aivika-4.5: A multi-method simulation library

Simulation.Aivika.Ref

Description

Tested with: GHC 8.0.1

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

Synopsis

# Documentation

data Ref a Source #

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

 Source # Methods

refChanged :: Ref a -> Signal a Source #

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

refChanged_ :: Ref a -> Signal () Source #

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

newRef :: a -> Simulation (Ref a) Source #

Create a new reference.

readRef :: Ref a -> Event a Source #

Read the value of a reference.

writeRef :: Ref a -> a -> Event () Source #

Write a new value into the reference.

modifyRef :: Ref a -> (a -> a) -> Event () Source #

Mutate the contents of the reference.