[rules-dev] modify (expr) catch 22

[Mark Proctor]

On 08/04/2011 13:17, Michael Anstis wrote:
> OK, answers my question :)
The limitation is it will only work for direct accessors. Anything else 
and it gets too hard and expensive to maintain and track.

Mark
>
> It is on the "to do" list already.
>
> On 8 April 2011 13:11, Mark Proctor <mproctor at codehaus.org 
> <mailto:mproctor at codehaus.org>> wrote:
>
>     On 08/04/2011 12:39, Geoffrey De Smet wrote:
>     > Related to the modify expression,
>     > I 've always wondered about this code:
>     >
>     > rule "MyRule"
>     >     when
>     >       $p : Person(name = "Yoda")
>     >     then
>     >       modify ($p) {
>     >         setAge(300)
>     >       }
>     > end
>     >
>     > Doesn't this create an infinite loop? (In my experience it does
>     or at
>     > least it takes a lot longer)
>     > Because the modify ($p) schedules any rule using a Person back
>     on the
>     > agenda to be re-evaluated,
>     > so also that rule, which is evaluated and executed again,
>     modifying $p
>     > again, ... hence the infinite loop?
>     It would, unless you have slot specific - which Jess does. Slot
>     specific
>     is something I really want to add, I think it will resolve a lot of
>     recursion problems and make Drools a lot easier to use. I took the
>     slot
>     specific problem and genericsed it further for "slot listeners". I
>     discussed this here:
>     http://blog.athico.com/2010/07/slot-specific-and-refraction.html. I
>     think Laune added some refinements to this in a mailing list entry
>     somewhere.
>
>     Mark
>
>
>
>     _______________________________________________
>     rules-dev mailing list
>     rules-dev at lists.jboss.org <mailto:rules-dev at lists.jboss.org>
>     https://lists.jboss.org/mailman/listinfo/rules-dev
>
>
>
> _______________________________________________
> rules-dev mailing list
> rules-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-dev/attachments/20110408/46367d33/attachment-0001.html