[rules-users] MVEL performance penalty

Drools 5.3.0 FINAL. This experiment was inspired by code posted with the insinuation that MVEL would "optimize" condition evaluation. - Consider this rule: rule "Term - java" dialect "java" when $ea : EasyApp( Test.valueInList( $ea.getProductCode(), "CAR" )==true && age < 0 ) then end You'd expect that Test.valueInList() is called once per inserted EasyApp fact, and this can be verified easily. - Now the same rule, with MVEL's syntactic sugar: rule "Term - mvel" dialect "mvel" when $ea : EasyApp( Test.valueInList( productCode, "CAR" )==true && age < 0 ) then end *Now Test.valueInList() is called twice for each inserted fact.* Cheers Wolfgang