X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Control%2FException.hs;h=8a66e9710fccfd9e80465352dfd8234088a42f0a;hb=f7a485978f04e84b086f1974b88887cc72d832d0;hp=444ac876f6c146a779e1ad03c81a22e630363ad5;hpb=7f1f4e7a695c402ddd3a1dc2cc7114e649a78ebc;p=ghc-base.git

diff --git a/Control/Exception.hs b/Control/Exception.hs
index 444ac87..8a66e97 100644
--- a/Control/Exception.hs
+++ b/Control/Exception.hs
@@ -1,15 +1,13 @@
 -----------------------------------------------------------------------------
--- 
+-- |
 -- Module      :  Control.Exception
 -- Copyright   :  (c) The University of Glasgow 2001
--- License     :  BSD-style (see the file libraries/core/LICENSE)
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
 -- 
 -- Maintainer  :  libraries@haskell.org
 -- Stability   :  experimental
 -- Portability :  non-portable
 --
--- $Id: Exception.hs,v 1.1 2001/06/28 14:15:01 simonmar Exp $
---
 -- The External API for exceptions.  The functions provided in this
 -- module allow catching of exceptions in the IO monad.
 --
@@ -29,9 +27,12 @@ module Control.Exception (
 	catch,     -- :: IO a -> (Exception -> IO a) -> IO a
 	catchJust, -- :: (Exception -> Maybe b) -> IO a -> (b -> IO a) -> IO a
 
+	handle,	   -- :: (Exception -> IO a) -> IO a -> IO a
+	handleJust,-- :: (Exception -> Maybe b) -> (b -> IO a) -> IO a -> IO a
+
 	evaluate,  -- :: a -> IO a
 
-	-- Exception predicates (for catchJust, tryJust)
+	-- Exception predicates (for tryJust, catchJust, handleJust)
 
 	ioErrors,		-- :: Exception -> Maybe IOError
 	arithExceptions, 	-- :: Exception -> Maybe ArithException
@@ -44,10 +45,7 @@ module Control.Exception (
 	-- Throwing exceptions
 
 	throw,		-- :: Exception -> a
-#ifndef __STGHUGS__
-	-- for now
 	throwTo,	-- :: ThreadId -> Exception -> a
-#endif
 
 	-- Dynamic exceptions
 
@@ -76,7 +74,8 @@ module Control.Exception (
 
 #ifdef __GLASGOW_HASKELL__
 import Prelude 		hiding (catch)
-import GHC.Prim		( assert )
+import System.IO.Error
+import GHC.Base		( assert )
 import GHC.Exception 	hiding (try, catch, bracket, bracket_)
 import GHC.Conc		( throwTo, ThreadId )
 import GHC.IOBase	( IO(..) )
@@ -105,10 +104,10 @@ INSTANCE_TYPEABLE0(AsyncException,asyncExceptionTc,"AsyncException")
 -----------------------------------------------------------------------------
 -- Catching exceptions
 
--- PrelException defines 'catchException' for us.
+-- GHC.Exception defines 'catchException' for us.
 
-catch :: IO a -> (Exception -> IO a) -> IO a
-catch =  catchException
+catch	  :: IO a -> (Exception -> IO a) -> IO a
+catch 	  =  catchException
 
 catchJust :: (Exception -> Maybe b) -> IO a -> (b -> IO a) -> IO a
 catchJust p a handler = catch a handler'
@@ -116,6 +115,12 @@ catchJust p a handler = catch a handler'
 			Nothing -> throw e
 			Just b  -> handler b
 
+handle	   :: (Exception -> IO a) -> IO a -> IO a
+handle     =  flip catch
+
+handleJust :: (Exception -> Maybe b) -> (b -> IO a) -> IO a -> IO a
+handleJust p =  flip (catchJust p)
+
 -----------------------------------------------------------------------------
 -- evaluate
 
@@ -193,7 +198,7 @@ dynExceptions _ = Nothing
 asyncExceptions (AsyncException e) = Just e
 asyncExceptions _ = Nothing
 
-userErrors (UserError e) = Just e
+userErrors e | isUserError e = Just (ioeGetErrorString e)
 userErrors _ = Nothing
 
 -----------------------------------------------------------------------------