Book Image

Implementing Domain-Specific Languages with Xtext and Xtend

By : Lorenzo Bettini
Book Image

Implementing Domain-Specific Languages with Xtext and Xtend

By: Lorenzo Bettini

Overview of this book

Xtext is an open source Eclipse framework for implementing domain-specific languages together with its IDE functionalities. It lets you implement languages really quickly, and, most of all, it covers all aspects of a complete language infrastructure, starting from the parser, code generator, interpreter, and more. "Implementing Domain-Specific Languages with Xtext and Xtend" will teach you how to develop a DSL with Xtext, an Eclipse framework for implementing domain-specific languages. The chapters are like tutorials that describe the main concepts of Xtext such as grammar definition, validation, code generation, customizations, and many more, through uncomplicated and easy-to-understand examples. Starting with briefly covering the features of Xtext that are involved in a DSL implementation, including integration in an IDE, the book will then introduce you to Xtend as this language will be used in all the examples throughout the book. We then proceed by explaining the main concepts of Xtext, such as validation, code generation, and customizations of runtime and UI aspects. By the end of the book, you will have learned how to test a DSL implemented in Xtext with Junit, in order to follow a test-driven development strategy that will help the developer implement maintainable code that is much faster and cleaner. A test-driven approach is used throughout the book when presenting advanced concepts such as type checking and scoping. The book also shows you how to build and release a DSL so that it can be installed in Eclipse, and gives you hints on how to build the DSL headlessly in a continuous integration server. "Implementing Domain-Specific Languages with Xtext and Xtend" aims to complement the official Xtext documentation to explain the main concepts through simplified examples and to teach the best practices for a DSL implementation in Xtext. It is a Beginner's Guide which should set you up for professional development DSL and its Eclipse IDE tooling.
Table of Contents (21 chapters)
Implementing Domain-Specific Languages with Xtext and Xtend
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
13
Bibliography
Index

Customizations


Depending on the complexity of your DSL, you might want to customize the default implementation of several components of Xbase, such as scoping and validation. This can be achieved by subclassing the corresponding Xbase classes and by specifying the bindings in the Guice module. Note that the Xbase scope provider implementation is not based on AbstractDeclarativeScopeProvider, thus, you cannot rely on the convention for method names that we used in Chapter 10, Scoping; you will have to redefine the getScope method. Moreover, you will have to inspect the implementation of Xbase scope provider and validator to understand which method to override.

It is also possible to override some rules of the Xbase grammar in order to change the syntactic shape of some expressions. Moreover, you can change an Xbase expression rule in order to add syntax for new expressions which are specific to your DSL. In this case, you also need to provide custom implementations for some classes of Xbase...