Some helpers when moving elements around in Clojure vectors

vec-utils.cljs

(defn vec-remove
  "Remove elem in coll by index."
  [coll pos]
  (vec (concat (subvec coll 0 pos) (subvec coll (inc pos)))))

(defn vec-add
  "Add elem in coll by index."
  [coll pos el]
  (concat (subvec coll 0 pos) [el] (subvec coll pos)))

(defn vec-move
  "Move elem in coll by index"
  [coll pos1 pos2]
  (let [el (nth coll pos1)]
    (if (= pos1 pos2)
      coll
      (into [] (vec-add (vec-remove coll pos1) pos2 el)))))

(defn vec-swap
  "Swap position of 2 elem in a vector by index."
  [v pos1 pos2]
  (assoc v pos2 (v pos1) pos1 (v pos2)))