Can you give examples of libraries or tools that implement the principles of reactive programming?

In iOS, the following libraries and tools are often used for reactive programming:

• RxSwift — a popular library based on ReactiveX, providing a powerful set of operators for working with asynchronous data streams.
• Combine — a framework from Apple, built into iOS starting from version 13, allows working with reactive streams and integrates with other Apple APIs.
• ReactiveCocoa — one of the first reactive libraries for iOS, which inspired many subsequent solutions.

Example with Combine:

import Combine

let publisher = [1, 2, 3, 4].publisher

let subscription = publisher
    .filter { $0 % 2 == 0 }
    .sink { value in
        print("Even number: \(value)")
    }

These tools help simplify working with asynchrony, events, and states in applications.