title: how do I create a large vector in clojure
body: <p>How do i allocate a vector with 1042 empty indexes?<br>
  Will the storage for it be lazily allocated?<br>
  like this</p>
  
  <pre><code>(def a (array-creation-function 1042))
  (def b (assoc a 1041 42))
  (b 1041) 
  --&gt; 42
  </code></pre>