Kit.Core/LibExternal/System.Reactive/Linq/Observable/TakeWhile.cs

119 lines
3.9 KiB
C#

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT License.
// See the LICENSE file in the project root for more information.
namespace System.Reactive.Linq.ObservableImpl
{
internal static class TakeWhile<TSource>
{
internal sealed class Predicate : Producer<TSource, Predicate._>
{
private readonly IObservable<TSource> _source;
private readonly Func<TSource, bool> _predicate;
public Predicate(IObservable<TSource> source, Func<TSource, bool> predicate)
{
_source = source;
_predicate = predicate;
}
protected override _ CreateSink(IObserver<TSource> observer) => new(_predicate, observer);
protected override void Run(_ sink) => sink.Run(_source);
internal sealed class _ : IdentitySink<TSource>
{
private readonly Func<TSource, bool> _predicate;
private bool _running;
public _(Func<TSource, bool> predicate, IObserver<TSource> observer)
: base(observer)
{
_predicate = predicate;
_running = true;
}
public override void OnNext(TSource value)
{
if (_running)
{
try
{
_running = _predicate(value);
}
catch (Exception exception)
{
ForwardOnError(exception);
return;
}
if (_running)
{
ForwardOnNext(value);
}
else
{
ForwardOnCompleted();
}
}
}
}
}
internal sealed class PredicateIndexed : Producer<TSource, PredicateIndexed._>
{
private readonly IObservable<TSource> _source;
private readonly Func<TSource, int, bool> _predicate;
public PredicateIndexed(IObservable<TSource> source, Func<TSource, int, bool> predicate)
{
_source = source;
_predicate = predicate;
}
protected override _ CreateSink(IObserver<TSource> observer) => new(_predicate, observer);
protected override void Run(_ sink) => sink.Run(_source);
internal sealed class _ : IdentitySink<TSource>
{
private readonly Func<TSource, int, bool> _predicate;
private bool _running;
private int _index;
public _(Func<TSource, int, bool> predicate, IObserver<TSource> observer)
: base(observer)
{
_predicate = predicate;
_running = true;
}
public override void OnNext(TSource value)
{
if (_running)
{
try
{
_running = _predicate(value, checked(_index++));
}
catch (Exception exception)
{
ForwardOnError(exception);
return;
}
if (_running)
{
ForwardOnNext(value);
}
else
{
ForwardOnCompleted();
}
}
}
}
}
}
}