title: lazy-seq -- cons outside or in
body: <p>Should cons be inside (lazy-seq ...)</p>
  
  <pre><code>(def lseq-in (lazy-seq (cons 1 (more-one))))
  </code></pre>
  
  <p>or out?</p>
  
  <pre><code>(def lseq-out (cons 1 (lazy-seq (more-one))))
  </code></pre>
  
  <p>I noticed</p>
  
  <pre><code>(realized? lseq-in)
          ;;; ⇒ false
  
  (realized? lseq-out)
          ;;; ⇒ &lt;err&gt;
          ;;;   ClassCastException clojure.lang.Cons cannot be cast to clojure.lang.IPending  clojure.core/realized? (core.clj:6773)
  </code></pre>
  
  <p>All the examples on the <a href="http://clojuredocs.org/clojure_core/clojure.core/lazy-seq" rel="noreferrer">clojuredocs.org</a> use "out".</p>
  
  <p>What are the tradeoffs involved?</p>