mirror of
https://github.com/mlua-rs/mlua
synced 2026-06-08 16:05:43 +00:00
Alex Orlenko
53 lines
1.6 KiB
Markdown
53 lines
1.6 KiB
Markdown
Create a type that implements [`AsChunk`] and can capture Rust variables.
|
|
|
|
This macro allows to write Lua code directly in Rust code.
|
|
|
|
Rust variables can be referenced from Lua using `$` prefix, as shown in the example below.
|
|
User's Rust types needs to implement [`UserData`] or [`IntoLua`] traits.
|
|
|
|
Captured variables are **moved** into the chunk.
|
|
|
|
```rust
|
|
use mlua::{Lua, Result, chunk};
|
|
|
|
fn main() -> Result<()> {
|
|
let lua = Lua::new();
|
|
let name = "Rustacean";
|
|
lua.load(chunk! {
|
|
print("hello, " .. $name)
|
|
}).exec()
|
|
}
|
|
```
|
|
|
|
## Syntax issues
|
|
|
|
Since the Rust tokenizer will tokenize Lua code, this imposes some restrictions.
|
|
The main thing to remember is:
|
|
|
|
- Use double quoted strings (`""`) instead of single quoted strings (`''`).
|
|
|
|
(Single quoted strings only work if they contain a single character, since in Rust,
|
|
`'a'` is a character literal).
|
|
|
|
- Using Lua comments `--` is not desirable in **stable** Rust and can have bad side effects.
|
|
|
|
This is because procedural macros have Line/Column information available only in
|
|
**nightly** Rust. Instead, Lua chunks represented as a big single line of code in stable Rust.
|
|
|
|
As workaround, Rust comments `//` can be used.
|
|
|
|
Other minor limitations:
|
|
|
|
- Certain escape codes in string literals don't work. (Specifically: `\a`, `\b`, `\f`, `\v`,
|
|
`\123` (octal escape codes), `\u`, and `\U`).
|
|
|
|
These are accepted: : `\\`, `\n`, `\t`, `\r`, `\xAB` (hex escape codes), and `\0`.
|
|
|
|
- The `//` (floor division) operator is unusable, as its start a comment.
|
|
|
|
Everything else should work.
|
|
|
|
[`AsChunk`]: crate::chunk::AsChunk
|
|
[`UserData`]: crate::UserData
|
|
[`IntoLua`]: crate::IntoLua
|