+-----------------------------------------------------------------------------
+-- |
+-- Module : Control.Monad.Instances
+-- Copyright : (c) The University of Glasgow 2001
+-- License : BSD-style (see the file libraries/base/LICENSE)
+--
+-- Maintainer : libraries@haskell.org
+-- Stability : provisional
+-- Portability : portable
+--
+-- 'Functor' and 'Monad' instances for @(->) r@ and
+-- 'Functor' instances for @(,) a@ and @'Either' a@.
+
+module Control.Monad.Instances () where
+
+import Prelude
+
+instance Functor ((->) r) where
+ fmap = (.)
+
+instance Monad ((->) r) where
+ return = const
+ f >>= k = \ r -> k (f r) r
+
+instance Functor ((,) a) where
+ fmap f (x,y) = (x, f y)
+
+instance Functor (Either a) where
+ fmap _ (Left x) = Left x
+ fmap f (Right y) = Right (f y)