Lua类继承（二）

Lua类继承（二）

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 setmetatable(new_table, getmetatable(object))    end    return _copy(object)end--Create an class.function class(classname, super)    local superType = type(super)    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(...)            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(...)            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)            instance.class = cls            instance:ctor(...)            return instance        end    end    return clsend