/a>) has been
         encountered,</li>
<li>the end-of-input has been reached.</li>
</ul>

      Hence, this conversion always succeeds: it returns an empty
      string if the bounding condition holds when the scan begins.</li>
<li><code class="code"><span class="constructor">S</span></code>: reads a delimited string argument (delimiters and special
      escaped characters follow the lexical conventions of OCaml).</li>
<li><code class="code">c</code>: reads a single character. To test the current input c