【高级技巧】Lua __tostring：裁决之杖库存表打印不再是地址

local stock = {wand = 120, gold = 3000}
sendmsg(actor, 1, "库存 " .. tostring(stock))
-- 输出 table: 0x...，等于没看

local stock = setmetatable({wand = 120, gold = 3000}, {
    __tostring = function(t)
        local p = {}
        for k, v in pairs(t) do
            p[#p + 1] = k .. "=" .. v
        end
        return "{" .. table.concat(p, ",") .. "}"
    end})
sendmsg(actor, 1, "裁决之杖库存 " .. tostring(stock))
-- 输出 {wand=120,gold=3000}