[project @ 2001-03-23 16:36:20 by simonmar]

[ghc-hetmet.git] / ghc / lib / std / Monad.lhs

diff --git a/ghc/lib/std/Monad.lhs b/ghc/lib/std/Monad.lhs
index b1c5a9c..ca370ae 100644 (file)
--- a/ghc/lib/std/Monad.lhs
+++ b/ghc/lib/std/Monad.lhs
@@ -1,18 +1,19 @@
+% -----------------------------------------------------------------------------
+% $Id: Monad.lhs,v 1.11 2000/06/30 13:39:35 simonmar Exp $
 %
-% (c) The AQUA Project, Glasgow University, 1994-1999
+% (c) The University of Glasgow, 1994-2000
 %
+
 \section[Monad]{Module @Monad@}
 
 \begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
-
 module Monad 
     ( MonadPlus (   -- class context: Monad
          mzero     -- :: (MonadPlus m) => m a
        , mplus     -- :: (MonadPlus m) => m a -> m a -> m a
        )
     , join          -- :: (Monad m) => m (m a) -> m a
-    , guard        -- :: (Monad m) => Bool -> m ()
+    , guard        -- :: (MonadPlus m) => Bool -> m ()
     , when          -- :: (Monad m) => Bool -> m () -> m ()
     , unless        -- :: (Monad m) => Bool -> m () -> m ()
     , ap           -- :: (Monad m) => (m (a -> b)) -> (m a) -> m b
@@ -39,14 +40,7 @@ module Monad
     , (=<<)         -- :: (Monad m) => (a -> m b) -> m a -> m b
     ) where
 
-#ifndef __HUGS__
-import PrelList
-import PrelTup
-import PrelBase
-import PrelMaybe ( Maybe(..) )
-
-infixr 1 =<<
-#endif
+import Prelude
 \end{code}
 
 %*********************************************************
@@ -80,30 +74,6 @@ instance MonadPlus Maybe where
 %*********************************************************
 
 \begin{code}
-#ifdef __HUGS__
--- These functions are defined in the Prelude.
--- sequence       :: Monad m => [m a] -> m [a] 
--- sequence_        :: Monad m => [m a] -> m () 
--- mapM            :: Monad m => (a -> m b) -> [a] -> m [b]
--- mapM_           :: Monad m => (a -> m b) -> [a] -> m ()
-#else
-sequence       :: Monad m => [m a] -> m [a] 
-sequence []     = return []
-sequence (m:ms) = do { x <- m; xs <- sequence ms; return (x:xs) }
-
-sequence_        :: Monad m => [m a] -> m () 
-{-# INLINE sequence_ #-}
-sequence_        =  foldr (>>) (return ())
-
-mapM            :: Monad m => (a -> m b) -> [a] -> m [b]
-{-# INLINE mapM #-}
-mapM f as       =  sequence (map f as)
-
-mapM_           :: Monad m => (a -> m b) -> [a] -> m ()
-{-# INLINE mapM_ #-}
-mapM_ f as      =  sequence_ (map f as)
-#endif
-
 guard           :: MonadPlus m => Bool -> m ()
 guard pred
  | pred      = return ()
@@ -123,15 +93,6 @@ filterM  predM (x:xs) = do
 msum        :: MonadPlus m => [m a] -> m a
 {-# INLINE msum #-}
 msum        =  foldr mplus mzero
- 
-#ifdef __HUGS__
--- This function is defined in the Prelude.
---(=<<)           :: Monad m => (a -> m b) -> m a -> m b
-#else
-{-# SPECIALISE (=<<) :: (a -> [b]) -> [a] -> [b] #-}
-(=<<)           :: Monad m => (a -> m b) -> m a -> m b
-f =<< x                = x >>= f
-#endif
 \end{code}