Hi. Thank you.
On Wed, Feb 6, 2013 at 10:50 AM, Christophe Grand <[email protected]>wrote: > Hi > > On Mon, Feb 4, 2013 at 2:29 PM, AtKaaZ <[email protected]> wrote: > >> => (class {:x "a" :y 3}) >> clojure.lang.Persistent*Array*Map >> => (def m {:x "a" :y 3}) >> #'runtime.q/m >> => (class m) >> clojure.lang.Persistent*Hash*Map >> > > huh? that one I can't explain, I'll have to do some research. > > => (def m (let [] {:x "a" :y 3})) > #'user/m > => (class m) > clojure.lang.PersistentArrayMap > > >> => (time (dotimes [n 10000000] (hash m))) >> "Elapsed time: 168.162927 msecs" >> nil >> => (time (dotimes [n 10000000] (hash m))) >> "Elapsed time: 161.341094 msecs" >> nil >> => (time (dotimes [n 10000000] (hash m))) >> "Elapsed time: 159.444025 msecs" >> nil >> >> > Since hash is cached and m doesn't change, more runs are just measuring > the time to lookup the cache. There may be a sligt overhead due to m being > a var. > > To properly isolate this you have to use locals: > => (let [m (hash-map :x "a" :y 3)] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentHashMap > "Elapsed time: 221.62 msecs" > nil > => (let [m (hash-map :x "a" :y 3)] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentHashMap > "Elapsed time: 214.624 msecs" > nil > => (let [m (hash-map :x "a" :y 3)] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentHashMap > "Elapsed time: 212.505 msecs" > nil > => (let [m {:x "a" :y 3}] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentArrayMap > "Elapsed time: 232.872 msecs" > nil > => (let [m {:x "a" :y 3}] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentArrayMap > "Elapsed time: 218.141 msecs" > nil > => (let [m {:x "a" :y 3}] > (println (class m)) > (time (dotimes [n 10000000] (hash m)))) > clojure.lang.PersistentArrayMap > "Elapsed time: 220.813 msecs" > nil > > No significant change -- hopefully since 1e7-1 times out od 1z7 we are > measuring the cost of looking up a cache. > > Christophe > > -- > On Clojure http://clj-me.cgrand.net/ > Clojure Programming http://clojurebook.com > Training, Consulting & Contracting http://lambdanext.eu/ > > -- > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to [email protected] > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > [email protected] > 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 [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- Please correct me if I'm wrong or incomplete, even if you think I'll subconsciously hate it. -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to [email protected] Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to [email protected] 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 [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
