Lua表拷贝：引用传递与深拷贝

-- 错误：这只是别名，不是拷贝
local copy = cfg
copy.color = "red"

local function deepcopy(t, seen)
    seen = seen or {}
    if seen[t] then return seen[t] end
    local out = {}
    seen[t] = out
    for k, v in pairs(t) do
        if type(v) == "table" then
            out[k] = deepcopy(v, seen)
        else
            out[k] = v
        end
    end
    return out
end
local src = {color = "blue", pos = {x = 1}}
local mine = deepcopy(src)
mine.pos.x = 99
local p = getplayerbyname("cpy01")
sendmsg(p, 1, src.pos.x .. "/" .. mine.pos.x)