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current_after_event(?Event)

Check or find currently pending after events (inside handler).
Event
Atom or variable

This built-in predicate is obsolete!

Description

If Event is an atom, succeeds if Event is a currently pending after event, i.e. an event which is setup by either event_after/2 or event_after_every/2, and which is waiting to be raised (event_after_every/2 will always be pending as it is raised repeatedly). If Event is a variable, then all the currently pending events are returned as a list. An event will appear as many times as it had been setup.

Note that this predicate can only be called from within an after event handler, i.e. when the timer is paused, and the after event state can be safely examined. An error would be raised otherwise.

Modes and Determinism

Fail Conditions

Fails if Event is not a pending after event

Exceptions

(1) general error
Predicate is called while after events was not frozen.
(5) type error
Event is not an atom or variable.

Examples

   setup :-
      set_event_handler(hi, hi/0),
      event_after_every(hi, 3.2).

   hi :-
      current_after_event(Es),
      writeln(hi),
      writeln('Pending events'-Es).

   :- setup, repeat, fail.  
   % just spinning after the setup for events to be raised.

See Also

event_after / 2, event_after_every / 2, event / 1, set_event_handler / 2, cancel_after_event / 1