Implmement display system

src/Game/Display.hs

@@ -0,0 +1,24 @@
+{-# LANGUAGE Arrows #-}
+{-# LANGUAGE OverloadedRecordDot #-}
+{-# LANGUAGE ViewPatterns #-}
+
+module Game.Display where
+
+import Control.Monad
+import Control.Monad.Trans.MSF.Reader
+import Control.Monad.Trans.MSF.Writer
+import Data.Maybe
+import Data.MonadicStreamFunction
+import Game.State
+import Game.Utils
+import Graphics.Gloss
+import Graphics.Gloss.Interface.IO.Game
+
+getSquare :: (Int, Int) -> Picture
+getSquare (toEnum -> x, toEnum -> y) =
+  translate (x * 25) (y * 25) $ rectangleSolid 25 25
+
+displayState :: Monad m => MSF (DrawerT m) GameState ()
+displayState = proc state -> do
+  draw -< mconcat $ color green . getSquare <$> state.snakePos
+  draw -< color red $ getSquare state.berryPos

src/Game/Engine.hs

@@ -59,4 +59,5 @@ mainSF = proc () -> do
   -- undefined is safe here because the first frame is guaranteed to be a tick
   state <- hold undefined -< state'
 
-  returnA -< ()
+  -- Display the current state
+  displayState -< state