lua的类

lua的类有点像javascript,但是更简明灵活，table即对象，对象就是类。Metatables比起ruby里的MetaClass更加好用，缺点是实例化和继承的代码有点多，

不像ruby里的“<”和“<<”,继承链就是查找方法时的方法链。 

  1 Account={

  2    test1=function(a) print("Account test1") end

  3 }

  4 

  5 Account.test2=function(a) print("Account test2") end

  6 

  7 function Account.test3(a) print("Account test3") end

  8 

  9 

 10 function Account:new (o)  --类的实例化

 11 

 12     o = o or {}

 13 

 14     setmetatable(o, self)

 15 

 16     self.__index = self

 17 

 18     return o

 19 

 20 end

 21 

 22 function Account.print0(o,a)

 23     print(a)

 24 end

 25 

 26 function Account:print1(a)

 27     print(a)

 28 end

 29 

 30 

 31 --方法定义测试

 32 Account.test1()

 33 Account.test2()

 34 Account.test3()

 35 

 36 --类测试

 37 acc=Account:new()

 38 acc.test1()

 39 acc.print0(acc,"dot print0")

 40 acc:print0("not dot print0")

 41 acc.print1(acc,"dot print1")

 42 acc:print1("not dot print1")

 43 

 44 acc.specialMethod=function(specialMethodTest)

 45    print(specialMethodTest)

 46 end

 47 

 48 acc.specialMethod("smt test")

 49 

 50 --继承测试

 51 SpecialAccount = Account:new()

 52 s = SpecialAccount:new{limit=1000.00}

 53 

 54 --多重继承测试

 55 Named = {}

 56 

 57 function Named:getname ()

 58 

 59     return self.name

 60 

 61 end

 62 

 63 function Named:setname (n)

 64 

 65     self.name = n

 66 

 67 end

 68 

 69 local function search (k, plist)

 70 

 71     for i=1, table.getn(plist) do

 72 

 73        local v = plist[i][k]

 74 

 75        if v then return v end

 76 

 77     end

 78 

 79 end

 80 

 81 function createClass (...)

 82 

 83     local c = {}      -- new class

 84 

 85     setmetatable(c, {__index = function (t, k)

 86 

 87     return search(k, arg)

 88 

 89 end})

 90 

 91 c.__index = c

 92 

 93 function c:new (o)

 94 

 95     o = o or {}

 96 

 97     setmetatable(o, c)

 98 

 99     return o

 

 end

 

     return c

 

 end

 NamedAccount = createClass(Account, Named)

 

 account = NamedAccount:new{name = "Paul"}

 

 print(account:getname())