove_thread_callbacks();
+    drop(t);
+    lua.gc_collect()?;
+    assert_eq!(count.load(Ordering::Relaxed), 3);
+
+    // Test error inside callback
+    lua.set_thread_creation_callback(move |_, _| Err(Error::runtime("error when processing thread event")));
+    let result = lua.create_thread(lua.load("return 123").into_function()?);
+    assert!(result.is_err());
+    assert!(
+        matches!(result, Err(Error::RuntimeError(err)) if err.contains("error when processing thread event"))
+    );
+
+    // Test context switch when running Lua script
+    let count = Cell::new(0);
+    lua.set_thread_creation_callback(move |_, _| {
+        count.set(count.get() + 1);
+        if count.get() == 2 {
+            return Err(Error::runtime("thread limit exceeded"));
+        }
+        Ok(())
+    });
+    let result = lua
+        .load(
+            r#"
+            local co = coroutine.wrap(function() return coroutine.create(print) end)
+            co()
+    "#,
+        )
+        .exec();
+    assert!(result.is_err());
+    assert!(matches!(result, Err(Error::RuntimeError(err)) if err.contains("thread limit exceeded")));
+
+    Ok(())
+}
+
+#[test]
+fn test_loadstring() -> Result<()> {
+    let lua = Lua::new();
+
+    let f = lua.load(r#"loadstring("return 123")"#).eval::<Function>()?;
+    assert_eq!(f.call::<i32>(())?, 123);
+
+    let err = lua
+        .load(r#"loadstring("retur 123", "chunk")"#)
+        .exec()
+        .err()
+        .unwrap();
+    assert!(err.to_string().contains(
+        r#"syntax error: [string "chunk"]:1: Incomplete statement: expected assignment or a function call"#
+    ));
+
+    Ok(())
+}
+
+#[test]
+fn test_typeof_error() -> Result<()> {
+    let lua = Lua::new();
+
+    let err = Error::runtime("just a test error");
+    let res = lua.load("return typeof(...)").call::<String>(err)?;
+    assert_eq!(res, "error");
+
+    Ok(())
+}
+
+#[path = "luau/require.rs"]
+mod require;

tests/luau/require.rs

@@ -0,0 +1,248 @@
+use std::io::Result as IoResult;
+use std::result::Result as StdResult;
+
+use mlua::{Error, IntoLua, Lua, MultiValue, NavigateError, Require, Result, TextRequirer, Value};
+
+fn run_require(lua: &Lua, path: impl IntoLua) -> Result<Value> {
+    lua.load(r#"return require(...)"#).call(path)
+}
+
+fn run_require_pcall(lua: &Lua, path: impl IntoLua) -> Result<MultiValue> {
+    lua.load(r#"return pcall(require, ...)"#).call(path)
+}
+
+#[track_caller]
+fn get_str(value: &Value, key: impl IntoLua) -> String {
+    value.as_table().unwrap().get::<String>(key).unwrap()
+}
+
+#[test]
+fn test_require_errors() {
+    let lua = Lua::new();
+
+    // RequireAbsolutePath
+    let res = run_require(&lua, "/an/absolute/path");
+    assert!(res.is_err());
+    assert!(
+        (res.unwrap_err().to_string()).contains("require path must start with a valid prefix: ./, ../, or @")
+    );
+
+    // RequireUnprefixedPath
+    let res = run_require(&lua, "an/unprefixed/path");
+    assert!(res.is_err());
+    assert!(
+        (res.unwrap_err().to_string()).contains("require path must start with a valid prefix: ./, ../, or @")
+    );
+
+    // Pass non-string to require
+    let res = run_require(&lua, true);
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string())
+        .contains("bad argument #1 to 'require' (string expected, got boolean)"));
+
+    // Require from loadstring
+    let res = lua
+        .load(r#"return loadstring("require('./a/relative/path')")()"#)
+        .eval::<Value>();
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string()).contains("require is not supported in this context"));
+
+    // Test throwing mlua::Error
+    struct MyRequire(TextRequirer);
+
+    impl Require for MyRequire {
+        fn is_require_allowed(&self, chunk_name: &str) -> bool {
+            self.0.is_require_allowed(chunk_name)
+        }
+
+        fn reset(&mut self, _chunk_name: &str) -> StdResult<(), NavigateError> {
+            Err(Error::runtime("test error"))?
+        }
+
+        fn jump_to_alias(&mut self, path: &str) -> StdResult<(), NavigateError> {
+            self.0.jump_to_alias(path)
+        }
+
+        fn to_parent(&mut self) -> StdResult<(), NavigateError> {
+            self.0.to_parent()
+        }
+
+        fn to_child(&mut self, name: &str) -> StdResult<(), NavigateError> {
+            self.0.to_child(name)
+        }
+
+        fn has_module(&self) -> bool {
+            self.0.has_module()
+        }
+
+        fn cache_key(&self) -> String {
+            self.0.cache_key()
+        }
+
+        fn has_config(&self) -> bool {
+            self.0.has_config()
+        }
+
+        fn config(&self) -> IoResult<Vec<u8>> {
+            self.0.config()
+        }
+
+        fn loader(&self, lua: &Lua) -> Result<mlua::Function> {
+            self.0.loader(lua)
+        }
+    }
+
+    let require = lua
+        .create_require_function(MyRequire(TextRequirer::new()))
+        .unwrap();
+    lua.globals().set("require", require).unwrap();
+    let res = lua.load(r#"return require('./a/relative/path')"#).exec();
+    assert!((res.unwrap_err().to_string()).contains("test error"));
+}
+
+#[test]
+fn test_require_without_config() {
+    let lua = Lua::new();
+
+    // RequireSimpleRelativePath
+    let res = run_require(&lua, "./tests/luau/require/without_config/dependency").unwrap();
+    assert_eq!("result from dependency", get_str(&res, 1));
+
+    // RequireSimpleRelativePathWithinPcall
+    let res = run_require_pcall(&lua, "./tests/luau/require/without_config/dependency").unwrap();
+    assert!(res[0].as_boolean().unwrap());
+    assert_eq!("result from dependency", get_str(&res[1], 1));
+
+    // RequireRelativeToRequiringFile
+    let res = run_require(&lua, "./tests/luau/require/without_config/module").unwrap();
+    assert_eq!("result from dependency", get_str(&res, 1));
+    assert_eq!("required into module", get_str(&res, 2));
+
+    // RequireLua
+    let res = run_require(&lua, "./tests/luau/require/without_config/lua_dependency").unwrap();
+    assert_eq!("result from lua_dependency", get_str(&res, 1));
+
+    // RequireInitLuau
+    let res = run_require(&lua, "./tests/luau/require/without_config/luau").unwrap();
+    assert_eq!("result from init.luau", get_str(&res, 1));
+
+    // RequireInitLua
+    let res = run_require(&lua, "./tests/luau/require/without_config/lua").unwrap();
+    assert_eq!("result from init.lua", get_str(&res, 1));
+
+    // RequireSubmoduleUsingSelfIndirectly
+    let res = run_require(&lua, "./tests/luau/require/without_config/nested_module_requirer").unwrap();
+    assert_eq!("result from submodule", get_str(&res, 1));
+
+    // RequireSubmoduleUsingSelfDirectly
+    let res = run_require(&lua, "./tests/luau/require/without_config/nested").unwrap();
+    assert_eq!("result from submodule", get_str(&res, 1));
+
+    // CannotRequireInitLuauDirectly
+    let res = run_require(&lua, "./tests/luau/require/without_config/nested/init");
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string()).contains("could not resolve child component \"init\""));
+
+    // RequireNestedInits
+    let res = run_require(&lua, "./tests/luau/require/without_config/nested_inits_requirer").unwrap();
+    assert_eq!("result from nested_inits/init", get_str(&res, 1));
+    assert_eq!("required into module", get_str(&res, 2));
+
+    // RequireWithFileAmbiguity
+    let res = run_require(
+        &lua,
+        "./tests/luau/require/without_config/ambiguous_file_requirer",
+    );
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string())
+        .contains("could not resolve child component \"dependency\" (ambiguous)"));
+
+    // RequireWithDirectoryAmbiguity
+    let res = run_require(
+        &lua,
+        "./tests/luau/require/without_config/ambiguous_directory_requirer",
+    );
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string())
+        .contains("could not resolve child component \"dependency\" (ambiguous)"));
+
+    // CheckCachedResult
+    let res = run_require(&lua, "./tests/luau/require/without_config/validate_cache").unwrap();
+    assert!(res.is_table());
+}
+
+#[test]
+fn test_require_with_config() {
+    let lua = Lua::new();
+
+    // RequirePathWithAlias
+    let res = run_require(&lua, "./tests/luau/require/with_config/src/alias_requirer").unwrap();
+    assert_eq!("result from dependency", get_str(&res, 1));
+
+    // RequirePathWithAlias (case-insensitive)
+    let res2 = run_require(&lua, "./tests/luau/require/with_config/src/alias_requirer_uc").unwrap();
+    assert_eq!("result from dependency", get_str(&res2, 1));
+    assert_eq!(res.to_pointer(), res2.to_pointer());
+
+    // RequirePathWithParentAlias
+    let res = run_require(&lua, "./tests/luau/require/with_config/src/parent_alias_requirer").unwrap();
+    assert_eq!("result from other_dependency", get_str(&res, 1));
+
+    // RequirePathWithAliasPointingToDirectory
+    let res = run_require(
+        &lua,
+        "./tests/luau/require/with_config/src/directory_alias_requirer",
+    )
+    .unwrap();
+    assert_eq!("result from subdirectory_dependency", get_str(&res, 1));
+
+    // RequireAliasThatDoesNotExist
+    let res = run_require(&lua, "@this.alias.does.not.exist");
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string()).contains("@this.alias.does.not.exist is not a valid alias"));
+
+    // IllegalAlias
+    let res = run_require(&lua, "@");
+    assert!(res.is_err());
+    assert!((res.unwrap_err().to_string()).contains("@ is not a valid alias"));
+}
+
+#[cfg(all(feature = "async", not(windows)))]
+#[tokio::test]
+async fn test_async_require() -> Result<()> {
+    let lua = Lua::new();
+
+    let temp_dir = tempfile::tempdir().unwrap();
+    let temp_path = temp_dir.path().join("async_chunk.luau");
+    std::fs::write(
+        &temp_path,
+        r#"
+        sleep_ms(10)
+        return "result_after_async_sleep"
+    "#,
+    )
+    .unwrap();
+
+    lua.globals().set(
+        "sleep_ms",
+        lua.create_async_function(|_, ms: u64| async move {
+            tokio::time::sleep(std::time::Duration::from_millis(ms)).await;
+            Ok(())
+        })?,
+    )?;
+    lua.globals().set("tmp_dir", temp_dir.path().to_str().unwrap())?;
+    lua.globals().set(
+        "curr_dir_components",
+        std::env::current_dir().unwrap().components().count(),
+    )?;
+
+    lua.load(
+        r#"
+        local path_to_root = string.rep("/..", curr_dir_components - 1)
+        local result = require(`.{path_to_root}{tmp_dir}/async_chunk`)
+        assert(result == "result_after_async_sleep")
+        "#,
+    )
+    .exec_async()
+    .await
+}

tests/luau/require/with_config/.luaurc

@@ -0,0 +1,6 @@
+{
+    "aliases": {
+        "dep": "./this_should_be_overwritten_by_child_luaurc",
+        "otherdep": "./src/other_dependency"
+    }
+}

tests/luau/require/with_config/src/.luaurc

@@ -0,0 +1,6 @@
+{
+    "aliases": {
+        "dep": "./dependency",
+        "subdir": "./subdirectory"
+    }
+}

tests/luau/require/with_config/src/alias_requirer.luau

@@ -0,0 +1 @@
+return require("@dep")

tests/luau/require/with_config/src/alias_requirer_uc.luau

@@ -0,0 +1 @@
+return require("@DeP")

tests/luau/require/with_config/src/dependency.luau

@@ -0,0 +1 @@
+return {"result from dependency"}

tests/luau/require/with_config/src/directory_alias_requirer.luau

@@ -0,0 +1 @@
+return(require("@subdir/subdirectory_dependency"))

tests/luau/require/with_config/src/other_dependency.luau

@@ -0,0 +1 @@
+return {"result from other_dependency"}

tests/luau/require/with_config/src/parent_alias_requirer.luau

@@ -0,0 +1 @@
+return require("@otherdep")

tests/luau/require/with_config/src/subdirectory/subdirectory_dependency.luau

@@ -0,0 +1 @@
+return {"result from subdirectory_dependency"}

tests/luau/require/without_config/ambiguous/directory/dependency.luau

@@ -0,0 +1 @@
+return {"result from dependency"}

tests/luau/require/without_config/ambiguous/directory/dependency/init.luau

@@ -0,0 +1 @@
+return {"result from dependency"}

tests/luau/require/without_config/ambiguous/file/dependency.lua

@@ -0,0 +1 @@
+return {"result from dependency"}