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| 1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file | |
| 2 // for details. All rights reserved. Use of this source code is governed by a | |
| 3 // BSD-style license that can be found in the LICENSE file. | |
| 4 // VMOptions=--enable_type_checks --enable_asserts | |
| 5 | |
| 6 interface Link<T> extends Iterable<T> default LinkFactory<T> { | |
| 7 Link(T head, [Link<T> tail]); | |
| 8 Link<T> prepend(T element); | |
| 9 } | |
| 10 | |
| 11 interface EmptyLink<T> extends Link<T> default LinkTail<T> { | |
| 12 const EmptyLink(); | |
| 13 } | |
| 14 | |
| 15 class LinkFactory<T> { | |
| 16 factory Link(T head, [Link<T> tail]) { | |
| 17 return new LinkEntry<T>(head, tail); | |
| 18 } | |
| 19 } | |
| 20 | |
| 21 class AbstractLink<T> implements Link<T> { | |
| 22 const AbstractLink(); | |
| 23 Link<T> prepend(T element) { | |
| 24 print("$element"); | |
| 25 if (0 is T) { | |
| 26 throw "0 is not a T"; | |
| 27 } | |
| 28 return new Link<T>(element, this); | |
| 29 } | |
| 30 } | |
| 31 | |
| 32 class LinkTail<T> extends AbstractLink<T> implements EmptyLink<T> { | |
| 33 const LinkTail(); | |
| 34 } | |
| 35 | |
| 36 class LinkEntry<T> extends AbstractLink<T> { | |
| 37 LinkEntry(T head, Link<T> realTail); | |
| 38 } | |
| 39 | |
| 40 class Fisk { | |
| 41 Link<Fisk> nodes = const EmptyLink<Fisk>(); | |
| 42 final int id; | |
| 43 Fisk(this.id); | |
| 44 toString() => id.toString(); | |
| 45 } | |
| 46 | |
| 47 main() { | |
| 48 new Fisk(0).nodes.prepend(new Fisk(1)).prepend(new Fisk(2)); | |
| 49 } | |
| 50 | |
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