Control.Monad.Ref

Documentation

class Monad m => MonadRef m where

Associated Types

type Ref m :: * -> *

Methods

newRef :: a -> m (Ref m a)

readRef :: Ref m a -> m a

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

atomicModifyRef :: Ref m a -> (a -> (a, b)) -> m b

Instances

MonadRef IO

MonadRef SpiderHostFrame

MonadRef SpiderHost

MonadRef EventM

MonadRef m => MonadRef (ReaderT r m)

(Monoid w, MonadRef m) => MonadRef (WriterT w m)

cacheM :: (MonadRef m, MonadRef m', Ref m ~ Ref m') => m' a -> m (m' a, m ())

cacheMWithTry :: (MonadRef m, MonadRef m', Ref m ~ Ref m') => m' a -> m (m' a, m (Maybe a), m ())

memoM :: (MonadRef m, MonadRef m', Ref m ~ Ref m') => m' a -> m (m' a)

Not thread-safe or reentrant

replaceRef :: MonadRef m => Ref m a -> a -> m a

modifyRef :: MonadRef m => Ref m a -> (a -> a) -> m ()