Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/same_name_getters_type_t07.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/**
 * @assertion We define inherited(J, K) to be
 * the set of members m such that all of the following hold:
 * • m is accessible to K and
 * • A is a direct superinterface of J and either
 * – A declares a member m or
 * – m is a member of inherited(A, K).
 * • m is not overridden by J.
 * ...
 * If some but not all of the mi, 1 ≤ i ≤ k are getters none of the mi are
 * inherited, and a static warning is issued.
 * Otherwise, if the static types T1,...,Tk of the members m1,...,mk are not
 * identical, then there must be a member mx such that Tx <: Ti, 1 ≤ x ≤ k for
 * all i ∈ 1..k, or a static type warning occurs.
 * @description Checks that if all inherited members with the same name are
 * methods and their static types are not identical, but there is a method
 * such that its type is subtype of types of all other methods then, anyway, a
 * compile error occurs. Test methods with parameters
 * @compile-error
 * @author sgrekhov@unipro.ru
 */

abstract class SI1 {
  int m1(int v1);
  int m2(String v1);
  List<int> m3(List<int> v1);
  int m4(int v1);
}

abstract class SI2 {
  bool m1(double v1);
  double m2(Object v1);
  List<String> m3(List<double> v1);
  bool m4(int v1);
}

abstract class SI3 {
  Object m1(num v1); // subtype of m1() in SI1 and SI2
  num m2(Object v1);   // subtype of m2() in SI1 and SI2
  List m3(List v1);  // subtype of m3() in SI1 and SI2
  m4(num v1);  // subtype of m4() in SI1 and SI2
}

abstract class I implements SI1, SI2, SI3 {
}

main() {
  I? i = null;
}