-- Stability : experimental
-- Portability : non-portable (requires universal quantification for runST)
--
--- The State Transformer Monad, ST
+-- This library provides support for /strict/ state threads, as
+-- described in the PLDI \'94 paper by John Launchbury and Simon Peyton
+-- Jones /Lazy State Threads/.
--
-----------------------------------------------------------------------------
module Control.Monad.ST
- (
- ST -- abstract, instance of Functor, Monad, Typeable.
- , runST -- :: (forall s. ST s a) -> a
- , fixST -- :: (a -> ST s a) -> ST s a
- , unsafeInterleaveST -- :: ST s a -> ST s a
+ (
+ -- * The 'ST' Monad
+ ST, -- abstract, instance of Functor, Monad, Typeable.
+ runST, -- :: (forall s. ST s a) -> a
+ fixST, -- :: (a -> ST s a) -> ST s a
- , unsafeIOToST -- :: IO a -> ST s a
+ -- * Unsafe operations
+ unsafeInterleaveST, -- :: ST s a -> ST s a
+ unsafeIOToST, -- :: IO a -> ST s a
- , RealWorld -- abstract
- , stToIO -- :: ST RealWorld a -> IO a
+ -- * Converting 'ST' to 'IO'
+ RealWorld, -- abstract
+ stToIO -- :: ST RealWorld a -> IO a
) where
import Prelude
import Control.Monad.Fix
import Data.Dynamic
+#ifdef __HUGS__
+import Hugs.ST
+#endif
+
#ifdef __GLASGOW_HASKELL__
import GHC.ST
import GHC.Base ( unsafeCoerce#, RealWorld )