I have a question regarding order of operations in the consequence of a rule when using the mvel dialect. When executed the Drl below provides Right =30.0 and Wrong =140.0. The only difference is the parens around the multiplying expressions, which shouldn't be necessary given order of operations. Is this a problem with the drools/mvel interaction or is it completely an issue with mvel? Is the general expectation that all expressions must be completely scoped by parens when using mvel? *package* test; *dialect* "mvel" *rule* "test 11" *when* *then* *double* rightVal=((10-5)*2) + (5*(8-4)); *double* wrongVal=(10-5)*2 + 5*(8-4); System.out.println("Right ="+rightVal); System.out.println("Wrong ="+wrongVal); *End* * * *After execution:* Right =30.0 Wrong =140.0 Thank you for all of your help. We are using drools 4.0.4. Joe Also, I haven't figured out how it arrives at 140. The following format also produces 140, which seems a little more strange. *double* wrongVal=10-5*2 + 5*8-4; _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Another bug that I just came across while working on getting my parens to work involved not handling scoped numbers properly. Similar to the previous one, but different in that it ends the expression evaluation prematurely. See the drl and result below: *package* test; *dialect* "mvel" *rule* "test 12" *when* *then* *double* rightVal=(10 + 12); *double* wrongVal=(10) + (12); *double* wrongValTwo = ((10)+12) System.out.println("Right "+rightVal); System.out.println("Wrong "+wrongVal); System.out.println("WrongTwo "+wrongValTwo); *End* * * *Results in:* Right 22.0 Wrong 10.0 WrongTwo 10.0 Thanks, Joe *From:* rules-users-bounces(a)lists.jboss.org [mailto: rules-users-bounces(a)lists.jboss.org] *On Behalf Of *Edson Tirelli *Sent:* Wednesday, April 09, 2008 12:39 PM *To:* Rules Users List *Subject:* Re: [rules-users] Order of operations Hi Joe, It seems someone skipped the elementary math lessons at school... :( Will open a JIRA for that. []s Edson 2008/4/9 Joe White <Joe.White(a)recondotech.com&gt;: I have a question regarding order of operations in the consequence of a rule when using the mvel dialect. When executed the Drl below provides Right =30.0 and Wrong =140.0. The only difference is the parens around the multiplying expressions, which shouldn't be necessary given order of operations. Is this a problem with the drools/mvel interaction or is it completely an issue with mvel? Is the general expectation that all expressions must be completely scoped by parens when using mvel? *package* test; *dialect* "mvel" *rule* "test 11" *when* *then* *double* rightVal=((10-5)*2) + (5*(8-4)); *double* wrongVal=(10-5)*2 + 5*(8-4); System.out.println("Right ="+rightVal); System.out.println("Wrong ="+wrongVal); *End* * * *After execution:* Right =30.0 Wrong =140.0 Thank you for all of your help. We are using drools 4.0.4. Joe Also, I haven't figured out how it arrives at 140. The following format also produces 140, which seems a little more strange. *double* wrongVal=10-5*2 + 5*8-4; _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -- Edson Tirelli JBoss Drools Core Development Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users