hengyang_client/lua_probject/extend_project/extend/majiang/lichuan/EXPlayBackView.lua

local MJPlayBackView = require("main.majiang.MJPlayBackView")
local EXRoomConfig = import(".EXRoomConfig")
local EXClearingView = import(".EXClearingView")
local HuCardImg = import(".HuCardImg")
local FZTipList = require("main.majiang.FZData")
local MJPlayerCardInfoView = require("main.majiang.MJPlayerCardInfoView")


local Record_Event = import(".RecordEvent")


local M = {}

--- Create a new
function M.new()
    setmetatable(M, { __index = MJPlayBackView })
    local self = setmetatable({}, { __index = M })
    self.class = "PlayBackView"
    self:init()

    return self
end

function M:InitView(url)
    local room = self._room
    UIPackage.AddPackage("extend/majiang/lichuan/ui/Extend_MJ_LiChuan")
    MJPlayBackView.InitView(self, string.format("ui://Main_Majiang/Main_new_%d_jiangxi", room.room_config.people_num))
    local _cardbox = self._view:GetChild("cardbox")
    --self._view:GetChild("panel_record"):GetChild("btn_LastStep").enabled = false
    self._ctr_cardbox = _cardbox:GetController("c1")
    self._tex_round = self._view:GetChild("tex_round")
    self._tex_LeftCard = self._view:GetChild("remaining_card")
    self._anchor = self._view:GetChild("mask_tips")
    self.jing = self._view:GetChild('jing')

    self.HuCardImg = setmetatable(HuCardImg, { __index = self.HuCardImg })
    self.asset_group = "LiChuan_MJ"
    self.HuCardImg_path = "ui://Extend_MJ_LiChuan/"
    self.Sound_path = "extend/majiang/lichuan/sound/"

    self._eventmap = {}

    self._cmdmap = {}
    self._cmdmap[Record_Event.Evt_GetCard] = self.CmdGetCard
    self._cmdmap[Record_Event.Evt_OutCard] = self.CmdOutCard
    self._cmdmap[Record_Event.Evt_Action] = self.CmdAction
    self._cmdmap[Record_Event.Evt_Win] = self.CmdWin
    self._cmdmap[Record_Event.Evt_Niao] = self.CmdNiao
    self._cmdmap[Record_Event.Evt_Piao] = self.CmdPiao
    self._cmdmap[Record_Event.Evt_Result] = self.CmdResult
    self._cmdmap[Record_Event.Evt_FZTip] = self.CmdFZTip
    self._cmdmap[Record_Event.Evt_GangScore] = self.GangScore

    self.com_logocType.selectedIndex = 2
end

function M:FillRoomData(data)
    MJPlayBackView.FillRoomData(self)
    if self._win_pic then self._win_pic:Dispose() end
    if self._niao then self._niao:Dispose() end
    self._currentStep = 0
    local room = DataManager.CurrenRoom
    local _player_card_info = self._player_card_info
    local left_count = data.info.left_card
    self:UpdateLeftCard(left_count)
    local round = data.info.round
    self:UpdateRound(round)
    self:ShowJing()

    local roominfo_panel = self._view:GetChild("roominfo_panel1")
    roominfo_panel:GetChild("tex_roomid").text = room.room_id
    roominfo_panel:GetChild("tex_gametype").text = room.room_config:GetGameName()

    for i = 1, #room.player_list do
        local p = room.player_list[i]
        local card_info = _player_card_info[self:GetPos(p.seat)]
        card_info:Clear()
        table.sort(p.card_list, self.HandCardSortAndJing)
        card_info:UpdateHandCard(false, true)
        self._player_info[i]._view:GetController("piao_niao").selectedIndex = 0
    end

    self:GenerateAllStepData(data)
    self:UpdateStep(1)
    self:Play()
    self._laiziMove:Play()
    self._touxiangMove:Play()
    -- self:ShowStep(0)
end

function M:ShowStep(index)
    local step = self._step[index + 1]
    self:UpdateLeftCard(step.left_card)
    -- self._ctr_cardbox.selectedIndex = step.current_out_seat
    self:UpdateCardBox(self:GetPos(step.current_out_seat))
    self:UpdateStep(index + 1)
    if step.cmd ~= Record_Event.Evt_OutCard then
        self:RemoveCursor()
    end
    for i = 1, #step.player_card_data do
        local p = self._room:GetPlayerBySeat(i)
        local info = self._player_card_info[self:GetPos(i)]
        p.card_list = step.player_card_data[i].card_list
        p.outcard_list = step.player_card_data[i].outcard_list
        p.fz_list = step.player_card_data[i].fz_list
        p.hand_left_count = #p.card_list
        -- info:Clear()
        -- info:ResetFzList()
        p.piao_niao = step.player_card_data[i].piao_niao
        local head_info = self._player_info[self:GetPos(i)]
        if p.piao_niao and p.piao_niao > 0 then
            head_info._view:GetChild("mask_piao").title = "飘分 " .. p.piao_niao
            head_info._view:GetController("piao_niao").selectedIndex = 1
        else
            head_info._view:GetController("piao_niao").selectedIndex = 0
        end
        if step.cmd == Record_Event.Evt_OutCard and i == step.last_out_seat then
            local card = p.outcard_list[#p.outcard_list]
            info:UpdateOutCardList(nil, card, self._cursor)
            self:PlayMJSound("chupai.mp3")
            self:PlaySound("LiChuan_MJ", p.self_user.sex, tostring(card))
        else
            info:UpdateOutCardList()
        end
        ---显示提示按钮
        local _ctr_tips = info._view:GetController('tip2')
        local _lit_fanzi = info._view:GetChild("Comp_Back_FZTips")
        local _flag_tipGetCard = false
        if step.cmd == Record_Event.Evt_FZTip then
            if p.seat == step.seat then
                local tip = step.tiplist
                local _tlist = tip.tip_sortList
                _lit_fanzi.itemRenderer = function(index, obj)
                    local type = obj:GetController('type')
                    if index == tip.tip_num then
                        type.selectedIndex = 0
                    else
                        index = index + 1
                        if _tlist[index].type == FZType.HU then
                            type.selectedIndex = 4
                            obj:GetChild('btn_Card1').icon = string.format('ui://Main_Majiang/b202_%d',
                                _tlist[index].card)
                            _flag_tipGetCard = self.last_get_seat ~= step.seat
                        elseif _tlist[index].type == FZType.Chi then
                            type.selectedIndex = FZType.Chi
                            for i = 1, 3 do
                                obj:GetChild(string.format('btn_Card%d', i)).icon = string.format(
                                    'ui://Main_Majiang/b202_%d',
                                    _tlist[index].opcard[i])
                            end
                        elseif _tlist[index].type == FZType.Peng then
                            type.selectedIndex = FZType.Peng
                            for i = 1, 3 do
                                obj:GetChild(string.format('btn_Card%d', i)).icon = string.format(
                                    'ui://Main_Majiang/b202_%d',
                                    _tlist[index].card)
                            end
                        else
                            for i = 1, 4 do
                                obj:GetChild(string.format('btn_Card%d', i)).icon = string.format(
                                    'ui://Main_Majiang/b202_%d',
                                    _tlist[index].card)
                            end
                            type.selectedIndex = FZType.Gang
                            if _tlist[index].type == FZType.Gang_An then
                                obj:GetChild('btn_Card4').icon = 'ui://Main_Majiang/b202_00'
                            end
                            _flag_tipGetCard = true
                        end
                    end
                end
                _ctr_tips.selectedIndex = 1
                _lit_fanzi.numItems = tip.tip_num + 1
            end
        else
            _ctr_tips.selectedIndex = 0
            _lit_fanzi.numItems = 0
        end
        ----多人胡的时候，同时显示胡
        if step.cmd == Record_Event.Evt_Result then
            --所有都显示胡吧，暂时没做胡和自摸的判断
            if not self.result then
                if step.result_data.info_list[i].is_win then
                    local info2 = self._player_card_info[self:GetPos(step.result_data.info_list[i].seat)]
                    local loader_HuEffect = info2._viewLoader_selfHuCardEffect
                    local isZiMo = false
                    DataManager.CurrenRoom.isZiMoHu = isZiMo
                    local hu_sound = isZiMo and ("zimo") or ("hu")
                    printlog("声音====>>>", hu_sound)
                    self:PlaySound(self.asset_group, p.self_user.sex, hu_sound)

                    local effects = isZiMo and ("tile_zimo") or ("tile_hu")
                    loader_HuEffect.visible = true
                    loader_HuEffect.url = "ui://Main_Majiang/" .. effects
                    loader_HuEffect:SetScale(2, 2)
                    local hu_tween = loader_HuEffect:TweenScale(Vector2(1, 1), 0.3)
                    hu_tween:SetEase(EaseType.QuartOut)
                    hu_tween:OnComplete(function()
                        loader_HuEffect.visible = false
                    end)
                end
            end
        end
        if step.cmd ~= Record_Event.Evt_OutCard and step.cmd ~= Record_Event.Evt_GangScore and step.cmd ~= Record_Event.Evt_Win and step.cmd ~= Record_Event.Evt_Niao and p.seat == step.current_out_seat or step.cmd == Record_Event.Evt_Result then
            if step.cmd == Record_Event.Evt_Action then
                pt("lingmeng step ", step)
                local fz = step.fz
                local info = self._player_card_info[self:GetPos(i)]
                local loader_HuEffect = info._viewClip_Peng_Gang
                local effects = ""
                if fz.type == FZType.Peng then
                    self:PlaySound("Main_Majiang", p.self_user.sex, "peng")
                    effects = "clip_peng"
                elseif fz.type == FZType.Chi then

                else
                    self:PlaySound("Main_Majiang", p.self_user.sex, "gang")
                    effects = "clip_gang"
                end
                local clip = UIPackage.CreateObjectFromURL(string.format("ui://Main_Majiang/%s", effects))
                clip:SetSize(loader_HuEffect.width, loader_HuEffect.height)
                loader_HuEffect:AddChild(clip)
                clip:SetPlaySettings(0, -1, 1, -1)
                clip.onPlayEnd:Add(function()
                    if clip.parent then
                        clip.parent:RemoveChild(clip)
                    end
                    clip:Dispose()
                end)
                clip.playing = true
                info:UpdateFzList(fz, index, true, self:GetPos(fz.from_seat))
            end
            printlog("lingmeng UpdateHandCard", step.cmd, p.seat, step.fz and step.fz.type or -1, FZType.Peng,
                _flag_tipGetCard)
            if step.cmd == Record_Event.Evt_Action and step.fz.type ~= FZType.Peng then
                info:UpdateHandCard(false, true)
            elseif step.cmd == Record_Event.Evt_FZTip and not _flag_tipGetCard then
                info:UpdateHandCard(false, true)
            elseif step.cmd == Record_Event.Evt_Result then
                local _flag_result = false
                for i = 1, #step.result_data.info_list do
                    printlog("lingmeng UpdateHandCard3", step.result_data.info_list[i].is_win,
                        step.result_data.info_list[i].seat)

                    if step.result_data.info_list[i].is_win and p.seat == step.result_data.info_list[i].seat then
                        _flag_result = true
                    end
                end
                printlog("lingmeng UpdateHandCard3", _flag_result)
                info:UpdateHandCard(_flag_result, true)
            else
                info:UpdateHandCard(true, true)
            end
        else
            if step.cmd == Record_Event.Evt_Win or step.cmd == Record_Event.Evt_Niao then
            else
                info:UpdateHandCard(false, true)
            end
        end
    end

    --统一在大结算时显示
    if step.cmd == Record_Event.Evt_Win then
    else
        if self._win_pic then
            self._win_pic:Dispose()
        end
    end
    --统一在大结算时显示
    if step.cmd == Record_Event.Evt_Niao then
        local niao_list = step.niao
    else
    end
    if step.cmd == Record_Event.Evt_Result then
        print("lingmeng playerback", self.result)
        if not self.result then
            local result = step.result_data
            result.cardList = step.residual_card
            self.result = EXClearingView.new(self, { flag_back = true })
            self.result:InitData(0, self._room, result)
            self.result._view.x = (GRoot.inst.width - self.result._view.width) * -0.5
            self.result._view.width = GRoot.inst.width
            self.result._view.height = GRoot.inst.height
            self._anchor:AddChild(self.result._view)
            self.result._view.visible = false
            self.result._view.x = self._anchor.x * -1
            self.result._view.y = self._anchor.y * -1

            local liuju = result and result.liuju or nil
            coroutine.start(function()
                coroutine.wait(0.3)

                --逐个显示胡的特效
                for i = 1, #result.info_list do
                    local hu_info = result.info_list[i]
                    local player = self._room:GetPlayerBySeat(hu_info.seat)
                    local info = self._player_card_info[self:GetPos(hu_info.seat)]

                    if hu_info.is_win then
                        local win_list = hu_info.win_list

                        local list_HuCardEffect = info._viewList_HuEffect
                        local Effects = {}
                        --先循环一遍把杠上开花放在最前面
                        for i = 1, #win_list do
                            local HuMsg = win_list[i]
                            if HuMsg.type > 2 and HuMsg.type < 60 then
                                if self.HuCardImg[HuMsg.type][1] == "tile_cs_gangshanghua" then
                                    local imgPath = "ui://Main_Majiang/tile_cs_gangshanghua"
                                    local imgObj = list_HuCardEffect:AddItemFromPool()
                                    local imgLoader = imgObj:GetChild("loader_img")
                                    imgLoader.url = imgPath
                                    imgObj.visible = false
                                    Effects[#Effects + 1] = imgObj
                                    table.remove(win_list, i)
                                    break
                                end
                            end
                        end

                        for i = 1, #win_list do
                            local HuMsg = win_list[i]

                            -- ↓↓↓先排列好特效图片
                            if HuMsg.type > 2 and HuMsg.type < 60 then
                                local sound_name = string.format(self.Sound_path .. "%s/%s.mp3",
                                    ViewUtil.Sex_Chat[player.self_user.sex],
                                    "he" .. HuMsg.type)
                                ViewUtil.PlaySound(self.asset_group, sound_name)

                                local imgList = self.HuCardImg[HuMsg.type]
                                for _, img in pairs(imgList) do
                                    local imgPath = "ui://Main_Majiang/" .. img
                                    local imgObj = list_HuCardEffect:AddItemFromPool()
                                    local imgLoader = imgObj:GetChild("loader_img")
                                    imgLoader.url = imgPath
                                    imgObj.visible = false
                                    Effects[#Effects + 1] = imgObj
                                end
                            end
                        end

                        --小于四个字段时动态调整胡特效
                        if info._viewText_cardInfo["huEffet_columnGap"] and #Effects < 4 then
                            list_HuCardEffect.columnGap = tonumber(info._viewText_cardInfo["huEffet_columnGap"])
                        else
                            list_HuCardEffect.columnGap = 0
                        end

                        -- ↓↓↓播放动画
                        for _, imgObj in pairs(Effects) do
                            imgObj.visible = true

                            local effect_xingxing = imgObj:GetChild("effect_xingxing")
                            effect_xingxing:SetPlaySettings(0, -1, 1, -1);
                            effect_xingxing.visible = true
                            effect_xingxing.playing = true
                            effect_xingxing.onPlayEnd:Set(function()
                                effect_xingxing.visible = false
                            end)

                            local imgLoader = imgObj:GetChild("loader_img")
                            imgLoader:SetScale(2, 2)
                            imgLoader:Center()
                            imgLoader:TweenScale(Vector2(1, 1), 0.3)
                            coroutine.wait(0.5)
                        end

                        coroutine.wait(0.3)
                        list_HuCardEffect:RemoveChildrenToPool()
                    end
                end

                --展示摸鸟
                local niao_list = result.niao
                self._niao = UIPackage.CreateObject("Extend_MJ_LiChuan", "Panel_Birds")
                self._view:GetChild('jiangma_show'):AddChild(self._niao)
                self._niao:Center()
                local list_niao_card = self._niao:GetChild("Lst_birds")
                list_niao_card:RemoveChildrenToPool()
                for i = 1, #niao_list do
                    --顯示正面
                    local item = list_niao_card:AddItemFromPool()
                    local card = niao_list[i].card
                    item.icon = UIPackage.GetItemURL("Main_Majiang", "b202_" .. card)
                    if niao_list[i].score > 0 then
                        item:GetController("select").selectedIndex = 1
                    else
                        item:GetController("select").selectedIndex = 0
                    end
                    coroutine.wait(2 / #niao_list)
                end
                coroutine.wait(0.3)
                self._niao:Dispose()

                --统一显示弹出分数
                for i = 1, #result.info_list do
                    local hu_info = result.info_list[i]
                    local head_info = self._player_info[self:GetPos(hu_info.seat)]

                    -- 扣分动画
                    head_info:UpdateScore(hu_info.total_score, true)
                end
                coroutine.wait(0.3)

                if liuju then
                    self:PlayMJSound("liuju.mp3")
                    coroutine.wait(3)
                    self:PlayMJSound("end_music.mp3")
                else
                    self:PlayMJSound("end_music.mp3")
                end
                coroutine.wait(0.5)
                self.result._view.visible = true
            end)
        else
            -- self.result._view.visible = true
        end
    end
    --显示杠分
    if step.cmd == Record_Event.Evt_GangScore then
        local totalScoreList = step.totalScoreList
        local playerList = step.playerList
        local addScoreList = step.addScoreList
        local scoreData = {}
        for i = 1, #totalScoreList do
            local p = {}

            p.totalScore = totalScoreList[i]
            p.player = playerList[i]
            p.addScore = addScoreList[i]

            scoreData[#scoreData + 1] = p
        end

        for _, p in pairs(scoreData) do
            local player = self._room:GetPlayerById(p.player)
            local infoView = self._player_info[self:GetPos(player.seat)]
            player.cur_hp = p.totalScore

            if p.addScore ~= 0 then
                infoView:ScoreAnimation(p.addScore)
                if player.cur_hp >= 0 then
                    infoView._view:GetChild("text_jifen").text = "+" .. player.cur_hp
                else
                    infoView._view:GetChild("text_jifen").text = player.cur_hp
                end
            end
        end
    end
end

function M:GenerateAllStepData(data)
    local cmdList = self.cmdList
    self._step = {}
    local step = {}
    local info = data.info
    step.cmd = ""
    step.left_card = info.left_card
    step.last_get_seat = 0
    step.last_out_seat = 0
    step.current_out_seat = 1
    step.win = 0
    step.niao = 0
    step.residual_card = info.residual_card

    step.player_card_data = {}
    for i = 1, #self._room.player_list do
        local p = info.playerData[i]
        local u = {}
        u.seat = p.seat
        u.card_list = p.hand_card
        u.hand_left_count = #u.card_list
        u.fz_list = {}
        u.outcard_list = {}
        u.piao_niao = p.piao_niao
        step.player_card_data[u.seat] = u
    end
    self._step[#self._step + 1] = step

    for i = 1, #cmdList do
        local tem = cmdList[i]
        self._cmdmap[tem.cmd](self, tem, i)
    end
end

function M:CmdGetCard(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.current_out_seat = cmd.seat
    data.last_get_seat = cmd.seat
    data.left_card = cmd.data.left_count
    local u = data.player_card_data[cmd.seat]
    u.card_list[#u.card_list + 1] = cmd.data.card
end

function M:CmdOutCard(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.last_out_seat = cmd.seat
    local u = data.player_card_data[cmd.seat]
    list_remove(u.card_list, cmd.data.card)
    table.sort(u.card_list, self.HandCardSortAndJing)
    u.outcard_list[#u.outcard_list + 1] = cmd.data.card
end

function M:CmdAction(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.last_out_seat = 0
    data.current_out_seat = cmd.seat
    local u = data.player_card_data[cmd.seat]
    local fz = nil
    local index = -1
    local ftype = cmd.data.type
    if (ftype == FZType.Gang_Peng) then
        for i = 1, #u.fz_list do
            if (u.fz_list[i].card == cmd.data.card) then
                u.fz_list[i].card = cmd.data.card
                fz = u.fz_list[i]
                fz.type = cmd.data.type
                index = i - 1
                break
            end
        end
    end
    fz = {}
    fz.card = cmd.data.card
    fz.type = cmd.data.type
    if (index == -1) then
        u.fz_list[#u.fz_list + 1] = fz
    end
    fz.from_seat = cmd.data.from_seat
    local remove_num = #cmd.data.opcard

    for i = 1, remove_num do
        if ftype == FZType.Gang_Peng then
            list_remove(u.card_list, cmd.data.card)
        else
            list_remove(u.card_list, cmd.data.opcard[i])
        end
    end

    u.hand_left_count = u.hand_left_count - remove_num
    if cmd.data.from_seat ~= u.seat and ftype ~= FZType.Gang_Peng then
        local u = data.player_card_data[cmd.data.from_seat]
        table.remove(u.outcard_list, #u.outcard_list)
    end
    data.fz = fz
end

function M:CmdWin(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.win = cmd.seat
end

function M:CmdNiao(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.niao = cmd.data.niao
end

function M:CmdPiao(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.player_card_data[cmd.seat].piao_niao = cmd.data.num
end

function M:CmdFZTip(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.seat = cmd.seat
    local tiplist = FZTipList.new()
    local list = cmd.data.tip_list
    for i = 1, #list do
        local dtip = list[i]
        local tip = {}
        tip.id = dtip["id"]
        tip.weight = dtip["weight"]
        tip.card = dtip["card"]
        tip.type = dtip["type"]
        tip.opcard = dtip["opcard"]
        tiplist:AddTip(tip)
    end
    --排序规则，胡杠碰
    tiplist:SortList(function(a, b)
        return a.type < b.type
    end)
    data.tiplist = tiplist
    data.weight = cmd.data.weight
end

function M:GangScore(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.seat = cmd.seat
    data.totalScoreList = cmd.data.totalScoreList
    data.playerList = cmd.data.playerList
    data.addScoreList = cmd.data.addScoreList
end

function M:CmdResult(cmd, index)
    local data = self:CopyLastStep(index)
    data.cmd = cmd.cmd
    data.seat = 0
    data.result_data = cmd.data
    if not data._flag_result then
        for i = 1, #cmd.data.info_list do
            local info = cmd.data.info_list[i]
            if info.is_win and info.seat ~= data.current_out_seat then
                local u = data.player_card_data[info.seat]
                u.card_list[#u.card_list + 1] = info.win_card
                local u = data.player_card_data[data.last_out_seat]
                table.remove(u.outcard_list, #u.outcard_list)
            end
        end
    end
    data._flag_result = true
end

function M:CopyLastStep(index)
    local step = {}
    local last_step = self._step[index]
    step = membe_deep_clone(last_step)
    self._step[#self._step + 1] = step
    step.result_data = nil
    return step
end

function M:UpdateLeftCard(num)
    self._tex_LeftCard.text = "余" .. num .. "张"
end

function M:UpdateCardBox(seat)
    local index = seat
    local people_num = self._room.room_config.people_num
    if people_num == 2 and seat == 2 then
        index = 3
    elseif people_num == 3 and seat == 3 then
        index = 4
    end
    self._ctr_cardbox.selectedIndex = index
end

function M:UpdateRound()
    self._view:GetChild("text_round").text = string.format("局数：%d /%d", self._room.curren_round,
        self._room.room_config.round)
end

function M:ShowJing()
    print("lingmeng jing ", self._room.jing)
    if self._room.jing then
        self.jing.visible = true
        MJPlayerCardInfoView.fillCard2(self, self.jing, "b202_", self._room.jing)
    else
        self.jing.visible = false
    end
end

function M:UpdateStep(step)
    self._record:GetChild("tex_step").text = "第 " .. step .. " / " .. #self._step .. "步"
end

function M.HandCardSortAndJing(a, b)
    local jing = DataManager.CurrenRoom.jing
    if a == jing or b == jing then
        if a == b then
            return a < b
        end
        return a == jing
    else
        if a < 200 then
            a = a + 1000
        elseif a < 300 then
            a = a + 3000
        elseif a < 400 then
            a = a + 2000
        else
            a = a + 4000
        end
        if b < 200 then
            b = b + 1000
        elseif b < 300 then
            b = b + 3000
        elseif b < 400 then
            b = b + 2000
        else
            b = b + 4000
        end
        return a < b
    end
end

return M