define_events/5¶
Description¶
define_events(Event, Object, Message, Sender, Monitor)
Defines a new set of events. The two types of events are represented by
the atoms before
and after
. When the predicate is called with
the first argument unbound, both types of events are defined. The object
Monitor
must define the event handler methods required by the
Event
argument.
Modes and number of proofs¶
define_events(@term, @term, @term, @term, +object_identifier) - one
Errors¶
Event is neither a variable nor a valid event identifier:
type_error(event, Event)
Object is neither a variable nor a valid object identifier:
type_error(object_identifier, Object)
Message is neither a variable nor a callable term:
type_error(callable, Message)
Sender is neither a variable nor a valid object identifier:
type_error(object_identifier, Sender)
Monitor is a variable:
instantiation_error
Monitor is neither a variable nor a valid object identifier:
existence_error(object_identifier, Monitor)
Monitor does not define the required
before/3
method:existence_error(procedure, before/3)
Monitor does not define the required
after/3
method:existence_error(procedure, after/3)
Examples¶
% define "debugger" as a monitor for member/2 messages
% sent to the "list" object:
| ?- define_events(_, list, member(_, _), _ , debugger).
See also