Book Image

Clojure High Performance Programming

By : Shantanu Kumar
Book Image

Clojure High Performance Programming

By: Shantanu Kumar

Overview of this book

<p>Clojure is a young, dynamic, functional programming language that runs on the Java Virtual Machine. It is built with performance, pragmatism, and simplicity in mind. Like most general purpose languages, Clojure’s features have different performance characteristics that one should know in order to write high performance code.<br /><br />Clojure High Performance Programming is a practical, to-the-point guide that shows you how to evaluate the performance implications of different Clojure abstractions, learn about their underpinnings, and apply the right approach for optimum performance in real-world programs.<br /><br />This book discusses the Clojure language in the light of performance factors that you can exploit in your own code.</p> <p>You will also learn about hardware and JVM internals that also impact Clojure’s performance. Key features include performance vocabulary, performance analysis, optimization techniques, and how to apply these to your programs. You will also find detailed information on Clojure's concurrency, state-management, and parallelization primitives.</p> <p>This book is your key to writing high performance Clojure code using the right abstraction, in the right place, using the right technique.</p>
Table of Contents (15 chapters)
Clojure High Performance Programming
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Arrays


Beside objects and primitives, Java has a special type of collection storage structure called arrays. Once created, arrays cannot be grown or shrunk without copying data and creating another array to hold the result. Array elements are always homogeneous in type. Array elements are like places that you can mutate to hold new values. Unlike collections such as list and vector, arrays can contain primitive elements, which make them a very fast storage mechanism without Garbage Collection (GC) overhead.

Arrays often form a basis for mutable data structures. For example, Java's java.lang.ArrayList implementation uses arrays internally. In Clojure, arrays can be used for fast numeric storage and processing, efficient algorithms, and so on. Unlike collections, arrays can have one or more dimensions. So, you could lay out data in an array such as a matrix or cube. Let us see Clojure's support for arrays:

Description

Example

Notes

Create array

(make-array Integer 20)

Array of type (boxed...