On 16 November 2016 at 03:39, Didier <didi...@gmail.com> wrote:
>
> Currently, this takes about 30s in Clojure, while it only takes around 3s
> for OCaml, Rust and F#.
>
> From what I see, the differences between my code and theirs are:
>
> - Lack of a Point struct, I'm just using a vector.
> - They use a mutable set, I don't.
> - They overrode Hashing for their point struct, as well as equality. I
> rely on Clojure's default hashing, and vector equality.
>
> I'm not sure if any of these things should really impact performance that
> much though. And what I could do in Clojure if I wanted to improve it.
>
It's the mutability of the set that's causing the greatest performance
impact. You can't substitute in an immutable data structure into an
algorithm that makes heavy use of a mutable structure, and expect it to
have the same performance.
Something like this is more faithful to the original F# benchmark you
posted:
(defn nth* [n p]
(loop [n n, s1 (java.util.HashSet. [p]), s2 (java.util.HashSet.)]
(if (= n 0)
s1
(let [s0 (java.util.HashSet.)]
(letfn [(add [p]
(when-not (or (.contains s1 p) (.contains s2 p))
(.add s0 p)))]
(doseq [p s1] (iter-neighbors add p))
(recur (dec n) s0 s1))))))
- James
>
> Any Help?
>
>
> Thanks.
>
> --
> 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
> ---
> 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 clojure+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>
--
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
---
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 clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
