[project @ 2004-02-05 18:55:47 by ross]

[ghc-base.git] / Control / Monad / List.hs

diff --git a/Control/Monad/List.hs b/Control/Monad/List.hs
deleted file mode 100644 (file)
index 9acb29c..0000000
--- a/Control/Monad/List.hs
+++ /dev/null
@@ -1,84 +0,0 @@
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Monad.List
--- Copyright   :  (c) Andy Gill 2001,
---               (c) Oregon Graduate Institute of Science and Technology, 2001
--- License     :  BSD-style (see the file libraries/base/LICENSE)
--- 
--- Maintainer  :  libraries@haskell.org
--- Stability   :  experimental
--- Portability :  non-portable (multi-parameter type classes)
---
--- The List monad.
---
------------------------------------------------------------------------------
-
-module Control.Monad.List (
-       ListT(..),
-       mapListT,
-       module Control.Monad,
-       module Control.Monad.Trans,
-  ) where
-
-import Prelude
-
-import Control.Monad
-import Control.Monad.Trans
-import Control.Monad.Reader
-import Control.Monad.State
-import Control.Monad.Cont
-import Control.Monad.Error
-
--- ---------------------------------------------------------------------------
--- Our parameterizable list monad, with an inner monad
-
-newtype ListT m a = ListT { runListT :: m [a] }
-
-instance (Monad m) => Functor (ListT m) where
-       fmap f m = ListT $ do
-               a <- runListT m
-               return (map f a)
-
-instance (Monad m) => Monad (ListT m) where
-       return a = ListT $ return [a]
-       m >>= k  = ListT $ do
-               a <- runListT m
-               b <- mapM (runListT . k) a
-               return (concat b)
-       fail _ = ListT $ return []
-
-instance (Monad m) => MonadPlus (ListT m) where
-       mzero       = ListT $ return []
-       m `mplus` n = ListT $ do
-               a <- runListT m
-               b <- runListT n
-               return (a ++ b)
-
-instance MonadTrans ListT where
-       lift m = ListT $ do
-               a <- m
-               return [a]
-
-instance (MonadIO m) => MonadIO (ListT m) where
-       liftIO = lift . liftIO
-
-instance (MonadReader s m) => MonadReader s (ListT m) where
-       ask       = lift ask
-       local f m = ListT $ local f (runListT m)
-
-instance (MonadState s m) => MonadState s (ListT m) where
-       get = lift get
-       put = lift . put
-
-instance (MonadCont m) => MonadCont (ListT m) where
-       callCC f = ListT $
-               callCC $ \c ->
-               runListT (f (\a -> ListT $ c [a]))
-
-instance (MonadError e m) => MonadError e (ListT m) where
-       throwError       = lift . throwError
-       m `catchError` h = ListT $ runListT m
-               `catchError` \e -> runListT (h e)
-
-mapListT :: (m [a] -> n [b]) -> ListT m a -> ListT n b
-mapListT f m = ListT $ f (runListT m)