Building Your Own DSL with Xtext

©2016 GlobalLogic Inc.

Build your own DSL with Xtext

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About me - Tomasz Kleszczyński

• Software Engineer @ REC - a GlobalLogic Company

• Focused in JVM technologies– Java EE– Eclipse RCP

• Interested in software architecture

• [email protected]

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Agenda

• Introduction of DSL• Eclipse Modelling Framework• Xtext• Demos• What’s new in Xtext 2.9

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Introduction of DSL

• What is a Domain-Specific Language?• Internal or external?• Is it difficult to build one?

• Examples:– SQL– Css (LESS / SASS)– MATLAB

YourOwn

select * from Named n where n.name = ”foo*” and n.used order by n.name desc

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Eclipse Modelling FrameworkEMF Components• Core Runtime

– Ecore metamodel

– Notification framework

– Persistence (XML/XMI), validation, change model

• EMF.Edit– Support for model-based editors and viewers

– Default reflective editor

• Codegen– Code generator for application models and editors

– Extensible model importer / exporter framework

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• Eclipse project – EPL license– Uses ANTLR3, EMF, Google Guice

• Language development framework– Set of DSLs and API to describe the different aspects of

programming language– Compiler components independent of Eclipse or OSGi:

• parser

• type-safe abstract syntax tree (AST)

• serializer

• code formatter

• scoping framework

• linking

– IDE components• Eclipse• IntelliJ IDEA

– Translation to Java using XBase

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Grammar• Language Declaration• EPackage Declaration

– EPackage Generation

– EPackage Import

• Rules– Terminal Rules

– Parser Rules

– Hidden Terminal Symbols

– Data type Rules

– Enum Rules

• Ecore Model Inference– Epackage

– EClass

– EEnum

– EStructuralFeature

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DemoAll demos are based on Xtext 2.9.2• Formatting• Generation• Scoping• Validation• Content assist• Labels / outline• Quick fix• Web editor

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Xtext 2.9 - What’s new• IntelliJ IDEA As An Alternative To Eclipse

– Language Editors for IntelliJ IDEA• Headless Builds For Xtext Projects

– Gradle / Maven– Target selection (Eclipse, IntelliJ IDEA, web)

• New Project Wizard• Web Support• New Grammar Language Features

– Explicit rule calls and super rule calls– Parser rule fragments

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Q & A

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References

• EMF Fundamentals• www.eclipse.org/Xtext• zarnekow.blogspot.de• blog.efftinge.de• Scoping and linking

Examples:• github.com/tkleszczynski/xtext-jug.git

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Thank you