Reactive programming¶

Category: Async · Status: stub

One line: Describing a program as streams of values over time and the values derived from them, with changes propagating through automatically.

Also called: Rx, ReactiveX, Reactive Extensions, observables.

How it connects¶

flowchart LR
  n_async_stream["Async stream"]
  n_event_driven_programming["Event-driven programming"]
  n_reactive_programming["Reactive programming"]
  n_event_driven_programming ---|vs| n_reactive_programming
  n_reactive_programming -->|uses| n_async_stream
  classDef center stroke-width:3px
  class n_reactive_programming center
  classDef outside stroke-dasharray: 4 3
  class n_async_stream,n_event_driven_programming outside

Is built on: Async stream
Often confused with: Event-driven programming
See also: Dataflow programming, Publish-subscribe and broadcast

In each language¶


Java	`Flow` ↗, the JDK's version of the reactive-streams interfaces
C#	`IObservable<T>` ↗, a provider for push-based notification
Kotlin	`Flow` ↗, including `StateFlow`, a `SharedFlow` that always holds the latest state value
Swift	Combine ↗: publishers expose values that change over time, and subscribers receive them
Elsewhere	ReactiveX ↗, whose Observable is the asynchronous, push counterpart of an Iterable

Where to read more¶

In the books: Async Rust, Maxwell Flitton, Caroline Morton — ch. 6, 'Reactive Programming'
In the books: C++ Reactive Programming, Praseed Pai, Peter Abraham — ch. 1, 'Reactive Programming Model – Overview and History'
In the books: Learning Concurrent Programming in Scala, Aleksandar Prokopec — ch. 6, 'Concurrent Programming with Reactive Extensions'
In the books: Concurrency in .NET, Riccardo Terrell — ch. 6, 'Real-time event streams: functional reactive programming'
In the books: Combine: Asynchronous Programming with Swift, Shai Mishali, Florent Pillet, Marin Todorov, Scott Gardner — ch. 1, 'Hello, Combine!'
In the books: Kotlin Coroutines by Tutorials, Filip Babić, Nishant Srivastava — ch. 1, 'What Is Asynchronous Programming' → 'Using reactive extensions for background work'
In the books: Concurrency in C# Cookbook, Stephen Cleary — ch. 1, 'Concurrency: An Overview' → 'Introduction to Reactive Programming (Rx)'
In the books: Programming C# 12, Ian Griffiths — ch. 11, 'Rx: Reactive Extensions'
Notes: Reactive Programming vs Asynchronous Programming ↗
Reference: Wikipedia: Reactive programming ↗