I think Steffen Luypaert wrote: [Charset iso-8859-1 unsupported, filtering to ASCII...]
> The solution I use now first binds the variables by using regular > patterns, for which no backward chaining is done. For example, if all > faa facts are present in working memory, the constraint (faa (id ? > id&~2)) (foo (?id)) will assert need-foo facts for every id for which a > faa fact exists, except for the faa fact with id 2, which will result > in the desired behaviour for the sample rule. > > I am sure the values of the slots of facts(not patterns) have to be > bound in the current version of Jess, but I was just wondering that > this will ever change, or at least, was ever considered? > You've got some interesting ideas here. As I think you've guessed, the issue is that things like "~2" or "red|blue" are compiled when a rule is defined into structures in the Rete network; there's currently no code in Jess that could interpret these at runtime. But I could imagine a new Value subclass named TestValue, which could wrap constraints such that they could indeed be evaluated at runtime. I agree that this would make Jess's backward chaining much more powerful. This is something we could consider for Jess 7.1. I'll make a note of it. --------------------------------------------------------- Ernest Friedman-Hill Science and Engineering PSEs Phone: (925) 294-2154 Sandia National Labs FAX: (925) 294-2234 PO Box 969, MS 9012 [EMAIL PROTECTED] Livermore, CA 94550 http://herzberg.ca.sandia.gov -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] --------------------------------------------------------------------
