I was trying to write a function next-branch. I wrote somthing like: (use 'clojure.zip) (def zp (seq-zip '(+ 1 2 (+ 3 4) (+ 5 6)))) (defn next-branch [loc] (second (filter branch? (iterate next loc))))
(next-branch (next-branch (next-branch zp))) this results in: NullPointerException clojure.zip/branch? (zip.clj:73) Reading the docs of next "returns a distinguished loc", this seams to imply next should always return a loc even when at the end. The docs of branch? "Returns true if the node at loc is a branch" seam to imply any loc will do. So this would lead me to concluded that next always returns a "loc" and since branch? is supposed to take a "loc" it should work. Why doesn't next return a loc at the end? Looking at the code I know "why" but is it intended to be this way? If so why? -- -- 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/groups/opt_out.
