Hello, We have a rule set that need to be rewritten before being loaded into the knowledge base. The rewrite can only be determined by data known at runtime. Currently we can achieve this by performing string subsitutions on the rules, however I'd like to explore more efficient (and less clumsy) ways of doing this. It looks like rule templates could be a less error-prone way of achieving the same end through the use of place holders, but it still requires for the resultant rule strings to be recompiled. I was wondering whether it is practical to store the rules in compiled form, and then perform the rewriting on the loaded data structures? Any suggestions and/or experience of techniques would be very welcome. Thanks, James -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Rewriting-rules-tp245... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Hi Wolfgang, For example, the user may specify something along the lines of: rule "example" when Object(slot = "value")

then .. end Minimally we might want to rewrite the rule to strengthen the condition: rule "example" when Object(slot = "value", id = 125)

then .. end Where 125 is not known until runtime. We may want to handle more complex cases where the user refers to "facts" that are conceptually scoped, but we may want to rewrite using "from": rule "example" when $op : ObjectProvider() Object(slot = "value") from op.eval()

then .. end Thanks, James -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Rewriting-rules-tp245... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

> rule "example" > when > $op : ObjectProvider() > Object(slot = "value") from op.eval() Because getting the value returned by op.eval() is extremely expensive and should only be done if this component of the rule is evaluated (assuming that the rule has a more complex pattern implicating other types).

Thanks, James --