Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Groovy for Domain-Specific Languages, Second Edition
  • Table Of Contents Toc
  • Feedback & Rating feedback
Groovy for Domain-Specific Languages, Second Edition

Groovy for Domain-Specific Languages, Second Edition

By : Dearle
4.7 (3)
close
close
Groovy for Domain-Specific Languages, Second Edition

Groovy for Domain-Specific Languages, Second Edition

4.7 (3)
By: Dearle

Overview of this book

The times when developing on the JVM meant you were a Java programmer have long passed. The JVM is now firmly established as a polyglot development environment with many projects opting for alternative development languages to Java such as Groovy, Scala, Clojure, and JRuby. In this pantheon of development languages, Groovy stands out for its excellent DSL enabling features which allows it to be manipulated to produce mini languages that are tailored to a project’s needs. A comprehensive tutorial on designing and developing mini Groovy based Domain Specific Languages, this book will guide you through the development of several mini DSLs that will help you gain all the skills needed to develop your own Groovy based DSLs with confidence and ease. Starting with the bare basics, this book will focus on how Groovy can be used to construct domain specific mini languages, and will go through the more complex meta-programming features of Groovy, including using the Abstract Syntax Tree (AST). Practical examples are used throughout this book to de-mystify these seemingly complex language features and to show how they can be used to create simple and elegant DSLs. Packed with examples, including several fully worked DSLs, this book will serve as a springboard for developing your own DSLs.
Table of Contents (14 chapters)
close
close
Free Chapter
1
1. Introduction to DSLs and Groovy
13
Index

What is a closure?


Closures are such an unfamiliar concept to begin with that it can be hard to grasp initially. Closures have characteristics that make them look like a method in so far as we can pass parameters to them and they can return a value. However, unlike methods, closures are anonymous. A closure is just a snippet of code that can be assigned to a variable and executed later:

def flintstones = ["Fred","Barney"]
def greeter = { println "Hello, ${it}" }
flintstones.each( greeter )
greeter "Wilma"
greeter = { }
flintstones.each( greeter )
greeter "Wilma"

Because closures are anonymous, they can easily be lost or overwritten. In the preceding example, we defined a variable greeter to contain a closure that prints a greeting. After greeter is overwritten with an empty closure, any reference to the original closure is lost.

Tip

It's important to remember that greeter is not the closure. It is a variable that contains a closure, so it can be supplanted at any time.

Given that greeter is a...

Unlock full access

Continue reading for free

A Packt free trial gives you instant online access to our library of over 7000 practical eBooks and videos, constantly updated with the latest in tech

Create a Note

Modal Close icon
You need to login to use this feature.
notes
bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Delete Note

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Edit Note

Modal Close icon
Write a note (max 255 characters)
Cancel
Update Note

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY