The difference is not HUGE, but in a critical section it might be a valid micro-optimization. I'd also be interested to know why, but I bet you're assumption of apply being thrown in the mix is probably pretty close to true.
user=> (time (dotimes [_ 1e6] (doall (map #(filter even? %) (for [i (range 0 100 4)] (range i (+ i 4))))))) "Elapsed time: 6589.49 msecs" nil user=> (time (dotimes [_ 1e6] (doall (map #(filter even? %) (for [i (range 0 100 4)] (range i (+ i 4))))))) "Elapsed time: 6620.396 msecs" nil user=> (time (dotimes [_ 1e6] (doall (map (partial filter even?) (for [i (range 0 100 4)] (range i (+ i 4))))))) "Elapsed time: 8899.466 msecs" nil user=> (time (dotimes [_ 1e6] (doall (map (partial filter even?) (for [i (range 0 100 4)] (range i (+ i 4))))))) "Elapsed time: 8949.646 msecs" nil (sorry for further hijacking the thread) On Aug 23, 6:09 pm, Alan <a...@malloys.org> wrote: > Really? I would be interested to hear why; is it maybe because partial > has to take any number of arguments and then (apply even? args)? > > I've taken to using partial when I can, precisely because of the > difficulty of nesting anonymous functions, and while performance isn't > a big deal for me I'm curious. > > On Aug 23, 12:30 pm, Cameron <cpuls...@gmail.com> wrote: > > > > > Again with the bad examples but... > > > (map #(even? %) coll) is faster than > > (map (partial even?) coll) > > > So it's at least got that going for it. > > > (I know this SHOULD be written as (map even? coll)) > > > On Aug 23, 1:59 pm, Michael Gardner <gardne...@gmail.com> wrote: > > > > On Aug 23, 2010, at 11:13 AM, Luka Stojanovic wrote: > > > > > On Mon, 23 Aug 2010 18:01:13 +0200, Joop Kiefte <iko...@gmail.com> > > > > wrote: > > > > >> bad example =/ > > > > >> Yes, it is > > > > >> but you get the gist I hope > > > > >> better example: #(first (sort %)) ;) > > > > > (comp first sort) > > > > > and #(some-fn x %) can be written as > > > > (partial some-fn x) > > > > > which leaves #(some-fn % x) as case not trivial with other syntax > > > > > again (fn [y] (some-fn y x)) is about 8 chars longer, so I guess #() > > > > form really is not something that should be used that often > > > > I don't know about you, but I find #(= 2 (count %)) much nicer and easier > > > to read than (comp (partial = 2) count). -- 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
