title: Check for NaN in ClojureScript
body: <p>How can I check if a value is <code>NaN</code>?  I'd prefer a solution that can be used in Clojure too without much extra stuff (so I don't want to use an external library, such as underscore).  Here is what I tried</p>
  
  <pre><code>(number? js/NaN) ;=&gt; true, well I'd expect false
  (= js/NaN (js/parseInt "xx")) ;=&gt; false
  (= js/NaN js/NaN) ;=&gt; false, even worse
  
  ; This is the best I could come up with
  (defn actual-number? 
    [n] 
    (or (&gt; 0 n) (&lt;= 0 n)))
  </code></pre>