Simulation.Aivika.Event

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.

Event Monad

data Event a

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

Instances

Monad Event

Functor Event

MonadFix Event

MonadIO Event

ParameterLift Event

SimulationLift Event

DynamicsLift Event

EventLift Event

class EventLift m where

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

Methods

liftEvent :: Event a -> m a

Lift the specified Event computation to another computation.

Instances

EventLift Event

EventLift Cont

EventLift Process

data EventProcessing

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

Eq EventProcessing

Ord EventProcessing

Show EventProcessing

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

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

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

Run the Event computation in the start time.

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

Run the Event computation in the stop time.

Event Queue

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

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 EventCancellation

Enqueue the event with an ability to cancel it.

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

Actuate the event handler in the specified time points.

enqueueEventWithIntegTimes :: Event () -> Event ()

Actuate the event handler in the integration time points.

eventQueueCount :: Event Int

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

Cancelling Event

data EventCancellation

It allows cancelling the event.

cancelEvent :: EventCancellation -> Event ()

Cancel the event.

eventCancelled :: EventCancellation -> Event Bool

Test whether the event was cancelled.

eventFinished :: EventCancellation -> Event Bool

Test whether the event was processed and finished.

Error Handling

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

Exception handling within Event computations.

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

A computation with finalization part like the finally function.

throwEvent :: IOException -> Event a

Like the standard throw function.

Memoization

memoEvent :: Event a -> Simulation (Event a)

Memoize the Event computation, always returning the same value within a simulation run.