 class="fsharp"><a
      href="../reference/charstream.html#CharStream"><span class="ci">CharStream</span></a></code> may change its state, parser functions have to be
      careful about when and how they change the <code class="fsharp"><a href="../reference/charstream.html#CharStream"><span
      class="ci">CharStream</span></a></code> state, because it obviously may affect all parsers subsequently called.
     </p>
    </div>
    <div class="para _2">
     <p>
      In the example above, <code class="fsh