ported.
      </p>
<p>
        By contrast, the sequence operator (<code class="computeroutput"><span class="identifier">a</span>
        <span class="special">&gt;&gt;</span> <span class="identifier">b</span></code>)
        does not require that the following parser match the input, which allows
        for backtracking or simply returning false from the parse function with no
        exceptions.
      </p>
<p>
        The expect directive (<code class="computeroutput"><span class="identifier">expect</spa