Nested dereference of delay

Question

@(delay (delay 1)) ; equals to unrealized delay object, containing 1.

Is there an easy (without a head-first macross which tests each block with realized?) way to deref all inner delays recursively?

Answer 1

Arthur's code certainly works for the example you've posted, but here is an example of how you could handle mixed sequences:

(defn deref-delays [x]
  (cond
    (sequential? x) (map deref-delays x)
    (= clojure.lang.Delay (class x)) (recur @x)
    :else x))

(deref-delays [1 2 (delay 3) (delay [4 (delay (delay 5)) 6]) 7])
;(1 2 3 (4 5 6) 7)