namespace System.Reactive.Linq.ObservableImpl { internal sealed class AverageSingleNullable : Producer<float?, AverageSingleNullable._> { internal sealed class _ : Sink<float?>, IObserver<float?> { private double _sum; private long _count; public _(IObserver<float?> observer, IDisposable cancel) : base(observer, cancel) { _sum = 0; _count = 0; } public void OnNext(float? value) { try { if (value.HasValue) { _sum += (double)value.Value; checked { _count++; } } } catch (Exception error) { _observer.OnError(error); base.Dispose(); } } public void OnError(Exception error) { _observer.OnError(error); base.Dispose(); } public void OnCompleted() { if (_count > 0) _observer.OnNext((float)(_sum / (double)_count)); else _observer.OnNext(null); _observer.OnCompleted(); base.Dispose(); } } private readonly IObservable<float?> _source; public AverageSingleNullable(IObservable<float?> source) { _source = source; } protected override _ CreateSink(IObserver<float?> observer, IDisposable cancel) { return new _(observer, cancel); } protected override IDisposable Run(_ sink) { return _source.SubscribeSafe(sink); } } }