| // Copyright (c) 2015, 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 'dart:async'; |
| |
| import '../typed/future.dart'; |
| |
| /// A wrapper that forwards calls to a [Future]. |
| class DelegatingFuture<T> implements Future<T> { |
| /// The wrapped [Future]. |
| final Future<T> _future; |
| |
| DelegatingFuture(this._future); |
| |
| /// Creates a wrapper which throws if [future]'s value isn't an instance of |
| /// `T`. |
| /// |
| /// This soundly converts a [Future] to a `Future<T>`, regardless of its |
| /// original generic type, by asserting that its value is an instance of `T` |
| /// whenever it's provided. If it's not, the future throws a [CastError]. |
| static Future<T> typed<T>(Future future) => |
| future is Future<T> ? future : new TypeSafeFuture<T>(future); |
| |
| Stream<T> asStream() => _future.asStream(); |
| |
| Future<T> catchError(Function onError, {bool test(Object error)}) => |
| _future.catchError(onError, test: test); |
| |
| Future<S> then<S>(FutureOr<S> onValue(T value), {Function onError}) => |
| _future.then(onValue, onError: onError); |
| |
| Future<T> whenComplete(action()) => _future.whenComplete(action); |
| |
| Future<T> timeout(Duration timeLimit, {onTimeout()}) => |
| _future.timeout(timeLimit, onTimeout: onTimeout); |
| } |