better lens for fetching EditState from AppMode

src/Hamming/App/Types.hs

@@ -36,7 +36,7 @@ module Hamming.App.Types (
   -- ** AppMode
   AppMode (..),
   -- *** Lenses
-  editStateL,
+  editState,
   -- ** EditState,
   EditState (..),
   -- *** Lenses
@@ -54,7 +54,6 @@ module Hamming.App.Types (
 
 import Brick.Types (BrickEvent, EventM)
 import Data.Word (Word16)
-import Lens.Micro (Lens', lens)
 import Lens.Micro.TH (makeLenses)
 
 -- | The main state of the application
@@ -66,7 +65,9 @@ data AppState = AppState
 -- | The application's main mode
 data AppMode
   = DisplayMode
-  | EditMode EditState
+  | EditMode
+    { _editState :: EditState
+    }
   deriving (Eq, Show)
 
 -- | The state of the editor
@@ -91,20 +92,10 @@ type Handler = Event -> Action ()
 
 concat <$> mapM makeLenses
   [ ''AppState
+  , ''AppMode
   , ''EditState
   ]
 
-editStateL :: Lens' AppMode (Maybe EditState)
-editStateL = lens
-  ( \case
-    DisplayMode -> Nothing
-    EditMode s  -> Just s
-  )
-  ( const $ \case
-    Just s  -> EditMode s
-    Nothing -> DisplayMode
-  )
-
 -- | Initial application state
 initialState :: AppState
 initialState = AppState DisplayMode 0