fix warnings

app/Main.hs

@@ -1,8 +1,5 @@
 module Main where
 
-import           Prelude( IO
-                        , return )
-
 import           Lib( run )
 
 main :: IO ()

src/Animation.hs

@@ -79,7 +79,7 @@ animate :: (Tree -> Tree)
         -> Tree
         -> Animation
         -> IO (Maybe Animation)
-animate pureAnim ioAnim state a@(Animation _) = do
+animate pureAnim ioAnim state (Animation _) = do
   let newState = pureAnim state
   putStrLn "animation is rendered"
   return $ Just (Animation $ ioAnim newState) -- When returning Nothing here the problem disappears