To use the zipper library you have to be able to provide branch? children and make-node functions that apply to your data structure.
I don't see a way to provide a meaningful branch? or children function for the structure you describe. Vector? will not work as branch? as it will not return true if passed the first element in a vector, and next will not work as it will not return the children if passed the first element of a vector. It looks to me like you don't get past the first element because the call to z/next fails both (and (branch? loc) (down loc)), (right loc) and (up loc) and therefore marks the first element as the end of the of the structure. Is there a compelling reason for not using the vector-zip structure for your specific use-case? On Wednesday, November 27, 2013 2:59:40 AM UTC+1, dabd wrote: > > The built-in vector-zip will build a tree with a different structure than > what I need. > I want build a tree as described in the first post: the node value is the > first element of the vector and the children the rest of the elements. > > > zipper.core> (loop [loc (tree-zipper [1 2 [3 4 5]])] > (if (z/end? loc) > (z/root loc) > (do (println (z/node loc)) > (recur (z/next loc))))) > [1 2 [3 4 5]] > > 2 > > [3 4 5] > > 4 > > 5 > > [1 2 [3 4 5]] > zipper.core> (loop [loc (z/vector-zip [1 2 [3 4 5]])] > (if (z/end? loc) > (z/root loc) > (do (println (z/node loc)) > (recur (z/next loc))))) > [1 2 [3 4 5]] > > 1 > > 2 > > [3 4 5] > > 3 > > 4 > > 5 > > [1 2 [3 4 5]] > > > On Tuesday, November 26, 2013 11:56:45 PM UTC, martin_clausen wrote: >> >> With a nested vector tree you can use the built in vector-zip function to >> create your zipper. >> >> As to the editing, the source >> code<https://github.com/clojure/clojure/blob/master/src/clj/clojure/zip.clj> >> contains >> a very similar use-case, which can be adapted to something like the >> following: >> >> (let [vz (vector-zip [1 2 [3 4 5]])] >> (loop [loc vz] >> (if (end? loc) >> (root loc) >> (recur (next (if (and (integer? (node loc)) (odd? (node loc))) >> (replace loc (* 2 (node loc))) >> loc)))))) >> >> > [2 2 [6 4 10]] >> >> On Tuesday, November 26, 2013 10:50:34 PM UTC+1, dabd wrote: >>> >>> I am trying to work with a tree representation using vectors where the >>> first element is the node value and the rest are the children as suggested >>> here: >>> >>> http://grokbase.com/t/gg/clojure/12afy2cz9p/how-to-represent-trees-for-use-with-zippers >>> >>> However I am having trouble using clojure.zip/edit to change a simple >>> tree. I'd like to multiply the odd numbers by 2 in this case. >>> https://gist.github.com/dabd/7666778 >>> >>> It looks like after editing the first (branch) node clojure.zip/next >>> will get to the end of the tree. >>> How can I correct this code? >>> >>> Thanks. >>> >>> -- -- 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.
