Book Image

Introduction to JVM Languages

By : van der Leun
Book Image

Introduction to JVM Languages

By: van der Leun

Overview of this book

Anyone who knows software development knows about the Java Virtual Machine. The Java Virtual Machine is responsible for interpreting Java byte code and translating it into actions. In the beginning, Java was the only programming language used for the JVM. But increasing complexity of the language and the remarkable performance of the JVM created an opening for a new generation of programming languages. If you want to build a strong foundation with the Java Virtual Machine and get started with popular modern programming languages, then this book is for you. The book will begin with a general introduction of the JVM and its features, which are common to the JVM languages, helping you get abreast with its concepts. It will then dive into explaining languages such as Java, Scala, Clojure, Kotlin, and Groovy and will show how to work with each language, their features, use cases, and pros and cons. By writing example projects in those languages and focusing on each language’s strong points, it will help you find the programming language that is most appropriate for your particular needs. By the end of the book, you will have written multiple programs that run on the Java Virtual Machine and know about the differences between the various languages.
Table of Contents (15 chapters)

Clojure language


Since Clojure is so different from many mainstream programming languages, we'll place more emphasis on the basics of Clojure than for other languages in this book. Here are the basics we'll discuss:

  • Syntax
  • Expressions
  • Defining variables
  • Defining functions
  • Data structures (numerals, strings, and collections)
  • Iteration over arrays and loops
  • Conditions

Syntax

Lisp and Clojure both adhere to the code is data and data is code principle. This property of Lisp is called homoiconicity, which means that a language's syntax is similar to its program structure. Among Lisp's built-in datatypes is a list. This list type is used when writing code. After you define a list, you can add expressions to it. An expression contains a function reference and its parameters. When closing a list, the list is evaluated dynamically at runtime. Basically, entire programs are represented by Clojure's internal data structures. Clojure has a process, called the reader, that reads and evaluates each entry in the...