before(Object, Message, Sender)
User-defined method for handling before events.
This method is declared in the monitoring built-in
protocol as a public predicate and automatically called by the runtime for
messages sent using the (::)/2 control construct
from within objects compiled with the events flag set
Note that you can make this predicate scope protected or private by using,
respectively, protected or private implementation
Modes and number of proofs
before(?object_identifier, ?callable, ?object_identifier) - zero_or_more
:- object(..., implements(monitoring), ...). % write a log message when a message is sent: before(Object, Message, Sender) :- writeq(Object), write('::'), writeq(Message), write(' from '), writeq(Sender), nl.