And I guess it is so because into, being called numerous times, keeps transforming bigger and bigger vectors into transient vectors, and back to persistent vectors, etc.
2012/7/24 Laurent PETIT <laurent.pe...@gmail.com> > Oh, and finally, note that even without transients, you get 6x better perf > by not calling into directly: > > => (defrecord Tree [h l r]) > > > (defn generate-tree [c] > (when-let [s (seq c)] > (let [lr (generate-tree (rest s))] > (Tree. (first s) lr lr)))) > > (defn to-list > ([t] (to-list t [])) > > ([t b] > (if t > (let [b (to-list (:l t) b), > b (conj b (:h t)), > > b (to-list (:r t) b)] > b) > b))) > (defn tree [n] > (generate-tree (range 1 n))) > > (let [t (tree 21)] > (dotimes [_ 10] > (time > (dotimes [_ 1] > (println (count (to-list t))))))) > user.Tree > #'user/generate-tree > #'user/to-list > #'user/tree > 1048575 > "Elapsed time: 174.14 msecs" > 1048575 > "Elapsed time: 124.218 msecs" > 1048575 > "Elapsed time: 130.186 msecs" > 1048575 > "Elapsed time: 109.883 msecs" > 1048575 > "Elapsed time: 104.221 msecs" > 1048575 > "Elapsed time: 98.387 msecs" > 1048575 > "Elapsed time: 98.21 msecs" > 1048575 > "Elapsed time: 103.543 msecs" > 1048575 > "Elapsed time: 98.663 msecs" > 1048575 > "Elapsed time: 101.913 msecs" > nil > => (defrecord Tree [h l r]) > > > (defn generate-tree [c] > (when-let [s (seq c)] > (let [lr (generate-tree (rest s))] > (Tree. (first s) lr lr)))) > > (defn to-list > ([t] (to-list t [])) > > ([t b] > (if t > (into (conj (to-list (:l t) b) (:h t)) (to-list (:r t) b)) > > b))) > (defn tree [n] > (generate-tree (range 1 n))) > > (let [t (tree 21)] > (dotimes [_ 10] > (time > (dotimes [_ 1] > (println (count (to-list t))))))) > user.Tree > #'user/generate-tree > #'user/to-list > #'user/tree > 1048575 > "Elapsed time: 1149.562 msecs" > 1048575 > "Elapsed time: 846.225 msecs" > 1048575 > "Elapsed time: 605.007 msecs" > 1048575 > "Elapsed time: 604.409 msecs" > 1048575 > "Elapsed time: 625.605 msecs" > 1048575 > "Elapsed time: 626.066 msecs" > 1048575 > "Elapsed time: 605.502 msecs" > 1048575 > "Elapsed time: 621.007 msecs" > 1048575 > "Elapsed time: 606.064 msecs" > 1048575 > "Elapsed time: 642.739 msecs" > nil > > > 2012/7/23 Laurent PETIT <laurent.pe...@gmail.com> > >> 2012/7/23 Mark Engelberg <mark.engelb...@gmail.com> >> >>> As David was posting his code, I was wrapping up my own experimentation >>> with how transients apply here. Mine is similar, but doesn't use pattern >>> matching -- seems a bit faster: >>> >>> >>> (defrecord Tree [h l r]) >>> >>> (defn generate-tree [c] >>> (when-let [s (seq c)] >>> (let [lr (generate-tree (rest s))] >>> (Tree. (first s) lr lr)))) >>> >>> (defn to-list >>> ([t] (persistent! (to-list t (transient [])))) >>> ([t b] >>> (if t >>> (let [b (to-list (:l t) b), >>> b (conj! b (:h t)), >>> b (to-list (:r t) b)] >>> b) >>> b))) >>> >>> >> True, >> >> and notice you can also drop records altogether: >> >> >> (defn generate-tree [c] >> (when-let [s (seq c)] >> (let [lr (generate-tree (rest s))] >> [(first s) lr lr]))) >> >> >> (defn to-list >> ([t] (persistent! (to-list t (transient [])))) >> ([t b] >> (if t >> (let [b (to-list (t 1) b), >> b (conj! b (t 0)), >> b (to-list (t 2) b)] >> b) >> b))) >> >> (defn tree [n] >> (generate-tree (range 1 n))) >> >> (let [t (tree 21)] >> (dotimes [_ 10] >> (time >> (dotimes [_ 1] >> (println (count (to-list t))))))) >> >> 1048575 >> "Elapsed time: 346.446 msecs" >> 1048575 >> "Elapsed time: 37.2 msecs" >> 1048575 >> "Elapsed time: 32.795 msecs" >> 1048575 >> "Elapsed time: 31.655 msecs" >> 1048575 >> "Elapsed time: 45.388 msecs" >> 1048575 >> "Elapsed time: 30.612 msecs" >> 1048575 >> "Elapsed time: 27.141 msecs" >> 1048575 >> "Elapsed time: 40.887 msecs" >> 1048575 >> "Elapsed time: 27.526 msecs" >> 1048575 >> "Elapsed time: 26.747 msecs" >> nil >> > > -- 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
