[rules-users] Combined OR/NOT Rules results in NullPointerException

[Wolfgang Laun]

Oops, the correct form is actually

  not (Input(...))

with an additional pair of parens just around the fact.

-W



On 3/29/10, Sebastian Furth <sebastian.furth at googlemail.com> wrote:
> Thanks for your reply. If I formulate the rules this way I get the following
> error from the KnowledgeBuilder:
>
> [21,4]: [ERR 102] Line 21:4 mismatched input 'not' expecting ')' in rule
> "R50"
> [24,66]: [ERR 102] Line 24:66 mismatched input ')' expecting 'then' in rule
> "R50
> Best Regards
>
> Sebastian Furth
>
>
> 2010/3/29 Wolfgang Laun <wolfgang.laun at gmail.com>
>
>> If you mean
>>
>> when
>>   ( $value1: Value(...)
>>     not Input(...)
>>   or
>>     $value2: Value(...)
>>     not Input(...)  )
>>
>>  $solution: SolutionInput(...)
>> then
>> ...
>>
>> you'll have to use parentheses. If not, what *do* you mean?
>> -W
>>
>>
>> On 3/29/10, Sebastian Furth <sebastian.furth at googlemail.com> wrote:
>> > Hello,
>> >
>> > i've already mailed last week with the same problem and with your help I
>> was
>> > able to locate the source of the following NullPointerException which
>> > happens if we try to insert the Fact "knocking" (@see Source Code of the
>> > Java Class here: http://www.pastie.org/private/juv7hh7rxahpluo5agu3q) :
>> >
>> > *java.lang.NullPointerException
>> >     at org.drools.reteoo.LeftTuple.get(LeftTuple.java:265)
>> >     at org.drools.reteoo.LeftTuple.get(LeftTuple.java:300)
>> >     at
>> >
>> org.drools.rule.VariableRestriction$ObjectVariableContextEntry.updateFromTuple(VariableRestriction.java:320)
>> >     at
>> >
>> org.drools.common.SingleBetaConstraints.updateFromTuple(SingleBetaConstraints.java:119)
>> >     at org.drools.reteoo.NotNode.assertLeftTuple(NotNode.java:98)
>> >     at
>> >
>> org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:117)
>> >     at
>> >
>> org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:34)
>> >     at org.drools.reteoo.NotNode.assertLeftTuple(NotNode.java:123)
>> >     at
>> >
>> org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:145)
>> >     at
>> >
>> org.drools.reteoo.CompositeLeftTupleSinkAdapter.createAndPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:57)
>> >     at
>> >
>> org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:142)
>> >     at
>> >
>> org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:42)
>> >     at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:147)
>> >     at
>> >
>> org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:360)
>> >     at
>> >
>> org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:344)
>> >     at
>> > org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:185)
>> >     at
>> > org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:146)
>> >     at
>> >
>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1046)
>> >     at
>> >
>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1001)
>> >     at
>> >
>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:788)
>> >     at
>> >
>> org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:216)
>> >     at de.d3web.we.drools.DroolsAction.addFacts(DroolsAction.java:334)
>> > *
>> >
>> > The source of the problem is the following rule:
>> >
>> > *rule "R50"
>> >   when
>> >     $value1 : Value(value == "knocking")
>> >     not Input(name == "Engine noises" && values contains $value1)
>> >     or
>> >     $value2 : Value(value == "ringing")
>> >     not Input(name == "Engine noises" && values contains $value2)
>> >     $solution : SolutionInput(name == "Bad ignition timing")
>> >   then
>> >     $solution.setValue(N3);
>> > end
>> > *
>> >
>> > Could you please tell me how I have to formulate the rule to avoid the
>> > NullPointerException while inserting the fact?
>> >
>> > Thank you in advance for your help.
>> >
>> > Best regards
>> >
>> > Sebastian Furth
>> >
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