namespace System.Reactive.Linq.ObservableImpl { internal sealed class MaxDecimalNullable : Producer<decimal?, MaxDecimalNullable._> { internal sealed class _ : Sink<decimal?>, IObserver<decimal?> { private decimal? _lastValue; public _(IObserver<decimal?> observer, IDisposable cancel) : base(observer, cancel) { _lastValue = null; } public void OnNext(decimal? value) { if (value.HasValue) { if (_lastValue.HasValue) { if (value > _lastValue) _lastValue = value; } else _lastValue = value; } } public void OnError(Exception error) { _observer.OnError(error); base.Dispose(); } public void OnCompleted() { _observer.OnNext(_lastValue); _observer.OnCompleted(); base.Dispose(); } } private readonly IObservable<decimal?> _source; public MaxDecimalNullable(IObservable<decimal?> source) { _source = source; } protected override _ CreateSink(IObserver<decimal?> observer, IDisposable cancel) { return new _(observer, cancel); } protected override IDisposable Run(_ sink) { return _source.SubscribeSafe(sink); } } }