【高级技巧】Lua常量提升：祖玛教主掉落表别在函数里重建

local function roll(actor)
    local rates = {500, 200, 50}     -- 每次调用新建，白造表
    local r = math.random(1, rates[1])
    if r <= 1 then
        giveitem(actor, "祖玛教主馈赠", 1, 0, "掉落")
    end
end

local RATES = {500, 200, 50}         -- 提升为upvalue，只造一次
local function roll(actor)
    local r = math.random(1, RATES[1])
    if r <= 1 then
        giveitem(actor, "祖玛教主馈赠", 1, 0, "掉落")
    end
end