namespace System.Reactive.Linq.ObservableImpl { internal static class Select<TSource, TResult> { internal sealed class Selector : Producer<TResult, Selector._> { internal sealed class _ : Sink<TSource, TResult> { private readonly Func<TSource, TResult> _selector; public _(Func<TSource, TResult> selector, IObserver<TResult> observer) : base(observer) { _selector = selector; } public override void OnNext(TSource value) { TResult val = default(TResult); try { val = _selector(value); } catch (Exception error) { ForwardOnError(error); return; } ForwardOnNext(val); } } private readonly IObservable<TSource> _source; private readonly Func<TSource, TResult> _selector; public Selector(IObservable<TSource> source, Func<TSource, TResult> selector) { _source = source; _selector = selector; } protected override _ CreateSink(IObserver<TResult> observer) { return new _(_selector, observer); } protected override void Run(_ sink) { sink.Run(_source); } } internal sealed class SelectorIndexed : Producer<TResult, SelectorIndexed._> { internal sealed class _ : Sink<TSource, TResult> { private readonly Func<TSource, int, TResult> _selector; private int _index; public _(Func<TSource, int, TResult> selector, IObserver<TResult> observer) : base(observer) { _selector = selector; } public override void OnNext(TSource value) { TResult val = default(TResult); try { val = _selector(value, checked(_index++)); } catch (Exception error) { ForwardOnError(error); return; } ForwardOnNext(val); } } private readonly IObservable<TSource> _source; private readonly Func<TSource, int, TResult> _selector; public SelectorIndexed(IObservable<TSource> source, Func<TSource, int, TResult> selector) { _source = source; _selector = selector; } protected override _ CreateSink(IObserver<TResult> observer) { return new _(_selector, observer); } protected override void Run(_ sink) { sink.Run(_source); } } } }