global zipper

gistfile1.clj

(def global-list (atom []))

(defn zip-create [xs]
  (do
    (reset! global-list xs)
    [0 (first xs) xs]))

(defn zip-assoc [[index head v] element]
  (let [new-vec (assoc v index element)]
    (reset! global-list new-vec)
    [index element new-vec]))

(defn zip-head [[_ head _2]]
  head)

(defn zip-next [[index head v]]
  [(inc index) (nth v (inc index)) v])

(defn zip-prev [[index head v]]
  [(dec index) (nth v (dec index)) v])