Macro function

macro_rules! function {
    {
        $(#[$($attr: tt)*])*
        $lua: ident fn $name: ident(
            $l: ident $(: $lty: ty)?
            $(, $arg: ident : $aty: ty)*
        ) $(-> $ret: ty)? {
            $($body: tt)*
        }
    } => { ... };
    {
        $(#[$($attr: tt)*])*
        $lua: ident fn $source: ident $(::$inner: ident)* . $name: ident(
            $l: ident $(: $lty: ty)?
            $(, $arg: ident : $aty: ty)*
        ) $(-> $ret: ty)? {
            $($body: tt)*
        }
    } => { ... };
}

Write a lua function similar to Rust’s syntax

Example

use mlua::Lua;

let lua = Lua::new();
lua.create_function(|lua, ()| Ok(()))

vs

use mlua_extras::{mlua::Lua, function};

let lua = Lua::new();
function! {
    lua fn name(lua) {
        Ok(())
    }
}

It can also be used to asssign functions to nested tables. This requires the LuaExtras crate when you start with lua as the source, and the Require trait when using any other table as the source.

use mlua::{Lua, Table};

let lua = Lua::new();
lua.globals().get::<_, Table>("nested")?.set("name", lua.create_function(|lua, ()| Ok(()))?)?;

let nested = lua.globals().get::<_, Table>("deep")?.get::<_, Table>("nested");
nested.set("name", lua.create_function(|lua, ()| Ok(())))?;

vs

use mlua_extras::{
    mlua::{Lua, Table},
    extras::{LuaExtras, Require},
};

let lua = Lua::new();
function! {
    lua fn lua::nested.name(lua) {
        Ok(())
    }
}

let nested = lua.globals().get::<_, Table>("deep")?;
function! {
    lua fn deep::nested.name(lua) {
        Ok(())
    }
}