Simulation.Aivika.Trans.Ref

Tested with: GHC 7.8.3

This module defines an updatable reference that depends on the event queue.

Documentation

data Ref m a

The Ref type represents a mutable variable similar to the IORef variable but only dependent on the event queue, which allows synchronizing the reference with the model explicitly through the Event monad.

Instances

MonadComp m => ResultComputing Ref m

refChanged :: MonadComp m => Ref m a -> Signal m a

Return a signal that notifies about every change of the reference state.

refChanged_ :: MonadComp m => Ref m a -> Signal m ()

Return a signal that notifies about every change of the reference state.

newRef :: MonadComp m => a -> Simulation m (Ref m a)

Create a new reference.

readRef :: MonadComp m => Ref m a -> Event m a

Read the value of a reference.

writeRef :: MonadComp m => Ref m a -> a -> Event m ()

Write a new value into the reference.

modifyRef :: MonadComp m => Ref m a -> (a -> a) -> Event m ()

Mutate the contents of the reference.