Groovy in 2014 and beyond at GR8Conf Europe 2014

Groovy 2.3 coverage and what the future holds

Transcript

1. Groovy in 2014 & beyond
   Guillaume Laforge
   Groovy Project Manager
   http://glaforge.appspot.com
   @glaforge
   

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3. Stay up-to-date
   Groovy Weekly newsletter (Every Tuesday)
   
   http://bit.ly/groovy-weekly-subscribe
   

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4. Stay up-to-date
   Groovy Google+ page

   https://google.com/+groovy
   

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5. Stay up-to-date
   Groovy Google+ community
   http://bit.ly/g-community
   

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6. Agenda
   

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7. The Groovy roadmap…
   2015
   2014
   2013
   Groovy 2.3
   Groovy 2.4
   Groovy 2.2
   Groovy 3.0
   

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8. Groovy 2.3
   • JDK 8 runtime support
   
   • Traits
   
   • New and updates AST transformations
   
   • NIO2 module
   
   • JSON improvements & performance gains
   
   • New Markup template engine
   
   • Documentation overhaul
   

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9. Groovy 3.0
   !
   • New Meta-Object Protocol
   
   !
   • Invoke-dynamic based runtime
   
   !
   • Rewritten language grammar with Antlr v4
   

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10. @YourTwitterHandle
    #DVXFR14{session
    hashtag}
    Groovy 2.3
    

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11. @YourTwitterHandle
    JDK 8 support
    

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12. JDK 8 support — closures & lambdas
    IntStream.range(1,  100).forEach(s  -­‐>      
                                             System.out.println(s));  
    !
    Files.lines(Paths.get('README.adoc'))  
             .map(it  -­‐>  it.toUpperCase())  
             .forEach(it  -­‐>  System.out.println(it));
    

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13. JDK 8 support — closures & lambdas
    IntStream.range(1,  100).forEach(s  -­‐>      
                                             System.out.println(s));  
    !
    Files.lines(Paths.get('README.adoc'))  
             .map(it  -­‐>  it.toUpperCase())  
             .forEach(it  -­‐>  System.out.println(it));
    IntStream.range(1,  100).forEach  {  println  it  }  
    !
    Files.lines(Paths.get('README.adoc'))  
             .map  {  it.toUpperCase()  }  
             .forEach  {  println  it  }
    

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14. JDK 8 support — closures & lambdas
    IntStream.range(1,  100).forEach(s  -­‐>      
                                             System.out.println(s));  
    !
    Files.lines(Paths.get('README.adoc'))  
             .map(it  -­‐>  it.toUpperCase())  
             .forEach(it  -­‐>  System.out.println(it));
    IntStream.range(1,  100).forEach  {  println  it  }  
    !
    Files.lines(Paths.get('README.adoc'))  
             .map  {  it.toUpperCase()  }  
             .forEach  {  println  it  }
    Use Groovy closures
    wherever you pass
    lambdas in Java 8
    

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15. @YourTwitterHandle
    Traits
    

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16. Traits
    • Like interfaces, but with method bodies
    
    • similar to Java 8 interface default methods
    
    • Elegant way to compose behavior
    
    • multiple inheritance, without the « diamond problem »
    
    • Traits can also be stateful
    
    • traits can have properties like normal classes
    
    • Compatible with static typing & compilation
    • class methods coming from traits are also visible from Java
    
    • Also possible to implement traits at runtime
    

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17. trait  FlyingAbility  {  
           String  fly()  {  "I'm  flying!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird()  
    !
    assert  b.fly()  ==  "I'm  flying!"
    Traits: a simple example
    

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18. trait  FlyingAbility  {  
           String  fly()  {  "I'm  flying!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird()  
    !
    assert  b.fly()  ==  "I'm  flying!"
    Traits: a simple example
    « trait », a new keyword
    for a new concept
    

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19. trait  FlyingAbility  {  
           String  fly()  {  "I'm  flying!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird()  
    !
    assert  b.fly()  ==  "I'm  flying!"
    Traits: a simple example
    a class 

    « implements »

    a trait
    

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20. trait  FlyingAbility  {  
           String  fly()  {  "I'm  flying!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird()  
    !
    assert  b.fly()  ==  "I'm  flying!"
    Traits: a simple example
    the fly() method
    from the trait is
    available
    

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21. trait  FlyingAbility  {  
           String  fly()  {  "I'm  flying!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird()  
    !
    assert  b.fly()  ==  "I'm  flying!"
    Traits: a simple example
    

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22. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    

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23. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    a Groovy property
    

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24. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    implement the trait
    

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25. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    Groovy named
    argument constructor
    

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26. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    access the property
    

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27. trait  Named  {  
           String  name  
    }  
    !
    class  Bird  implements  Named  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'
    Traits: stateful
    

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28. trait  Named  {  String  name  }  
    !
    trait  FlyingAbility  extends  Named  {  
           String  fly()  {  "I'm  a  flying  ${name}!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: inheritance
    

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29. trait  Named  {  String  name  }  
    !
    trait  FlyingAbility  extends  Named  {  
           String  fly()  {  "I'm  a  flying  ${name}!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: inheritance
    extend the Named trait
    

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30. trait  Named  {  String  name  }  
    !
    trait  FlyingAbility  extends  Named  {  
           String  fly()  {  "I'm  a  flying  ${name}!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: inheritance
    access the name
    property
    

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31. trait  Named  {  String  name  }  
    !
    trait  FlyingAbility  extends  Named  {  
           String  fly()  {  "I'm  a  flying  ${name}!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: inheritance
    implement the composite trait
    

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32. trait  Named  {  String  name  }  
    !
    trait  FlyingAbility  extends  Named  {  
           String  fly()  {  "I'm  a  flying  ${name}!"  }  
    }  
    !
    class  Bird  implements  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: inheritance
    

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33. trait  FlyingAbility  {  
           String  fly()  {  "I'm  a  flying  $name!"  }  
    }  
    !
    trait  Named  {  String  name  }  
    !
    class  Bird  implements  Named,  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: multiple inheritance (+dyn.)
    

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34. trait  FlyingAbility  {  
           String  fly()  {  "I'm  a  flying  $name!"  }  
    }  
    !
    trait  Named  {  String  name  }  
    !
    class  Bird  implements  Named,  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: multiple inheritance (+dyn.)
    access a dynamic property
    

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35. trait  FlyingAbility  {  
           String  fly()  {  "I'm  a  flying  $name!"  }  
    }  
    !
    trait  Named  {  String  name  }  
    !
    class  Bird  implements  Named,  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: multiple inheritance (+dyn.)
    implements two traits!
    

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36. trait  FlyingAbility  {  
           String  fly()  {  "I'm  a  flying  $name!"  }  
    }  
    !
    trait  Named  {  String  name  }  
    !
    class  Bird  implements  Named,  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: multiple inheritance (+dyn.)
    dynamic ‘name’ property
    interpolated
    

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37. trait  FlyingAbility  {  
           String  fly()  {  "I'm  a  flying  $name!"  }  
    }  
    !
    trait  Named  {  String  name  }  
    !
    class  Bird  implements  Named,  FlyingAbility  {}  
    def  b  =  new  Bird(name:  'Colibri')  
    !
    assert  b.name  ==  'Colibri'  
    assert  b.fly()  ==  "I'm  a  flying  Colibri!"
    Traits: multiple inheritance (+dyn.)
    

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38. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    

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39. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    two surf() methods
    

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40. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    

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41. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    extending a class and
    implementing the two traits
    

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42. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    

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43. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    last declared trait wins!
    

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44. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  KiteSurfer,  WebSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'web'
    Traits: what about conflicts?
    

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45. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    

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46. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    reverse the order!
    

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47. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {}  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    

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48. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {  
           String  surf()  {  KiteSurfer.super.surf()  }  
    }  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    

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49. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {  
           String  surf()  {  KiteSurfer.super.surf()  }  
    }  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    Be explicit!
    Override surf() 

    & use ‘super’
    

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50. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {  
           String  surf()  {  KiteSurfer.super.surf()  }  
    }  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    Your class method takes
    precedence over the traits
    

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51. trait  KiteSurfer  {  String  surf()  {  'kite'  }  }  
    !
    trait  WebSurfer    {  String  surf()  {    'web'  }  }  
    !
    class  Person  {  String  name  }  
    !
    class  Hipster  extends  Person  
                         implements  WebSurfer,  KiteSurfer  {  
           String  surf()  {  KiteSurfer.super.surf()  }  
    }  
    !
    def  h  =  new  Hipster()  
    assert  h.surf()  ==  'kite'
    Traits: what about conflicts?
    

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52. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    class  NamedAnimal  implements  Named  {}  
    !
    def  na  =  new  NamedAnimal(name:  'Felix')  
    !
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    

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53. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    class  NamedAnimal  implements  Named  {}  
    !
    def  na  =  new  NamedAnimal(name:  'Felix')  
    !
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    Somewhat artificial to have to
    create an intermediary class to
    get named animals
    

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54. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    class  NamedAnimal  implements  Named  {}  
    !
    def  na  =  new  NamedAnimal(name:  'Felix')  
    !
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    

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55. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    !
    !
    def  na  =  new  Animal()  as  Named  
    na.name  =  'Felix'  
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    

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56. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    !
    !
    def  na  =  new  Animal()  as  Named  
    na.name  =  'Felix'  
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    Runtime trait, 

    with Groovy’s usual
    coercion mechanism
    

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57. trait  Named  {  
           String  name  
    }  
    !
    class  Animal  {}  
    !
    !
    def  na  =  new  Animal()  as  Named  
    na.name  =  'Felix'  
    assert  na.name  ==  'Felix'
    Traits: runtime implementation
    

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58. trait  Named  {  String  name  }  
    !
    trait  Quacks  {  
           String  quack()  {  'Quack!'  }  
    }  
    !
    class  Animal  {}  
    !
    def  na  =  new  Animal().withTraits  Named,  Quacks  
    na.name  =  'Daffy'  
    assert  na.name  ==  'Daffy'  
    assert  na.quack()  ==  'Quack!'
    Traits: runtime implementation
    

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59. trait  Named  {  String  name  }  
    !
    trait  Quacks  {  
           String  quack()  {  'Quack!'  }  
    }  
    !
    class  Animal  {}  
    !
    def  na  =  new  Animal().withTraits  Named,  Quacks  
    na.name  =  'Daffy'  
    assert  na.name  ==  'Daffy'  
    assert  na.quack()  ==  'Quack!'
    Traits: runtime implementation
    Implement several traits at
    once, at runtime
    

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60. trait  Named  {  String  name  }  
    !
    trait  Quacks  {  
           String  quack()  {  'Quack!'  }  
    }  
    !
    class  Animal  {}  
    !
    def  na  =  new  Animal().withTraits  Named,  Quacks  
    na.name  =  'Daffy'  
    assert  na.name  ==  'Daffy'  
    assert  na.quack()  ==  'Quack!'
    Traits: runtime implementation
    

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61. Traits: miscellaneous
    • Traits can…
    
    !
    • have private fields and methods
    
    • have abstract methods
    
    • implement interfaces
    
    • extend other traits or implement several traits
    
    • be statically type checked and compiled
    

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62. @YourTwitterHandle
    AST
    transforms
    

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63. New: @TailRecursive
    import  groovy.transform.TailRecursive  
    !
    @TailRecursive  
    def  fact(BigInteger  n,  accu  =  1G)  {  
           if  (n  <  2)  accu  
           else  fact(n  -­‐  1,  n  *  accu)  
    }  
    !
    assert  fact(1000)  >  10e2566
    

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64. New: @TailRecursive
    import  groovy.transform.TailRecursive  
    !
    @TailRecursive  
    def  fact(BigInteger  n,  accu  =  1G)  {  
           if  (n  <  2)  accu  
           else  fact(n  -­‐  1,  n  *  accu)  
    }  
    !
    assert  fact(1000)  >  10e2566
    Rewrites tail recursive
    friendly function serially
    

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65. New: @TailRecursive
    import  groovy.transform.TailRecursive  
    !
    @TailRecursive  
    def  fact(BigInteger  n,  accu  =  1G)  {  
           if  (n  <  2)  accu  
           else  fact(n  -­‐  1,  n  *  accu)  
    }  
    !
    assert  fact(1000)  >  10e2566
    Doesn’t blow up with a
    stack overflow error
    

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66. New: @TailRecursive
    import  groovy.transform.TailRecursive  
    !
    @TailRecursive  
    def  fact(BigInteger  n,  accu  =  1G)  {  
           if  (n  <  2)  accu  
           else  fact(n  -­‐  1,  n  *  accu)  
    }  
    !
    assert  fact(1000)  >  10e2566
    Downside of tail recursion is 

    you might have to rewrite 

    your algo to be tailrec friendly
    

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67. New: @TailRecursive
    import  groovy.transform.TailRecursive  
    !
    @TailRecursive  
    def  fact(BigInteger  n,  accu  =  1G)  {  
           if  (n  <  2)  accu  
           else  fact(n  -­‐  1,  n  *  accu)  
    }  
    !
    assert  fact(1000)  >  10e2566
    

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68. New: @Sortable
    import  groovy.transform.*  
    !
    @Sortable  
    class  Person  {  
           String  lastName  
           String  firstName  
           int  age  
    }
    

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69. New: @Sortable
    import  groovy.transform.*  
    !
    @Sortable  
    class  Person  {  
           String  lastName  
           String  firstName  
           int  age  
    }
    Makes the class Comparable
    by multiple Comparators
    

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70. New: @Sortable
    import  groovy.transform.*  
    !
    @Sortable  
    class  Person  {  
           String  lastName  
           String  firstName  
           int  age  
    }
    First compare by lastName,
    then by firstName, etc.
    

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71. New: @Sortable
    import  groovy.transform.*  
    !
    @Sortable  
    class  Person  {  
           String  lastName  
           String  firstName  
           int  age  
    }
    You can also specify
    ‘includes’ / ‘excludes’
    properties
    

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72. New: @Sortable
    import  groovy.transform.*  
    !
    @Sortable  
    class  Person  {  
           String  lastName  
           String  firstName  
           int  age  
    }
    

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73. @BaseScript improvements
    abstract  class  CustomBase  extends  Script  {  
           int  meaningOfLife  =  42  
    }
    @BaseScript(CustomBase)  
    import  groovy.transform.BaseScript  
    !
    assert  meaningOfLife  ==  42
    

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74. @BaseScript improvements
    abstract  class  CustomBase  extends  Script  {  
           int  meaningOfLife  =  42  
    }
    @BaseScript(CustomBase)  
    import  groovy.transform.BaseScript  
    !
    assert  meaningOfLife  ==  42
    You can add your own base methods and
    properties to all compiled scripts
    

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75. @BaseScript improvements
    abstract  class  CustomBase  extends  Script  {  
           int  meaningOfLife  =  42  
    }
    @BaseScript(CustomBase)  
    import  groovy.transform.BaseScript  
    !
    assert  meaningOfLife  ==  42
    Define the base script
    class for this script
    

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76. @BaseScript improvements
    abstract  class  CustomBase  extends  Script  {  
           int  meaningOfLife  =  42  
    }
    @BaseScript(CustomBase)  
    import  groovy.transform.BaseScript  
    !
    assert  meaningOfLife  ==  42
    In 2.3, ability to put the
    annotation on imports &
    package
    

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77. @BaseScript improvements
    abstract  class  CustomBase  extends  Script  {  
           int  meaningOfLife  =  42  
    }
    @BaseScript(CustomBase)  
    import  groovy.transform.BaseScript  
    !
    assert  meaningOfLife  ==  42
    

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78. @BaseScript custom abstract method
    abstract  class  CustomBase  extends  Script  {  
       def  run()  {  
           before()  
           internalRun()  
           after()  
       }  
    !
       abstract  internalRun()  
    !
       def  before()  {  println  'before'  }  
       def  after()    {  println  'after'    }  
    }
    

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79. @BaseScript custom abstract method
    abstract  class  CustomBase  extends  Script  {  
       def  run()  {  
           before()  
           internalRun()  
           after()  
       }  
    !
       abstract  internalRun()  
    !
       def  before()  {  println  'before'  }  
       def  after()    {  println  'after'    }  
    }
    import  groovy.transform.BaseScript  
    @BaseScript  CustomBase  script  
    !
    println  'Hello'
    

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80. @BaseScript custom abstract method
    abstract  class  CustomBase  extends  Script  {  
       def  run()  {  
           before()  
           internalRun()  
           after()  
       }  
    !
       abstract  internalRun()  
    !
       def  before()  {  println  'before'  }  
       def  after()    {  println  'after'    }  
    }
    import  groovy.transform.BaseScript  
    @BaseScript  CustomBase  script  
    !
    println  'Hello'
    You can define your own abstract
    method for script bodies
    

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81. @BaseScript custom abstract method
    abstract  class  CustomBase  extends  Script  {  
       def  run()  {  
           before()  
           internalRun()  
           after()  
       }  
    !
       abstract  internalRun()  
    !
       def  before()  {  println  'before'  }  
       def  after()    {  println  'after'    }  
    }
    import  groovy.transform.BaseScript  
    @BaseScript  CustomBase  script  
    !
    println  'Hello'
    

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82. @YourTwitterHandle
    NIO2 module
    

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83. JDK 7+ NIO2 module
    • All the familiar methods on File 

    retrofitted on Path as well
    path.withReader  {  Reader  r  -­‐>  ...  }  
    path.eachLine  {  String  line  -­‐>  ...  }  
    path.eachFileRecurse  {  Path  p  -­‐>  ...  }  
    path  <<  'some  content'  
    path  <<  bytes  
    path.readLines()  
    …
    

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84. JDK 7+ NIO2 module
    • All the familiar methods on File 

    retrofitted on Path as well
    path.withReader  {  Reader  r  -­‐>  ...  }  
    path.eachLine  {  String  line  -­‐>  ...  }  
    path.eachFileRecurse  {  Path  p  -­‐>  ...  }  
    path  <<  'some  content'  
    path  <<  bytes  
    path.readLines()  
    …
    Feature request to add all the
    java.nio.file.Files static utility
    methods as GDK
    

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85. JDK 7+ NIO2 module
    • All the familiar methods on File 

    retrofitted on Path as well
    path.withReader  {  Reader  r  -­‐>  ...  }  
    path.eachLine  {  String  line  -­‐>  ...  }  
    path.eachFileRecurse  {  Path  p  -­‐>  ...  }  
    path  <<  'some  content'  
    path  <<  bytes  
    path.readLines()  
    …
    

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86. @YourTwitterHandle
    JSON
    

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87. JSON parser / builder perf. increase
    • Re-implementation of JSON support 

    for speed & efficiency
    
    • parser forked off the Boon JSON project
    
    • serializer carefully fine-tuned
    
    !
    • Article on the parsing speed improvements
    
    • http://rick-hightower.blogspot.fr/2014/04/groovy-and-boon-provide-fastest-json.html
    

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88. JSON parser / builder perf. increase
    • Re-implementation of JSON support 

    for speed & efficiency
    
    • parser forked off the Boon JSON project
    
    • serializer carefully fine-tuned
    
    !
    • Article on the parsing speed improvements
    
    • http://rick-hightower.blogspot.fr/2014/04/groovy-and-boon-provide-fastest-json.html
    

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89. JSON parser / builder perf. increase
    • Re-implementation of JSON support 

    for speed & efficiency
    
    • parser forked off the Boon JSON project
    
    • serializer carefully fine-tuned
    
    !
    • Article on the parsing speed improvements
    
    • http://rick-hightower.blogspot.fr/2014/04/groovy-and-boon-provide-fastest-json.html
    Benchmark gives 3x to 4x
    performance factor 

    over Jackson and GSON
    

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90. JSON parser / builder perf. increase
    • Re-implementation of JSON support 

    for speed & efficiency
    
    • parser forked off the Boon JSON project
    
    • serializer carefully fine-tuned
    
    !
    • Article on the parsing speed improvements
    
    • http://rick-hightower.blogspot.fr/2014/04/groovy-and-boon-provide-fastest-json.html
    

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91. New modes for parsing
    • Original JsonSlurper renamed to JsonSlurperClassic
    
    !
    • Additional parsing modes:
    
    • INDEX_OVERLAY: super fast for <2MB payloads
    
    • using a « parsing overlay » technique
    
    • CHARACTER_SOURCE: for >2MB payloads
    
    • implemented with sliding windows over readers
    
    • LAX: beyond the JSON spec, nice for configuration files
    
    • support single quotes, / and # comments
    
    • CHAR_BUFFER: general purpose
    

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92. JsonSlurper for configuration files
    import  groovy.json.*  
    import  static  groovy.json.JsonParserType.*  
    !
    def  parser  =  new  JsonSlurper().setType(LAX)  
    !
    def  conf  =  parser.parseText  '''  
           //  configuration  file  
           {  
                   //  no  quote  for  key,  single  quoted  value  
                   environment:  'production'  
                   #  pound-­‐style  comment  
                   'server':  5  
           }  
    '''  
    !
    assert  conf.environment  ==  'production'  
    assert  conf.server  ==  5
    

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93. JsonSlurper for configuration files
    import  groovy.json.*  
    import  static  groovy.json.JsonParserType.*  
    !
    def  parser  =  new  JsonSlurper().setType(LAX)  
    !
    def  conf  =  parser.parseText  '''  
           //  configuration  file  
           {  
                   //  no  quote  for  key,  single  quoted  value  
                   environment:  'production'  
                   #  pound-­‐style  comment  
                   'server':  5  
           }  
    '''  
    !
    assert  conf.environment  ==  'production'  
    assert  conf.server  ==  5
    More tolerant parser: 

    single quotes, 

    non-quoted keys, 

    // and # comments,
    missing comas
    

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94. JsonSlurper for configuration files
    import  groovy.json.*  
    import  static  groovy.json.JsonParserType.*  
    !
    def  parser  =  new  JsonSlurper().setType(LAX)  
    !
    def  conf  =  parser.parseText  '''  
           //  configuration  file  
           {  
                   //  no  quote  for  key,  single  quoted  value  
                   environment:  'production'  
                   #  pound-­‐style  comment  
                   'server':  5  
           }  
    '''  
    !
    assert  conf.environment  ==  'production'  
    assert  conf.server  ==  5
    

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95. @YourTwitterHandle
    Markup
    template engine
    

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96. Markup template engine
    • Based on the principles of Groovy’s « builders »
    
    • and particularly the MarkupBuilder class

    for generating arbitrary XML / HTML payloads
    
    • Compiled statically for fast template rendering
    
    • Internationalization aware
    
    •provide the desired Locale in the configuration object
    
    •usual suffix notation template_fr_FR.tpl
    
    • Custom base template class
    
    •ability to provide reusable methods across your templates
    

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97. Markup template engine — the idea
    cars  {  
         cars.each  {  
                 car(make:  it.make,  name:  it.name)  
         }  
    }
    

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98. Markup template engine — the idea
    cars  {  
         cars.each  {  
                 car(make:  it.make,  name:  it.name)  
         }  
    }
    Your template
    

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99. Markup template engine — the idea
    cars  {  
         cars.each  {  
                 car(make:  it.make,  name:  it.name)  
         }  
    }
    model = [cars: [!
    new Car(make: 'Peugeot', name: '508'), !
    new Car(make: 'Toyota', name: 'Prius’)!
    ]]
    

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100. Markup template engine — the idea
     cars  {  
          cars.each  {  
                  car(make:  it.make,  name:  it.name)  
          }  
     }
     model = [cars: [!
     new Car(make: 'Peugeot', name: '508'), !
     new Car(make: 'Toyota', name: 'Prius’)!
     ]]
     Feed a model into
     your template
     

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101. Markup template engine — the idea
     cars  {  
          cars.each  {  
                  car(make:  it.make,  name:  it.name)  
          }  
     }
     model = [cars: [!
     new Car(make: 'Peugeot', name: '508'), !
     new Car(make: 'Toyota', name: 'Prius’)!
     ]]
     !
     !
     !
     
     

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102. Markup template engine — the idea
     cars  {  
          cars.each  {  
                  car(make:  it.make,  name:  it.name)  
          }  
     }
     model = [cars: [!
     new Car(make: 'Peugeot', name: '508'), !
     new Car(make: 'Toyota', name: 'Prius’)!
     ]]
     !
     !
     !
     
     Generate the
     XML output
     

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103. Markup template engine — the idea
     cars  {  
          cars.each  {  
                  car(make:  it.make,  name:  it.name)  
          }  
     }
     model = [cars: [!
     new Car(make: 'Peugeot', name: '508'), !
     new Car(make: 'Toyota', name: 'Prius’)!
     ]]
     !
     !
     !
     
     

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104. Markup template engine — in action
     import  groovy.text.markup.*  
     !
     def  config  =  new  TemplateConfiguration()  
     def  engine  =  new  MarkupTemplateEngine(config)  
     def  tmpl  =  engine.createTemplate('''  
            p("Hello  ${model.name}")  
     ''')  
     def  model  =  [name:  'World']  
     System.out  <<  tmpl.make(model)
     

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105. Markup template engine — includes
     //  include  another  template  
     include  template:  'foo.tpl'  
            
     //  include  raw  content  
     include  unescaped:  'raw.txt'  
     !
     //  escape  &  include  
     include  escaped:  'to_escape.txt'
     

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106. Markup template engine
     //  escaped  automatically  
     yield  'some  raw  content'  
     !
     //  include  raw  content  
     yieldUnescaped  'content'  
     !
     //    
     xmlDeclaration()                
     

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107. Markup template engine
     //  escaped  automatically  
     yield  'some  raw  content'  
     !
     //  include  raw  content  
     yieldUnescaped  'content'  
     !
     //    
     xmlDeclaration()                
     //    
     comment  'comment'                
     !
     //  adds  new  lines  
     newLine()                                
     !
     //  process.  instruct.  
     pi(/*  ...  */)                      
     

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108. Markup template engine
     !
     • Configuration options
     
     !
     • declaration encoding
     
     !
     • expand empty
     elements
     
     !
     • use double quotes
     
     !
     • newline string
     
     !
     !
     !
     !
     !
     !
     !
     • auto escape
     
     !
     • auto indent
     
     !
     • base template class
     
     !
     • locale
     

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109. Markup template engine — static!
     • Type-checked templates available
     
     • use createTypeCheckedModelTemplate() 

     instead of createTemplate()
     
     • Advantages
     
     • get compilation errors
     
     • if a variable is not available
     
     • if you make mistakes in the code snippets
     
     • even faster templates
     

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110. Markup template engine — static!
     • With typed check model creation method
     
     !
     !
     !
     !
     • Or declare your model types in the template
     

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111. Markup template engine — static!
     • With typed check model creation method
     
     !
     !
     !
     !
     • Or declare your model types in the template
     def  modelTypes  =  [cars:  "List"]  
     !
     def  tmpl  =  engine.  
        createTypeCheckedModelTemplate(

                "page.tpl",  modelTypes)
     

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112. Markup template engine — static!
     • With typed check model creation method
     
     !
     !
     !
     !
     • Or declare your model types in the template
     def  modelTypes  =  [cars:  "List"]  
     !
     def  tmpl  =  engine.  
        createTypeCheckedModelTemplate(

                "page.tpl",  modelTypes)
     modelTypes  =  {  
            List  cars  
     }  
     !
     cars.each  {  car  -­‐>  
            p("Car  name:  $car.name")  
     }
     

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113. Markup template engine — static!
     • With typed check model creation method
     
     !
     !
     !
     !
     • Or declare your model types in the template
     def  modelTypes  =  [cars:  "List"]  
     !
     def  tmpl  =  engine.  
        createTypeCheckedModelTemplate(

                "page.tpl",  modelTypes)
     modelTypes  =  {  
            List  cars  
     }  
     !
     cars.each  {  car  -­‐>  
            p("Car  name:  $car.name")  
     }
     Works with
     createTemplate() too
     

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114. Markup template engine — static!
     • With typed check model creation method
     
     !
     !
     !
     !
     • Or declare your model types in the template
     def  modelTypes  =  [cars:  "List"]  
     !
     def  tmpl  =  engine.  
        createTypeCheckedModelTemplate(

                "page.tpl",  modelTypes)
     modelTypes  =  {  
            List  cars  
     }  
     !
     cars.each  {  car  -­‐>  
            p("Car  name:  $car.name")  
     }
     

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115. @YourTwitterHandle
     Documentation
     overhaul
     

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116. GroovyDoc
     

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117. GroovyDoc
     

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118. GroovyDoc
     

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119. Groovy GDK documentation
     

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120. Groovy GDK documentation
     

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121. Brand new documentation
     

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122. Future groovy-lang.org website
     

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123. Future groovy-lang.org website
     

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124. Future groovy-lang.org website
     

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125. @YourTwitterHandle
     #DVXFR14{session
     hashtag}
     Groovy 3.0
     

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126. View Slide

127. @YourTwitterHandle
     MOP 2
     

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128. Goals for the new MOP
     • Leverage & build upon JDK 7+ invoke dynamic
     
     • get Java-like performance even for dynamic code
     
     • Rationalize the sedimentation of meta-
     programming
     
     • more coherence, less corner cases & inconsistencies
     
     • Provide a notion of « realm »
     
     • shield users of « monkey patching »
     
     • finer-grained control of meta-programming reach
     
     • Private visibility anyone?
     

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129. @YourTwitterHandle
     Antlr v4
     Grammar
     

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130. Antlr v4 grammar
     • Problems
     • Groovy still uses Antlr v2!
     
     • but version 3 and 4 are out
     
     • Groovy’s grammar evolved from a Java grammar
     
     • harder to fix and evolve, especially with Antlr v2
     
     • Advantages
     • Start from a clean slate
     
     • Antlr 4 more tolerant 

     and powerful regarding ambiguities
     
     • Time to clean some grammar & syntax warts!
     
     • Need to implement the Java 8 constructs!
     

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131. Antlr v4 grammar
     • Problems
     • Groovy still uses Antlr v2!
     
     • but version 3 and 4 are out
     
     • Groovy’s grammar evolved from a Java grammar
     
     • harder to fix and evolve, especially with Antlr v2
     
     • Advantages
     • Start from a clean slate
     
     • Antlr 4 more tolerant 

     and powerful regarding ambiguities
     
     • Time to clean some grammar & syntax warts!
     
     • Need to implement the Java 8 constructs!
     A « Google Summer of Code »
     student to help
     

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132. @YourTwitterHandle
     Java 8
     support
     

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133. Java 8 support
     • Additional grammar & semantic features to support
     
     • to keep saying Groovy / Java interoperability is awesome!
     
     • New in Java 8
     
     • lambdas
     
     • method references
     
     • default methods in interfaces
     
     • stream API, date / time API
     
     • annotations on types & repeated annotations
     

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134. Java 8 support
     • Additional grammar & semantic features to support
     
     • to keep saying Groovy / Java interoperability is awesome!
     
     • New in Java 8
     
     • lambdas
     
     • method references
     
     • default methods in interfaces
     
     • stream API, date / time API
     
     • annotations on types & repeated annotations
     Groovy had already:
     closures, method pointers, mixins,
     enriched collection & time APIs
     

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135. @YourTwitterHandle
     #DVXFR14{session
     hashtag}
     Summary
     

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136. View Slide

137. Groovy rocks the JVM 

     since 2003!
     

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138. @YourTwitterHandle
     #DVXFR14{session
     hashtag}
     Q & A
     

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139. Image credits / Creative Commons
     • Rue pavée — By-Nc-Sa
     
     • http://www.flickr.com/photos/22914687@N05/4957591422/sizes/l/
     
     • Sous la Tour Eiffel — By-Nc-Sa
     
     • http://www.flickr.com/photos/stewiedewie/244850735/sizes/l/in/photostream/
     
     • Sous le pont — By-Nc-Nd
     
     • http://www.landscape-photo.net/displayimage.php?pid=5194
     
     • Paris Metro - By-Nc-Sa
     
     • http://www.flickr.com/photos/22914687@N05/6317047263/sizes/l/
     

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