[rules-users] How can I know, how many facts are processed by stateFulSession?

[tom ska]

Hello,
I think you understood me. Your solution is to validate facts in the rule.
OK - I think this is a good idea, but... What if rules are created by no-IT
(no-Math-aware ;) ) people? I can imagine situation where they do not
validate this issue (div by 0). What then? If I send 1000 facts to ksession,
and 901 has value set to 0? I want my 900 correct facts back. How can I
know, how many have been processed?

P.S. I don't want to use globals to count this.

Thanks,
tom.

2010/8/31 Edson Tirelli <tirelli at post.com>

>    I am not sure I understand your problem. The rule clearly should NOT
> match facts with value 0, as it will raise division by zero error all the
> time. So, the solution, in my mind is:
>
> rule "r1"
>     when
>         p : CTestObj( value != 0 )
>
>     then
>         p.setValue( 1 / p.getValue() );
> end
>
>    If you need to give a different treatment to objects with value == 0,
> just add another rule for them.
>
>    []s
>    Edson
>
>
> 2010/8/31 tom ska <tiberium.linux at gmail.com>
>
>> Hello,
>> I have a class and rule:
>>
>> class CTestObj
>> {
>>         private double value;
>>
>>         void setValue(double v) {
>>                 this.value = v;
>>         }
>>
>>         double getValue() {
>>                 return this.value;
>>         }
>> }
>>
>> rule "r1"
>>     when
>>         p : CTestObj
>>     then
>>         p.setValue( 1 / p.getValue() );
>> end
>>
>> As you can see, in this rule, there is risk, to put into stateFulSession
>> object with value set 0. I can't validate this, because, this problem has a
>> variation where I put into stateFulSession object with set no 0, but the
>> rule will modify it...
>> So - I can't validate this = fact with value 0 is correct.
>>
>> But I process with stateFulSession many, many facts... For example 1000.
>> And, after 900 facts it occurs, that fact number 901 has value set on 0. In
>> effect I get an exception:  org.drools.runtime.rule.ConsequenceException:
>> java.lang.ArithmeticException: / by zero. And ksession stops processing
>> facts. But, 900 facts are processed! I don't want to process them second
>> time.
>> And this is my question:
>>
>> How can I know, which fact is first no-processed fact? Which one stoped
>> fireAllRules method?
>> Beacuse I don't want to process them another time.
>>
>> Greetings :)
>> tom.
>>
>>
>>
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
>
> --
>   Edson Tirelli
>   JBoss Drools Core Development
>   JBoss by Red Hat @ www.jboss.com
>
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>
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