title: Exporting utility functions in typescript?
body: <p>I'm trying to do this (Pseudo code):</p>
  
  <pre><code>export const isDefined:Function&lt;boolean&gt; = ((value:any)) =&gt; {
      return !(value==null);
  };
  </code></pre>
  
  <p>The <code>isDefined</code> function returns a boolean if the value argument is not null or undefined, and takes <code>any</code> type as an argument.  Thoughts on how to get it working?</p>