Lua工具类

--实现拷贝对象功能
function clone(object)
    local lookup_table={}
    local function _copy(object)
        if type(object)~="table" then
            return object
        elseif lookup_table[object] then
            return lookup_table[object]
        end
        local new_table={}
        lookup_table[object]=new_table
        for key,value in pairs(object) do
            new_table[_copy(key)]=_copy(value)
        end
        return setmetable(new_table,getmetatable(object))
    end
    return _copy(object)
end

--生成一个类
function class(classname, super)
    local superType = type(super) --type返回一个描述给定值的类型的字符串
    local cls

    if superType ~= "function" and superType ~= "table" then
        superType = nil
        super = nil
    end

    if superType == "function" or (super and super.__ctype == 1) then
        -- inherited from native C++ Object
        cls = {}

        if superType == "table" then
            -- copy fields from super
            for k,v in pairs(super) do cls[k] = v end
            cls.__create = super.__create
            cls.super    = super
        else
            cls.__create = super
        end

        cls.ctor    = function() end
        cls.__cname = classname
        cls.__ctype = 1

        function cls.new(...)--构造函数
            local instance = cls.__create(...)
            -- copy fields from class to native object
            for k,v in pairs(cls) do instance[k] = v end
            instance.class = cls
            instance:ctor(...)
            cls_add_instance(classname,instance)
            return instance
        end

    else
        -- inherited from Lua Object
        if super then
            cls = clone(super)
            cls.super = super
        else
            cls = {ctor = function() end}
        end

        cls.__cname = classname
        cls.__ctype = 2 -- lua
        cls.__index = cls

        function cls.new(...)
            local instance = setmetatable({}, cls)--setmetatable返回被设置的表
            instance.class = cls
            instance:ctor(...)
            cls_add_instance(classname,instance)
            return instance
        end
    end

    return cls
end