Get all realized values from a lazy seq

Question

;; create lazy infinite seq of random ints
(def infi-seq (repeatedly #(rand-int 11)))
(take 5 infi-seq) ; => (8 2 9 9 5)

How can I get all values realized (8 2 9 9 2) without knowing that the first five values have been realized?

Answer 1

This should do the trick:

(defn take-realized
  [coll]
  (if-not (instance? clojure.lang.IPending coll)
    (cons (first coll) (take-realized (rest coll)))
    (when (realized? coll)
       (cons (first coll) (take-realized (rest coll))))))