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LfrlAnvil.Reactive.Core

This project contains a few reactive programming functionalities.

Documentation

Technical documentation can be found here.

Examples

Following is an example of an event publisher usage:

// creates a new event publisher with events of 'string' type var publisher = new EventPublisher<string>(); // attaches a new event listener to the publisher var subscriber = publisher.Listen( EventListener.Create<string>( e => Console.WriteLine( $"First: '{e}'" ) ) ); // attaches another event listener to decorated version of the publisher // this listener will be invoked only for events that contain // at least two characters and that can be parsed to 32-bit integers publisher .Where( e => e.Length > 1 ) .Select( e => int.TryParse( e, out var r ) ? r : ( int? )null ) .WhereNotNull() .Listen( EventListener.Create<int>( e => Console.WriteLine( $"Second: {e}" ) ) ); // publishes a few events publisher.Publish( "foo" ); publisher.Publish( "1" ); publisher.Publish( "123" ); publisher.Publish( "1r" ); publisher.Publish( "bar" ); publisher.Publish( "42" ); // expected console output: // First: 'foo' // First: '1' // First: '123' // Second: 123 // First: '1r' // First: 'bar' // First: '42' // Second: 42 // removes the first event listener from the publisher subscriber.Dispose(); // publishes a few more events publisher.Publish( "qux" ); publisher.Publish( "10" ); // expected console output: // Second: 10 // removes all listeners from the publisher and disposes it publisher.Dispose();

There exist plenty of other built-in event source decorators. It's also possible to create entirely new decorators.

Following is an example of conversions between event streams and dotnet tasks:

// creates a new event publisher with events of 'string' type var publisher = new EventPublisher<string>(); // creates a new task from the event stream // this task will complete with the last emitted event, // once the underlying event stream is disposed var task = publisher.ToTask( CancellationToken.None ); // publishes a few events publisher.Publish( "foo" ); publisher.Publish( "bar" ); publisher.Publish( "qux" ); // at this point, the task is still running // disposing the publisher will cause the task to complete publisher.Dispose(); // gets the task's result, which should be equal to 'qux' var result = await task; // ---------- // creates a new task var taskSource = new TaskCompletionSource<string>(); var task = taskSource.Task; // creates a new event source based on the task // provided task factory will be invoked for each listener // and listeners will react to task's result, once it completes var source = EventSource.FromTask( _ => task ); // attaches a new listener to the task event source source.Listen( EventListener.Create<FromTask<string>>( e => Console.WriteLine( $"Task: '{e.Result}'" ) ) ); // completes the task with a result taskSource.SetResult( "foo" ); // expected console output: // Task: 'foo'

Following is an example of an in-memory event exchange:

// creates a new empty exchange, where publishers are identified by their event type var exchange = new EventExchange(); // registers a new publisher with events of 'string' type exchange.RegisterPublisher<string>(); // registers a new publisher with events of 'string' type exchange.RegisterPublisher<int>(); // attaches listeners to registered publishers exchange.Listen( EventListener.Create<string>( e => Console.WriteLine( $"String: '{e}'" ) ) ); exchange.Listen( EventListener.Create<int>( e => Console.WriteLine( $"Int: '{e}'" ) ) ); // publishes a few events exchange.Publish( "foo" ); exchange.Publish( 42 ); exchange.Publish( "bar" ); exchange.Publish( "qux" ); exchange.Publish( 123 ); // expected console output: // String: 'foo' // Int: 42 // String: 'bar' // String: 'qux' // Int: 123