SingleAsync<TSource>
namespace System.Reactive.Linq.ObservableImpl
{
internal static class SingleAsync<TSource>
{
internal sealed class Sequence : Producer<TSource, Sequence._>
{
internal sealed class _ : Sink<TSource>, IObserver<TSource>
{
private TSource _value;
private bool _seenValue;
public _(IObserver<TSource> observer, IDisposable cancel)
: base(observer, cancel)
{
_value = default(TSource);
_seenValue = false;
}
public void OnNext(TSource value)
{
if (_seenValue) {
_observer.OnError(new InvalidOperationException(Strings_Linq.MORE_THAN_ONE_ELEMENT));
base.Dispose();
} else {
_value = value;
_seenValue = true;
}
}
public void OnError(Exception error)
{
_observer.OnError(error);
base.Dispose();
}
public void OnCompleted()
{
if (!_seenValue)
_observer.OnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS));
else {
_observer.OnNext(_value);
_observer.OnCompleted();
}
base.Dispose();
}
}
private readonly IObservable<TSource> _source;
public Sequence(IObservable<TSource> source)
{
_source = source;
}
protected override _ CreateSink(IObserver<TSource> observer, IDisposable cancel)
{
return new _(observer, cancel);
}
protected override IDisposable Run(_ sink)
{
return ObservableExtensions.SubscribeSafe<TSource>(_source, (IObserver<TSource>)sink);
}
}
internal sealed class Predicate : Producer<TSource, Predicate._>
{
internal sealed class _ : Sink<TSource>, IObserver<TSource>
{
private readonly Func<TSource, bool> _predicate;
private TSource _value;
private bool _seenValue;
public _(Func<TSource, bool> predicate, IObserver<TSource> observer, IDisposable cancel)
: base(observer, cancel)
{
_predicate = predicate;
_value = default(TSource);
_seenValue = false;
}
public void OnNext(TSource value)
{
bool flag = false;
try {
flag = _predicate(value);
} catch (Exception error) {
_observer.OnError(error);
base.Dispose();
return;
}
if (flag) {
if (_seenValue) {
_observer.OnError(new InvalidOperationException(Strings_Linq.MORE_THAN_ONE_MATCHING_ELEMENT));
base.Dispose();
} else {
_value = value;
_seenValue = true;
}
}
}
public void OnError(Exception error)
{
_observer.OnError(error);
base.Dispose();
}
public void OnCompleted()
{
if (!_seenValue)
_observer.OnError(new InvalidOperationException(Strings_Linq.NO_MATCHING_ELEMENTS));
else {
_observer.OnNext(_value);
_observer.OnCompleted();
}
base.Dispose();
}
}
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, IDisposable cancel)
{
return new _(_predicate, observer, cancel);
}
protected override IDisposable Run(_ sink)
{
return ObservableExtensions.SubscribeSafe<TSource>(_source, (IObserver<TSource>)sink);
}
}
}
}