    {-# OPTIONS_NHC98 --prelude #-}
    {-# OPTIONS_GHC -fno-warn-orphans #-}
    -----------------------------------------------------------------------------
    -- |
    -- 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 (Functor(..),Monad(..)) 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)