I have the following vector, [-1 1 2 -1 3 0 -1 2 -1 4 0 3 0 0]
which represents the tree [[1 2 [3] [2 [4] 3]]]
where -1 begins a new branch and 0 ends it. How can I convert the original vector into a usable tree-like clojure structure (nested vector, nested map)? I think clojure.zip/zipper
might do it but I'm not sure how to build those function args.
Zippers are a good tool for this:
(require '[clojure.zip :as zip])
(def in [-1 1 2 -1 3 0 -1 2 -1 4 0 3 0 0])
(def out [[1 2 [3] [2 [4] 3]]])
(defn deepen [steps]
(->> steps
(reduce (fn [loc step]
(case step
-1 (-> loc
(zip/append-child [])
(zip/down)
(zip/rightmost))
0 (zip/up loc)
(zip/append-child loc step)))
(zip/vector-zip []))
(zip/root)))
(assert (= (deepen in) out))