yparser.html" title="BinaryParser"><code class="computeroutput"><span class="identifier">BinaryParser</span></code></a></code> and <code class="computeroutput"><a class="link" href="../../qi/reference/parser_concepts/naryparser.html" title="NaryParser"><code class="computeroutput"><span class="identifier">NaryParser</span></code></a></code> provide the
          necessary facilities for parser detection, introspection, transformation
          and visitation.
        </p>
<p>
          Derived parsers must 