Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/inheritance_t05.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.
/// ...
/// 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. The member that is inherited
/// is mx, if it exists; otherwise: let numberOf P ositionals(f) denote the
/// number of positional parameters of a function f, and let numberOf
/// RequiredParams(f) denote the number of required parameters of a function f.
/// Furthermore, let s denote the set of all named parameters of the m1,...,mk.
/// Then let
/// h = max(numberOf Positionals(mi)),
/// r = min(numberOf RequiredParams(mi)), i ∈ 1..k.
/// Then I has a method named n, with r required parameters of type dynamic,
/// h positional parameters of type dynamic, named parameters s of type dynamic
/// and return type dynamic.
/// @description Checks that there's no static warning produced when the
/// subinterface member being accessed is actually inherited. Members tested
/// include variables, methods, getters, setters and operators. There's no way
/// to check whether the resulting inherited method signature is actually as
/// described above, but we can check that it's inherited at all.
/// @author rodionov

import '../../../../Utils/expect.dart';

class C {}
class D extends C {}

abstract class SI1 {
  int method(num? v, String? p, {int? o1, Pattern? o2});
  int method2(C? v, [D? o]);
  int? get gett0r;
  void set sett0r(int? v);
  C operator +(C v);
}

abstract class SI2 {
  void method(num? v, String? p, {int? o1, Pattern? o2});
  num method2(C? v, [D? o]);
  num? get gett0r;
  void set sett0r(num? v);
  C operator +(C v);
}

abstract class I implements SI1, SI2 {}

main() {
  I? i = null;
  dynamic d = null;

  i?.method(null, null, o1:null, o2:null);
  var v = i?.method2(null, null);
  num? n = i?.gett0r;
  i?.sett0r = null;
}