Lua面向对象编程

--[[
1.定义基类
A = class()

function A:init(a, b) -- 构造函数
    self.a = a
    self.b = b
    print("A:init", a, b)
end

function A:Test()
    print("A:Test")
    for k,v in pairs(self) do
        print(k,v)
    end
end

2.继承
B = class(A)

function B:init(a, b, c, d) -- 先调用父类构造
    self.c = c
    self.d = d
    print("B:init", c, d)
end

function B:Test() -- 重载
    print("B:Test1")
end

a = A(100, 200)
b = B(1, 2, 3, 4)

a:Test()
b:Test()
--b:Test1()

--]]

local function class(base)
    assert(base == nil or type(base) == "table")

    local cls = {}
    local mt = {}
    local obj_mt = { 
        __index = cls,
        __newindex = function(self, key, value)
            if cls[key] ~= nil then
                Debug.LogError(debug.traceback("[ERROR] '" .. key .. "' is keyword", 2))
                return
            end

            rawset(self, key, value)
        end,
    }

    function cls.attach(obj)
        return setmetatable(obj, obj_mt)
    end

    -- function cls.new(_, ...)
    --  return cls.attach({}):__init(...)
    -- end

    function cls.new(...)
        return cls.attach({}):__init(...)
    end

    function cls.inherit(base)
        assert(type(base) == "table")

        cls.super = base
        mt.__index = base
    end

    function cls.__init(obj, ...)
        local super = cls.super
        if super then
            super.__init(obj, ...)
        end

        local init = rawget(cls, "init")
        if init then
            init(obj, ...)
        end

        return obj
    end

    function cls.get(self, key)
        if key == nil then
            return nil
        end

        return self[key]
    end

    function cls.set(self, key, value)
        if key == nil then
            return
        end

        self[key] = value
    end

    -- mt.__call = cls.new

    if base then
        cls.inherit(base)
    end

    return setmetatable(cls, mt)
end

return class