Book Image

Groovy for Domain-Specific Languages, Second Edition

By : Fergal Dearle
Book Image

Groovy for Domain-Specific Languages, Second Edition

By: Fergal Dearle

Overview of this book

Table of Contents (20 chapters)
Groovy for Domain-specific Languages Second Edition
About the Author
About the Reviewers
Free Chapter
Introduction to DSLs and Groovy

Chapter 5. Groovy Closures

In this chapter, we will focus exclusively on closures. We touched upon closures already in the previous chapter. Now, we will take a close look at them from every angle. Why devote a whole chapter of the book to one aspect of the language? The reason is that closures are the single most important feature of the Groovy language. Closures are the special seasoning that helps Groovy stand out from Java. They are also the single most powerful feature that we will use when implementing DSLs. In this chapter, we will discuss the following topics:

  • We will start by explaining just what a closure is and how we can define some simple closures in our Groovy code

  • We will look at how many of the built-in collection methods make use of closures for applying iteration logic, and see how this is implemented by passing a closure as a method parameter

  • We will look at the various mechanisms for calling closures, and we will take a look under the covers at how Groovy implements its...