Java DSLs with Xtext

Jan Koehnlein

Mittwoch, 27. März 13

Mittwoch, 27. März 13

Mittwoch, 27. März 13

public class Customer implements Serializable {

private String name; private Address address; private List<Item> purchase;

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; } public List<Item> getPurchase() { return purchase; } public void setPurchase(List<Item> items) { this.purchase = purchase; }}

Mittwoch, 27. März 13

@Entity public class Customer implements Serializable { @Id private String name; private Address address; private List<Item> purchase;

public String getName() { return name; } public void setName(String name) { this.name = name; } @Column(name="ADDR", nullable=false) public Address getAddress() return address; } public void setAddress(Address address) { this.address = address; } @ManyToMany public List<Item> getPurchase() { return purchase; } public void setPurchase(List<Item> items) { this.purchase = purchase; }}

Mittwoch, 27. März 13

Domain-Specific Languages

Mittwoch, 27. März 13

@Entity public class Customer implements Serializable { @Id private String name; private Address address; private List<Item> purchase;

public String getName() { return name; } public void setName(String name) { this.name = name; } @Column(name="ADDR", nullable=false) public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } @ManyToMany public List<Item> getPurchase() { return purchase; } public void setPurchase(List<Item> items) { this.purchase = purchase; }}

entity Customer { name: String address: Address purchase: Item*}

CodeGeneration

DSL Java

Mittwoch, 27. März 13

Methods Logic

ArithmeticsBehavior ?

Mittwoch, 27. März 13

entity Customer { name: String address: Address purchase: Item* double sales() { double result = 0.0; for(Item item: purchase) result += item.getPrice(); return result; }}

Mittwoch, 27. März 13

Typesystem

Compiler / Interpreter

Complex Syntax

Expressions

Mittwoch, 27. März 13

Integration Patterns

Generatedcode

Manually writtencode

Mittwoch, 27. März 13

Reusable powerful expression library language

Java‘s Typesystem

Compile to Java Code

Access to Java-elements

Mittwoch, 27. März 13

DSLs for

JavaMittwoch, 27. März 13

Type System

Interpreter /

Debugger

Grammar (Parser, Lexer)Linker

Advanced Editor

Eclipse IntegrationJvm

Model

MyLanguage

grammar inheritance

JvmModelInferrer

Mittwoch, 27. März 13

Model Inference

entity Customer { name: String address: Address purchasedItems: Item* double sales() { purchasedItems .map[price] .reduce[a,b|a+b] }}

Class Customer

parameter name

returnType String

Field name

Method getName

Method setName

type String

Mittwoch, 27. März 13

Model Inference

entity Customer { name: String address: Address purchasedItems: Item* double sales() { purchasedItems .map[price] .reduce[a,b|a+b] }}

returnType double

Method sales

body Expression

Mittwoch, 27. März 13

class ScriptingJvmModelInferrer extends AbstractModelInferrer { @Inject extension JvmTypesBuilder

def dispatch void infer(Script script, IJvmDeclaredTypeAcceptor acceptor, boolean isPreIndexingPhase) {

acceptor.accept(script.toClass('MyClass')).initializeLater [

// the class gets one main method members += script.toMethod(

'main', script.newTypeRef(Void::TYPE)) [

parameters += script.toParameter("args", script.newTypeRef(typeof(String))

.addArrayTypeDimension) static = true varArgs = true // Associate the script as the body of the main method body = script ] ] }}

Mittwoch, 27. März 13

The 7 LanguagesScripting Language

Http Routing Language

Templates Language

DSL for Guice

Build Language

Tortoise

DSL for MongoDB

Mittwoch, 27. März 13

www.eclipse.org/Xtext/7languages.html

Find more at

Mittwoch, 27. März 13