Fix rb scrolling

src/Dodge/Creature/State.hs

@@ -3,6 +3,7 @@ module Dodge.Creature.State (
     doDamage,
 ) where
 
+import Data.Maybe
 import Dodge.Creature.Test
 import Data.Foldable
 import Dodge.Base
@@ -64,13 +65,12 @@ stateUpdate f =
         ]
 
 heldAimEffects :: Creature -> World -> World
-heldAimEffects cr 
-    | crIsAiming cr = case cr ^? crInv . ix (cr ^. crInvSel . iselPos) of
-        Just itm -> case itm ^? itEffect . ieWhileAiming of
-            Just f -> doInvEffect f itm cr
-            _ -> id
-        _ -> id
-    | otherwise = id
+heldAimEffects cr = fromMaybe id $ do
+    guard (crIsAiming cr)
+    ipos <- cr ^? crInvSel . iselPos
+    itm <- cr ^? crInv . ix ipos
+    f <- itm ^? itEffect . ieWhileAiming
+    return $ doInvEffect f itm cr
 
 checkDeath :: Creature -> World -> World
 checkDeath cr w