X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Futils%2FMaybes.lhs;h=1f443db28d6b83202044e3543e9497c5f5f7cca2;hb=e9f9ec1e57d53b9302a395ce0d02c0fa59e28341;hp=8a6a5f441e2db9fc62b4345047c70d605984c803;hpb=3659ebdaca5124c4efb9dd9e8894054d34187deb;p=ghc-hetmet.git

diff --git a/compiler/utils/Maybes.lhs b/compiler/utils/Maybes.lhs
index 8a6a5f4..1f443db 100644
--- a/compiler/utils/Maybes.lhs
+++ b/compiler/utils/Maybes.lhs
@@ -10,6 +10,7 @@ module Maybes (
         MaybeErr(..), -- Instance of Monad
         failME, isSuccess,
 
+        fmapM_maybe,
         orElse,
         mapCatMaybes,
         allMaybes,
@@ -74,6 +75,14 @@ orElse :: Maybe a -> a -> a
 Nothing  `orElse` y = y
 \end{code}
 
+\begin{code}
+fmapM_maybe :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b)
+fmapM_maybe _ Nothing = return Nothing
+fmapM_maybe f (Just x) = do
+        x' <- f x
+        return $ Just x'
+\end{code}
+
 %************************************************************************
 %*									*
 \subsection[MaybeT type]{The @MaybeT@ monad transformer}