 = digits:[0-9]+ { return parseInt(digits.join(""), 10); }

letter = [a-z]+</textarea></form>
      <script>
        var editor = CodeMirror.fromTextArea(document.getElementById("code"), {
          mode: {name: "pegjs"},
          lineNumbers: true
        });
      </script>
      <h3>The PEG.js Mode</h3>
      <p> Created by Forbes Lindesay.</p>
    </article>
  </body>
</html>
