Clojure trampolined continuation passing style

trampolined-cps.clj

(defmacro trampolined
  "Wraps recursive calls."
  [& body]
  `(fn [] ~@body))

(defn trampolined-k-fn
  "Takes a k-fn and returns a stackless fn.
  k-fn should be a CPS function with k as the first arg.
  In k-fn, all recursive calls should be wrapped using `trampolined`."
  [k-fn]
  (fn [& args]
    (trampoline #(apply k-fn identity args))))


;; Example usage
;; =============
(defn k-A
  "Ackermann function.
  Implemented in trampolined Continuation Passing Style."
  [k m n]
  (cond
    (zero? m)
    (k (inc n))

    (zero? n)
    (recur k (dec m) 1)

    :else
    (recur (fn [n']
             (trampolined
              (k-A k (dec m) n')))
           m
           (dec n))))

(def A
  (trampolined-k-fn k-A))

(A 3 10) ;; => 8189