Well, at some point I'll open up the code and check. Though I'll be overly tempted to write some comments, fix the indentation and write some tests if I do!
On Thu, Mar 12, 2009 at 2:36 PM, Jarkko Oranen <chous...@gmail.com> wrote: > > > On Mar 12, 11:15 pm, Howard Lewis Ship <hls...@gmail.com> wrote: >> I have to wonder a bit about the ability to optimize. Everything >> boils down to one of the seven or so basic forms. That's a lot of >> function calls to do even small things, like adding numbers. You might >> think that simple math would be optimized and inlined, but it isn't: >> >> Clojure >> user=> (doc +) >> ------------------------- >> clojure.core/+ >> ([] [x] [x y] [x y & more]) >> Returns the sum of nums. (+) returns 0. >> nil >> user=> (ns clojure.core) >> #<Namespace clojure.core> >> clojure.core=> (defn + [x y] (* x y)) >> #'clojure.core/+ >> clojure.core=> (+ 3 5) >> 15 >> clojure.core=> >> >> This implies, to me, that Clojure is doing a full functional call, >> with dynamic lookup via the namespace, even for +. > > I think this is mistaken. Sure, for (+ foo bar) calls in the repl > Clojure will do a full lookup, but if you have addition in a tight > loop, the JVM should notice this and optimise it further. (I think > Clojure also does some kind of caching.) You can also use type casts > to make clojure use primitive instead of boxed math, bringing > performance very close to Java. > > Now, it's probably true that the most straightforward Clojure > implementation of an algorithm is likely not quite as fast as the Java > equivalent, with a few tricks, you can often get pretty close. > > I don't have very in-depth knowledge of how Clojure handles these > performance issues, but I believe your assumption is overly > pessimistic. :) > > -- > Jarkko > > > -- Howard M. Lewis Ship Creator Apache Tapestry and Apache HiveMind --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
