http://live.eclipse.org/node/705
Eclipse Live Webinar on
Sven Efftinge, Heiko Behrens
itemis

Agenda
What is Xtext?
DSLs - An Example
Underlying Technology
Advanced Topics
Questions & Answers

?
What is

A Language Framework

Yet another
Parser Generator?
JavaCC

Yet another
Parser Generator?
t ha t!
than
ore
it’sm
No,
JavaCC

How does Xtext
relate to ...
IDE Meta-tooling Platform (IMP)
Dynamic Language Toolkit (DLTK)

How does Xtext
relate to ...
IDE Meta-tooling Platform (IMP) !
at
an th
o re th
t is m
Xt ex Language Toolkit (DLTK)
Dynamic

Is it a language workbench?
JetBrains Meta Programming System
Intentional Domain Workbench Microsoft Oslo

Is it a language workbench?
le te ly
m p rc e!
it’s co s ou
ut en
JetBrains Meta Programming System
,b op
Y es a nd
as ed
t ex t-b
Intentional Domain Workbench Microsoft Oslo

Xtext is a complete environment
for development of textual
- programming languages and
- domain-specific languages.
It is implemented in Java and is
based on Eclipse, EMF, and Antlr.

Domain-Specific Language (DSL)
A DSL is a formal, processable language
targeting at a specific viewpoint or
aspect of a software system.
Its semantics, flexibility and notation is
designed in order to support working
with that viewpoint as good as possible.

Rd2-c2

“ Queen to c7.
Check.”
“ Rd2-c2 ,
rook at d2 moves to c2.”

Moves in Chess:
!ook at a1 moves to a5.
P
iece S q uare A
ction
De stin ation
"ishop at c8 captures knight at h3.n
P
iece S q uare io
Action
D
es tinat
# b1 x c3
Piece S qua re ction stination
AD e
$2 - g4
ation
S A D
quar
e ction e stin

Rook a1 move a5
Bishop c8 capture h3 Knight
Knight b1 capture c3 Queen
Pawn g2 move g4
Game Move
Source «enum»
WhitePlayer
* Destination Piece
BlackPlayer
Piece

"ishop at c8 captures knight at h3
" c8 x h3

Model (textfile)
White: "Mayfield"
Black: "Trinks"
pawn at e2 moves to e4
pawn at f7 moves to g5
K b1 - c3
f7 - f5
queen at d1 moves to h5
// 1-0

DEMO

Underlying Technology

ar
Model
m
m
ra
G
Generator
Runtime
Superclass
Subclass Class
LL(*) Parser ecore meta model editor

Java Persistence API (JPA)
package templates;
import java.io.Serializable;
import java.util.*;
import javax.persistence.*;
@SuppressWarnings("serial")
@Entity
public class Customer implements Serializable {
! private Long id;
! private String name;
! private Address address;
! private Set<Order> orders = new HashSet<Order>();
! // No-arg constructor
! public Customer() {
! }
! @Id
! public Long getId() { entity Customer {
! ! return id;
! } ! property name : String
! public void setId(Long id) { ! property address : Address
! ! this.id = id;
! } ! property orders : Order[]
! public String getName() {
! ! return name; }
! }
! public void setName(String name) {
! ! this.name = name;
! }
! public Address getAddress() {
! ! return address;
! }
! public void setAddress(Address address) {
! ! this.address = address;
! }
! @OneToMany
! public Collection<Order> getOrders() {
! ! return orders;
! }
! public void setOrders(Set<Order> orders) {
! ! this.orders = orders;
! }
}

DEMO

ar
Model
m
m
ra
G
Generator Fragments
Generator
Runtime
Superclass
Subclass Class
LL(*) Parser ecore meta model editor

Composable
Code Generator
! generator is composed of “fragments”
! fragments can contribute to:
! Manifest.MF
! plugin.xml
! Guice modules
! Add your own fragments

ar
Model
m
m
ra
G
Generator
Runtime
Google Guice
Superclass
Subclass Class
LL(*) Parser ecore meta model editor

licensed by http://www.wordle.net/

MyCustomLabelProvider
licensed by http://www.wordle.net/

Dependency Injection with
Googlee
!No dependency to concrete implementation
!No explicit construction
!Easy testing
!Easy composition

Configuration of Components
in Xtext
/**
* used to register components to be used within the IDE.
*/
public class DomainmodelUiModule
! ! extends GeneratedDomainmodelUiModule {
!
! @Override
! public Class<? extends ILabelProvider> bindILabelProvider() {
! ! return MySpecialLabelProvider.class;
! }
}

DEMO

Advanced Topics

Integration with EMF
eclipse
Any EMF-based modeling
Code Generator GMF Editor P R O J E C T
Component
<<abstract>> XMI
XMIResource
Resource
XtextResource Text
Parser Linker Serializer
ValueConverter ScopeProvider Formatter

Working with Xtext
// initialization and setup (only needed in standalone mode)
new EntityStandaloneSetup().createInjectorAndDoEMFRegistration();
// standard EMF API usage
ResourceSet resourceSet = new ResourceSet();
Resource resource = resourceSet.getResource(uriToModelFile, true);
Model model = (Model) resource.getContents().get(0);
// print the name of all types to the console
for (Type type : model.getElements()) {
System.out.println(type.getName());
}

Eclipse Helios
•Model Index
• Grammar Mixins
• Base Language
• UI Features

Questions & Answers