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)

Concurrency Utilities in Clojure

Writing multithreaded programs is not an easy task. Such programs are often difficult to reason about and debug. Sometimes, they provide different output due to changes in the execution order. Yet many programmers write multithreaded software, because today's demands require utilizing available CPU cores.

In Java, developers can use threads and locks. Such tools are not easy to use. We can see this by examining how thick the books on concurrency in Java[1] are. While Clojure does not provide a silver bullet to solve all concurrency issues, it does provide well-thought-out tools to manage multithreading.

In this chapter, we will do the following:

  • Explain why concurrency is important in Clojure
  • Examine the often overlooked difference between concurrency and parallelism
  • Discuss problems with mutable states
  • Explore Clojure's approach to...