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.
