Kit.Core/LibExternal/System.Reactive/Linq/Observable/If.cs

55 lines
1.7 KiB
C#

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT License.
// See the LICENSE file in the project root for more information.
namespace System.Reactive.Linq.ObservableImpl
{
internal sealed class If<TResult> : Producer<TResult, If<TResult>._>, IEvaluatableObservable<TResult>
{
private readonly Func<bool> _condition;
private readonly IObservable<TResult> _thenSource;
private readonly IObservable<TResult> _elseSource;
public If(Func<bool> condition, IObservable<TResult> thenSource, IObservable<TResult> elseSource)
{
_condition = condition;
_thenSource = thenSource;
_elseSource = elseSource;
}
public IObservable<TResult> Eval() => _condition() ? _thenSource : _elseSource;
protected override _ CreateSink(IObserver<TResult> observer) => new(this, observer);
protected override void Run(_ sink) => sink.Run();
internal sealed class _ : IdentitySink<TResult>
{
private readonly If<TResult> _parent;
public _(If<TResult> parent, IObserver<TResult> observer)
: base(observer)
{
_parent = parent;
}
public void Run()
{
IObservable<TResult> result;
try
{
result = _parent.Eval();
}
catch (Exception exception)
{
ForwardOnError(exception);
return;
}
SetUpstream(result.SubscribeSafe(this));
}
}
}
}