stm 2.2.0.0 → 2.2.0.1

raw patch · 3 files changed

+40/−5 lines, 3 files

Files

• Control/Concurrent/STM/TArray.hs +1/−2
• Control/Monad/STM.hs +38/−2
• stm.cabal +1/−1

@@ -1,5 +1,4 @@-{-# OPTIONS -fglasgow-exts #-}-{-# LANGUAGE DeriveDataTypeable #-}+{-# LANGUAGE CPP, DeriveDataTypeable, FlexibleInstances, MultiParamTypeClasses #-}  ----------------------------------------------------------------------------- -- |

@@ -1,4 +1,5 @@ {-# OPTIONS_GHC -fno-warn-orphans #-}+{-# LANGUAGE MagicHash #-} ----------------------------------------------------------------------------- -- | -- Module      :  Control.Monad.STM@@ -36,9 +37,13 @@   ) where  #ifdef __GLASGOW_HASKELL__-import GHC.Conc #if ! (MIN_VERSION_base(4,3,0))-import Control.Monad	( MonadPlus(..) )+import GHC.Conc hiding (catchSTM)+import Control.Monad    ( MonadPlus(..) )+import GHC.Exts (raiseIO#, catchSTM#)+import Control.Exception+#else+import GHC.Conc #endif #else import Control.Sequential.STM@@ -53,4 +58,35 @@  check :: Bool -> STM a check b = if b then return undefined else retry+#endif++#if ! (MIN_VERSION_base(4,3,0))+-- |Exception handling within STM actions.+catchSTM :: Exception e => STM a -> (e -> STM a) -> STM a+catchSTM (STM m) handler = STM $ catchSTM# m handler'+    where+      handler' e = case fromException e of+                     Just e' -> case handler e' of STM m' -> m'+                     Nothing -> raiseIO# e++-- | A variant of 'throw' that can only be used within the 'STM' monad.+--+-- Throwing an exception in @STM@ aborts the transaction and propagates the+-- exception.+--+-- Although 'throwSTM' has a type that is an instance of the type of 'throw', the+-- two functions are subtly different:+--+-- > throw e    `seq` x  ===> throw e+-- > throwSTM e `seq` x  ===> x+--+-- The first example will cause the exception @e@ to be raised,+-- whereas the second one won\'t.  In fact, 'throwSTM' will only cause+-- an exception to be raised when it is used within the 'STM' monad.+-- The 'throwSTM' variant should be used in preference to 'throw' to+-- raise an exception within the 'STM' monad because it guarantees+-- ordering with respect to other 'STM' operations, whereas 'throw'+-- does not.+throwSTM :: Exception e => e -> STM a+throwSTM e = STM $ raiseIO# (toException e) #endif

@@ -1,5 +1,5 @@ name:		stm-version:        2.2.0.0+version:        2.2.0.1 license:	BSD3 license-file:	LICENSE maintainer:	libraries@haskell.org