map-vector-zipper.clj

;; A version of  zipper that allows mixing maps and vectors 
;; Note that it traverses map entries too
(require '[clojure.zip :as z])
(defn map-vec-zipper [m]
  (z/zipper
    (fn [x] (or (map? x) (sequential? x)))
    seq
    (fn [p xs]
      (if (isa? (type p) clojure.lang.MapEntry)
        (into [] xs)
        (into (empty p) xs)))
    m))
(-> (map-vec-zipper [{4 [22 21] 1 [3]}])
  z/down
  (z/edit assoc :e 99)
  z/down
  ;; Note that the map does not guarantee particular ordering.
  z/down ;; Getting into map entry. 
  z/next
  (z/edit conj 77)
  z/root)
;;=> [{1 [21 22 77], 3 [4], :e 99}]