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nemonik / Intellect

DSL and Rules Engine For Python
http://pypi.python.org/pypi/Intellect
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Inserted fact not available for next rule #12

Open psantann opened 9 years ago

psantann commented 9 years ago

I have a sequence of rules as below. Even though I'm inserting a new AlarmFact and I can see it was created with the proper name, the next rule "We got a new alarm" is still executed so I end up with two AlarmFacts one with count=2 and another with count=1

rule "Process an incoming alarm": agenda-group "process alarm 1" when: $alarm := Alarm() then: log("We got an alarm with name {0}".format($alarm.name)) attribute current_alarm_name = $alarm.name forget $alarm

rule "We got an alarm already existent": agenda-group "process alarm 2" when: $alarm_fact := AlarmFact( name == current_alarm_name) then: log("We got another alarm with name {0}".format($alarm_fact.name)) modify $alarm_fact: count = $alarm_fact.count + 1

rule "We got a new alarm": agenda-group "process alarm 3" when: not exists $alarm_fact := AlarmFact( name == current_alarm_name) then: log("We got a new alarm with name {0}".format(current_alarm_name)) insert AlarmFact(current_alarm_name)

psantann commented 9 years ago

The problem seems to be that a "not" before an exists does not apply to the whole expression: DEBUG:intellect:intellect.Node.When :: Filter using the following list comprehension: matches = [fact for fact in policy.intellect.knowledge if reflection.is_instance(fact, klazz) and not (fact.name == current_alarm_name)] So if I have another AlarmFact with the attribute name set to something different, it will evaluate the when clause to True and add one more instance of AlarmFact.