Class = {};

Class.__index = Class

Class.objCount = 0;

Class.name = "Object";

local Class_Constructor = {};

Class_Constructor.__call = function (type)

Class.objCount = Class.objCount + 1;

local instance = {};

instance.class = type;

setmetatable(instance, type.prototype);

return instance;

end

setmetatable(Class, Class_Constructor);

Class.__call = Class_Constructor.__call;

-- function Class:create()

-- Class.objCount = Class.objCount + 1;

-- local instance = {};

-- instance.class = self;

-- setmetatable(instance, self.prototype);

-- return instance;

-- end

function Class:subclass(typeName)

-- 以传入类型名称作为全局变量名称创建table

_G[typeName] = {};

-- 设置元方法__index,并绑定父级类型作为元表

local subtype = _G[typeName];

subtype.name = typeName;

subtype.super = self;

subtype.__call = Class_Constructor.__call;

subtype.__index = subtype;

setmetatable(subtype, self);

-- 创建prototype并绑定父类prototype作为元表

subtype.prototype = {};

subtype.prototype.__index = subtype.prototype;

subtype.prototype.__gc = self.prototype.__gc;

subtype.prototype.__tostring = self.prototype.__tostring;

setmetatable(subtype.prototype, self.prototype);

return subtype;

end

Class.prototype = {};

Class.prototype.__index = Class.prototype;

Class.prototype.__gc = function (instance)

print(instance, "destroy");

end

Class.prototype.tag = 999;

Class.prototype.__tostring = function (instance)

return "[" .. instance.class.name .." object]";

end

function Class.prototype:add(a, b)

-- body

return a + b;

end

Class:subclass("Child");

function Child.prototype:sumSquare(a, b)

-- body

local sum = Child.super.prototype.add(self, a, b);

return sum ^ 2;

end

local c = Child();

print (c:sumSquare(2, 2));

local obj = Class();

print (obj);

-- print (obj.tag);

-- obj.tag = 999;

-- obj = nil;

-- local obj2 = Class:create();

-- print (obj2.tag);

-- obj2 = nil;

-- print (Class.objCount);

Class:subclass("Person")

Person.prototype.name = "vim";

-- function Person.prototype:output(msg)

-- msg = self.name .. ":" .. msg;

-- Person.super.prototype.output(self, msg);

-- -- self.super.output(self, msg);

-- end

local p = Person();

print (p);

print (p.name);

-- p:output("Hello World!");

-- p = nil;

-- Person:subclass("Chinese");

-- Chinese.prototype.skin = "yellow";

-- function Chinese.prototype:output(msg)

-- -- body

-- msg = "(" .. self.skin.. ")" .. msg;

-- Chinese.super.prototype.output(self, msg);

-- end

-- local ch = Chinese:create();

-- print (ch.name, ch.skin);

-- ch:output("Hello World!");

-- ch = nil;

collectgarbage("collect")