lua table面向对象扩展

一 、table扩展

-- 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

二、面向对象扩展

-- 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