/*
 * Return the Node's _aid_ member.  The return type is a
 * Symbol.
 */
static VALUE node_aid(VALUE self)
{
  NODE * n;
  Data_Get_Struct(self, NODE, n);
  if(n->nd_aid == 0)
  {
    return Qfalse;
  }
  else if(n->nd_aid == 1)
  {
    return Qtrue;
  }
  else
  {
    return ID2SYM(n->nd_aid);
  }
}