Groovy AST - 18va reunion Spring Hispano

1. Groovy
AST

3. Agenda
• Local
ASTTransforma5ons
– Groovy
– Grails
– Griffon
• Como
funcionan?
• Otras
formas
de
modificar
AST

4. LISTADO
DE
TRANSFORMACIONES
DE
AST
(NO
EXHAUSTIVO)

5. @Singleton
@Singleton
class AccountManager {
void process(Account account) { ... }
}
def account = new Account()
AccountManager.instance.process(account)

6. @Delegate
class Event {
@Delegate Date when
String title, url
}
df = new SimpleDateFormat("MM/dd/yyyy")
so2gx = new Event(title: "SpringOne2GX",
url: "http://springone2gx.com",
when: df.parse("10/19/2010"))
oredev = new Event(title: "Oredev",
url: "http://oredev.org",
when: df.parse("11/02/2010"))
assert oredev.after(so2gx.when)

7. @Immutable
@Immutable
class Person {
String name
}
def person1 = new Person("ABC")
def person2 = new Person(name: "ABC")
assert person1 == person2
person1.name = "Boom!” // error!

8. @Category
@Category(Integer)
class Pouncer {
String pounce() {
(1..this).collect([]) {
'boing!' }.join(' ')
}
}
use(Pouncer) {
3.pounce() // boing! boing! boing!
}

9. @Mixin
class Pouncer {
String pounce() {
(1..this.times).collect([]) {
'boing!' }.join(' ')
}
}
@Mixin(Pouncer)
class Person{
int times
}
person1 = new Person(times: 2)
person1.pounce() // boing! boing!

10. @Grab
@Grab('net.sf.json-lib:json-lib:2.3:jdk15')
def builder = new
net.sf.json.groovy.JsonGroovyBuilder()
def books = builder.books {
book(title: "Groovy in Action",
name: "Dierk Koenig")
}
assert books.name == ["Dierk Koenig"]

11. @Log
@groovy.util.logging.Log
class Person {
String name
void talk() {
log.info("$name is talking…")
}
}
def person = new Person(name: "Duke")
person.talk()
// Oct 7, 2010 10:36:09 PM sun.reflect.NativeMethodAccessorImpl invoke0
// INFO: Duke is talking…

12. @InheritConstructors
@groovy.transform.InheritConstructors
class MyException extends RuntimeException {}
def x1 = new MyException("Error message")
def x2 = new MyException(x1)
assert x2.cause == x1

13. @Canonical
@groovy.transform.Canonical
class Person {
String name
}
def person1 = new Person("Duke")
def person2 = new Person(name: "Duke")
assert person1 == person2
person2.name = "Tux"
assert person1 != person2

14. @Scalify
trait Output {
@scala.reflect.BeanProperty
var output:String = ""
}
@groovyx.transform.Scalify
class GroovyOutput implements Output {
String output
}

15. @En5ty
@grails.persistence.Entity
class Book {
String title
}
def book = new Book().save()
assert book.id
assert book.version

16. @Bindable
@groovy.beans.Bindable
class Book {
String title
}
def book = new Book()
book.addPropertyChangeListener({e ->
println "$e.propertyName $e.oldValue ->
$e.newValue"
} as java.beans.PropertyChangeListener)
book.title = "Foo” // prints "title Foo"
book.title = "Bar” // prints "title Foo Bar"

17. @Listener
@groovy.beans.Bindable
class Book {
@griffon.beans.Listener(snooper)
String title
private snooper = {e ->
println "$e.propertyName $e.oldValue ->
$e.newValue"
}
}
def book = new Book()
book.title = "Foo" // prints "title Foo"
book.title = "Bar" // prints "title Foo Bar"

18. @EventPublisher
@Singleton
@griffon.util.EventPublisher
class AccountManager {
void process(Account account) {
publishEvent("AccountProcessed", [account)]
}
}
def am = AccountManager.instance
am.addEventListener("AccountProcessed") { account ->
println "Processed account $account"
}
def acc = new Account()
AccountManager.instance.process(acc)
// prints "Processed account Account:1"

19. @Scaffold
class Book {
String title
}
@griffon.presentation.Scaffold
class BookBeanModel {}
def model = new BookBeanModel()
def book = new Book(title: "Foo")
model.value = book
assert book.title == model.title.value
model.value = null
assert !model.title.value
assert model.title

20. @En5ty
@griffon.persistence.Entity(‘gsql’)
class Book {
String title
}
def book = new Book().save()
assert book.id
assert book.version

21. Y
otras
tantas
…
• @PackageScope
• @Lazy
• @Newify
• @Field
• @Synchronized
• @Vetoable
• @ToString,
@EqualsAndHashCode,
@TupleConstructor
• @AutoClone,
@AutoExternalize
• …

22. LA
RECETA
SECRETA
PARA
HACER
TRANSFORMACIONES
DE
AST

23. 1
Definir
interface
@Retention(RetentionPolicy.SOURCE)
@Target({ElementType.FIELD, ElementType.TYPE})
@GroovyASTTransformationClass
("org.codehaus.griffon.ast.ListenerASTTransformation
")
public @interface Listener {
String value();
}

24. 2
Implementar
la
transformacion
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.transform.ASTTransformation;
import org.codehaus.groovy.transform.GroovyASTTransformation;
@GroovyASTTransformation(phase=CompilationPhase.CANONICALIZATION)
public class ListenerASTTransformation
implements ASTTransformation {
public void visit(ASTNode[] nodes, SourceUnit source) {
// MAGIC GOES HERE, REALLY! =)
}
}

25. 3
Anotar
el
codigo
@groovy.beans.Bindable
class Book {
@griffon.beans.Listener(snooper)
String title
private snooper = {e ->
// awesome code …
}
}

26. OTRO
TIPO
DE
TRANSFORMACIONES

27. GContracts

28. Spock

29. CodeNarc

30. Griffon

31. Gracias!
@aalmiray
hXp://jroller.com/aalmiray