On Tue, Dec 9, 2008 at 3:08 PM, Stephan Mühlstrasser < [EMAIL PROTECTED]> wrote:
> > > > On Dec 9, 8:48 pm, "Drew Olson" <[EMAIL PROTECTED]> wrote: > > On Tue, Dec 9, 2008 at 2:28 PM, Stephan Mühlstrasser < > > > > [EMAIL PROTECTED]> wrote: > > > > > On Dec 9, 12:34 am, "harrison clarke" <[EMAIL PROTECTED]> wrote: > > > > you're keeping the head of the sequence, and thus all the elements > > > between > > > > the head and nth. > > > > > > it's because you're using def, basically. > > > > Ok, I'm confused here. Why does wrapping his logic into a > > function alleviate this problem? Can you give a more detailed > explanation, > > I'd like to understand what's going on here. > > > > - Drew > > I hope that I understood it myself now, so I try to explain: > > The wrapping into a function in the second approach is just for > convenience, and doesn't really matter. This is equivalent: > > user=> (defn triangle-numbers [current cumulated] > (let [next (+ current cumulated)] > (lazy-cons next (triangle-numbers (inc current) next)))) > #'user/triangle-numbers > user=> (nth (triangle-numbers 1 0) 10000000) > 50000015000001 > > The problem with the first approach is that the head is assigned to a > variable, and this produces the caching effect. In the second approach > all items that are consumed from the sequence are discarded > afterwards, and thus no memory problem occurs. Thanks both of you for the responses. That makes a lot more sense to me. - Drew > > > Regards > Stephan > > > --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
