Language/Classes/Constructors/Generative_Constructors/execution_of_an_initializer_t01.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 Execution of an initializer of the form this.v = e proceeds as
 * follows:
 * First, the expression e is evaluated to an object o. Then, the instance
 * variable v of the object denoted by this is bound to o, unless v is a final
 * variable that has already been initialized, in which case a runtime error
 * occurs. It is a dynamic type error if o is not null and the interface of the
 * class of o is not a subtype of the actual type of the field v.
 * An initializer of the form v = e is equivalent to an initializer of the form
 * this.v = e.
 * @description Checks that RHS expression is evaluated in both forms of an
 * initializer.
 * @author iefremov
 */
import "../../../../Utils/expect.dart";

bool ok = false;
f() {
  ok = true;
}

class C {
  C() : this.x = f() {}
  C.c2() : x = f() {}
  var x;
}

main() {
  var x = new C();
  Expect.isTrue(ok, "Expression in initializer was not evaluated!");
  ok = false;
  x = new C.c2();
  Expect.isTrue(ok, "Expression in initializer was not evaluated!");
}