[project @ 2002-04-26 12:48:16 by simonmar]

[ghc-base.git] / GHC / IOBase.lhs

diff --git a/GHC/IOBase.lhs b/GHC/IOBase.lhs
index 6ef6b06..9c2c034 100644 (file)
--- a/GHC/IOBase.lhs
+++ b/GHC/IOBase.lhs
@@ -1,14 +1,18 @@
-% ------------------------------------------------------------------------------
-% $Id: IOBase.lhs,v 1.7 2002/03/14 12:09:50 simonmar Exp $
-% 
-% (c) The University of Glasgow, 1994-2001
-%
-
-% Definitions for the @IO@ monad and its friends.  Everything is exported
-% concretely; the @IO@ module itself exports abstractly.
-
 \begin{code}
 {-# OPTIONS -fno-implicit-prelude #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  GHC.IOBase
+-- Copyright   :  (c) The University of Glasgow 1994-2002
+-- License     :  see libraries/base/LICENSE
+-- 
+-- Maintainer  :  cvs-ghc@haskell.org
+-- Stability   :  internal
+-- Portability :  non-portable (GHC Extensions)
+--
+-- Definitions for the 'IO' monad and its friends.
+--
+-----------------------------------------------------------------------------
 
 module GHC.IOBase where
 
@@ -78,6 +82,12 @@ bindIO (IO m) k = IO ( \ s ->
     (# 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, a #) -> unIO k new_s
+  )
+
 returnIO :: a -> IO a
 returnIO x = IO (\ s -> (# s, x #))