ref-tf 0.1 → 0.2
raw patch · 2 files changed
+172/−11 lines, 2 filesdep +stmdep +transformers
Dependencies added: stm, transformers
Files
- Control/Monad/Ref.hs +163/−8
- ref-tf.cabal +9/−3
Control/Monad/Ref.hs view
@@ -33,25 +33,50 @@ -- Maintainer : mainland@eecs.harvard.edu -- -- Stability : experimental--- Portability : non-portable (uses Control.Monad.ST)------ Mutable references in the (strict) ST monad.+-- Portability : non-portable -- -------------------------------------------------------------------------------- {-# LANGUAGE TypeFamilies #-} module Control.Monad.Ref (- MonadRef(..)+ MonadRef(..),+ MonadAtomicRef(..) ) where -import Control.Monad.ST-import Data.IORef-import Data.STRef+import Control.Concurrent.STM (STM)+import Control.Concurrent.STM.TVar (TVar,+ newTVar,+ readTVar,+ writeTVar)+import Control.Monad.ST (ST)+import Control.Monad.Trans.Cont (ContT)+import Control.Monad.Trans.Error (ErrorT, Error)+import Control.Monad.Trans.Identity (IdentityT)+import Control.Monad.Trans.List (ListT)+import Control.Monad.Trans.Maybe (MaybeT)+import Control.Monad.Trans.Reader (ReaderT)+import Control.Monad.Trans.State.Lazy as Lazy (StateT)+import Control.Monad.Trans.State.Strict as Strict (StateT)+import Control.Monad.Trans.Writer.Lazy as Lazy (WriterT)+import Control.Monad.Trans.Writer.Strict as Strict (WriterT)+import Control.Monad.Trans.Class (lift)+import Data.IORef (IORef,+ atomicModifyIORef,+ modifyIORef,+ newIORef,+ readIORef,+ writeIORef)+import Data.Monoid (Monoid)+import Data.STRef (STRef,+ modifySTRef,+ newSTRef,+ readSTRef,+ writeSTRef) -- |The 'MonadRef' type class abstracts over the details of manipulating -- references, allowing one to write code that uses references and can operate--- in either the ST monad or the IO monad.+-- in any monad that supports reference operations. class (Monad m) => MonadRef m where type Ref m :: * -> *@@ -66,6 +91,10 @@ modifyRef :: Ref m a -> (a -> a) -> m () modifyRef r f = readRef r >>= writeRef r . f +class (MonadRef m) => MonadAtomicRef m where+ -- |Atomically mutate the contents of a reference+ atomicModifyRef :: Ref m a -> (a -> (a, b)) -> m b+ instance MonadRef (ST s) where type Ref (ST s) = STRef s @@ -81,3 +110,129 @@ readRef = readIORef writeRef = writeIORef modifyRef = modifyIORef++instance MonadRef STM where+ type Ref STM = TVar++ newRef = newTVar+ readRef = readTVar+ writeRef = writeTVar++instance MonadRef m => MonadRef (ContT r m) where+ type Ref (ContT r m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance (Error e, MonadRef m) => MonadRef (ErrorT e m) where+ type Ref (ErrorT e m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (IdentityT m) where+ type Ref (IdentityT m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (ListT m) where+ type Ref (ListT m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (MaybeT m) where+ type Ref (MaybeT m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (ReaderT r m) where+ type Ref (ReaderT r m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (Lazy.StateT s m) where+ type Ref (Lazy.StateT s m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadRef m => MonadRef (Strict.StateT s m) where+ type Ref (Strict.StateT s m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance (Monoid w, MonadRef m) => MonadRef (Lazy.WriterT w m) where+ type Ref (Lazy.WriterT w m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance (Monoid w, MonadRef m) => MonadRef (Strict.WriterT w m) where+ type Ref (Strict.WriterT w m) = Ref m++ newRef r = lift $ newRef r+ readRef r = lift $ readRef r+ writeRef r x = lift $ writeRef r x+ modifyRef r f = lift $ modifyRef r f++instance MonadAtomicRef IO where+ atomicModifyRef = atomicModifyIORef++instance MonadAtomicRef STM where+ atomicModifyRef r f = do x <- readRef r+ let (x', y) = f x+ writeRef r x'+ return y++instance MonadAtomicRef m => MonadAtomicRef (ContT r m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance (Error e, MonadAtomicRef m) => MonadAtomicRef (ErrorT e m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (IdentityT m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (ListT m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (MaybeT m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (ReaderT r m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (Lazy.StateT s m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance MonadAtomicRef m => MonadAtomicRef (Strict.StateT s m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance (Monoid w, MonadAtomicRef m) => MonadAtomicRef (Lazy.WriterT w m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f++instance (Monoid w, MonadAtomicRef m) => MonadAtomicRef (Strict.WriterT w m) where+ atomicModifyRef r f = lift $ atomicModifyRef r f
ref-tf.cabal view
@@ -1,6 +1,6 @@ name: ref-tf-version: 0.1-cabal-version: >= 1.2+version: 0.2+cabal-version: >= 1.6 license: BSD3 license-file: LICENSE copyright: (c) 2006-2010 Harvard University@@ -21,4 +21,10 @@ Control.Monad.Ref build-depends:- base >= 4 && < 5+ base >= 4 && < 5,+ stm >= 2.1 && < 2.2,+ transformers >= 0.2 && < 0.3++source-repository head+ type: svn+ location: http://senseless.eecs.harvard.edu/repos/mainland-projects/ref-tf/trunk/