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)

To get the most out of this book

This book assumes that you have a reasonably modern desktop or laptop computer as well as a working Clojure environment with Leiningen (see http://leiningen.org/) properly configured. Installation instructions depend on your platform and can be found on the Leiningen website (see http://leiningen.org/#install).

You are free to use any text editor of your choice, but popular choices include Eclipse (see https://eclipse.org/downloads/) with the Counterclockwise plugin (see https://github.com/laurentpetit/ccw), IntelliJ (https://www.jetbrains.com/idea/) with the Cursive plugin (see https://cursiveclojure.com/), Light Table (see http://lighttable.com/), Emacs, and Vim.

Download the example code files

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

  1. Log in or register at www.packt.com.
  2. Select the SUPPORT tab.
  3. Click on Code Downloads & Errata.
  4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

  • WinRAR/7-Zip for Windows
  • Zipeg/iZip/UnRarX for Mac
  • 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Hands-On-Reactive-Programming-with-Clojure-Second-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Download the color images

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "That's why the next thing we do is call move-forward!."

A block of code is set as follows:

(fn [ctx val] 
  (-> ctx 
      canvas/save 
      (canvas/translate (:x val) (:y val)) 

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

[default]
exten => s,1,Dial(Zap/1|30)
exten => s,2,Voicemail(u100)
exten => s,102,Voicemail(b100)
exten => i,1,Voicemail(s0)

Any command-line input or output is written as follows:

$ lein repl

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."

Warnings or important notes appear like this.
Tips and tricks appear like this.