title: YYSETSTATE how to know the identifier of YYFILL?
body: <p>The manual clearly says: </p>
  
  <pre><code>YYSETSTATE (s)
  
  [...]
  The parameter to YYSETSTATE is a signed integer that uniquely identifies
  the specific instance of YYFILL (n) that is about to be called.
  [...]
  </code></pre>
  
  <p>The problem is, I'm calling my YYSETSTATE defined macro from a bison parser. How can I begin a state without knowing the <code>integer</code> UI? In other words, how can I get the identifier of a state I want to begin.</p>
  
  <p>On lexer:</p>
  
  <pre><code>&lt;MY_STATE&gt;{NAME} {
      return FN_NAME;
  }
  </code></pre>
  
  <p>On parser:</p>
  
  <pre><code>expr: { push_state( ? ) } /* what's the identifier of MY_STATE? */
      '(' FN_NAME VALUE VALUE ')' { compile_expr($2, $3, $4); }
  ;
  </code></pre>