{-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE UndecidableInstances #-} module T14931_State (MonadState(..), Lazy.evalState) where import qualified Control.Monad.Trans.State.Lazy as Lazy (StateT, get, put, evalState) class Monad m => MonadState s m | m -> s where get :: m s put :: s -> m () instance Monad m => MonadState s (Lazy.StateT s m) where get = Lazy.get put = Lazy.put