Remove a lot of IO/maybe cruft

src/Dodge/Menu/Option.hs

@@ -2,7 +2,7 @@ module Dodge.Menu.Option
     where
 import Dodge.Data.Universe
 
-slTitleOptionsEff :: String -> [MenuOption] -> (Universe -> IO (Maybe Universe)) -> ScreenLayer
+slTitleOptionsEff :: String -> [MenuOption] -> (Universe -> Universe) -> ScreenLayer
 slTitleOptionsEff title ops eff =
     OptionScreen
         { _scTitle = const title

src/Dodge/Menu/OptionType.hs

@@ -7,12 +7,12 @@ import Dodge.Menu.PushPop
 
 makeBoolOption lns t =
     Toggle
-        (return . Just . (uvConfig . lns #%~ not))
+        (uvConfig . lns #%~ not)
         (\u -> MODStringOption t (show (u ^# uvConfig . lns)))
 
 makeEnumOption lns str sideeff =
     Toggle
-        (\u -> Just <$> sideeff (u & uvConfig . lns #%~ cycleEnum))
+        (\u -> sideeff (u & uvConfig . lns #%~ cycleEnum))
         (\u -> MODStringOption str (show (u ^# uvConfig . lns)))
 
 makeSubmenuOption submenu t = Toggle (pushScreen submenu) (const t)

src/Dodge/Menu/PushPop.hs

@@ -3,14 +3,9 @@ module Dodge.Menu.PushPop where
 import Dodge.Data.Universe
 import LensHelp
 
-popScreen' :: Universe -> Maybe Universe
-popScreen' = Just . (uvScreenLayers %~ tail)
+popScreen :: Universe -> Universe
+popScreen = uvScreenLayers %~ tail
 
-popScreen :: Universe -> IO (Maybe Universe)
-popScreen = return . popScreen'
+pushScreen :: ScreenLayer -> Universe -> Universe
+pushScreen ml = (uvScreenLayers .:~ ml)
 
-pushScreen' :: ScreenLayer -> Universe -> Maybe Universe
-pushScreen' ml = Just . (uvScreenLayers .:~ ml)
-
-pushScreen :: ScreenLayer -> Universe -> IO (Maybe Universe)
-pushScreen ml = return . pushScreen' ml