Control/Monad/ST/Imp.hs

    {-# LANGUAGE Unsafe #-}
    {-# OPTIONS_HADDOCK hide #-}

    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Control.Monad.ST.Imp
    -- 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 universal quantification for runST)
    --
    -- This library provides support for /strict/ state threads, as
    -- described in the PLDI \'94 paper by John Launchbury and Simon Peyton
    -- Jones /Lazy Functional State Threads/.
    --
    -----------------------------------------------------------------------------

    module Control.Monad.ST.Imp (
            -- * The 'ST' Monad
            ST,             -- abstract, instance of Functor, Monad, Typeable.
            runST,
            fixST,

            -- * Converting 'ST' to 'IO'
            RealWorld,              -- abstract
            stToIO,

            -- * Unsafe operations
            unsafeInterleaveST,
            unsafeDupableInterleaveST,
            unsafeIOToST,
            unsafeSTToIO
        ) where

    import GHC.ST           ( ST, runST, fixST, unsafeInterleaveST
                            , unsafeDupableInterleaveST )
    import GHC.Base         ( RealWorld )
    import GHC.IO           ( stToIO, unsafeIOToST, unsafeSTToIO )