Book Image

Clojure Programming Cookbook

Book Image

Clojure Programming Cookbook

Overview of this book

When it comes to learning and using a new language you need an effective guide to be by your side when things get rough. For Clojure developers, these recipes have everything you need to take on everything this language offers. This book is divided into three high impact sections. The first section gives you an introduction to live programming and best practices. We show you how to interact with your connections by manipulating, transforming, and merging collections. You’ll learn how to work with macros, protocols, multi-methods, and transducers. We’ll also teach you how to work with languages such as Java, and Scala. The next section deals with intermediate-level content and enhances your Clojure skills, here we’ll teach you concurrency programming with Clojure for high performance. We will provide you with advanced best practices, tips on Clojure programming, and show you how to work with Clojure while developing applications. In the final section you will learn how to test, deploy and analyze websocket behavior when your app is deployed in the cloud. Finally, we will take you through DevOps. Developing with Clojure has never been easier with these recipes by your side!
Table of Contents (16 chapters)
Clojure Programming Cookbook
About the Authors
About the Reviewer

Using protocols

Protocols provide polymorphism between different data types. Defining protocols are defining Java's interfaces in fact. We can define protocols for Clojure's records and types. It is also possible to define protocols for Java classes.

Getting ready

This section does not make use of any external library, so you can just start a REPL and be ready.

How to do it...

Let's start with defining records and types, and then look at how to define and use protocols.

Defining a record

Here, we will define a record of the author. We have shown how to express the author Sir Conan Doyle using a map in Chapter 2, Interacting with Collections:

{:name "Arthur Ignatius Conan Doyle" 
 :born "22-May-1859" 
 :died "7-July-1930" 
 :occupation ["novelist" "short story writer" "poet" "physician"] 
 :nationality "scottish" 
 :citizenship "United Kingdom" 
 :genre ["Detective fiction", "fantasy", "science fiction", "historical novels", "non-fiction"] 
 :notable-works ["Stories...