remove explicit return definitions

Author: L0neGamer

Control/Monad/Trans/Accum.hs

@@ -200,10 +200,6 @@ instance (Monoid w, Functor m, MonadPlus m) => Alternative (AccumT w m) where
     {-# INLINE (<|>) #-}
 
 instance (Monoid w, Functor m, Monad m) => Monad (AccumT w m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a  = AccumT $ const $ return (a, mempty)
-    {-# INLINE return #-}
-#endif
     m >>= k  = AccumT $ \ w -> do
         ~(a, w')  <- runAccumT m w
         ~(b, w'') <- runAccumT (k a) (w `mappend` w')

Control/Monad/Trans/Cont.hs

@@ -176,10 +176,6 @@ instance Applicative (ContT r m) where
     {-# INLINE (*>) #-}
 
 instance Monad (ContT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return x = ContT ($ x)
-    {-# INLINE return #-}
-#endif
     m >>= k  = ContT $ \ c -> runContT m (\ x -> runContT (k x) c)
     {-# INLINE (>>=) #-}
 

Control/Monad/Trans/Except.hs

@@ -214,10 +214,6 @@ instance (Functor m, Monad m, Monoid e) => Alternative (ExceptT e m) where
     {-# INLINEABLE (<|>) #-}
 
 instance (Monad m) => Monad (ExceptT e m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = ExceptT $ return (Right a)
-    {-# INLINE return #-}
-#endif
     m >>= k = ExceptT $ do
         a <- runExceptT m
         case a of

Control/Monad/Trans/Identity.hs

@@ -123,10 +123,6 @@ instance (Alternative m) => Alternative (IdentityT m) where
     {-# INLINE (<|>) #-}
 
 instance (Monad m) => Monad (IdentityT m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = IdentityT . return
-    {-# INLINE return #-}
-#endif
     m >>= k = IdentityT $ runIdentityT . k =<< runIdentityT m
     {-# INLINE (>>=) #-}
 #if !(MIN_VERSION_base(4,13,0))

Control/Monad/Trans/Maybe.hs

@@ -162,10 +162,6 @@ instance (Functor m, Monad m) => Alternative (MaybeT m) where
     {-# INLINE (<|>) #-}
 
 instance (Monad m) => Monad (MaybeT m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = MaybeT . return . Just
-    {-# INLINE return #-}
-#endif
     x >>= f = MaybeT $ do
         v <- runMaybeT x
         case v of

Control/Monad/Trans/RWS/CPS.hs

@@ -225,11 +225,6 @@ instance (Functor m, MonadPlus m) => Alternative (RWST r w s m) where
     {-# INLINE (<|>) #-}
 
 instance (Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s w -> return (a, s, w)
-    {-# INLINE return #-}
-#endif
-
     m >>= k = RWST $ \ r s w -> do
         (a, s', w')    <- unRWST m r s w
         unRWST (k a) r s' w'

Control/Monad/Trans/RWS/Lazy.hs

@@ -199,10 +199,6 @@ instance (Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m) where
     {-# INLINE (<|>) #-}
 
 instance (Monoid w, Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE return #-}
-#endif
     m >>= k  = RWST $ \ r s -> do
         ~(a, s', w)  <- runRWST m r s
         ~(b, s'',w') <- runRWST (k a) r s'

Control/Monad/Trans/RWS/Strict.hs

@@ -203,10 +203,6 @@ instance (Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m) where
     {-# INLINE (<|>) #-}
 
 instance (Monoid w, Monad m) => Monad (RWST r w s m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return a = RWST $ \ _ s -> return (a, s, mempty)
-    {-# INLINE return #-}
-#endif
     m >>= k  = RWST $ \ r s -> do
         (a, s', w)  <- runRWST m r s
         (b, s'',w') <- runRWST (k a) r s'

Control/Monad/Trans/Reader.hs

@@ -162,10 +162,6 @@ instance (Alternative m) => Alternative (ReaderT r m) where
     {-# INLINE (<|>) #-}
 
 instance (Monad m) => Monad (ReaderT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return   = lift . return
-    {-# INLINE return #-}
-#endif
     m >>= k  = ReaderT $ \ r -> do
         a <- runReaderT m r
         runReaderT (k a) r

Control/Monad/Trans/Select.hs

@@ -117,10 +117,6 @@ instance (Functor m, MonadPlus m) => Alternative (SelectT r m) where
     {-# INLINE (<|>) #-}
 
 instance (Monad m) => Monad (SelectT r m) where
-#if !(MIN_VERSION_base(4,8,0))
-    return = lift . return
-    {-# INLINE return #-}
-#endif
     SelectT g >>= f = SelectT $ \ k -> do
         let h x = runSelectT (f x) k
         y <- g ((>>= k) . h)