Implement combining of items

src/Dodge/FloorItem.hs

@@ -1,5 +1,6 @@
 module Dodge.FloorItem 
     (copyItemToFloor
+    ,copyItemToFloorID
     ) where
 import Dodge.Data
 import Dodge.Base
@@ -12,7 +13,11 @@ import Data.Maybe
 
 {- | Copy an item to the floor. -}
 copyItemToFloor :: Point2 -> Item -> World -> World
-copyItemToFloor pos it w = w'
+copyItemToFloor pos it = snd . copyItemToFloorID pos it
+
+{- | Copy an item to the floor, returns the floor item's id. -}
+copyItemToFloorID :: Point2 -> Item -> World -> (Int, World)
+copyItemToFloorID pos it w = (,) flid $ w'
     & floorItems %~ IM.insert flid theflit
     & updateLocation 
   where