| Index: packages/async/lib/result.dart
|
| diff --git a/packages/async/lib/result.dart b/packages/async/lib/result.dart
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| index 13e3dd94b288d8e579f3cc8a77eb88430f179356..627f2008b159246177dbc945c9457eecc6d8a8ec 100644
|
| --- a/packages/async/lib/result.dart
|
| +++ b/packages/async/lib/result.dart
|
| @@ -2,255 +2,12 @@
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| // 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.
|
|
|
| -/// Capture asynchronous results into synchronous values.
|
| -///
|
| -/// Capturing a result (either a returned value or a thrown error)
|
| -/// means converting it into a [Result] -
|
| -/// either a [ValueResult] or an [ErrorResult].
|
| -///
|
| -/// This value can release itself by writing itself either to a
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| -/// [EventSink] or a [Completer], or by becoming a [Future].
|
| +/// Import `async.dart` instead.
|
| +@Deprecated("Will be removed in async 2.0.0.")
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| library dart.pkg.async.results;
|
|
|
| -import "dart:async";
|
| -
|
| -/// The result of a computation.
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| -abstract class Result<T> {
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| - /// Create a `Result` with the result of calling [computation].
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| - ///
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| - /// This generates either a [ValueResult] with the value returned by
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| - /// calling `computation`, or an [ErrorResult] with an error thrown by
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| - /// the call.
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| - factory Result(T computation()) {
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| - try {
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| - return new ValueResult(computation());
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| - } catch (e, s) {
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| - return new ErrorResult(e, s);
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| - }
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| - }
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| -
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| - /// Create a `Result` holding a value.
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| - ///
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| - /// Alias for [ValueResult.ValueResult].
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| - factory Result.value(T value) = ValueResult<T>;
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| -
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| - /// Create a `Result` holding an error.
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| - ///
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| - /// Alias for [ErrorResult.ErrorResult].
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| - factory Result.error(Object error, [StackTrace stackTrace]) =>
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| - new ErrorResult(error, stackTrace);
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| -
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| - // Helper functions.
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| - static _captureValue(value) => new ValueResult(value);
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| - static _captureError(error, stack) => new ErrorResult(error, stack);
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| - static _release(Result v) {
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| - if (v.isValue) return v.asValue.value; // Avoid wrapping in future.
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| - return v.asFuture;
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| - }
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| -
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| - /// Capture the result of a future into a `Result` future.
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| - ///
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| - /// The resulting future will never have an error.
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| - /// Errors have been converted to an [ErrorResult] value.
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| - static Future<Result> capture(Future future) {
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| - return future.then(_captureValue, onError: _captureError);
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| - }
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| -
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| - /// Release the result of a captured future.
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| - ///
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| - /// Converts the [Result] value of the given [future] to a value or error
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| - /// completion of the returned future.
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| - ///
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| - /// If [future] completes with an error, the returned future completes with
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| - /// the same error.
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| - static Future release(Future<Result> future) {
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| - return future.then(_release);
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| - }
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| -
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| - /// Capture the results of a stream into a stream of [Result] values.
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| - ///
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| - /// The returned stream will not have any error events.
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| - /// Errors from the source stream have been converted to [ErrorResult]s.
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| - ///
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| - /// Shorthand for transforming the stream using [CaptureStreamTransformer].
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| - static Stream<Result> captureStream(Stream source) {
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| - return source.transform(const CaptureStreamTransformer());
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| - }
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| -
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| - /// Release a stream of [result] values into a stream of the results.
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| - ///
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| - /// `Result` values of the source stream become value or error events in
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| - /// the returned stream as appropriate.
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| - /// Errors from the source stream become errors in the returned stream.
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| - ///
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| - /// Shorthand for transforming the stream using [ReleaseStreamTransformer].
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| - static Stream releaseStream(Stream<Result> source) {
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| - return source.transform(const ReleaseStreamTransformer());
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| - }
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| -
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| - /// Converts a result of a result to a single result.
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| - ///
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| - /// If the result is an error, or it is a `Result` value
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| - /// which is then an error, then a result with that error is returned.
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| - /// Otherwise both levels of results are value results, and a single
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| - /// result with the value is returned.
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| - static Result flatten(Result<Result> result) {
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| - if (result.isError) return result;
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| - return result.asValue.value;
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| - }
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| -
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| - /// Whether this result is a value result.
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| - ///
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| - /// Always the opposite of [isError].
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| - bool get isValue;
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| -
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| - /// Whether this result is an error result.
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| - ///
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| - /// Always the opposite of [isValue].
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| - bool get isError;
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| -
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| - /// If this is a value result, return itself.
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| - ///
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| - /// Otherwise return `null`.
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| - ValueResult<T> get asValue;
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| -
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| - /// If this is an error result, return itself.
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| - ///
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| - /// Otherwise return `null`.
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| - ErrorResult get asError;
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| -
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| - /// Complete a completer with this result.
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| - void complete(Completer<T> completer);
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| -
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| - /// Add this result to an [EventSink].
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| - ///
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| - /// Calls the sink's `add` or `addError` method as appropriate.
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| - void addTo(EventSink<T> sink);
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| -
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| - /// Creates a future completed with this result as a value or an error.
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| - Future<T> get asFuture;
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| -}
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| -
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| -/// A result representing a returned value.
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| -class ValueResult<T> implements Result<T> {
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| - final T value;
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| - ValueResult(this.value);
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| - bool get isValue => true;
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| - bool get isError => false;
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| - ValueResult<T> get asValue => this;
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| - ErrorResult get asError => null;
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| - void complete(Completer<T> completer) {
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| - completer.complete(value);
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| - }
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| - void addTo(EventSink<T> sink) {
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| - sink.add(value);
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| - }
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| - Future<T> get asFuture => new Future.value(value);
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| -}
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| -
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| -/// A result representing a thrown error.
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| -class ErrorResult implements Result {
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| - final error;
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| - final StackTrace stackTrace;
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| - ErrorResult(this.error, this.stackTrace);
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| - bool get isValue => false;
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| - bool get isError => true;
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| - ValueResult get asValue => null;
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| - ErrorResult get asError => this;
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| - void complete(Completer completer) {
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| - completer.completeError(error, stackTrace);
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| - }
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| - void addTo(EventSink sink) {
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| - sink.addError(error, stackTrace);
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| - }
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| - Future get asFuture => new Future.error(error, stackTrace);
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| -
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| - /// Calls an error handler with the error and stacktrace.
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| - ///
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| - /// An async error handler function is either a function expecting two
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| - /// arguments, which will be called with the error and the stack trace,
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| - /// or it has to be a function expecting only one argument,
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| - /// which will be called with only the error.
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| - void handle(Function errorHandler) {
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| - if (errorHandler is ZoneBinaryCallback) {
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| - errorHandler(error, stackTrace);
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| - } else {
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| - errorHandler(error);
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| - }
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| - }
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| -}
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| -
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| -/// A stream transformer that captures a stream of events into [Result]s.
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| -///
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| -/// The result of the transformation is a stream of [Result] values and
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| -/// no error events.
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| -class CaptureStreamTransformer<T> implements StreamTransformer<T, Result<T>> {
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| - const CaptureStreamTransformer();
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| -
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| - Stream<Result<T>> bind(Stream<T> source) {
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| - return new Stream<Result<T>>.eventTransformed(source, _createSink);
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| - }
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| -
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| - static EventSink _createSink(EventSink<Result> sink) {
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| - return new CaptureSink(sink);
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| - }
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| -}
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| -
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| -/// A stream transformer that releases a stream of result events.
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| -///
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| -/// The result of the transformation is a stream of values and
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| -/// error events.
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| -class ReleaseStreamTransformer<T> implements StreamTransformer<Result<T>, T> {
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| - const ReleaseStreamTransformer();
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| -
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| - Stream<T> bind(Stream<Result<T>> source) {
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| - return new Stream<T>.eventTransformed(source, _createSink);
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| - }
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| -
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| - static EventSink<Result> _createSink(EventSink sink) {
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| - return new ReleaseSink(sink);
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| - }
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| -}
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| -
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| -/// An event sink wrapper that captures the incoming events.
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| -///
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| -/// Wraps an [EventSink] that expects [Result] values.
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| -/// Accepts any value and error result,
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| -/// and passes them to the wrapped sink as [Result] values.
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| -///
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| -/// The wrapped sink will never receive an error event.
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| -class CaptureSink<T> implements EventSink<T> {
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| - final EventSink _sink;
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| -
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| - CaptureSink(EventSink<Result<T>> sink) : _sink = sink;
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| - void add(T value) { _sink.add(new ValueResult(value)); }
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| - void addError(Object error, [StackTrace stackTrace]) {
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| - _sink.add(new ErrorResult(error, stackTrace));
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| - }
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| - void close() { _sink.close(); }
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| -}
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| -
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| -/// An event sink wrapper that releases the incoming result events.
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| -///
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| -/// Wraps an output [EventSink] that expects any result.
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| -/// Accepts [Result] values, and puts the result value or error into the
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| -/// corresponding output sink add method.
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| -class ReleaseSink<T> implements EventSink<Result<T>> {
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| - final EventSink _sink;
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| - ReleaseSink(EventSink<T> sink) : _sink = sink;
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| - void add(Result<T> result) {
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| - if (result.isValue) {
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| - _sink.add(result.asValue.value);
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| - } else {
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| - ErrorResult error = result.asError;
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| - _sink.addError(error.error, error.stackTrace);
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| - }
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| - }
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| - void addError(Object error, [StackTrace stackTrace]) {
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| - // Errors may be added by intermediate processing, even if it is never
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| - // added by CaptureSink.
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| - _sink.addError(error, stackTrace);
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| - }
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| -
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| - void close() { _sink.close(); }
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| -}
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| +export "src/result.dart";
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| +export "src/result/capture_transformer.dart";
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| +export "src/result/error.dart";
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| +export "src/result/release_transformer.dart";
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| +export "src/result/value.dart";
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|
|