Book Image

Julia 1.0 Programming. - Second Edition

By : Ivo Balbaert
Book Image

Julia 1.0 Programming. - Second Edition

By: Ivo Balbaert

Overview of this book

The release of Julia 1.0 is now ready to change the technical world by combining the high productivity and ease of use of Python and R with the lightning-fast speed of C++. Julia 1.0 programming gives you a head start in tackling your numerical and data problems. You will begin by learning how to set up a running Julia platform, before exploring its various built-in types. With the help of practical examples, this book walks you through two important collection types: arrays and matrices. In addition to this, you will be taken through how type conversions and promotions work. In the course of the book, you will be introduced to the homo-iconicity and metaprogramming concepts in Julia. You will understand how Julia provides different ways to interact with an operating system, as well as other languages, and then you'll discover what macros are. Once you have grasped the basics, you’ll study what makes Julia suitable for numerical and scientific computing, and learn about the features provided by Julia. By the end of this book, you will also have learned how to run external programs. This book covers all you need to know about Julia in order to leverage its high speed and efficiency for your applications.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Chapter 7. Metaprogramming in Julia

Everything in Julia is an expression that returns a value when executed. Every piece of the program code is internally represented as an ordinary Julia data structure, also called an expression. In this chapter, we will see how, by working on expressions, a Julia program can transform and even generate new code. This is a very powerful characteristic, also called homoiconicity. It inherits this property from Lisp, where code and data are just lists, and where it is commonly referred to with the phrase:

Code is data and data is code

.

In homoiconic languages, code can be expressed in terms of the language syntax. This is the case for the Lisp-like family of languages: Lisp, Scheme and, more recently, Clojure, which use s-expressions. Julia is homoiconic, as are others such as Prolog, IO, Rebol, and Red. As such, these are able to generate code during runtime, which can be subsequently executed.

We will explore this metaprogramming power by covering the following...