Here is my zipper: (z/zipper #(contains? % "children") #(get % "children") (fn [_ c] c) s)
On Friday, August 21, 2015 at 6:49:25 PM UTC+2, Moe Aboulkheir wrote: > > Hussein, > > How are you constructing your zipper, before passing it to traverse? > Note that clojure.zip doesn't work on arbitrary data structures > without being given some information about how to descend > into/construct nodes, etc. - i.e. z/next expects a zipper, and your > data structure isn't a zipper, but an input to a zipper. Unless > you've written a zipper you omitted from your post, zipping over maps, > in particular, may not be as convenient as you're imagining. > https://clojuredocs.org/clojure.zip/zipper has helpful examples in it. > > Take care, > Moe > > On Fri, Aug 21, 2015 at 5:06 PM, Hussein B. <hubag...@gmail.com > <javascript:>> wrote: > > Hi, > > > > I changed println to z/node , this time I'm getting: > > > > NullPointerException clojure.zip/branch? (zip.clj:73) > > > > On Friday, August 21, 2015 at 5:56:10 PM UTC+2, Moe Aboulkheir wrote: > >> > >> Hussein, > >> > >> The println inside (recur) will return nil. > >> > >> Take care, > >> Moe > >> > >> On Fri, Aug 21, 2015 at 4:35 PM, Hussein B. <hubag...@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 clo...@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+u...@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+u...@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 clo...@googlegroups.com > <javascript:> > > Note that posts from new members are moderated - please be patient with > your > > first post. > > To unsubscribe from this group, send email to > > clojure+u...@googlegroups.com <javascript:> > > 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+u...@googlegroups.com <javascript:>. > > 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.
