title: Export function in Typescript
body: <p>I have a <code>.ts</code> file with a module and a function outside module like this:</p>
  
  <pre><code>$(function () {
     populate()
  });
  
  function populate() {
  ...
  }
  
  module portfolio.charts {
     export function foo(){
     ...
     }
  }
  </code></pre>
  
  <p>Using Typescript compiler command <code>tsc --declaration</code> the declaration file is created. This <code>.d.ts</code> file contains the following code:</p>
  
  <pre><code> function populate(): void;
   module portfolio.charts {
         function foo(): void;
   }
  </code></pre>
  
  <p>Why <code>populate()</code> function and <code>portfolio.charts</code> module are exported? I thought it was necessary the keyword <code>export</code> to export a function or a module. If I add the <code>d.ts</code> file as a dependency on another file I can use all functions and the module. Can I declare them private? Thanks and sorry for my english.</p>