// union-type entry
sclass E {
  S q, a, state;
  bool test; // not used anymore probably
  S comment; // not checked for comparison
  
  *() {}
  *(S text, S type) {
    if (eq(type, "q")) q = text;
    else if (eq(type, "a")) a = text;
    else state = text;
  }
  
  // does not compare the "test" bit
  bool eqTo(E y) {
    E x = this;
    ret eq/*ic*/(x.q, y.q) && eq/*ic*/(x.a, y.a) && eq/*ic*/(x.state, y.state);
  }
  
  public bool equals(O o) {
    ret o is a E && eqTo((E) o);
  }
  
  public int hashCode() {
    ret stdHash(this, "q", "a", "state");
  }
  
  static E state(S state) {
    if (state == null) null; new E e; e.state = state; ret e;
  }
  
  static E q(S q) {
    if (q == null) null; new E e; e.q = q; ret e;
  }
  
  static E a(S a) {
    if (a == null) null; new E e; e.a = a; ret e;
  }
  
  public S toString() {
    ret unparsePoemLine(this);
  }
  
  bool q() { ret q != null; }
  bool a() { ret a != null; }
  bool state() { ret state != null; }
  S type() { ret q() ? "q" : a() ? "a" : "state"; }
  S text() { ret q() ? q : a() ? a : state; }
}