I think the point with `commute` is to allow for more concurrency at the expense of more computation.
If you want assurance that your function is only called once, you can use `alter`. Keep in mind that *any* code in a Ref transaction has the potential to be called more than once if there's a conflict. All this doesn't mean that it's impossible to avoid the duplicate computation on `commute`. The code to study would be here: https://github.com/clojure/clojure/blob/8fda34e4c77cac079b711da59d5fe49b74605553/src/jvm/clojure/lang/LockingTransaction.java#L459 -S -- 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
