深度克隆1个值
~~~ lua
-- 下面的代码，t2 是 t1 的援用，修改 t2 的属性时，t1 的内容也会产生变化
local t1 = {a = 1, b = 2}
local t2 = t1
t2.b = 3 -- t1 = {a = 1, b = 3} <-- t1.b 产生变化
-- clone() 返回 t1 的副本，修改 t2 不会影响 t1
local t1 = {a = 1, b = 2}
local t2 = clone(t1)
t2.b = 3 -- t1 = {a = 1, b = 2} <-- t1.b 不受影响
~~~
@param mixed object 要克隆的值
@return mixed
function clone(object)
local lookup_table = {}
local function _copy(object)
if type(object) ~= "table" then
return object
elseif lookup_table[object] then
return lookup_table[object]
end
local new_table = {}
lookup_table[object] = new_table
for key, value in pairs(object) do
new_table[_copy(key)] = _copy(value)
end
return setmetatable(new_table, getmetatable(object))
end
return _copy(object)
end