On Fri, Jun 8, 2012 at 4:35 AM, Gabo <delmasc...@gmail.com> wrote: > I'm actually working on a simple function which would replace the nth > element of a vector.
(assoc v n e) ;; returns a new vector with the nth element of v replaced by e Note that it does not change the original vector. > (def ids-in-use (ref [1 2 3])) > (defn update-vector [v tid] > (assoc v tid 10)) update-vector will return a new vector with the 'tid'th element replaced by 10, leaving the original v unchanged. > (update-ids-in-use [2]) Is this meant to be (update-vector @ids-in-use 2) ? That would return the current value of @ids-in-use with the 2nd element replaced by 10, i.e., [1 2 10] and would not change what ids-in-use referred to (still [1 2 3]). Since it sounds like you want to mutate ids-in-use and you just need to replace its value, the following might do what you want: (def ids-in-use (atom [1 2 3])) (defn update-vector [v tid] (assoc v tid 10)) (swap! ids-in-use update-vector 2) The latter will (atomically) replace the value inside ids-in-use with the result of (update-vector @ids-in-use 2) (defn update-ids-in-use [tid] (swap! ids-in-use update-vector tid)) -- Sean A Corfield -- (904) 302-SEAN An Architect's View -- http://corfield.org/ World Singles, LLC. -- http://worldsingles.com/ "Perfection is the enemy of the good." -- Gustave Flaubert, French realist novelist (1821-1880) -- 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
