Lua懒删除：先做记号的延迟清扫

flowchart TD
A[删除请求] --> B[盖记号 不搬移]
B --> C[遍历时跳过记号]
C --> D{记号过半了吗}
D -- 否 --> C
D -- 是 --> E[压实 活数据前移 记号清空]
E --> C

 fx-lazydel

-- @file LazyDelete.lua
-- 懒删除 —— 先做记号的延迟清扫

local LazyDelete = {}

local CONST = {
    SLOT_CAP      = 64,
    COMPACT_HALF  = true,

    AUTOINC_BASE  = 1145000,
}

local _slots     = {}
local _count     = 0
local _tombN     = 0

local function ShowTip(msg)
    if msg and msg ~= "" then SL:ShowSystemTips(msg) end
end

function LazyDelete.Count()
    return _count - _tombN
end

function LazyDelete.TombCount()
    return _tombN
end

function LazyDelete.Add(value)
    if _count >= CONST.SLOT_CAP then
        LazyDelete.Compact()
        if _count >= CONST.SLOT_CAP then
            ShowTip("账本真满了——压实也救不回")
            return nil
        end
    end
    _count = _count + 1
    _slots[_count] = { value = value, tomb = false }
    return _count
end

-- 记号删除：只盖记号不搬移
function LazyDelete.Remove(idx)
    local slot = _slots[idx]
    if not slot or slot.tomb then return false end
    slot.tomb = true
    _tombN = _tombN + 1
    if CONST.COMPACT_HALF
        and _tombN * 2 >= LazyDelete.Count() then
        LazyDelete.Compact()
    end
    return true
end

-- 遍历：跳过记号，遍历中删除安全
function LazyDelete.Each(func)
    for i = 1, _count do
        local slot = _slots[i]
        if not slot.tomb then
            if func(slot.value, i) == false then
                break
            end
        end
    end
end

-- 压实清扫：活数据前移，记号连格清空
function LazyDelete.Compact()
    local write = 0
    for read = 1, _count do
        local slot = _slots[read]
        if not slot.tomb then
            write = write + 1
            if write ~= read then
                _slots[write] = slot
                _slots[read] = nil
            end
        else
            _slots[read] = nil
        end
    end
    _count = write
    _tombN = 0
    ShowTip("压实了——真删发生在这一拍")
end

SL:ScheduleOnce(function()
    SL:BindDebugButton("演示增删", function()
        LazyDelete.Add("账" .. math.random(100, 999))
    end)
    ShowTip("技能已加载: 懒删除 (调试按钮触发)")
end, 1.0)

function LazyDelete.Unload()
    _slots = {}
    _count = 0
    _tombN = 0
end

return LazyDelete