aivika-0.7: A multi-paradigm simulation library

Stabilityexperimental
MaintainerDavid Sorokin <david.sorokin@gmail.com>
Safe HaskellSafe-Inferred

Simulation.Aivika.Event

Contents

Description

Tested with: GHC 7.6.3

The module defines the Event monad which is very similar to the Dynamics monad but only now the computation is strongly synchronized with the event queue.

Synopsis

Event Monad

data Event a Source

A value in the Event monad represents a polymorphic time varying function which is strongly synchronized with the event queue.

Instances

class Monad m => EventLift m whereSource

A type class to lift the Event computation to other monads.

Methods

liftEvent :: Event a -> m aSource

Lift the specified Event computation to another monad.

Instances

data EventProcessing Source

Defines how the events are processed.

Constructors

IncludingCurrentEvents

either process all earlier and then current events, or raise an error if the current simulation time is less than the actual time of the event queue

IncludingEarlierEvents

either process all earlier events not affecting the events at the current simulation time, or raise an error if the current simulation time is less than the actual time of the event queue

IncludingCurrentEventsOrFromPast

either process all earlier and then current events, or do nothing if the current simulation time is less than the actual time of the event queue (do not use unless the documentation states the opposite)

IncludingEarlierEventsOrFromPast

either process all earlier events, or do nothing if the current simulation time is less than the actual time of the event queue (do not use unless the documentation states the opposite)

Instances

data EventCancellation Source

It allows cancelling the event.

Constructors

EventCancellation 

Fields

cancelEvent :: Event ()

Cancel the event.

eventCanceled :: Event Bool

Test whether the event was canceled.

eventFinished :: Event Bool

Test whether the event was processed and finished.

runEvent :: EventProcessing -> Event a -> Dynamics aSource

Run the Event computation in the current simulation time within the Dynamics computation.

runEventInStartTime :: EventProcessing -> Event a -> Simulation aSource

Run the Event computation in the start time.

runEventInStopTime :: EventProcessing -> Event a -> Simulation aSource

Run the Event computation in the stop time.

Event Queue

enqueueEvent :: Double -> Event () -> Event ()Source

Enqueue the event which must be actuated at the specified time.

The events are processed when calling the runEvent function. So, if you want to insist on their immediate execution then you can apply something like 

   liftDynamics $ runEvent IncludingCurrentEvents $ return ()

although this is generally not good idea.

enqueueEventWithCancellation :: Double -> Event () -> Event EventCancellationSource

Enqueue the event with an ability to cancel it.

enqueueEventWithTimes :: [Double] -> Event () -> Event ()Source

Actuate the event handler in the specified time points.

enqueueEventWithIntegTimes :: Event () -> Event ()Source

Actuate the event handler in the integration time points.

enqueueEventWithStartTime :: Event () -> Event ()Source

Actuate the event handler in the start time.

enqueueEventWithStopTime :: Event () -> Event ()Source

Actuate the event handler in the stop time.

enqueueEventWithCurrentTime :: Event () -> Event ()Source

Actuate the event handler in the current time but through the event queue, which allows continuing the current tasks and then calling the handler after the tasks are finished. The simulation time will be the same.

eventQueueCount :: Event IntSource

Return the number of pending events that should be yet actuated.

Error Handling

catchEvent :: Event a -> (IOException -> Event a) -> Event aSource

Exception handling within Event computations.

finallyEvent :: Event a -> Event b -> Event aSource

A computation with finalization part like the finally function.

throwEvent :: IOException -> Event aSource

Like the standard throw function.