Re: [rules-dev] Changing a fact's hashCode causes rules not to fire

** On 23/06/2011 09:32, Wolfgang Laun wrote: If I have class Type { int field; setField( int f ){ field = f; } } and do modify( $type ){ setField( 42 ) } where is there a "nested accessor"? $one: One() $two: Two( $x: one == $one ) If you change a field on object "one". that field is a nested accessor to Two. one.field1 = "x" is the same as doing two.one.field1 = "x" so to "two" changing the field of 1 is a nested accessor. Think about how indexing works. left == right when two objects are == each other indexing creates a bucket for the left and a bucket for the right. If you change the hashcode of the one on the right, how will it find the bucket on the left? Mark -W On 23 June 2011 10:24, Mark Proctor <mproctor(a)codehaus.org&gt; wrote: > On 23/06/2011 07:03, Wolfgang Laun wrote: > > Eeek! > > Assume this: A is a field of B is a field of C is a field of D is a... > > Object references remain the same, in all objects; I simply modify A, and > "when you change [A] you are also changing [B], so I must notify the > engine for [B]" but that's a field of C... D... E... and so on, until > 'I' for infinity?! > > *It's just a change in some fact object's hashCode that causes this > problem.* > > If you don't want any indexing in your rule engine. If you want indexing, > you have to notify the engine. Changes to nested accessors have always been > invisible to the engine. If a nested access changes, you must notify the > engine of the root fact. > > Mark > > > -W > > > > On 22 June 2011 22:37, Mark Proctor <mproctor(a)codehaus.org&gt; wrote: > > As One is a field of Two. When you change One you are also changing Two, > so > > you most notify the engine for Two too. > > > > MArk > > On 22/06/2011 14:37, Wolfgang Laun wrote: > > > > To avoid misunderstandings: yes, equals() is written according to > hashCode, > > i.e., according to the usual Java conventions. > > > > If > > > > - an object of class Two contains a member of class One, and > > - one object Two and one object One are facts, and > > - a rule modifies One, changing its hashCode > > > > then > > > > another rule containing the patterns > > $one: One() > > $two: Two( $x: one == $one ) > > > > does NOT fire (any more). > > > > If you use the constraint > > one == $one || != $one > > the rule will fire, and you can observe that hashCode results for $one > and > > $x are the same and that $one.equals( $x ) returns true. > > > > Reproduced using 5.1.1 and 5.2.x > > > > -W > > > > > > > > > > _______________________________________________ > > rules-dev mailing list > > rules-dev(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-dev > > > > > > _______________________________________________ > > rules-dev mailing list > > rules-dev(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-dev > > > > > > > _______________________________________________ > rules-dev mailing listrules-dev@lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-dev > > > > _______________________________________________ > rules-dev mailing list > rules-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-dev > > _______________________________________________ rules-dev mailing listrules-dev@lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-dev _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev