namespace System.Reactive.Linq.ObservableImpl { internal sealed class SumDecimal : Producer<decimal, SumDecimal._> { internal sealed class _ : IdentitySink<decimal> { private decimal _sum; public _(IObserver<decimal> observer) : base(observer) { } public override void OnNext(decimal value) { _sum += value; } public override void OnCompleted() { ForwardOnNext(_sum); ForwardOnCompleted(); } } private readonly IObservable<decimal> _source; public SumDecimal(IObservable<decimal> source) { _source = source; } protected override _ CreateSink(IObserver<decimal> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_source); } } }