Modulelvar-0.2.0.0Haskell2010

Data.LVar

LVar is like Control.Concurrent.STM.TMVar but with a capability for listening to its changes.

Contents

Synopsis

Types

datadata LVar a

valuenew :: MonadIO m => a -> m (LVar a)

Create a new LVar with the given initial value

valueempty :: MonadIO m => m (LVar a)

Like new, but there is no initial value. A get will block until an initial value is set using set or modify

valueget :: MonadIO m => LVar a -> m a

Get the value of the LVar

valueset :: MonadIO m => LVar a -> a -> m ()

Set the LVar value; active listeners are automatically notifed.

valuemodify :: MonadIO m => LVar a -> (a -> a) -> m ()

Modify the LVar value; active listeners are automatically notified.

valuelistenNext :: MonadIO m => LVar a -> m a

Listen for the next value update (since the last listenNext or addListener).