【入门夯实】嵌套表判空：三级表访问的nil链与安全写法

local function readSlots()
    return CONFIG.guild.warehouse.slots
end

local function deepGet(tbl, path)
    local cur = tbl
    for key in string.gmatch(path, "[^%.]+") do
        if type(cur) ~= "table" then
            return nil
        end
        cur = cur[key]
    end
    return cur
end
local CONFIG = { guild = { warehouse = { slots = 40 } } }
local function readSlots(actor)
    actor = getplayerbyname(actor)
    local slots = deepGet(CONFIG, "guild.warehouse.slots") or 20
    sendmsg(actor, 1, "仓库格子上限：" .. slots)
end

local function ensurePath(tbl, path)
    local cur = tbl
    for key in string.gmatch(path, "[^%.]+") do
        if type(cur[key]) ~= "table" then
            cur[key] = {}
        end
        cur = cur[key]
    end
    return cur
end