using System.Collections.Generic; namespace System.Reactive.Linq.ObservableImpl { internal sealed class Max<TSource> : Producer<TSource, Max<TSource>._> { internal abstract class _ : IdentitySink<TSource> { protected readonly IComparer<TSource> _comparer; protected _(IComparer<TSource> comparer, IObserver<TSource> observer) : base(observer) { _comparer = comparer; } } private sealed class NonNull : _ { private bool _hasValue; private TSource _lastValue; public NonNull(IComparer<TSource> comparer, IObserver<TSource> observer) : base(comparer, observer) { } public override void OnNext(TSource value) { if (_hasValue) { int num = 0; try { num = _comparer.Compare(value, _lastValue); } catch (Exception error) { ForwardOnError(error); return; } if (num > 0) _lastValue = value; } else { _hasValue = true; _lastValue = value; } } public override void OnCompleted() { if (!_hasValue) ForwardOnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS)); else { ForwardOnNext(_lastValue); ForwardOnCompleted(); } } } private sealed class Null : _ { private TSource _lastValue; public Null(IComparer<TSource> comparer, IObserver<TSource> observer) : base(comparer, observer) { } public override void OnNext(TSource value) { if (value != null) { if (_lastValue == null) _lastValue = value; else { int num = 0; try { num = _comparer.Compare(value, _lastValue); } catch (Exception error) { ForwardOnError(error); return; } if (num > 0) _lastValue = value; } } } public override void OnError(Exception error) { ForwardOnError(error); } public override void OnCompleted() { ForwardOnNext(_lastValue); ForwardOnCompleted(); } } private readonly IObservable<TSource> _source; private readonly IComparer<TSource> _comparer; public Max(IObservable<TSource> source, IComparer<TSource> comparer) { _source = source; _comparer = comparer; } protected override _ CreateSink(IObserver<TSource> observer) { if (default(TSource) != null) return new NonNull(_comparer, observer); return new Null(_comparer, observer); } protected override void Run(_ sink) { sink.Run(_source); } } }