A simple rust configuration tool using lua.

I always have trouble configuring my rust applications. I wanted to try out lua as a tool for configurations as I could also do some logic while the config is being read. For example:

function Config()
	local config = {
		width = 800,
	}
	config.height = config.width * 3 / 4

	return config
end

As you can see the height value is calculated on the fly depending on the width.

Install using cargo add lua_config. Create a file for the default configuration, for example is:

function Default()
	return {
		name = "My Game",
		width = 800,
		height = 600,
	}
end

Than create a file for your configuration. This file should be alongside the application, if you are distributing your project, you will want to also distribute this file alongside the app. This can be done manually or automated with build.rs. For example:

function Config()
	local config = {
		width = 1280,
	}
	config.height = config.width * 3 / 4

	return config
end

Now you can use the configuration in your rusty code:

fn main() {
    let config = lua_config::LuaConfig::from_file("config.lua")
        .expect("Failed to load config")
        .with_default(include_bytes!("../default_config.lua"))
        .expect("Failed to load default config")
        .execute()
        .expect("Failed to execute config");

    println!("Width: {}\n", config.get("width").unwrap().to::<i32>().unwrap());
    println!("Height: {}\n", config.get("height").unwrap().to::<i32>().unwrap());
    println!("Config:\n{}", config);
}

The terminal output is:

Width: 800

Height: 600

Config:
height = Number(600)
name = String("My Game")
width = Integer(800)

To avoid execive .unwrap() you can add crash_on_none feature. That way get() and to<T>() functions are gonna return LuaType and T without Option respectivly. I case of an error the library will panic. This is added to avoid .unwrap() everywere, and gives the same result of crashing.

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

MIT