Lua多重继承

http://blog.****.net/ssihc0/article/details/7742421

代码收藏了,以后用的到
--多重继承
local function search(k,plist)
    for i=,#plist do
        local v=plist[i][k] --   取一个基类
        if v then return v end
    end
end

function createClass(...)
    local c={};
    local parents={...};

    setmetatable(c,{__index=function(t,k) return search(k,parents) end } );

    c.__index=c;

    function c:new(o)
        o=o or {};
        setmetatable(o,c);
        return o;
    end

    return c;
end

Named={};
function Named:getname()
    return self.name;
end

function Named:setname(n)
    self.name=n;
end

Account={balance=};

function Account:new(o)
    o= o or {}
    setmetatable(o,self);
    self.__index=self;
    return o;
end

function Account.deposit(self,v)
    self.balance=self.balance+v;
end

function Account:withdraw(v)
    if (v) > self.balance then error "insufficient funds"; end
    self.balance=self.balance-v;
end

NamedAccount=createClass(Account,Named);

user=NamedAccount:new{name="user admin"};
print (user:getname(),user.balance);

http://my.oschina.net/u/156466/blog/401576

local class1 = {}
function class1:new()
    local obj = {}
    setmetatable(obj, {__index= class1})
    return obj
end

function class1:print1()
    print("class1:print()")
end

local class2 = {}
function class2:new()
    local obj = {}
    setmetatable(obj, {__index= class2})
    return obj
end

function class2:print2()
    print("class2:print()")
end

function super(k, list)
    for i,v in ipairs(list) do
        local ret = v[k]
        if ret then
            return ret
        end
    end
end

local class3 = {}
function class3:new()
    local obj = {}
    local  base = {class1, class2}
    --t为调用的对象,k为方法名
    setmetatable(class3, {__index= function(t,k) return super(k, base) end})
    setmetatable(obj, {__index = class3})
    return obj
end