|  | // Copyright (c) 2012, 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. | 
|  |  | 
|  | import "package:expect/expect.dart"; | 
|  |  | 
|  | abstract class Interface { | 
|  | final x; | 
|  | Interface(this.x); | 
|  | } | 
|  |  | 
|  | abstract class Abstract implements Interface { | 
|  | String toString() => x.toString(); | 
|  | } | 
|  |  | 
|  | // This class does not implement "x" either, but it is not marked | 
|  | // abstract. | 
|  | class SubAbstract1 extends Abstract {} | 
|  | //    ^^^^^^^^^^^^ | 
|  | // [analyzer] COMPILE_TIME_ERROR.NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER | 
|  | // [cfe] The non-abstract class 'SubAbstract1' is missing implementations for these members: | 
|  |  | 
|  | // This class does not implement "x", but is itself abstract, so that's OK. | 
|  | abstract class SubAbstract2 extends Abstract { | 
|  | get x; // Abstract. | 
|  | } | 
|  |  | 
|  | // This class does not implement "x" either, but it is not marked | 
|  | // abstract. | 
|  | class SubSubAbstract2 extends SubAbstract2 {} | 
|  | //    ^^^^^^^^^^^^^^^ | 
|  | // [analyzer] COMPILE_TIME_ERROR.NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER | 
|  | // [cfe] The non-abstract class 'SubSubAbstract2' is missing implementations for these members: | 
|  |  | 
|  | class Concrete extends Abstract { | 
|  | get x => 7; | 
|  | } | 
|  |  | 
|  | class SubConcrete extends Concrete { | 
|  | final x; | 
|  | SubConcrete(this.x); | 
|  | } | 
|  |  | 
|  | void main() { | 
|  | new Abstract(); | 
|  | //  ^^^^^^^^ | 
|  | // [analyzer] COMPILE_TIME_ERROR.INSTANTIATE_ABSTRACT_CLASS | 
|  | // [cfe] The class 'Abstract' is abstract and can't be instantiated. | 
|  | Expect.equals('7', new Concrete().toString()); | 
|  | Expect.equals('42', new SubConcrete(42).toString()); | 
|  | Expect.equals('7', new SubConcrete(new Concrete()).toString()); | 
|  | } |