Match Multiple in Single Rule

[sdiemert]

It would be helpful to capture and operate on all of the nodes that match a particular pattern in one rule. This might be analgous to a "for all" statement in first order logic.

For example, to fire a worker from an organization you might have delete them from multiple departments. See #11 for example.

(rule 'fire-worker ['name]
    :read (pattern 
                 (node 'w :label "Worker" :asserts {:name 'name})
                 (node 'c :label "Company")
                 (node 'd :label "Department" :all)
                 (edge 'e1 :label "employer" :src 'w :tar 'c)
                 (edge 'e2 :label "in_dept" :src 'w :tar 'd)
    :delete ['e1 'e2])

This issue might superceed #11 since you can simple match multiple (0) versions of pattern.

@jenshweber - we discussed one way of doing this with "meta-rules", is that still the preferred solution?

[sdiemert]

Alternative syntax might be something like...

(pattern 
   (node 'n1 :label "foo")
   (forall 
        (node 'n2 :label "bar")
        (edge 'e :label "foobar" :src 'n1 :tar 'n2)))

This would match a single node labelled foo and all of the adjcent nodes (via edge foobar) that are themselves labelled bar.

[jenshweber]

Yes, this would be good. I am not sure how difficult this will be though. I'll have to think about this.