| // 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. |
| // VMOptions=--enable_checked_mode |
| |
| interface Link<T> extends Iterable<T> default LinkFactory<T> { |
| Link(T head, [Link<T> tail]); |
| Link<T> prepend(T element); |
| } |
| |
| interface EmptyLink<T> extends Link<T> default LinkTail<T> { |
| const EmptyLink(); |
| } |
| |
| class LinkFactory<T> { |
| factory Link(T head, [Link<T> tail]) { |
| return new LinkEntry<T>(head, tail); |
| } |
| } |
| |
| class AbstractLink<T> implements Link<T> { |
| const AbstractLink(); |
| Link<T> prepend(T element) { |
| print("$element"); |
| if (0 is T) { |
| throw "0 is not a T"; |
| } |
| return new Link<T>(element, this); |
| } |
| } |
| |
| class LinkTail<T> extends AbstractLink<T> implements EmptyLink<T> { |
| const LinkTail(); |
| } |
| |
| class LinkEntry<T> extends AbstractLink<T> { |
| LinkEntry(T head, Link<T> realTail); |
| } |
| |
| class Fisk { |
| Link<Fisk> nodes = const EmptyLink<Fisk>(); |
| final int id; |
| Fisk(this.id); |
| toString() => id.toString(); |
| } |
| |
| main() { |
| new Fisk(0).nodes.prepend(new Fisk(1)).prepend(new Fisk(2)); |
| } |
| |