-- -*-haskell-*- -- Vision (for the Voice): an XMMS2 client. -- -- Author: Oleg Belozeorov -- Created: 29 Jun. 2011 -- -- Copyright (C) 2011 Oleg Belozeorov -- -- This program is free software; you can redistribute it and/or -- modify it under the terms of the GNU General Public License as -- published by the Free Software Foundation; either version 3 of -- the License, or (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -- General Public License for more details. -- {-# LANGUAGE RankNTypes #-} module Control.Monad.W ( W (..) , ($>) ) where import Control.Monad.Trans newtype W m n = W { runW :: forall a. m a -> n a } ($>) :: MonadIO m => m (W n IO) -> n b -> m b w $> f = do W run <- w liftIO $ run f infixr 0 $>