mlua_utils.rs

use mlua::{IntoLua, Lua, Value};

fn main() -> Result<(), Box<dyn std::error::Error>> {
	let lua = Lua::new();
	let utils = lua.create_table()?;

	let double_fn = lua.create_function(|lua: &Lua, arg_0: i64| {
		let res = arg_0 * 2;
		res.into_lua(lua)
	})?;
	fn add_fn(lua: &Lua, (arg_0, arg_1): (i64, i64)) -> mlua::Result<Value> {
		let res = arg_0 + arg_1;
		res.into_lua(lua)
	}

	utils.set("double_stuff", double_fn)?;
	utils.set("add_stuff", lua.create_function(add_fn)?)?;
	lua.globals().set("utils", utils)?;

	let chunk = lua.load(
		r#"
			local num = 123

			local stuff = utils.double_stuff(1000)		
			local sum = utils.add_stuff(10000, 30000)

			return "" .. num .. " " .. stuff .. " " .. sum
		"#,
	);

	let res = chunk.eval::<Value>()?; 
	println!("->> {res:?}");
	Ok(())
}