transducers.clj

(defn char-to-index [c] (- (int c) 97))

(defn index-to-char [n] (char (+ n 97)))

(defn cesar [n] #(char (mod (- (char-index %) n) 26)))

(transduce (map (cesar 10)) str "abc")

;; common reducing functions:
;; str, conj, +, cons, into