Follow changes in the base library

[ghc-hetmet.git] / compiler / utils / Exception.hs

diff --git a/compiler/utils/Exception.hs b/compiler/utils/Exception.hs
index 11172b5..a316c56 100644 (file)
--- a/compiler/utils/Exception.hs
+++ b/compiler/utils/Exception.hs
@@ -1,19 +1,42 @@
 
 module Exception
     (
+    module Control.Exception,
+    module Exception
+    )
+    where
+
+import Prelude hiding (catch)
+import Control.Exception
+
+#if __GLASGOW_HASKELL__ < 609
+type SomeException = Exception
+
+onException :: IO a -> IO () -> IO a
+onException io what = io `catch` \e -> do what
+                                          throw e
+#endif
+
+catchIO :: IO a -> (IOException -> IO a) -> IO a
 #if __GLASGOW_HASKELL__ >= 609
-    module Control.OldException
+catchIO = catch
 #else
-    module Control.Exception
+catchIO io handler = io `catch` handler'
+    where handler' (IOException ioe) = handler ioe
+          handler' e                 = throw e
 #endif
-    )
-    where
 
-import Prelude ()
+handleIO :: (IOException -> IO a) -> IO a -> IO a
+handleIO = flip catchIO
 
+tryIO :: IO a -> IO (Either IOException a)
 #if __GLASGOW_HASKELL__ >= 609
-import Control.OldException
+tryIO = try
 #else
-import Control.Exception
+tryIO io = do ei <- try io
+              case ei of
+                  Right v -> return (Right v)
+                  Left (IOException ioe) -> return (Left ioe)
+                  Left e -> throwIO e
 #endif