From 70d7c4b1cdc78fe03f63180c318d2ca15f4f6a26 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Mon, 17 Jan 2005 11:08:52 +0000
Subject: [PATCH] [project @ 2005-01-17 11:08:52 by simonmar] Add
 Data.FunctorM

---
 Data/FunctorM.hs |   42 ++++++++++++++++++++++++++++++++++++++++++
 package.conf.in  |    1 +
 2 files changed, 43 insertions(+)
 create mode 100644 Data/FunctorM.hs

diff --git a/Data/FunctorM.hs b/Data/FunctorM.hs
new file mode 100644
index 0000000..193047d
--- /dev/null
+++ b/Data/FunctorM.hs
@@ -0,0 +1,42 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Data.FunctorM
+-- Copyright   :  (c) The University of Glasgow 2005
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  provisional
+-- Portability :  portable
+--
+-- fmapM generalises fmap, just as mapM generalises map.
+--
+-----------------------------------------------------------------------------
+
+module FunctorM (
+	FunctorM(..)
+  ) where
+
+import Prelude
+import Data.Array
+
+class FunctorM f where
+    fmapM  :: Monad m => (a -> m b) -> f a -> m (f b)
+    fmapM_ :: Monad m => (a -> m b) -> f a -> m ()
+
+    fmapM_ f t = fmapM f t >> return ()
+
+instance FunctorM [] where
+    fmapM  = mapM
+    fmapM_ = mapM_
+
+instance FunctorM Maybe where
+    fmapM _ Nothing = return Nothing
+    fmapM f (Just x) = f x >>= return . Just 
+
+    fmapM_ _ Nothing = return ()
+    fmapM_ f (Just x) = f x >> return ()
+
+instance Ix i => FunctorM (Array i) where
+    fmapM f a = do 
+	a' <- sequence [ f e >>= return . (,) i | (i,e) <- assocs a]
+	return (array (bounds a) a')
diff --git a/package.conf.in b/package.conf.in
index 2ddecaf..4f59dc5 100644
--- a/package.conf.in
+++ b/package.conf.in
@@ -39,6 +39,7 @@ exposed-modules:
 	Data.Dynamic,
 	Data.Either,
 	Data.FiniteMap,
+	Data.FunctorM,
 	Data.Generics,
 	Data.Generics.Aliases,
 	Data.Generics.Basics,
-- 
1.7.10.4