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

Inspect the equivalent Java source for Clojure code


Inspecting the equivalent Java source for a given Clojure code provides a great insight into how that might impact its performance. However, Clojure generates only Java bytecodes at runtime unless we compile a namespace out to disk. When developing with Leiningen, only selected namespaces under the :aot vector in the project.clj file are output as the compiled .class files containing bytecodes. Fortunately, an easy and quick way to know the equivalent Java source for Clojure code is to ahead-of-time (AOT) compile namespaces and then decompile the bytecodes into equivalent Java sources using a Java bytecode decompiler.

There are several commercial and open source Java bytecode decompilers available. One of the open source decompilers we will discuss here is JD-GUI, which you can download from its website (http://jd.benow.ca/#jd-gui). Use a version suitable for your operating system.

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