title: javascript multiple parentheses function call
body: <p>I'm trying to solve some javascript puzzle. I have some function (for example a function which calculates summa).
  But there is a weird calling of that function.
  example:</p>
  <p>sum(5)</p>
  <p>or sum(5,6) - should be 11</p>
  <p>or sum(5)(6) - should be 11</p>
  <p>or sum(1)(2)(3) - should be 6</p>
  <p>Have never seen such function calling <strong>sum(1)(2)(3)(4)</strong>....
  Can you please explain or maybe put into documentation where this stuff is explained?</p>
  <p>Thanks a lot.</p>