pipes-concurrency 2.0.3 → 2.0.4

raw patch · 2 files changed

+17/−1 lines, 2 files

Files

• pipes-concurrency.cabal +1/−1
• src/Pipes/Concurrent.hs +16/−0

@@ -1,5 +1,5 @@ Name: pipes-concurrency-Version: 2.0.3+Version: 2.0.4 Cabal-Version: >=1.8.0.2 Build-Type: Simple License: BSD3

@@ -14,6 +14,7 @@     -- * Actors     spawn,     spawn',+    withSpawn,     Buffer(..),     unbounded,     bounded,@@ -32,6 +33,7 @@ import Control.Concurrent (forkIO) import Control.Concurrent.STM (atomically, STM, mkWeakTVar, newTVarIO, readTVar) import qualified Control.Concurrent.STM as S+import Control.Exception (bracket) import Control.Monad (when,void, MonadPlus(..)) import Data.Monoid (Monoid(mempty, mappend)) import Pipes (MonadIO(liftIO), yield, await, Producer', Consumer')@@ -202,6 +204,20 @@         _recv   = readOrEnd   <* readTVar rRecv     return (Output _send, Input _recv, seal) {-# INLINABLE spawn' #-}++{-| 'withSpawn' passes its enclosed action an 'Output' and 'Input' like you'd get from 'spawn',+    but automatically @seal@s them after the action completes.  This can be used when you need the+    @seal@ing behavior available from 'spawn\'', but want to work at a bit higher level:++> withSpawn buffer $ \(output, input) -> ...++    'withSpawn' is exception-safe, since it uses 'bracket' internally.+-}+withSpawn :: Buffer a -> ((Output a, Input a) -> IO r) -> IO r+withSpawn buffer action = bracket+    (spawn' buffer)+    (\(_, _, seal) -> atomically seal)+    (\(output, input, _) -> action (output, input))  -- | 'Buffer' specifies how to buffer messages stored within the mailbox data Buffer a