Split a vector into a map of vectors

test.clj

(defn split-into-map [items key-fn]
  (when-not (key-fn (first items))
    (throw (ex-info "first item is not a key" {:items items})))

  (loop [result {} 
         current-parts []
         items items]
    (let [item (first items)]
      (cond
       (and (nil? item) (empty? items))
       (assoc result (first current-parts) (vec (rest current-parts)))

       (key-fn item)
       (recur (if (seq current-parts)
                (assoc result (first current-parts) (vec (rest current-parts)))
                result)
              [item]
              (rest items))

       :else
       (recur result (conj current-parts item) (rest items)) 
       ))))

(prn (split-into-map [:key1 1 2 3 :key2 4 :key3 5 6 7] keyword?))
(prn (split-into-map ["y" 1 2 "x" 3 4 5] string?))