Re: [rules-users] looking for more information on drools expert

Very good! :) Just FYI, in the case of accumulate, you could also use the collectList() function to simplify your rule. This: $alarmList : LinkedList() from accumulate ( ($e : Element(parentindex!=0) and $a : Alarm( origin matches $e.name&& probablecause==45)), init( LinkedList alarmList = new LinkedList();), action( alarmList.add($a);), reverse( alarmList.remove($a);), result( alarmList ) ); Is the same as: $alarmList : List() from accumulate ( ($e : Element(parentindex!=0) and $a : Alarm( origin matches $e.name&& probablecause==45)), collectList( $a ) ); Also, you can always implement your own functions for accumulate: http://blog.athico.com/2009/06/how-to-implement-accumulate-functions.html Finally, I see you are using "matches" operator to compare equal strings. Not sure if that is what you want, because "==" has different semantics and better performance than "matches" if what you really want is compare equality. Remember that in regexps, some characters have special meaning, for instance, "." is a wildcard for any character. Meaning: "abc" matches "a.c" -> true "abc" == "a.c" -> false Cheers, Edson 2009/7/16 Gab Aldian <aldian.gp(a)gmail.com&gt; -- Edson Tirelli JBoss Drools Core Development JBoss by Red Hat @ www.jboss.com