On Tue, Mar 3, 2009 at 2:54 PM, Mark Volkmann <r.mark.volkm...@gmail.com> wrote: > > I agree that using doseq instead of dorun results in code that is > easier to read. I don't understand though why it is more efficient. > They both walk the entire sequence, neither holds onto the head and > both return nil. Why is doseq more efficient than dorun?
A simple doseq does run about as fast as dorun on the same seq. Bus something like this would be more likely (let's pretend inc has useful side-effects): (defn f [] (dorun (map #(inc %) (range 10000000)))) (defn f2 [] (doseq [i (range 10000000)] (inc i))) The results would be the same, but dorun requires 'map', which creates another seq. 'doseq' is able to accomplish the same work with less allocation. user=> (time (f)) "Elapsed time: 1685.796066 msecs" user=> (time (f2)) "Elapsed time: 531.730209 msecs" --Chouser --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
