Book Image

Hands-On Reactive Programming with Clojure - Second Edition

By : Konrad Szydlo, Leonardo Borges
Book Image

Hands-On Reactive Programming with Clojure - Second Edition

By: Konrad Szydlo, Leonardo Borges

Overview of this book

Reactive Programming is central to many concurrent systems, and can help make the process of developing highly concurrent, event-driven, and asynchronous applications simpler and less error-prone. This book will allow you to explore Reactive Programming in Clojure 1.9 and help you get to grips with some of its new features such as transducers, reader conditionals, additional string functions, direct linking, and socket servers. Hands-On Reactive Programming with Clojure starts by introducing you to Functional Reactive Programming (FRP) and its formulations, as well as showing you how it inspired Compositional Event Systems (CES). It then guides you in understanding Reactive Programming as well as learning how to develop your ability to work with time-varying values thanks to examples of reactive applications implemented in different frameworks. You'll also gain insight into some interesting Reactive design patterns such as the simple component, circuit breaker, request-response, and multiple-master replication. Finally, the book introduces microservices-based architecture in Clojure and closes with examples of unit testing frameworks. By the end of the book, you will have gained all the knowledge you need to create applications using different Reactive Programming approaches.
Table of Contents (15 chapters)

Introduction to concurrency

Rich Hickey spent around two and a half years working on Clojure before releasing it to a wider audience[2]. One of his design goals was to create a programming language with first-class support for concurrency[3]. As a result, Clojure has well-thought-out concurrency tools.

Concurrency or parallelism

While some people use the terms concurrency and parallelism interchangeably, we need to make it clear that they are related, but are not the same[4].

Concurrency is about the coordination and composition of independent processes, while parallelism is the simultaneous execution of processes.

The following diagram illustrates how concurrency and parallelism handle processes during a program's execution...