Remove a lot of IO/maybe cruft

src/Dodge/Event/Keyboard.hs

@@ -47,9 +47,9 @@ On release, remove scancode from the 'Set' of pressed keys.
 On press, adds the scancode, and perhaps applies a direct effect:
 see 'handlePressedKeyInGame'.
 -}
-handleKeyboardEvent :: KeyboardEventData -> Universe -> IO (Maybe Universe)
+handleKeyboardEvent :: KeyboardEventData -> Universe -> Universe
 handleKeyboardEvent kev u = case keyboardEventKeyMotion kev of
-    Released -> return . Just $ u & uvWorld . input . pressedKeys . at scode .~ Nothing
+    Released -> u & uvWorld . input . pressedKeys . at scode .~ Nothing
     Pressed ->
         handlePressedKey
             (keyboardEventRepeat kev)
@@ -61,17 +61,17 @@ handleKeyboardEvent kev u = case keyboardEventKeyMotion kev of
         | otherwise = InitialPress
     scode = (keysymScancode . keyboardEventKeysym) kev
 
-handlePressedKey :: Bool -> Scancode -> Universe -> IO (Maybe Universe)
-handlePressedKey True _ u = return $ Just u
+handlePressedKey :: Bool -> Scancode -> Universe -> Universe
+handlePressedKey True _ u = u
 handlePressedKey _ scode u = case scode of
-    ScancodeF5 -> return . Just $ doQuicksave u
-    ScancodeF9 -> return . Just $ loadSaveSlot QuicksaveSlot u
-    ScancodeSemicolon -> return . Just $ gotoTerminal u
+    ScancodeF5 -> doQuicksave u
+    ScancodeF9 -> loadSaveSlot QuicksaveSlot u
+    ScancodeSemicolon -> gotoTerminal u
     _ | null (_uvScreenLayers u) -> case u ^? uvWorld . cWorld . lWorld . hud . hudElement . subInventory of
         Just (DisplayTerminal tmid)
             | inTermFocus (_uvWorld u) ->
-                return $ uvWorld (Just . handlePressedKeyTerminal tmid scode) u
-        _ -> return $ Just u
+                over uvWorld (handlePressedKeyTerminal tmid scode) u
+        _ -> u
     _ -> handlePressedKeyInMenu (head $ _uvScreenLayers u) scode u
 
 handlePressedKeyTerminal :: Int -> Scancode -> World -> World