X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FIORef.hs;h=a6f29e7fc6dfcc00067c48194af7315d399fd1ca;hb=41e8fba828acbae1751628af50849f5352b27873;hp=7a6ec7d4cb32ecbd1b935ab8272116c8e81ced25;hpb=d64471406f94b2906c68762a94c32575f98900b2;p=ghc-base.git diff --git a/Data/IORef.hs b/Data/IORef.hs index 7a6ec7d..a6f29e7 100644 --- a/Data/IORef.hs +++ b/Data/IORef.hs @@ -1,3 +1,5 @@ +{-# LANGUAGE CPP, NoImplicitPrelude, MagicHash, UnboxedTuples #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.IORef @@ -14,29 +16,29 @@ module Data.IORef ( - -- * IORefs - IORef, -- abstract, instance of: Eq, Typeable - newIORef, -- :: a -> IO (IORef a) - readIORef, -- :: IORef a -> IO a - writeIORef, -- :: IORef a -> a -> IO () - modifyIORef, -- :: IORef a -> (a -> a) -> IO () - atomicModifyIORef, -- :: IORef a -> (a -> (a,b)) -> IO b + -- * IORefs + IORef, -- abstract, instance of: Eq, Typeable + newIORef, -- :: a -> IO (IORef a) + readIORef, -- :: IORef a -> IO a + writeIORef, -- :: IORef a -> a -> IO () + modifyIORef, -- :: IORef a -> (a -> a) -> IO () + atomicModifyIORef, -- :: IORef a -> (a -> (a,b)) -> IO b #if !defined(__PARALLEL_HASKELL__) && defined(__GLASGOW_HASKELL__) - mkWeakIORef, -- :: IORef a -> IO () -> IO (Weak (IORef a)) + mkWeakIORef, -- :: IORef a -> IO () -> IO (Weak (IORef a)) #endif - ) where - -import Prelude -- Explicit dependency helps 'make depend' do the right thing + ) where #ifdef __HUGS__ import Hugs.IORef #endif #ifdef __GLASGOW_HASKELL__ -import GHC.Base ( mkWeak#, atomicModifyMutVar# ) +import GHC.Base import GHC.STRef -import GHC.IOBase +-- import GHC.IO +import GHC.IORef hiding (atomicModifyIORef) +import qualified GHC.IORef #if !defined(__PARALLEL_HASKELL__) import GHC.Weak #endif @@ -61,7 +63,7 @@ mkWeakIORef r@(IORef (STRef r#)) f = IO $ \s -> -- |Mutate the contents of an 'IORef' modifyIORef :: IORef a -> (a -> a) -> IO () -modifyIORef ref f = writeIORef ref . f =<< readIORef ref +modifyIORef ref f = readIORef ref >>= writeIORef ref . f -- |Atomically modifies the contents of an 'IORef'. @@ -76,13 +78,13 @@ modifyIORef ref f = writeIORef ref . f =<< readIORef ref -- atomicModifyIORef :: IORef a -> (a -> (a,b)) -> IO b #if defined(__GLASGOW_HASKELL__) -atomicModifyIORef (IORef (STRef r#)) f = IO $ \s -> atomicModifyMutVar# r# f s +atomicModifyIORef = GHC.IORef.atomicModifyIORef #elif defined(__HUGS__) -atomicModifyIORef = plainModifyIORef -- Hugs has no preemption +atomicModifyIORef = plainModifyIORef -- Hugs has no preemption where plainModifyIORef r f = do - a <- readIORef r - case f a of (a',b) -> writeIORef r a' >> return b + a <- readIORef r + case f a of (a',b) -> writeIORef r a' >> return b #elif defined(__NHC__) atomicModifyIORef r f = excludeFinalisers $ do