Note

This project is currently in preview. We are seeking a lot of feedback. We are considering fundamental changes such as changing the name of the library (Uni(fied)Rx) or reverting back to the use of IObservable<T> and others, if you have any opinions, please post them in the Issues.

The evolution of dotnet/reactive and UniRx, which support many platforms including Unity, Godot, Avalonia, WPF, etc(planning MAUI, Stride, LogicLooper).

I have over 10 years of experience with Rx, experience in implementing a custom Rx runtime (UniRx) for game engine, and experience in implementing an asynchronous runtime (UniTask) for game engine. Based on those experiences, I came to believe that there is a need to implement a new Reactive Extensions for .NET, one that reflects modern C# and returns to the core values of Rx.

Stopping the pipeline at OnError is a billion-dollar mistake.
IScheduler is the root of poor performance.
Frame-based operations, a missing feature in Rx, are especially important in game engines.
Single asynchronous operations should be entirely left to async/await.
Synchronous APIs should not be implemented.
Backpressure should be left to IAsyncEnumerable and Channels.
For distributed processing and transparent queries, there are GraphQL, Kubernetes, Orleans, gRPC, and MagicOnion.

In other words, LINQ is not for EveryThing, and we believe that the essence of Rx lies in the processing of in-memory messaging (LINQ to Events), which will be our focus. Our main intended uses are UI frameworks and game engines, and we are not concerned with communication processes like Reactive Streams.

To address the shortcomings of dotnet/reactive, we have made changes to the core interfaces, so R3 might appear to be an imitation of Rx. However, in recent years, Rx-like frameworks optimized for language features, such as Kotlin Flow and Swift Combine, have been standardized. C# has also evolved significantly, now at C# 12, and we believe there is a need for an Rx that aligns with the latest C#.

Getting Started

public abstract class Observable<T>
{
    public IDisposable Subscribe(Observer<T> observer);
}

public abstract class Observer<T> : IDisposable
{
    public void OnNext(T value);
    public void OnErrorResume(Exception error);
    public void OnCompleted(Result result);
}

public static Observable<Unit> Interval(TimeSpan period, TimeProvider timeProvider);
public static Observable<Unit> IntervalFrame(int periodFrame, FrameProvider frameProvider);

README.md

R3

Getting Started

TimeProvider instead of IScheduler

Frame based operations

Disposables

Subscription Management

Platform Supports

WPF

Avalonia

Unity

Godot

Operator Reference

License