I don't think you're missing anything James. It does not look like this example uses trampoline with the intended effect.
On Wednesday, April 20, 2016 at 2:45:05 PM UTC-4, James Elliott wrote: > > Does trampoline really help in this case? I don’t see where we are ever > returning a new function for trampoline to call, avoiding a new stack > frame. It seems to me no different than simply calling the other arities > directly in this example. What am I missing? > > On Wednesday, April 20, 2016 at 12:00:35 PM UTC-5, J.-F. Rompre wrote: >> >> You can prevent stack consumption by using trampoline for tail-recursive >> calls to a different arity, and recur for same arity, something like: >> >> (defn find-comment-in-line >> >> ([s] (when (pos? (count s)) >> (if-let [cs (seq (comment-s? s))] >> ;; yes, a comment symbol found, >> ;; just return the remainder of a string >> (subs s (count (first cs))) >> >> ;; no, lets check for an opening quote >> >> (if-let [qs (seq (quote-s? s))] >> >> ;; yes, an opening quote found, >> ;; now go look for an end quote >> (trampoline find-comment-in-line (subs s 1) qs) >> >> ;; no, just some other symbol found, >> ;; check for the rest >> (recur (subs s 1)))))) >> >> ([s q] (when (pos? (count s)) >> ;; lets check if it is a quote >> (if-let [qs (seq (quote-s? s))] >> >> ;; is it a closing quote? >> (if (= qs q) >> ;; yes, lets check for the rest >> (trampoline find-comment-in-line (subs s 1)) >> >> ;; no, just ignore the symbol, >> ;;continue looking for a closing quote >> (recur (subs s 1) q)))))) >> >> >> >> On Tuesday, April 19, 2016 at 11:18:40 AM UTC-4, andmed wrote: >>> >>> Thank you. That the point. If "recur" binds to fn, why it can not know >>> the binding point as the function method based on the number of arguments >>> passed to it? I mean it is clear that Clojure can't do that, but I can see >>> no reason why it could or should not if we choose to implement such >>> syntactic nicety as recur in a function >>> >> -- 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.
