title: Include struct in the %union def with Bison/Yacc
body: <p>I am trying to include a struct as part of the union with Bison, but I get an error on the 'struct node args' in %union:  </p>
  
  <pre><code>parser.y:17: error: field ‘args’ has incomplete type
  </code></pre>
  
  <p>The Code:<br></p>
  
  <pre><code>struct node {
      char * val;
      struct node * next;
  };
  
  %}
  
  %union {
      char * string;
      struct node args;
  }
  
  %token &lt;string&gt; CD WORD PWD EXIT
  
  %type &lt;args&gt; arg_list
  </code></pre>
  
  <p>Anyone know what I am doing wrong?</p>