[rules-users] Problem with Negative Patterns and Temporal Constraints

[Wolfgang Laun]

This is just following the basic principles of matching facts to patterns, e.g.
   $p1: Person( $age: age )
   $p2: Person( age >= $age )
binds (apart from many other results) each Person fact to both patterns.

The temporal operators are merely shortcuts for complex relations; do
not expect anything beyond that.

-W

On 17/01/2012, Weiss, Wolfgang <Wolfgang.Weiss at joanneum.at> wrote:
> Thank you for the quick answer! This makes absolutely sense and the rules
> work now as expected.
> Unfortunately, I was not able to find this somewhere in the documentation.
> It would be nice to see it in the documentation of drools fusion.
>
> Best,
> Wolfgang
>
>
> Von: rules-users-bounces at lists.jboss.org
> [mailto:rules-users-bounces at lists.jboss.org] Im Auftrag von Wolfgang Laun
> Gesendet: Montag, 16. Jänner 2012 15:58
> An: Rules Users List
> Betreff: Re: [rules-users] Problem with Negative Patterns and Temporal
> Constraints
>
> I don't see that the "not" CE excludes the AnalysisCue bound to $cue from
> being
> matched by the pattern inside the "not". I recommend using
>
>    not(AnalysisCue(this != $cue, this after[0ms,2500ms] $cue) from
>
> since "[0ms,..." does not inhibit the same event being matched by both
> patterns,
> which precludes the rule from firing.
>
> -W
>
> 2012/1/16 Weiss, Wolfgang
> <Wolfgang.Weiss at joanneum.at<mailto:Wolfgang.Weiss at joanneum.at>>
> Hi all!
>
> We have the problem that the following rule never fires:
>
> rule "test-rule"
>        agenda-group "evaluation"
>        salience 100
>
>        when
>              $cue : AnalysisCue() from entry-point "LowLevelCueStream"
>              not(AnalysisCue(this after[0ms,2500ms] $cue) from entry-point
> "LowLevelCueStream")
>        then
>              logger.debug("... some message ..");
> end
>
> We found out that the problem is the combination of the negation with the
> conditional element "not" and the temporal constraint "[0ms,2500ms]". Using
> the temporal operator "this after $cue" without a temporal constraint works
> correct in its semantics.
> Interestingly, when adding a constraint (cueType == 1) to the type in the
> negative pattern the rule begins to work. The rule would look like as
> follows:
>
> rule "test-rule"
>        agenda-group "evaluation"
>        salience 100
>
>        when
>              $cue : AnalysisCue() from entry-point "LowLevelCueStream"
>              not(AnalysisCue(cueType == 1, this after[0ms,2500ms] $cue) from
> entry-point "LowLevelCueStream")
>        then
>              logger.debug("... some message ..");
> end
>
> unfortunately the rule then fires with a delay of 4 to 5 seconds. The second
> parameter of the temporal constraint influences the delay.
> When changing the first parameter of the temporal constraint to a value
> greater than 0 the rule works as expected! The constraint would then look
> like as follows: "[1ms, 2500ms]". Whereas in our case, we want to evaluate
> the time window from 0 - 2500ms.
>
> Our system works in the stream mode and we could reproduce this behaviour
> with the versions 5.3.1 and 5.4.0 Beta 1.
> Can anybody confirm if this is a bug in Drools, or did I overlook here
> something?
>
>
> Best regards,
> Wolfgang Weiss
>
>
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