Hi,
> I have a piece of code, and I'd like to see how fast it can be.
> (defn count-num-chars [^String s]
> (loop [s s acc 0]
> (if (seq s)
> (recur (rest s) (if (= (first s) \space) acc (inc acc)))
> acc)))
I get an average of 46928 for this.
But for the straightforward option of reduce:
(defn count-num-chars3 [^String s]
(reduce (fn [acc c] (if (= c \space) acc (inc acc))) 0 s))
I get an average of 27424. Cool! So writing it the nicest way, is
also faster.
I tend to avoid spamming .charAt even in Java for things like this,
and often find converting to an array first to be faster, like this:
(defn count-num-chars4 [^String s]
(let [as (.toCharArray s)]
(areduce as idx acc 0 (if (= (int (aget as idx)) (int \space)) acc (inc
acc)))))
I get an average of 3631.
(needed to cast the char to int there, else clojure seems to hit
reflection problems)
--
Dave
--
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
