Language/Types/Function_Types/implements_function_t02.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 A function is always an instance of some class that implements the
 * class Function and implements a call method with the same signature as the
 * function. All function types are subtypes of Function.
 * @description Checks that both instance and static methods of classes also
 * implement Function.
 * @author iefremov
 */
import "../../../Utils/expect.dart";

class C {
  f1() {}
  void f2() {}
  Object f3() => new Object();
  int f4() => 42;
  f5(var x) {}
  void f6(var x) {}
  String f7([var x]) => "Lily was here";
  Object f8(var x, int z, [Object? o, var v = 1]) => new Object();
  Object f9(var x, int z, {o, v: 1}) => new Object();

  static f1s() {}
  static void f2s() {}
  static Object f3s() => new Object();
  static int f4s() => 42;
  static f5s(var x) {}
  static void f6s(var x) {}
  static String f7s([var x]) => "Show must go on";
  static Object f8s(var x, int z, [Object? o, var v = 1]) => new Object();
  static Object f9s(var x, int z, {o, v: 1}) => new Object();
}

main() {
  C c = new C();
  Expect.isTrue(c.f1 is Function);
  Expect.isTrue(c.f2 is Function);
  Expect.isTrue(c.f3 is Function);
  Expect.isTrue(c.f4 is Function);
  Expect.isTrue(c.f5 is Function);
  Expect.isTrue(c.f6 is Function);
  Expect.isTrue(c.f7 is Function);
  Expect.isTrue(c.f8 is Function);
  Expect.isTrue(c.f9 is Function);

  Expect.isTrue(C.f1s is Function);
  Expect.isTrue(C.f2s is Function);
  Expect.isTrue(C.f3s is Function);
  Expect.isTrue(C.f4s is Function);
  Expect.isTrue(C.f5s is Function);
  Expect.isTrue(C.f6s is Function);
  Expect.isTrue(C.f7s is Function);
  Expect.isTrue(C.f8s is Function);
  Expect.isTrue(C.f9s is Function);
}