Thank you; the template inheritance mechanism was the answer.
On Jul 30, 2013, at 8:11 AM, "Friedman-Hill, Ernest" <ejfr...@sandia.gov> wrote:
> The short answer is “no”. Templates are like Java classes, and so this is
> akin to asking if you can write Java code that reads the value of a “score”
> member variable in any class.
> But you can use template inheritance to achieve your goal. Templates can
> extend other templates; just put your “score” slot in a base template, and
> extend everything else that needs a “score” slot from that common base, and
> write your patterns to match the base template. Read about the use of
> “extends” in templates here:
> From: owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov] On
> Behalf Of Aurelien Mazurie
> Sent: Friday, July 26, 2013 4:43 PM
> To: jess-users
> Subject: JESS: [EXTERNAL] Matching facts based on a slot, but not the fact's
> Dear Jess users,
> I am still learning the ropes, and cannot find an answer to the following
> question either online or in the 'Jess in action' book. Is there a way to
> match facts in a LHS based on the presence of a slot?
> For example, I have two templates:
> (deftemplate A (slot score))
> (deftemplate B (slot score))
> I would like my rule to be triggered if any fact (either from template A, B,
> or others) have a 'score' slot with a specific value. For now I can do it by
> manually adding references to A and B in the LHS, but this will not scale
> well. I'm looking for a solution that can just work on any fact, regardless
> of the template they are defined from.