continuation passing transform macro

cps.clj

(defn & [f k]
  (fn [& args]
    (k (apply f args))))

(defmacro cps [steps]
  (if (seq steps)
    `(& ~(first steps)
        (cps ~(rest steps)))
    `identity))

(defmacro &-> [init & steps]
  (list `(cps ~(cons `(constantly ~init) steps))))

(&-> 1 #(* 2 %) inc) ;=> 3