[project @ 2000-07-09 16:00:55 by panne]

By definition (sec. 7.3 in the H98 report), userError raises an
IOError, so Prelude.catch should catch UserError exceptions, too.
Apart from not conforming to the report, without this patch GHC's
typechecker falls straight on its face.

diff --git a/ghc/lib/std/PrelException.lhs b/ghc/lib/std/PrelException.lhs
index b1f41e7..29f7edb 100644 (file)
--- a/ghc/lib/std/PrelException.lhs
+++ b/ghc/lib/std/PrelException.lhs
@@ -1,5 +1,5 @@
 % ------------------------------------------------------------------------------
-% $Id: PrelException.lhs,v 1.22 2000/07/07 11:03:58 simonmar Exp $
+% $Id: PrelException.lhs,v 1.23 2000/07/09 16:00:55 panne Exp $
 %
 % (c) The University of Glasgow, 1998-2000
 %
@@ -53,6 +53,7 @@ catchException (IO m) k =  IO $ \s -> catch# m (\ex -> unIO (k ex)) s
 catch           :: IO a -> (Exception -> IO a) -> IO a 
 catch m k      =  catchException m handler
   where handler err@(IOException _) = k err
+        handler err@(UserError   _) = k err
        handler other               = throw other
 \end{code}