I don't see how the macro version would offer any performance benefits - in both cases, x is evaluated once and pred is called once. Am I missing something?
Den fredagen den 24:e oktober 2014 kl. 15:47:50 UTC+2 skrev Fluid Dynamics: > > (defn if-its [pred x] > (if (pred x) x)) > > => (if-its even? 4) > 4 > => (if-its even? 5) > nil > > Or, if you want a macro for performance reasons or something, and don't > mind the loss of e.g. (filter identity (map (partial if-its pred) coll)): > > (defmacro if-its [pred x] > `(let [a# ~x] > (if (~pred a#) a#))) > > -- 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.
