demo/calculator.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8"/>
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
    <meta name="viewport" content="width=device-width"/>
    <!-- inspired by https://github.com/mdn/simple-web-worker -->

    <title>Web Workers calculator</title>
    <!-- <link rel="stylesheet" href="style.css"> -->
    <!--[if lt IE 9]>
      <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
    <![endif]-->
  </head>

  <body>
    <h1>Promise-Workers calculator</h1>

    <form>
      <div>
        <input type="text" id="number1" value="0" size="1"/>
        <select id="operator">
          <option value="plus">+</option>
          <option value="minus">-</option>
          <option value="times">*</option>
          <option value="divide">/</option>
        </select>
        <input type="text" id="number2" value="0" size="1"/>
        = <span id="result"/>
      </div>
      <div id="status"/>
    </form>

    <script>const module = {}</script>
    <script src="../dist/promise-worker.js"></script>
    <script src="calculator.js"></script>
  </body>
</html>