[commit: base] master: Add Functor instance for Handler (#7047) (53f4718)

[Simon Marlow]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/53f4718af482ca87d55b9dff8bf46ed5624ebe80

>---------------------------------------------------------------

commit 53f4718af482ca87d55b9dff8bf46ed5624ebe80
Author: Simon Marlow <marlowsd at gmail.com>
Date:   Wed Jul 4 12:30:51 2012 +0100

    Add Functor instance for Handler (#7047)

>---------------------------------------------------------------

 Control/Exception.hs |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/Control/Exception.hs b/Control/Exception.hs
index a13b990..fd4ea0e 100644
--- a/Control/Exception.hs
+++ b/Control/Exception.hs
@@ -164,6 +164,9 @@ import System (ExitCode())
 -- | You need this when using 'catches'.
 data Handler a = forall e . Exception e => Handler (e -> IO a)
 
+instance Functor Handler where
+     fmap f (Handler h) = Handler (fmap f . h)
+
 {- |
 Sometimes you want to catch two different sorts of exception. You could
 do something like