X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FConc.lhs;h=ee9477707779bf5349fc1ace5c2e200e61ae5017;hb=c71f875f0b7d51cb6a61396d5f3cc5771a638728;hp=b67847c0d6ec10d786620d4f27f049708152478f;hpb=7bce4ee1aa0287c9885647dfcf9de5072492a3fb;p=ghc-base.git

diff --git a/GHC/Conc.lhs b/GHC/Conc.lhs
index b67847c..ee94777 100644
--- a/GHC/Conc.lhs
+++ b/GHC/Conc.lhs
@@ -53,6 +53,7 @@ module GHC.Conc
 	, newTVar 	-- :: a -> STM (TVar a)
 	, readTVar	-- :: TVar a -> STM a
 	, writeTVar	-- :: a -> TVar a -> STM ()
+	, unsafeIOToSTM	-- :: IO a -> STM a
 
 #ifdef mingw32_TARGET_OS
 	, asyncRead     -- :: Int -> Int -> Int -> Ptr a -> IO (Int, Int)
@@ -79,7 +80,6 @@ import GHC.Base		( Int(..) )
 import GHC.Exception    ( Exception(..), AsyncException(..) )
 import GHC.Pack		( packCString# )
 import GHC.Ptr          ( Ptr(..), plusPtr, FunPtr(..) )
-import GHC.STRef
 
 infixr 0 `par`, `pseq`
 \end{code}
@@ -213,7 +213,7 @@ instance  Monad STM  where
     {-# INLINE return #-}
     {-# INLINE (>>)   #-}
     {-# INLINE (>>=)  #-}
-    m >> k      =  m >>= \_ -> k
+    m >> k      = thenSTM m k
     return x	= returnSTM x
     m >>= k     = bindSTM m k
 
@@ -232,6 +232,10 @@ thenSTM (STM m) k = STM ( \s ->
 returnSTM :: a -> STM a
 returnSTM x = STM (\s -> (# s, x #))
 
+-- | Unsafely performs IO in the STM monad.
+unsafeIOToSTM :: IO a -> STM a
+unsafeIOToSTM (IO m) = STM m
+
 -- |Perform a series of STM actions atomically.
 atomically :: STM a -> IO a
 atomically (STM m) = IO (\s -> (atomically# m) s )