Felipe, The NPE is a bug that was fixed already. I can't think in another way of doing without using a return value restriction as you are doing... []s Edson 2007/7/24, Felipe Piccolini <felipe.piccolini(a)bluesoft.cl&gt;: Hi, Im trying to compare a field to a Class type but when parsing I get NPE and when I debug, the constraint is a ReturnValueConstraint but the restriction.getRequiredDeclarations() return a Declaration[] array initializated, but empty, so I can't get the declaration evaluated... I needed because I'm working on a kind of parser for the rules for analisys and testing... but using the already parsed package. Here is a pseudo rule for test... rule "Test A" when $mf: MyFact(clazz == (SomeClass.class)) then System.out.println("Test A: OK" ); end Actualy, the rule compiles (with the NPE output, not stackTrace, just the java.lang.NullPointerException , and it works fine.. I mean I get "Test A: OK" as output, but cant get the SomeClass.class reference when I look into the debugger. Is this the right way to compare clases? if not, whats the right way? (Im trying to not do == "SomeClass") Felipe Piccolini M. felipe.piccolini(a)bluesoft.cl _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev