[project @ 2002-06-13 23:26:55 by sof]

[ghc-base.git] / Data / STRef / Lazy.hs

diff --git a/Data/STRef/Lazy.hs b/Data/STRef/Lazy.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Data.STRef.Lazy
+-- Copyright   :  (c) The University of Glasgow 2001
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  experimental
+-- Portability :  non-portable (requires non-portable module ST)
+--
+-- Mutable references in the lazy ST monad.
+--
+-----------------------------------------------------------------------------
+module Data.STRef.Lazy (
+       -- * STRefs
+       ST.STRef,       -- abstract, instance Eq
+       newSTRef,       -- :: a -> ST s (STRef s a)
+       readSTRef,      -- :: STRef s a -> ST s a
+       writeSTRef,     -- :: STRef s a -> a -> ST s ()
+       modifySTRef     -- :: STRef s a -> (a -> a) -> ST s ()
+ ) where
+
+import Control.Monad.ST.Lazy
+import qualified Data.STRef as ST
+import qualified Control.Monad.ST as ST
+
+newSTRef    :: a -> ST s (ST.STRef s a)
+readSTRef   :: ST.STRef s a -> ST s a
+writeSTRef  :: ST.STRef s a -> a -> ST s ()
+modifySTRef :: ST.STRef s a -> (a -> a) -> ST s ()
+
+newSTRef   = strictToLazyST . ST.newSTRef
+readSTRef  = strictToLazyST . ST.readSTRef
+writeSTRef r a = strictToLazyST (ST.writeSTRef r a)
+modifySTRef r f = strictToLazyST (ST.modifySTRef r f)
+
+