单例代码

Singleton = {};
 
local _instance;
 
function Singleton.getInstance()
    if not _instance then
        _instance = Singleton;
    end
 
    --'any new methods would be added to the _instance object like this'
    _instance.getType = function()
        return 'singleton';
    end
 
    return _instance
end
 
function Singleton:new()
    print('Singleton cannot be instantiated - use getInstance() instead');
end