Hussein, The println inside (recur) will return nil.
Take care, Moe On Fri, Aug 21, 2015 at 4:35 PM, Hussein B. <hubaghd...@gmail.com> wrote: > Hi, > > I have this structure: > > (def s [{"n" {"id" "a"} "d" 2 "children" [{"n" {"id" "c"} "d" 4 "children" > []}]} {"n" {"id" "b"} "d" 3 "children" []}]) > > > > And I wrote a function with zippers to traverse it: > > (defn traverse [col] > (loop [z col] > (if (= (z/next z) z) > z > (if (z/branch? z) > (recur (z/next z)) > (recur (-> z println z/next)))))) > > > But I'm getting: NullPointerException clojure.zip/next (zip.clj:236) > > Any ideas? > > Thanks for help. > > -- > 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.