namespace System.Reactive.Linq.ObservableImpl { internal sealed class MinDouble : Producer<double, MinDouble._> { internal sealed class _ : IdentitySink<double> { private bool _hasValue; private double _lastValue; public _(IObserver<double> observer) : base(observer) { } public override void OnNext(double value) { if (_hasValue) { if (value < _lastValue || double.IsNaN(value)) _lastValue = value; } else { _lastValue = value; _hasValue = true; } } public override void OnCompleted() { if (!_hasValue) ForwardOnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS)); else { ForwardOnNext(_lastValue); ForwardOnCompleted(); } } } private readonly IObservable<double> _source; public MinDouble(IObservable<double> source) { _source = source; } protected override _ CreateSink(IObserver<double> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_source); } } }