Clojure higher-order functions.

(defn traverse
  "A very general function for traversing sequences"
  ([s f comb]
  (if (empty? (rest s))
    (f (first s))
    (comb (traverse (rest s) f comb) (f (first s)))))
  ([s f comb seed]
   (if (empty? s) seed
     (comb (traverse (rest s) f comb seed) (f (first s))))))

(defn mymap [f s] (traverse s f conj '()))

(mymap inc '(1 2 3))

(mymap inc [1 2 3])

(defn myreduce [comb seed s] (traverse s identity comb seed))

(myreduce + 0 '(1 2 3))

;; define filter and flatten using traverse

CSci 4651 course web site.