This is a straightforward copy of the Lua example from the Vala web site

First, make sure you include the Lua namespace in your Vala program.

    using Lua;

Next, create the Vala functions that you want to bind to and call from the Lua script. They need to be of the form:

    [return type] function_name(LuaVM vm)

Now create two versions of the same function. In practice, you don't actually need to create both versions, but this example is pretty short and calling both versions won't make it longer.

    static int my_func_static (LuaVM vm) {
        stdout.printf ("Static Vala Code From Lua Code! (%f)\n", vm.to_number (1));
        return 1;
    }

    int my_func (LuaVM vm) {
        stdout.printf ("Vala Code From Lua Code! (%f)\n", vm.to_number (1));
        return 1;
    }

Now move on to things in the main function. You should already know how to set up your main function:

    static int main (string[] args) {

The next part of the main function is a string storing the Lua code. Use triple- quotes to write your script as a string in your vala code for now(We'll load the code from a file in the next tutorial). This lua script calls both the functions we created earlier.

        string code = """
            print "Lua Code From Vala Code!"
            my_func(33)
            my_func_static(44)
        """;

Next you need to instantiate a Lua virtual machine. You'll probably do this the same way most of the times that you use Lua from Vala and Vala from Lua.

        var vm = new LuaVM ();
        vm.open_libs ();

Now, another important part, this is where you register the functions that you will be calling from Lua with the Lua virtual machine in your Vala program.

        vm.register ("my_func_static", my_func_static);
        vm.register ("my_func", my_func);

Finally, execute the Lua code in the variable from earlier in the virtual machine by calling the .do_string(string lua_script) function.

        vm.do_string (code);

        return 0;
    }

And that's about as detailed a beginning example I can think up.

Compile Line

    valac --save-temps --pkg lua -X -llua5.1 luatest.vala -o luatest

Original Source

Full Example Code

    using Lua;

    static int my_func_static (LuaVM vm) {
        stdout.printf ("Static Vala Code From Lua Code! (%f)\n", vm.to_number (1));
        return 1;
    }

    int my_func (LuaVM vm) {
        stdout.printf ("Vala Code From Lua Code! (%f)\n", vm.to_number (1));
        return 1;
    }

    static int main (string[] args) {

        string code = """
                print "Lua Code From Vala Code!"
                my_func(33)
                my_func_static(44)
            """;

        var vm = new LuaVM ();
        vm.open_libs ();
        vm.register ("my_func_static", my_func_static);
        vm.register ("my_func", my_func);
        vm.do_string (code);

        return 0;
    }