how can you interleave two vectors of differing lengths in clojure

Question

What is the simplest way to interleave two vectors with n+1 and n members?

(def a [:a :c :e])
(def b [:b :d])
(interleave a b ); truncates to shortest list
[:a :b :c :d]

;what I would like. 
(interleave-until-nil a b)
[:a :b :c :d :e]

Answer 1

Cons the first, interleave the rest with arguments reversed.

(cons (first a) (interleave b (rest a)))
;=> (:a :b :c :d :e)