gistfile1.clj

(defn group-by-delimiter-and-map* [pred keymap valmap [groups current-delim current-group] elem]
  (if (pred elem)
    [(if current-delim
       (assoc groups current-delim current-group)
       groups)
     (keymap elem) []]
    [groups current-delim (conj current-group (valmap elem))]))

(defn group-by-delimiter-and-map [pred keymap valmap coll]
  (let [[groups last-delim last-group]
        (reduce (partial group-by-delimiter-and-map* pred keymap valmap) [{}] coll)]
    (assoc groups last-delim last-group)))

; user> (group-by-delimiter-and-map number? #(* % %) str '(1 a b 5 c d e 7 x y z))
{49 ["x" "y" "z"], 25 ["c" "d" "e"], 1 ["a" "b"]}