diff --git a/gui.lua b/gui.lua
index 4680ef7..fa78a19 100644
--- a/gui.lua
+++ b/gui.lua
@@ -14,15 +14,6 @@ public.config = {
     off_color  = {0.7, 0.3, 0.3},
 }
 
-do
-    local x = 0
-
-    function private.id()
-        x = x + 1
-        return 'Aux_frame'..x
-    end
-end
-
 function public.inline_color(color)
     local r, g, b, a = unpack(color)
     return format('|c%02X%02X%02X%02X', a, r, g, b)
@@ -329,7 +320,7 @@ function public.item(parent)
     local item = CreateFrame('Button', nil, parent)
     item:SetWidth(193)
     item:SetHeight(40)
-    local icon = CreateFrame('CheckButton', m.id(), item, 'ActionButtonTemplate')
+    local icon = CreateFrame('CheckButton', 'aux_frame'..Aux.unique(), item, 'ActionButtonTemplate')
     icon:SetPoint('LEFT', 2, 0.5)
     icon:SetHighlightTexture(nil)
     icon:RegisterForClicks()
@@ -379,99 +370,53 @@ function public.vertical_line(parent, x_offset, top_offset, bottom_offset, inver
     return texture
 end
 
-do
-    local id = 0
-    function public.dropdown(parent)
-        id = id + 1
 
-        local dropdown = CreateFrame('Frame', 'aux_dropdown'..id, parent, 'UIDropDownMenuTemplate')
+function public.dropdown(parent)
+    local dropdown = CreateFrame('Frame', 'aux_frame'..Aux.unique(), parent, 'UIDropDownMenuTemplate')
 
-        dropdown:SetBackdrop{bgFile=[[Interface\Buttons\WHITE8X8]], edgeFile=[[Interface\Buttons\WHITE8X8]], edgeSize=m.config.edge_size, insets={top=5,bottom=5}}
-        dropdown:SetBackdropColor(unpack(m.config.content_color.backdrop))
-        dropdown:SetBackdropBorderColor(unpack(m.config.content_color.border))
-        local left = getglobal(dropdown:GetName()..'Left'):Hide()
-        local middle = getglobal(dropdown:GetName()..'Middle'):Hide()
-        local right = getglobal(dropdown:GetName()..'Right'):Hide()
+    dropdown:SetBackdrop{bgFile=[[Interface\Buttons\WHITE8X8]], edgeFile=[[Interface\Buttons\WHITE8X8]], edgeSize=m.config.edge_size, insets={top=5,bottom=5}}
+    dropdown:SetBackdropColor(unpack(m.config.content_color.backdrop))
+    dropdown:SetBackdropBorderColor(unpack(m.config.content_color.border))
+    local left = getglobal(dropdown:GetName()..'Left'):Hide()
+    local middle = getglobal(dropdown:GetName()..'Middle'):Hide()
+    local right = getglobal(dropdown:GetName()..'Right'):Hide()
 
-        local button = getglobal(dropdown:GetName()..'Button')
-        button:ClearAllPoints()
-        button:SetPoint('RIGHT', dropdown, 0, 0)
+    local button = getglobal(dropdown:GetName()..'Button')
+    button:ClearAllPoints()
+    button:SetPoint('RIGHT', dropdown, 0, 0)
 
-        local text = getglobal(dropdown:GetName()..'Text')
-        text:ClearAllPoints()
-        text:SetPoint('RIGHT', button, 'LEFT', -2, 0)
-        text:SetPoint('LEFT', dropdown, 'LEFT', 8, 0)
-        text:SetFont(m.config.content_font, 13)
-        text:SetShadowColor(0, 0, 0, 0)
+    local text = getglobal(dropdown:GetName()..'Text')
+    text:ClearAllPoints()
+    text:SetPoint('RIGHT', button, 'LEFT', -2, 0)
+    text:SetPoint('LEFT', dropdown, 'LEFT', 8, 0)
+    text:SetFont(m.config.content_font, 13)
+    text:SetShadowColor(0, 0, 0, 0)
 
-    --
-    --    dropdown:ClearAllPoints()
-    --    dropdown:SetPoint("BOTTOMRIGHT", frame, "BOTTOMRIGHT", -7, 0)
-    --    dropdown:SetScript("OnHide", nil)
-    --    dropdown:SetScript("OnEnter", Control_OnEnter)
-    --    dropdown:SetScript("OnLeave", Control_OnLeave)
-    --    dropdown:SetScript("OnMouseUp", function(self, button) Dropdown_TogglePullout(self.obj.button, button) end)
-    --    TSMAPI.Design:SetContentColor(dropdown)
-    --
-    --    local left = _G[dropdown:GetName().."Left"]
-    --    local middle = _G[dropdown:GetName().."Middle"]
-    --    local right = _G[dropdown:GetName().."Right"]
-    --
-    --    middle:ClearAllPoints()
-    --    right:ClearAllPoints()
-    --
-    --    middle:SetPoint("LEFT", left, "RIGHT", 0, 0)
-    --    middle:SetPoint("RIGHT", right, "LEFT", 0, 0)
-    --    right:SetPoint("TOPRIGHT", dropdown, "TOPRIGHT", 0, 17)
-    --
-    --    local button = _G[dropdown:GetName().."Button"]
-    --    button:RegisterForClicks("AnyUp")
-    --    button:SetScript("OnEnter", Control_OnEnter)
-    --    button:SetScript("OnLeave", Control_OnLeave)
-    --    button:SetScript("OnClick", Dropdown_TogglePullout)
-    --    button:ClearAllPoints()
-    --    button:SetPoint("RIGHT", dropdown, 0, 0)
-    --
-    --    local text = _G[dropdown:GetName().."Text"]
-    --    text:ClearAllPoints()
-    --    text:SetPoint("RIGHT", button, "LEFT", -2, 0)
-    --    text:SetPoint("LEFT", dropdown, "LEFT", 8, 0)
-    --    text:SetFont(TSMAPI.Design:GetContentFont("normal"))
-    --    text:SetShadowColor(0, 0, 0, 0)
-    --
-    --    local label = frame:CreateFontString(nil, "OVERLAY")
-    --    label:SetPoint("TOPLEFT", frame, "TOPLEFT", 0, 0)
-    --    label:SetPoint("TOPRIGHT", frame, "TOPRIGHT", 0, 0)
-    --    label:SetJustifyH("LEFT")
-    --    label:SetHeight(18)
-    --    label:SetFont(TSMAPI.Design:GetContentFont("small"))
-    --    label:SetShadowColor(0, 0, 0, 0)
-    --    label:Hide()
-    --
-    --    left:Hide()
-    --    middle:Hide()
-    --    right:Hide()
-    --
-    --    local widget = {
-    --        frame = frame,
-    --        label = label,
-    --        dropdown = dropdown,
-    --        text = text,
-    --        button = button,
-    --        count = count,
-    --        alignoffset = 30,
-    --        type = Type,
-    --    }
-    --    for method, func in pairs(methods) do
-    --        widget[method] = func
-    --    end
-    --    frame.obj = widget
-    --    dropdown.obj = widget
-    --    text.obj = widget
-    --    button.obj = widget
+--
+--    dropdown:ClearAllPoints()
+--    dropdown:SetPoint("BOTTOMRIGHT", frame, "BOTTOMRIGHT", -7, 0)
+--    dropdown:SetScript("OnHide", nil)
+--    dropdown:SetScript("OnEnter", Control_OnEnter)
+--    dropdown:SetScript("OnLeave", Control_OnLeave)
+--    dropdown:SetScript("OnMouseUp", function(self, button) Dropdown_TogglePullout(self.obj.button, button) end)
+--    TSMAPI.Design:SetContentColor(dropdown)
+--
+--    middle:ClearAllPoints()
+--    right:ClearAllPoints()
+--
+--    middle:SetPoint("LEFT", left, "RIGHT", 0, 0)
+--    middle:SetPoint("RIGHT", right, "LEFT", 0, 0)
+--    right:SetPoint("TOPRIGHT", dropdown, "TOPRIGHT", 0, 17)
+--
+--    local button = _G[dropdown:GetName().."Button"]
+--    button:RegisterForClicks("AnyUp")
+--    button:SetScript("OnEnter", Control_OnEnter)
+--    button:SetScript("OnLeave", Control_OnLeave)
+--    button:SetScript("OnClick", Dropdown_TogglePullout)
+--    button:ClearAllPoints()
+--    button:SetPoint("RIGHT", dropdown, 0, 0)
 
-        return dropdown
-    end
+    return dropdown
 end
 
 function public.slider(frame)
diff --git a/tables/auction_listing.lua b/tables/auction_listing.lua
index 7756cc0..0bfaf61 100644
--- a/tables/auction_listing.lua
+++ b/tables/auction_listing.lua
@@ -900,7 +900,7 @@ local methods = {
     end,
 
     RemoveAuctionRecord = function(self, record)
-        local index = Aux.util.index_of(record, self.records)
+        local index = Aux.util.key(record, self.records)
         if index then
             tremove(self.records, index)
         end
@@ -910,7 +910,7 @@ local methods = {
     RemoveSelectedRecord = function(self, count)
         count = count or 1
         for i=1, count do
-            local index = Aux.util.index_of(self.selected, self.records)
+            local index = Aux.util.key(self.selected, self.records)
             if index then
                 tremove(self.records, index)
             end
@@ -927,7 +927,7 @@ local methods = {
     end,
 
     ContainsRecord = function(rt, record)
-        if Aux.util.index_of(record, rt.records) then
+        if Aux.util.key(record, rt.records) then
             return true
         end
     end,
diff --git a/tabs/post/frames.lua b/tabs/post/frames.lua
index 93f24e5..72cafb8 100644
--- a/tabs/post/frames.lua
+++ b/tabs/post/frames.lua
@@ -75,7 +75,7 @@ Aux.post_tab.FRAMES(function(m, public, private)
     m.auction_listing:EnableSorting(false)
     m.auction_listing:DisableSelection(true)
     m.auction_listing:SetHandler('OnClick', function(table, row_data, column, button)
-        local column_index = Aux.util.index_of(column, column.row.cols)
+        local column_index = Aux.util.key(column, column.row.cols)
         local unit_start_price, unit_buyout_price = m.undercut(row_data.record, m.stack_size_slider:GetValue(), button == 'RightButton')
         if column_index == 3 then
             m.stack_size_slider:SetValue(row_data.record.stack_size)
diff --git a/tabs/search/core.lua b/tabs/search/core.lua
index 4e5b67b..2a75c3f 100644
--- a/tabs/search/core.lua
+++ b/tabs/search/core.lua
@@ -229,7 +229,7 @@ function private.get_form_filter()
         end
     end
 
-    local quality = UIDropDownMenu_GetSelectedValue(m.quality_dropdown) ~= 0 and UIDropDownMenu_GetSelectedValue(m.quality_dropdown)
+    local quality = UIDropDownMenu_GetSelectedValue(m.quality_dropdown) >= 0 and UIDropDownMenu_GetSelectedValue(m.quality_dropdown)
     if quality then
         add(strlower(getglobal('ITEM_QUALITY'..quality..'_DESC')))
     end
@@ -765,7 +765,7 @@ function private.initialize_quality_dropdown()
 
 	UIDropDownMenu_AddButton{
 		text = ALL,
-        value = 0,
+        value = -1,
 		func = on_click,
 	}
 	for i=0,4 do
@@ -777,3 +777,59 @@ function private.initialize_quality_dropdown()
 	end
 end
 
+function private.initialize_filter_dropdown()
+    local function on_click()
+        UIDropDownMenu_SetSelectedValue(m.filter_dropdown, this.value)
+        m.filter_button:SetText(this.value)
+        if Aux.safe(Aux).scan_util.filters[this.value].arity/0 == 0 then
+            m.filter_input:Hide()
+        else
+            m.filter_input:Show()
+        end
+    end
+
+    for _, filter in {'and', 'or', 'not', 'min-unit-buy', 'max-unit-bid', 'max-unit-bid', 'max-unit-buy', 'bid-profit', 'buy-profit', 'bid-vend-profit', 'buy-vend-profit', 'bid-dis-profit', 'buy-dis-profit', 'bid-pct', 'buy-pct', 'item', 'tooltip', 'min-lvl', 'max-lvl', 'rarity', 'left', 'utilizable', 'discard'} do
+        UIDropDownMenu_AddButton{
+            text = filter,
+            value = filter,
+            func = on_click,
+        }
+    end
+end
+
+do
+    local stack = {}
+
+    function private.add_post_filter()
+        local name = UIDropDownMenu_GetSelectedValue(m.filter_dropdown) or ''
+        local input = m.filter_input:GetText()
+        if Aux.safe(Aux).scan_util.filters[name].test(input)/true then
+            local filter = name
+            if Aux.safe(Aux).scan_util.filters[name].arity/0 > 0 then
+                filter = filter..'/'..input
+            end
+
+            local filters = m.filter_display:GetText() or ''
+            if filters ~= '' then
+                filters = filters..'|n'
+            end
+            for _=1,getn(stack) do
+                filters = filters..'    '
+            end
+            m.filter_display:SetText(filters..filter)
+
+            m.filter_input:SetText('')
+            m.filter_input:ClearFocus()
+
+            if Aux.util.set('and', 'or')[filter] then
+                tinsert(stack, 2)
+            else
+                local top = tremove(stack)
+                if top and top > 1 then
+                    tinsert(stack, top - 1)
+                end
+            end
+        end
+    end
+end
+
diff --git a/tabs/search/frames.lua b/tabs/search/frames.lua
index 051a523..21e64b2 100644
--- a/tabs/search/frames.lua
+++ b/tabs/search/frames.lua
@@ -517,186 +517,46 @@ Aux.search_tab.FRAMES(function(m, public, private)
         private.quality_dropdown = dropdown
     end
     Aux.gui.vertical_line(m.frame.filter, 332)
-    local function add_modifier(...)
-        local current_filter_string = m.search_box:GetText()
-        for i=1,arg.n do
-            if current_filter_string ~= '' and strsub(current_filter_string, -1) ~= '/' then
-                current_filter_string = current_filter_string..'/'
-            end
-            current_filter_string = current_filter_string..arg[i]
-        end
-        m.search_box:SetText(current_filter_string)
-    end
     do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPRIGHT', -362, -10)
-        btn:SetWidth(50)
-        btn:SetHeight(19)
-        btn:SetText('and')
-        btn:SetScript('OnClick', function()
-            add_modifier('and')
+        local dropdown = Aux.gui.dropdown(m.frame.filter)
+        dropdown:SetPoint('TOPRIGHT', -200, -10)
+        dropdown:SetWidth(170)
+        dropdown:SetHeight(10)
+        UIDropDownMenu_Initialize(dropdown, m.initialize_filter_dropdown)
+        dropdown:SetScript('OnShow', function()
+            UIDropDownMenu_Initialize(this, m.initialize_filter_dropdown)
         end)
-        private.and_operator_button = btn
+        getglobal(dropdown:GetName()..'Text'):Hide()
+        private.filter_dropdown = dropdown
     end
     do
         local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('LEFT', m.and_operator_button, 'RIGHT', 10, 0)
-        btn:SetWidth(50)
-        btn:SetHeight(19)
-        btn:SetText('or')
-        btn:SetScript('OnClick', function()
-            add_modifier('or')
+        btn:SetWidth(170)
+        btn:SetHeight(25)
+        btn:SetPoint('CENTER', m.filter_dropdown, 'CENTER', 0, 0)
+        btn:SetScript('OnClick', m.add_post_filter)
+        private.filter_button = btn
+    end
+    do
+        local input = Aux.gui.editbox(m.frame.filter)
+        input:SetPoint('LEFT', m.filter_dropdown, 'RIGHT', 10, 0)
+        input:SetWidth(150)
+        input:SetHeight(25)
+        --            editbox:SetNumeric(true)
+        --            editbox:SetMaxLetters(2)
+        input:SetScript('OnChar', function()
+            local filter = Aux.safe(Aux).scan_util.filters[UIDropDownMenu_GetSelectedValue(m.filter_dropdown)]
+            Aux.completion.complete(this, function() return ({filter.test()/nil})[2] end)
         end)
-        private.or_operator_button = btn
+        input:SetScript('OnEnterPressed', m.add_post_filter)
+        private.filter_input = input
     end
     do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('LEFT', m.or_operator_button, 'RIGHT', 10, 0)
-        btn:SetWidth(50)
-        btn:SetHeight(19)
-        btn:SetText('not')
-        btn:SetScript('OnClick', function()
-            add_modifier('not')
-        end)
-        private.not_operator_button = btn
-    end
-    private.modifier_buttons = {}
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.and_operator_button, 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['min-unit-bid'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['min-unit-bid'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['min-unit-buy'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['min-unit-buy'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['max-unit-bid'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['max-unit-bid'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['max-unit-buy'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['max-unit-buy'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['bid-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['bid-profit'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['buy-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['buy-profit'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['bid-vend-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['bid-vend-profit'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['buy-vend-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['buy-vend-profit'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['bid-dis-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['bid-dis-profit'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['buy-dis-profit'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.and_operator_button, 'BOTTOMLEFT', 205, -10)
-        m.modifier_buttons['bid-pct'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['bid-pct'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['buy-pct'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['buy-pct'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['item'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['item'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['tooltip'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['tooltip'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['min-lvl'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['min-lvl'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['max-lvl'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['max-lvl'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['rarity'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['rarity'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['left'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['left'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['utilizable'] = btn
-    end
-    do
-        local btn = Aux.gui.button(m.frame.filter, 16)
-        btn:SetPoint('TOPLEFT', m.modifier_buttons['utilizable'], 'BOTTOMLEFT', 0, -10)
-        m.modifier_buttons['discard'] = btn
-    end
-    for modifier_name, btn in m.modifier_buttons do
-        local modifier_name = modifier_name
-        local btn = btn
-
-        local filter = Aux.scan_util.filters[modifier_name]
-
-        btn:SetWidth(100)
-        btn:SetHeight(19)
-        btn:SetText(modifier_name)
-        btn:SetScript('OnClick', function()
-            local args = Aux.util.map(btn.inputs, function(input) return input:GetText() end)
-            if filter.test(unpack(args)) then
-                add_modifier(modifier_name, unpack(args))
-                for _, input in btn.inputs do
-                    input:SetText('')
-                    input:ClearFocus()
-                end
-            end
-        end)
-        btn.inputs = {}
-        if filter.arity > 0 then
-            local editbox = Aux.gui.editbox(m.frame.filter)
-            editbox.complete = Aux.completion.complete(function() return ({filter.test()})[2] end)
-            editbox:SetPoint('LEFT', btn, 'RIGHT', 10, 0)
-            editbox:SetWidth(80)
-            --            editbox:SetNumeric(true)
-            --            editbox:SetMaxLetters(2)
-            editbox:SetScript('OnChar', function()
-                this:complete()
-            end)
-            local on_click = btn:GetScript('OnClick')
-            editbox:SetScript('OnEnterPressed', function()
-                on_click()
-            end)
-            tinsert(btn.inputs, editbox)
-        end
+        local label = Aux.gui.label(m.frame.filter, 13)
+        label:SetPoint('TOPLEFT', 340, -50)
+        label:SetWidth(200)
+        label:SetJustifyH('LEFT')
+        private.filter_display = label
     end
 
     private.status_bars = {}
diff --git a/util/core.lua b/util/core.lua
index 1158ebe..ddfbd90 100644
--- a/util/core.lua
+++ b/util/core.lua
@@ -3,6 +3,22 @@ local m, public, private = Aux.module'util'
 function public.pass()
 end
 
+function public.sum(...)
+	local x = 0
+	for i=1,arg.n do
+		x = x + arg[i]
+	end
+	return x
+end
+
+function public.product(...)
+	local x = 0
+	for i=1,arg.n do
+		x = x * arg[i]
+	end
+	return x
+end
+
 function public.id(value)
 	return value
 end
@@ -179,10 +195,10 @@ function public.take(n, xs)
 	return ys
 end
 
-function public.index_of(value, array)
-	for i, item in ipairs(array) do
-		if item == value then
-			return i
+function public.key(value, t)
+	for k, v in t do
+		if v == value then
+			return k
 		end
 	end
 end
diff --git a/util/scan_util.lua b/util/scan_util.lua
index bdef823..030f588 100644
--- a/util/scan_util.lua
+++ b/util/scan_util.lua
@@ -79,13 +79,9 @@ public.filters = {
                 return false, {'poor', 'common', 'uncommon', 'rare', 'epic'}, 'Erroneous rarity modifier'
             end
 
-            local code = ({
-                ['poor'] = 0,
-                ['common'] = 1,
-                ['uncommon'] = 2,
-                ['rare'] = 3,
-                ['epic'] = 4,
-            })[rarity or '']
+            local code = Aux.util.key(rarity, {'poor', 'common', 'uncommon', 'rare', 'epic'})
+            code = code and code - 1
+
             if not code then
                 return false, {}, 'Erroneous rarity modifier'
             end