 by the second letter for regular integers.</li>
<li><code class="code">[&nbsp;range&nbsp;]</code>: reads characters that matches one of the characters
      mentioned in the range of characters <code class="code">range</code> (or not mentioned in
      it, if the range starts with <code class="code">^</code>). Reads a <code class="code">string</code> that can be
      empty, if the next input character does not match the range. The set of
      characters from <code class="code">c1</code> to <code class="c