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{-# OPTIONS_GHC -Wall #-}	{-# OPTIONS_GHC -Wall #-}
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
{- |	{- |
Module : Control.MonadOr	Module : Control.MonadOr
Description : MonadOr definition.	Description : MonadOr definition.
Copyright : (c) Paulo Silva	Copyright : (c) Paulo Silva
License : LGPL	License : LGPL
Maintainer : paufil@di.uminho.pt	Maintainer : paufil@di.uminho.pt
Stability : experimental	Stability : experimental
Portability : portable	Portability : portable
Monad definition satisfying the Monoid and Left Catch laws as refered in	Monad definition satisfying the Monoid and Left Catch laws as refered in
<http://www.haskell.org/haskellwiki/MonadPlus_reform_proposal>	<http://www.haskell.org/haskellwiki/MonadPlus_reform_proposal>
-}	-}
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
module Control.MonadOr (	module Control.MonadOr (
MonadOr,	MonadOr,
morelse	morelse
) where	) where
import Control.Monad	import Control.Monad.Error
	import Control.Monad.State
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
class MonadPlus m => MonadOr m where	class MonadPlus m => MonadOr m where
morelse :: m a -> m a -> m a	morelse :: m a -> m a -> m a
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
instance MonadOr [] where	instance MonadOr [] where
morelse [] b = b	morelse [] b = b
morelse a _ = a	morelse a _ = a
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
-- This instance is equal to mplus for maybe	-- This instance is equal to mplus for maybe
instance MonadOr Maybe where	instance MonadOr Maybe where
morelse = mplus	morelse = mplus
-------------------------------------------------------------------------------	-------------------------------------------------------------------------------
	instance (Monad m, Error e) => MonadOr (ErrorT e m) where
	morelse = mplus
	-------------------------------------------------------------------------------
	instance MonadOr m => MonadOr (StateT s m) where
	m `morelse` n = StateT $ \s -> runStateT m s `morelse` runStateT n s
	-------------------------------------------------------------------------------
	Generated by GNU enscript 1.6.4.