[rules-users] Adding a custom operator to drools?

Hi there, you might see this as a follow up to a discussion named "Query by Example" a couple of days ago, see here: http://lists.jboss.org/pipermail/rules-users/2008-September/006520.html Question to the devs: Having looked through the code, adding support for a custom operator requires - changing the DRL.g - regenerating the DRLLexer and DRLParser classes from this grammar - changing the XyzEvaluator and related classes in org.drools.base.evaluators. If I skip MVEL, the BRMS and other places like decision tables for now, is this all to expand the DRL syntax? Or are any further steps required to connect the grammar with the "java logic"? Thanks! Michael