import GHC.Prim
import {-# SOURCE #-} GHC.Show
import {-# SOURCE #-} GHC.Err
+import {-# SOURCE #-} GHC.IO (failIO)
-- These two are not strictly speaking required by this module, but they are
-- implicit dependencies whenever () or tuples are mentioned, so adding them
%*********************************************************
%* *
+\subsection{@Functor@ and @Monad@ instances for @IO@}
+%* *
+%*********************************************************
+
+\begin{code}
+instance Functor IO where
+ fmap f x = x >>= (return . f)
+
+instance Monad IO where
+ {-# INLINE return #-}
+ {-# INLINE (>>) #-}
+ {-# INLINE (>>=) #-}
+ m >> k = m >>= \ _ -> k
+ return = returnIO
+ (>>=) = bindIO
+ fail s = GHC.IO.failIO s
+
+returnIO :: a -> IO a
+returnIO x = IO $ \ s -> (# s, x #)
+
+bindIO :: IO a -> (a -> IO b) -> IO b
+bindIO (IO m) k = IO $ \ s -> case m s of (# new_s, a #) -> unIO (k a) new_s
+
+thenIO :: IO a -> IO b -> IO b
+thenIO (IO m) k = IO $ \ s -> case m s of (# new_s, _ #) -> unIO k new_s
+
+unIO :: IO a -> (State# RealWorld -> (# State# RealWorld, a #))
+unIO (IO a) = a
+\end{code}
+
+%*********************************************************
+%* *
\subsection{@getTag@}
%* *
%*********************************************************
-- #hide
module GHC.IO (
- IO(..), unIO, failIO, liftIO, bindIO, thenIO, returnIO,
+ IO(..), unIO, failIO, liftIO,
unsafePerformIO, unsafeInterleaveIO,
unsafeDupablePerformIO, unsafeDupableInterleaveIO,
noDuplicate,
--SDM
-}
-unIO :: IO a -> (State# RealWorld -> (# State# RealWorld, a #))
-unIO (IO a) = a
-
-instance Functor IO where
- fmap f x = x >>= (return . f)
-
-instance Monad IO where
- {-# INLINE return #-}
- {-# INLINE (>>) #-}
- {-# INLINE (>>=) #-}
- m >> k = m >>= \ _ -> k
- return x = returnIO x
-
- m >>= k = bindIO m k
- fail s = failIO s
-
liftIO :: IO a -> State# RealWorld -> STret RealWorld a
liftIO (IO m) = \s -> case m s of (# s', r #) -> STret s' r
-bindIO :: IO a -> (a -> IO b) -> IO b
-bindIO (IO m) k = IO ( \ s ->
- case m s of
- (# new_s, a #) -> unIO (k a) new_s
- )
-
-thenIO :: IO a -> IO b -> IO b
-thenIO (IO m) k = IO ( \ s ->
- case m s of
- (# new_s, _ #) -> unIO k new_s
- )
-
-returnIO :: a -> IO a
-returnIO x = IO (\ s -> (# s, x #))
-
failIO :: String -> IO a
failIO s = IO (raiseIO# (toException (userError s)))