Language/Expressions/Identifier_Reference/evaluation_library_or_getter_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 Evaluation of an identifier expression e of the form id proceeds
/// as follows:
/// Let d be the innermost declaration in the enclosing lexical scope whose name
/// is id or id=. If no such declaration exists in the lexical scope, let d be
/// the declaration of the inherited member named id if it exists.
/// ...
/// • If d is the declaration of a library variable, top-level getter or
///   top-level setter, then e is equivalent to the getter invocation id.
/// @description  Checks that references to a library variables is evaluated
/// correctly and that initializer expression is evaluated only once.
/// @author msyabro

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

var tlVar = new C(1).id;
int tlTyped = new C(2).id;
final tlFinal = new C(3).id;
final int tlFinalTyped = new C(4).id;

class C {
  static Map map = {};
  factory C(i) {
    if (map[i] == null)
      map[i] = new C._ctor(i);
    else {
      Expect.fail('Initializer expression was evaluated twice');
    }
    return map[i];
  }
  var id;
  C._ctor(this.id);
}

main() {
  Expect.equals(1, tlVar);
  Expect.equals(1, tlVar); //The second getter invocation should not evaluate
                           // the initializer expression

  Expect.equals(2, tlTyped);
  Expect.equals(2, tlTyped);

  Expect.equals(3, tlFinal);
  Expect.equals(3, tlFinal);

  Expect.equals(4, tlFinalTyped);
  Expect.equals(4, tlFinalTyped);
}