【Lua实战】闭包缓存：重复计算的函数级缓存写法

-- 闭包缓存：工厂封装
local function memoize(fn)
    local store = {}
    return function(...)
        local key = table.concat({...}, "|")
        local hit = store[key]
        if hit ~= nil then
            return hit, true
        end
        local value = fn(...)
        store[key] = value
        return value, false
    end
end

-- 装备评分：缓存化改造
local player = class(actor)
local function rawScore(atk, def, hp)
    return atk * 0.5 + def * 0.3 + hp * 0.2
end
local scoreOf = memoize(rawScore)
local function onEquipChange(player, atk, def, hp)
    scoreOf = memoize(rawScore)
    sendmsg(player, 1, 0, "装备评分：" .. string.format("%.1f", scoreOf(atk, def, hp)))
end