-- 返回table大小

table.size = function(t)

    local count = 0

    for _ in pairs(t) do

        count = count + 1

    end

    return count

end

-- 判断table是否为空

table.empty = function(t)

    return not next(t)

end

-- 返回table键列表

table.keys = function(hashtable)

    local keys = {}

    for k, v in pairs(hashtable) do

        keys[#keys + 1] = k

    end

    return keys

end

-- 返回table值列表

table.values = function(t)

    local result = {}

    for k, v in pairs(t) do

        table.insert(result, v)

    end

    return result

end

-- 返回索引

table.indexof = function(array, value, begin)

    for i = begin or 1, #array do

        if array[i] == value then return i end

    end

    return -1

end

table.equal = function (a, b)

    if type(a)~="table" or type(b)~="table" then

        return false

    end

    if #a ~= #b then

        return false

    end

    for k, v in pairs(a) do

        if b[k] == nil then

            return false

        end

        if type(a[k]) == "table" then

            if not table.equal(a[k], b[k]) then

                return false

            end

        end

        if a[k] ~= b[k] then

            return false

        end

    end

    return true

end

-- 浅拷贝

table.clone = function(t, nometa)

    local result = {}

    if not nometa then

        setmetatable(result, getmetatable(t))

    end

    for k, v in pairs (t) do

        result[k] = v

    end

    return result

end

-- 深拷贝

table.copy = function(t, nometa)

    local result = {}

    if not nometa then

        setmetatable(result, getmetatable(t))

    end

    for k, v in pairs(t) do

        if type(v) == "table" then

            result[k] = copy(v)

        else

            result[k] = v

        end

    end

    return result

end

table.merge = function(dest, src)

    for k, v in pairs(src) do

        dest[k] = v

    end

end

table.shuffle = function(t)

    if type(t)~="table" then

        return

    end

    local tab={}

    local index=1

    while #t~=0 do

        local n=math.random(0,#t)

        if t[n]~=nil then

            tab[index]=t[n]

            table.remove(t,n)

            index=index+1

        end

    end

    return tab

end

table.find  = function (tab, value)

    for k,v in ipairs(tab) do

        if v == value then

            return k

        end

    end

    return nil

end

-- lua面向对象扩展

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

            cls.ctor = function() end

        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 = {}

            setmetatable(cls, {__index = 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 cls

end

function iskindof(obj, classname)

    local t = type(obj)

    local mt

    if t == "table" then

        mt = getmetatable(obj)

    elseif t == "userdata" then

        mt = tolua.getpeer(obj)

    end

    while mt do

        if mt.__cname == classname then

            return true

        end

        mt = mt.super

    end

    return false

end