built-in accumulate functions shall ignore NULLs ------------------------------------------------ Key: DROOLS-1242 URL: https://issues.jboss.org/browse/DROOLS-1242 Project: Drools Issue Type: Enhancement Components: core engine Reporter: Matteo Mortari Assignee: Mario Fusco Priority: Optional This is a spin-off out of another problem [here|https://issues.jboss.org/browse/GUVNOR-2589?focusedCommentId=1326892...] for a proposal of improvement. It could actually be beneficial for built-in accumulate functions to ignore NULLs. This would be similar behavior of other languages such: * SQL (e.g.: MySQL, Oracle, ..) * Clojure Currently it is up to the rule author to put a guarding condition in the first accumulate {{<source pattern>}} to manually ignore null sources to avoid the built-in accumulate functions to break trying to accumulate on NULLs.