Book Image

Clojure for Java Developers

Book Image

Clojure for Java Developers

Overview of this book

We have reached a point where machines are not getting much faster, software projects need to be delivered quickly, and high quality in software is more demanding as ever. We need to explore new ways of writing software that helps achieve those goals. Clojure offers a new possibility of writing high quality, multi-core software faster than ever, without having to leave your current platform. Clojure for Java developers aims at unleashing the true potential of the Clojure language to use it in your projects. The book begins with the installation and setup of the Clojure environment before moving on to explore the language in-depth. Get acquainted with its various features such as functional programming, concurrency, etc. with the help of example projects. Additionally, you will also, learn how the tooling works, and how it interacts with the Java environment. By the end of this book, you will have a firm grip on Clojure and its features, and use them effectively to write more robust programs.
Table of Contents (14 chapters)
Clojure for Java Developers
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Specific collection types in Clojure


Now that you know about Clojure's general collection properties and the sequence abstraction, it is a good time to get to know about Clojure's specific collection implementations.

Vectors

Vectors are Clojure's workhorse; together with map, it is the most used collection. Don't be afraid of them; they have nothing to do with Java's java.util.Vector. They are just a series of ordered values, such as a list or an array.

They have the following properties:

  • They are immutable

  • They can be accessed sequentially

  • They are associative (they are maps of their indices, meaning that their keys are 0, 1, 2, and so on)

  • They are counted, meaning they have a finite size

  • They have random access, so you can access any element with almost constant time (with the nth function)

  • The conj function appends a given element to them

Tip

The nth function allows us to get the nth element of any seq, but you shouldn't use it without care. It has no problem handling vectors and it returns in constant...