{-# LANGUAGE ExistentialQuantification, DeriveDataTypeable #-} module Player ( Player(..) , SomePlayer(..) ) where import Data.Fixed import Data.Typeable import Tank import GLDriver (SomeEvent) class Player a where playerUpdate :: a -> Tank -> (a, Maybe Micro, Bool, Maybe Micro) handleEvent :: a -> SomeEvent -> a handleEvent player _ = player data SomePlayer = forall a. Player a => SomePlayer a instance Player SomePlayer where playerUpdate (SomePlayer player) tank = let (p, angle, move, aangle) = playerUpdate player tank in (SomePlayer p, angle, move, aangle) handleEvent (SomePlayer player) event = SomePlayer $ handleEvent player event