dariooddenino

; A modified group-by for jsons.
; Eg. [{:id "id1" :title "one"} {:id "id2" :title "two"}]
; to, for example, this: {:id1 {:id "id1 :title "one"} :id2 {:id "id2" :title "two"}}

(defn group-json
  [f coll]
  (persistent!
    (reduce
     (fn [ret x]
       (let [k (keyword (f x))]