[rules-users] ClassCastException using memberOf operator

[Wolfgang Laun]

A better approach for your use case would be to use additional facts:

declare Cont
  name: String
  objects: Collection
end

rule "define Cont(s)"
salience 999999999
when
then
    insert( new Cont( "A", setOf(1, 2, 3) ) );
end

Cont( name == "A", $coll )
i: Item ( f memberOf $coll )

-W


On 24/01/2013, Marco Malziotti <marco.malziotti at trs.it> wrote:
> Thanks Wolfgang
> In addition to using 'memberOf' operator, there is a way to retain in
> RHS result from makeA(), without calling one more time makeA() function
> ?
> In consequence (then) of my example I want print 'a' that already holds
> (?) the function result.
> Once again thanks.
>
> Marco
>
> On Wed, 23 Jan 2013 17:49:04 +0100, Wolfgang Laun wrote:
>> The simple
>>   i: Item ( f memberOf (makeA()) )
>> should do.
>> -W
>>
>> On 23/01/2013, Marco Malziotti <marco.malziotti at trs.it> wrote:
>>> Hello
>>> I am a beginner in Drools 5.1.1 and try to use 'memberOf' operator.
>>> Simply I want check whether a short field 'f' (belonging to Item
>>> class)
>>> is a member of an array 'a': retrieved by a function 'makeA'.
>>> In my .drl file I try with :
>>>
>>> function Short[] makeA() {
>>>    return  (new Short[] {1, 2, 3} );
>>> }
>>>
>>> rule "chek"
>>> when
>>>    a: Short[]() from makeA()
>>>    i: Item ( f memberOf a )
>>> then
>>> ... 'f' is member of array 'a' !
>>> end
>>>
>>> I have following stack trace:
>>> java.lang.ClassCastException: Can't check if an attribute is member
>>> of
>>> an object of class class java.lang.Short
>>> at
>>>
>>> org.drools.base.evaluators.SetEvaluatorsDefinition$BaseMemberOfEvaluator.evaluateCachedRight(SetEvaluatorsDefinition.java:532)
>>> at
>>>
>>> org.drools.rule.VariableRestriction.isAllowedCachedRight(VariableRestriction.java:117)
>>> at
>>>
>>> org.drools.rule.VariableConstraint.isAllowedCachedRight(VariableConstraint.java:121)
>>> at
>>>
>>> org.drools.common.SingleBetaConstraints.isAllowedCachedRight(SingleBetaConstraints.java:151)
>>> at org.drools.reteoo.JoinNode.assertObject(JoinNode.java:125)
>>> at
>>>
>>> org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:59)
>>> at
>>>
>>> org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:190)
>>> at
>>>
>>> org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:145)
>>> at
>>>
>>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1174)
>>> at
>>>
>>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1123)
>>> at
>>>
>>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:917)
>>> at
>>>
>>> org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:251)
>>>
>>> In :
>>>
>>> http://lists.jboss.org/pipermail/rules-users/2008-October/006746.html
>>> and
>>>
>>> http://lists.jboss.org/pipermail/rules-users/2007-September/003010.html
>>> I haven't found the solution to my problem.
>>>
>>> I don't know if it is already open a related issue.
>>>
>>> Thanks for your attention.
>>> Regards.
>>>
>>> Marco Malziotti
>>> Tecnologie nelle Reti e nei Sistemi T.R.S. S.p.A.
>>> Integration Test Engineer
>>> Tel.  + 39 06.87281.407
>>> Fax.  + 39 06.87281.550
>>> E-mail: marco.malziotti at trs.it
>>>
>>>
>>> Tecnologie nelle Reti e nei Sistemi T.R.S. SpA
>>> Via della Bufalotta, 378 - 00139 Roma
>>> Tel +39.06.87.28.1.1 - Fax +39.06.87.28.1.550
>>>
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>
>
> Tecnologie nelle Reti e nei Sistemi T.R.S. SpA
> Via della Bufalotta, 378 - 00139 Roma
> Tel +39.06.87.28.1.1 - Fax +39.06.87.28.1.550
>
> -------------------------------------------------------
>
> Ai sensi del D.Lgs. 196/2003 si precisa che le informazioni contenute in
> questo messaggio
> sono riservate ed a uso esclusivo del destinatario. Qualora il messaggio in
> parola Le
> fosse pervenuto per errore, la preghiamo di eliminarlo senza copiarlo e di
> non inoltrarlo
> a terzi, dandocene gentilmente comunicazione. Grazie.
> This message, for the law 196/2003, may contain confidential and/or
> privileged information.
> If you are not the addressee or authorized to receive this for the
> addressee, you must not
> use, copy, disclose or take any action based on this message or any
> information herein.
> If you have received this message in error, please advise the sender
> immediately by reply
> e-mail and delete this message. Thank you for your cooperation.
>
> -------------------------------------------------------
>
> This message has been scanned for viruses and dangerous content by
> MailScanner, and is believed to be clean.
>
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