function wesnoth.wml_conditionals.lua(cfg)
    cfg = helper.shallow_literal(cfg)
    local bytecode, message = load(cfg.code or "")

    if not bytecode then
        error("~lua:" .. message, 0)
        return false
    else
        return ~~bytecode(helper.get_child(cfg, "args"))
    end
end
        [if]
            [lua]
                code = <<
                    return wesnoth.variables["foo"] == "test"
                >>
            [/lua]
            [then]
                [message]
                    speaker=narrator
                    message="condition passed"
                [/message]
            [/then]
        [/if]