【高级技巧】比较器契约：invalid order function的成因与规避

local function badCompare(a, b)
    if a.pts == b.pts then
        return math.random(1, 2) == 1
    end
    return a.pts > b.pts
end
local function goodCompare(a, b)
    if a.pts ~= b.pts then
        return a.pts > b.pts
    end
    return a.name < b.name
end
local function safeSort(rows)
    local ok, err = pcall(table.sort, rows, badCompare)
    if not ok then
        sendmsg(nil, 1, "比较器违约已拦截：" .. tostring(err))
        table.sort(rows, goodCompare)
    end
    return rows
end

local function showBoard(actor, rows)
    actor = getplayerbyname(actor)
    rows = safeSort(rows)
    sendmsg(actor, 1, "榜首：" .. rows[1].name .. "（裁决之杖战力榜）")
end