or even better (using future themselves as a "marker" in the atom):
(defmacro map-future-swap! [a k f] `(locking ~a (when (not (contains? @~a ~k)) (swap! ~a assoc ~k (future (swap! ~a assoc ~k (~f ~k)))) ) ) ) -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.