struct token_data
{
  enum token_data_type type;
  union
    {
      struct
	{
	  char *text;
	}
      u_t;
      struct
	{
	  builtin_func *func;
	  boolean traced;
	}
      u_f;
    }
  u;
};

foo ()
{
  while (1)
    {
      foobar ();
    }

  do
    {
      ralph ();
    }
  while (nigel ());

  switch (x)
    {
    case 33:
      break;

    case 49:
      printf ("foobar");
      {
	int i;
	i = 23;
	f (i);
      }

    default:
      {int x; abort ();}
      ;
    }
}