Clojurians Log v2

@ggaillard when you perform the side-effect, you can insert a fact that indicates that the side effect was performed

you can then have a rule that uses that to “retract” the side effects

you likely need to make these effects “idempotent” so they can be replaced multiple times without causing issues

maybe something like

(r/defrule do-thing
  [A (= v :something) (= ?id id)]
  =>
  (do-side-effect ?a)
  (r/insert! (->DidSideEffectFor ?id)))

(r/defrule undo-thing
  [?effect-data <- DidSideEffectFor (= ?id id)]
  [:not [A (= ?id id)]]
  =>
  (retract-side-effect ?effect-data))

If that’s the case, you may just want to handle the side-effects externally and clean up the DidSideEffectFor as well

My post on ways to update facts may be somewhat related to, if you are interested http://www.metasimple.org/2017/12/23/clara-updating-facts.html

Awesome answer! Thank you!