Implement copier, an item that copies the value displayed by other items

src/Dodge/ItEffect.hs

@@ -1,13 +1,17 @@
 {-# LANGUAGE LambdaCase #-}
+
 module Dodge.ItEffect (
     doInvEffect,
 ) where
 
-import Dodge.BlBl
-import Dodge.Item.Location
 import Control.Lens
+import Data.Maybe
+import Dodge.BlBl
 import Dodge.Data.World
 import Dodge.Euse
+import Dodge.Inventory.Path
+import Dodge.Inventory.SelectionList
+import Dodge.Item.Location
 
 doInvEffect :: ItInvEffect -> Item -> Creature -> World -> World
 doInvEffect = \case
@@ -17,9 +21,20 @@ doInvEffect = \case
     RemoveShieldWall -> removeShieldWall
     EffectWhileRoot f -> rootNotrootEff f NoInvEffect
     EffectWhileAttached f -> effectWhileAttached f
-    ItemUseToggle f -> \itm _ 
-        -> pointerToItemID (itm ^. itID) . itUse . useToggle %~ doBlBl f
+    ItemUseToggle f -> \itm _ ->
+        pointerToItemID (itm ^. itID) . itUse . useToggle %~ doBlBl f
     ItemCancelExamineInventory -> \_ _ -> cancelExamineInventory
+    ItemCopierUpdate -> copierItemUpdate
+
+copierItemUpdate :: Item -> Creature -> World -> World
+copierItemUpdate itm cr w = fromMaybe w $ do
+    x <- itm ^? itScroll . itsInt
+    invid <- itm ^? itLocation . ilInvID
+    ip <- itm ^? itType . ibtPathing
+    i <- getInventoryPath x ip invid cr
+    itm' <- cr ^? crInv . ix i
+    v <- getItemValue itm' w cr
+    return $ w & pointerToItem itm . itUse . uValue .~ v
 
 cancelExamineInventory :: World -> World
 cancelExamineInventory = hud . hudElement . subInventory %~ f