diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown --- a/CHANGELOG.markdown +++ b/CHANGELOG.markdown @@ -7,11 +7,32 @@ *de facto* standard Haskell versioning scheme. -1.1.2.1 [2017-06-07] (tag: [concurrency-1.1.2.1][]) +1.2.0.0 ------- -https://hackage.haskell.org/package/concurrency-1.1.2.1 +- **Date** 2017-09-16 +- **Git tag** [concurrency-1.2.0.0][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.2.0.0 +### Control.Monad.STM.Class + +- `MonadSTM` now has a `MonadPlus` constraint. +- The `orElse` and `retry` functions have been promoted to top-level definitions, and are aliases + for `mplus` and `mzero`. + +[concurrency-1.2.0.0]: https://github.com/barrucadu/dejafu/releases/tag/concurrency-1.2.0.0 + + +--------------------------------------------------------------------------------------------------- + + +1.1.2.1 +------- + +- **Date** 2017-06-07 +- **Git tag** [concurrency-1.1.2.1][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.1.2.1 + ### Changed - The `isEmptyMVar` function is now implemented using `tryReadMVar` instead of a combination of @@ -28,10 +49,12 @@ --------------------------------------------------------------------------------------------------- -1.1.2.0 [2017-04-05] (tag: [concurrency-1.1.2.0][]) +1.1.2.0 ------- -https://hackage.haskell.org/package/concurrency-1.1.2.0 +- **Date** 2017-04-05 +- **Git tag** [concurrency-1.1.2.0][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.1.2.0 ### Control.Concurrent.Classy.Async @@ -66,10 +89,12 @@ --------------------------------------------------------------------------------------------------- -1.1.1.0 [2017-03-04] (git tag: [concurrency-1.1.1.0][]) +1.1.1.0 ------- -https://hackage.haskell.org/package/concurrency-1.1.1.0 +- **Date** 2017-03-04 +- **Git tag** [concurrency-1.1.1.0][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.1.1.0 ### Miscellaneous @@ -82,10 +107,12 @@ --------------------------------------------------------------------------------------------------- -1.1.0.0 [2017-02-21] (git tag: [concurrency-1.1.0.0][]) +1.1.0.0 ------- -https://hackage.haskell.org/package/concurrency-1.1.0.0 +- **Date** 2017-02-21 +- **Git tag** [concurrency-1.1.0.0][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.1.0.0 ### Control.Monad.Conc.Class @@ -100,10 +127,12 @@ --------------------------------------------------------------------------------------------------- -1.0.0.0 [2016-09-10] (git tag: [concurrency-1.0.0.0][]) +1.0.0.0 ------- -https://hackage.haskell.org/package/concurrency-1.0.0.0 +- **Date** 2016-09-10 +- **Git tag** [concurrency-1.0.0.0][] +- **Hackage** https://hackage.haskell.org/package/concurrency-1.0.0.0 Initial release. Go read the API docs. diff --git a/Control/Monad/STM/Class.hs b/Control/Monad/STM/Class.hs --- a/Control/Monad/STM/Class.hs +++ b/Control/Monad/STM/Class.hs @@ -17,22 +17,21 @@ -- import "Control.Concurrent.Classy.STM" (which exports -- "Control.Monad.STM.Class"). -- --- __Deviations:__ An instance of @MonadSTM@ is not required to be an --- @Alternative@, @MonadPlus@, and @MonadFix@, unlike @STM@. The --- @always@ and @alwaysSucceeds@ functions are not provided; if you --- need these file an issue and I'll look into it. +-- __Deviations:__ An instance of @MonadSTM@ is not required to be a +-- @MonadFix@, unlike @STM@. The @always@ and @alwaysSucceeds@ +-- functions are not provided; if you need these file an issue and +-- I'll look into it. module Control.Monad.STM.Class ( MonadSTM(..) + , retry , check + , orElse , throwSTM , catchSTM - - -- * Utilities for instance writers - , liftedOrElse ) where import Control.Exception (Exception) -import Control.Monad (unless) +import Control.Monad (MonadPlus(..), unless) import Control.Monad.Reader (ReaderT) import Control.Monad.Trans (lift) import Control.Monad.Trans.Control (MonadTransControl, StT, liftWith) @@ -53,12 +52,10 @@ -- each 'MonadConc' has an associated @MonadSTM@ from which it can -- atomically run a transaction. -- --- @since 1.0.0.0 -class Ca.MonadCatch stm => MonadSTM stm where +-- @since 1.2.0.0 +class (Ca.MonadCatch stm, MonadPlus stm) => MonadSTM stm where {-# MINIMAL - retry - , orElse - , (newTVar | newTVarN) + (newTVar | newTVarN) , readTVar , writeTVar #-} @@ -70,22 +67,6 @@ -- @since 1.0.0.0 type TVar stm :: * -> * - -- | Retry execution of this transaction because it has seen values - -- in @TVar@s that it shouldn't have. This will result in the - -- thread running the transaction being blocked until any @TVar@s - -- referenced in it have been mutated. - -- - -- @since 1.0.0.0 - retry :: stm a - - -- | Run the first transaction and, if it @retry@s, run the second - -- instead. If the monad is an instance of - -- 'Alternative'/'MonadPlus', 'orElse' should be the '(<|>)'/'mplus' - -- function. - -- - -- @since 1.0.0.0 - orElse :: stm a -> stm a -> stm a - -- | Create a new @TVar@ containing the given value. -- -- > newTVar = newTVarN "" @@ -118,12 +99,32 @@ -- @since 1.0.0.0 writeTVar :: TVar stm a -> a -> stm () +-- | Retry execution of this transaction because it has seen values in +-- @TVar@s that it shouldn't have. This will result in the thread +-- running the transaction being blocked until any @TVar@s referenced +-- in it have been mutated. +-- +-- This is just 'mzero'. +-- +-- @since 1.2.0.0 +retry :: MonadSTM stm => stm a +retry = mzero + -- | Check whether a condition is true and, if not, call @retry@. -- -- @since 1.0.0.0 check :: MonadSTM stm => Bool -> stm () check b = unless b retry +-- | Run the first transaction and, if it @retry@s, run the second +-- instead. +-- +-- This is just 'mplus'. +-- +-- @since 1.2.0.0 +orElse :: MonadSTM stm => stm a -> stm a -> stm a +orElse = mplus + -- | Throw an exception. This aborts the transaction and propagates -- the exception. -- @@ -141,8 +142,6 @@ instance MonadSTM STM.STM where type TVar STM.STM = STM.TVar - retry = STM.retry - orElse = STM.orElse newTVar = STM.newTVar readTVar = STM.readTVar writeTVar = STM.writeTVar @@ -154,8 +153,6 @@ instance C => MonadSTM (T stm) where { \ type TVar (T stm) = TVar stm ; \ \ - retry = lift retry ; \ - orElse = liftedOrElse F ; \ newTVar = lift . newTVar ; \ newTVarN n = lift . newTVarN n ; \ readTVar = lift . readTVar ; \ @@ -186,17 +183,3 @@ INSTANCE(RS.RWST r w s, (MonadSTM stm, Monoid w), (\(a,_,_) -> a)) #undef INSTANCE - -------------------------------------------------------------------------------- - --- | Given a function to remove the transformer-specific state, lift --- an @orElse@ invocation. --- --- @since 1.0.0.0 -liftedOrElse :: (MonadTransControl t, MonadSTM stm) - => (forall x. StT t x -> x) - -> t stm a -> t stm a -> t stm a -liftedOrElse unst ma mb = liftWith $ \run -> - let ma' = unst <$> run ma - mb' = unst <$> run mb - in ma' `orElse` mb' diff --git a/concurrency.cabal b/concurrency.cabal --- a/concurrency.cabal +++ b/concurrency.cabal @@ -2,7 +2,7 @@ -- documentation, see http://haskell.org/cabal/users-guide/ name: concurrency -version: 1.1.2.1 +version: 1.2.0.0 synopsis: Typeclasses, functions, and data types for concurrency and STM. description: @@ -32,7 +32,7 @@ source-repository this type: git location: https://github.com/barrucadu/dejafu.git - tag: concurrency-1.1.2.1 + tag: concurrency-1.2.0.0 library exposed-modules: Control.Monad.Conc.Class