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

Clojure collections and their basic functions

There are four collection types in Clojure:

  • Lists

  • Vectors

  • Maps

  • Sets

In this recipe, we will describe what these types are and some basic functions for them.

Getting ready

You only need REPL described in the recipe Repl up! in Chapter 1, Live Programming with Clojure, and no additional libraries. Start REPL so that you can review the sample code in this recipe.

How to do it...

We will learn collection types in Clojure including lists, vectors, maps, and sets. We will learn how to create them and use basic functions for them.


Lists are commonly used in Lisp. Clojure also supports the list data type. Lists are internally implemented as a linked list. To create a list, begin with quote (') and then enclose elements with (). If you want to create an empty list, use ' (), or (list):

'("A Study in Scarlet" 
"The Sign of the Four" 
"The Hound of the Baskervilles" 
"The Valley of Fear") 
;;=> ("A Study in Scarlet" "The Sign of the Four...