Determine thunk leak when marking seen walls

src/Dodge/Update.hs

@@ -11,7 +11,6 @@ import Dodge.Config.Data
 import Dodge.Base
 import Dodge.Zone
 import Dodge.WallCreatureCollisions
---import Dodge.LevelGen.Block
 import Dodge.Update.Camera
 import Dodge.SoundLogic
 import Dodge.Inventory
@@ -178,12 +177,14 @@ ppEvents :: World -> World
 ppEvents w = IM.foldl' (flip $ \pp w' -> _ppEvent pp pp w') w $ _pressPlates w
 
 updateSeenWalls :: World -> World
-updateSeenWalls w = foldl' (flip markSeen) w wallsToUpdate
+updateSeenWalls w = foldl' markWallSeen w wallsToUpdate
   where 
     vPos = _cameraViewFrom w
     wallsToUpdate = concatMap (\p -> visibleWalls vPos (vPos +.+p) $ wallsAlongLine vPos (vPos +.+ p) w)
                              $ nRays 20
-    markSeen i = set (walls . ix i . wlSeen) True
+
+markWallSeen :: World -> Wall -> World
+markWallSeen w wl = w & walls . ix (_wlID wl) . wlSeen .~ True
 
 --setTestStringIO :: IO World -> IO World
 --setTestStringIO = fmap (\ w -> set testString (show $ s w) w)
@@ -301,15 +302,14 @@ rotateToOverlappingWall w = case theWall of
     theWall = overlapCircWallsReturnWall p (_crRad cr + 5) (IM.filter _wlRotateTo $ wallsNearPoint p w)
 
 {-
-Finds the IDs of visible walls from a point to another point.  -}
-visibleWalls :: Point2 -> Point2 -> IM.IntMap Wall -> [Int]
+Finds the visible walls from a point to another point.  -}
+visibleWalls :: Point2 -> Point2 -> IM.IntMap Wall -> [Wall]
 visibleWalls p1 p2 ws 
-    = map fst 
-    . takeUntil (_wlIsSeeThrough . snd) 
+    = takeUntil _wlIsSeeThrough 
     . map snd 
     . sortOn (dist p1 . fromJust . fst) 
     . filter ((/=) Nothing . fst) 
     . map f 
     $ IM.toList ws
   where 
-    f (i,wl) = (uncurry intersectSegSeg (_wlLine wl) p1 p2, (i,wl))
+    f (i,wl) = (uncurry intersectSegSeg (_wlLine wl) p1 p2, wl)