Details
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Type:
Bug
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Status:
Closed
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Priority:
Major
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Resolution: Fixed
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Affects Version/s: 1.1, 1.2.26
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Fix Version/s: 1.3.0
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Component/s: None
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Labels:None
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Number of attachments :
Description
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;
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