title: What's the naming convention of a lexer?
body: <pre><code>    function yy_r9_1($yy_subpatterns)
      {
  
    $this-&gt;token = Smarty_Internal_Templateparser::TP_PHP_CODE;  
    $this-&gt;yypopstate();
      }
  </code></pre>
  
  <p>The above is from the lexer of smarty in PHP,anyone knows what <code>yy_r9_1</code> means?</p>