persistent-refs-0.4: Haskell references backed by an IntMap for persistence and reversibility.

Copyright(c) Adam C. Foltzer 2013
LicenseBSD3
Maintaineracfoltzer@gmail.com
Stabilityexperimental
Portabilitynon-portable (requires rank-2 types for runST)
Safe HaskellNone
LanguageHaskell98

Data.STRef.Persistent

Contents

Description

Mutable references in the persistent ST monad.

Synopsis

STRefs

data STRef s a Source

Instances

Monad m => MonadRef (STRef s) (STT s m) 
Eq (STRef s a) 
Show (STRef s a) 

asInt :: STRef s a -> Int Source

Get the underlying Int from an STRef. Useful for debugging.

MonadRef Operations

class Monad m => MonadRef r m | m -> r where

The MonadRef type class abstracts over the details of manipulating references, allowing one to write code that uses references and can operate in any monad that supports reference operations.

Minimal complete definition

newRef, readRef, writeRef

Methods

newRef :: a -> m (r a)

Create a new reference

readRef :: r a -> m a

Read the value of a reference

writeRef :: r a -> a -> m ()

Write a new value to a reference

modifyRef :: r a -> (a -> a) -> m ()

Mutate the contents of a reference

modifyRef' :: r a -> (a -> a) -> m ()

Strict version of modifyRef

Instances

MonadRef TVar STM 
MonadRef IORef IO 
MonadRef r m => MonadRef r (MaybeT m) 
MonadRef r m => MonadRef r (ListT m) 
MonadRef r m => MonadRef r (IdentityT m) 
(Monoid w, MonadRef r m) => MonadRef r (WriterT w m) 
(Monoid w, MonadRef r m) => MonadRef r (WriterT w m) 
MonadRef r m => MonadRef r (StateT s m) 
MonadRef r m => MonadRef r (StateT s m) 
MonadRef r m => MonadRef r (ReaderT r' m) 
(Error e, MonadRef r m) => MonadRef r (ErrorT e m) 
MonadRef r m => MonadRef r (ContT r' m) 
MonadRef (STRef s) (ST s) 
Monad m => MonadRef (STRef s) (STT s m)