Groovy in 2014 and beyond -- JavaOne 2014

The latest developments in the Groovy programming language proejct

Transcript

1. Groovy in 2014 and beyond Guillaume Laforge Groovy project lead Pivotal @glaforge
2. Stay up-to-date Groovy Weekly Newsletter (Every Tuesday) http://beta.groovy-lang.org/groovy-weekly.html 2
3. The Groovy roadmap 3 2015 2014 2013 Groovy 2.3 Groovy 2.4 Groovy 2.2 Groovy 2.5 ? Groovy 3.0 ?
4. @glaforge — Groovy in 2014 and beyond Groovy 2.3
5. @glaforge — Groovy in 2014 and beyond JDK 8 support
6. JDK 8 support — closures vs lambdas 6 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));
7. JDK 8 support — closures vs lambdas 6 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  }
8. JDK 8 support — closures vs lambdas 6 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
9. @glaforge — Groovy in 2014 and beyond Traits
10. 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 and static compilation • class methods from traits also visible from Java classes • Also possible to implement traits at runtime 8
11. Traits: a simple example 9 trait  FlyingAbility  {          String  fly()  {  "I'm  flying!"  }   }   ! class  Bird  implements  FlyingAbility  {}   def  b  =  new  Bird()   ! assert  b.fly()  ==  "I'm  flying!"
12. Traits: a simple example 9 trait  FlyingAbility  {          String  fly()  {  "I'm  flying!"  }   }   ! class  Bird  implements  FlyingAbility  {}   def  b  =  new  Bird()   ! assert  b.fly()  ==  "I'm  flying!" « trait », a new keyword for a new concept
13. Traits: a simple example 9 trait  FlyingAbility  {          String  fly()  {  "I'm  flying!"  }   }   ! class  Bird  implements  FlyingAbility  {}   def  b  =  new  Bird()   ! assert  b.fly()  ==  "I'm  flying!" a class 
 « implements »
 a trait
14. Traits: a simple example 9 trait  FlyingAbility  {          String  fly()  {  "I'm  flying!"  }   }   ! class  Bird  implements  FlyingAbility  {}   def  b  =  new  Bird()   ! assert  b.fly()  ==  "I'm  flying!" the fly() method from the trait is available
15. Traits: a simple example 9 trait  FlyingAbility  {          String  fly()  {  "I'm  flying!"  }   }   ! class  Bird  implements  FlyingAbility  {}   def  b  =  new  Bird()   ! assert  b.fly()  ==  "I'm  flying!"
16. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri'
17. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri' a Groovy property
18. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri' implement the trait
19. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri' Groovy named argument constructor
20. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri' access the property
21. Traits: stateful 10 trait  Named  {          String  name   }   ! class  Bird  implements  Named  {}   def  b  =  new  Bird(name:  'Colibri')   ! assert  b.name  ==  'Colibri'
22. Traits: inheritance 11 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!"
23. Traits: inheritance 11 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!" extend the Named trait
24. Traits: inheritance 11 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!" access the name property
25. Traits: inheritance 11 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!" implement the composite trait
26. Traits: inheritance 11 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!"
27. Traits: what about conflicts? 12 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'
28. Traits: what about conflicts? 12 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' two surf() methods
29. Traits: what about conflicts? 12 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'
30. Traits: what about conflicts? 12 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' extending a class and implementing the two traits
31. Traits: what about conflicts? 12 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'
32. Traits: what about conflicts? 12 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' last declared trait wins!
33. Traits: what about conflicts? 12 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'
34. Traits: what about conflicts? 13 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'
35. Traits: what about conflicts? 13 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' reverse the order!
36. Traits: what about conflicts? 13 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'
37. Traits: what about conflicts? 14 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'
38. Traits: what about conflicts? 14 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' Be explicit! Override surf() 
 & use ‘super’
39. Traits: what about conflicts? 14 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' Your class method takes precedence over the traits
40. Traits: what about conflicts? 14 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'
41. trait  Named  {          String  name   }   ! class  Animal  {}   class  NamedAnimal  implements  Named  {}   ! def  na  =  new  NamedAnimal(name:  'Felix')   ! assert  na.name  ==  'Felix' Traits: runtime implementation 15
42. trait  Named  {          String  name   }   ! class  Animal  {}   class  NamedAnimal  implements  Named  {}   ! def  na  =  new  NamedAnimal(name:  'Felix')   ! assert  na.name  ==  'Felix' Traits: runtime implementation 15 Somewhat artificial to have to create an intermediary class to get named animals
43. trait  Named  {          String  name   }   ! class  Animal  {}   class  NamedAnimal  implements  Named  {}   ! def  na  =  new  NamedAnimal(name:  'Felix')   ! assert  na.name  ==  'Felix' Traits: runtime implementation 15
44. trait  Named  {          String  name   }   ! class  Animal  {}   ! ! def  na  =  new  Animal()  as  Named   na.name  =  'Felix'   assert  na.name  ==  'Felix' Traits: runtime implementation 16
45. trait  Named  {          String  name   }   ! class  Animal  {}   ! ! def  na  =  new  Animal()  as  Named   na.name  =  'Felix'   assert  na.name  ==  'Felix' Traits: runtime implementation 16 Runtime trait, 
 with Groovy’s usual coercion mechanism
46. trait  Named  {          String  name   }   ! class  Animal  {}   ! ! def  na  =  new  Animal()  as  Named   na.name  =  'Felix'   assert  na.name  ==  'Felix' Traits: runtime implementation 16
47. Traits: runtime implementation 17 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!'
48. Traits: runtime implementation 17 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!' Implement several traits at once, at runtime
49. Traits: runtime implementation 17 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!'
50. @glaforge — Groovy in 2014 and beyond AST transforms
51. New: @TailRecursive 19 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
52. New: @TailRecursive 19 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
53. New: @TailRecursive 19 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
54. New: @TailRecursive 19 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
55. New: @TailRecursive 19 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
56. New: @Sortable 20 import  groovy.transform.*   ! @Sortable   class  Person  {          String  lastName          String  firstName          int  age   }
57. New: @Sortable 20 import  groovy.transform.*   ! @Sortable   class  Person  {          String  lastName          String  firstName          int  age   } Makes the class Comparable by multiple Comparators
58. New: @Sortable 20 import  groovy.transform.*   ! @Sortable   class  Person  {          String  lastName          String  firstName          int  age   } First compare by lastName, then by firstName, etc.
59. New: @Sortable 20 import  groovy.transform.*   ! @Sortable   class  Person  {          String  lastName          String  firstName          int  age   } You can also specify ‘includes’ / ‘excludes’ properties
60. New: @Sortable 20 import  groovy.transform.*   ! @Sortable   class  Person  {          String  lastName          String  firstName          int  age   }
61. @BaseScript improvements 21 abstract  class  CustomBase  extends  Script  {          int  meaningOfLife  =  42   } @BaseScript(CustomBase)   import  groovy.transform.BaseScript   ! assert  meaningOfLife  ==  42
62. @BaseScript improvements 21 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
63. @BaseScript improvements 21 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
64. @BaseScript improvements 21 abstract  class  CustomBase  extends  Script  {          int  meaningOfLife  =  42   } @BaseScript(CustomBase)   import  groovy.transform.BaseScript   ! assert  meaningOfLife  ==  42 Ability to put the annotation on imports & package
65. @BaseScript improvements 21 abstract  class  CustomBase  extends  Script  {          int  meaningOfLife  =  42   } @BaseScript(CustomBase)   import  groovy.transform.BaseScript   ! assert  meaningOfLife  ==  42
66. @BaseScript custom abstract method 22 abstract  class  CustomBase  extends  Script  {      def  run()  {          before()          internalRun()          after()      }   !    abstract  internalRun()   !    def  before()  {  println  'before'  }      def  after()    {  println  'after'    }   }
67. @BaseScript custom abstract method 22 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'
68. @BaseScript custom abstract method 22 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
69. @BaseScript custom abstract method 22 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'
70. @glaforge — Groovy in 2014 and beyond NIO2 module
71. JDK 7+ NIO2 module • All the familiar methods on File 
 retrofitted on Path as well 24 path.withReader  {  Reader  r  -­‐>  ...  }   path.eachLine  {  String  line  -­‐>  ...  }   path.eachFileRecurse  {  Path  p  -­‐>  ...  }   path  <<  'some  content'   path  <<  bytes   path.readLines()   …
72. JDK 7+ NIO2 module • All the familiar methods on File 
 retrofitted on Path as well 24 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
73. JDK 7+ NIO2 module • All the familiar methods on File 
 retrofitted on Path as well 24 path.withReader  {  Reader  r  -­‐>  ...  }   path.eachLine  {  String  line  -­‐>  ...  }   path.eachFileRecurse  {  Path  p  -­‐>  ...  }   path  <<  'some  content'   path  <<  bytes   path.readLines()   …
74. @glaforge — Groovy in 2014 and beyond JSON
75. 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 26
76. 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 26
77. 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 26 Benchmark gives 3x to 4x performance factor 
 over Jackson and GSON
78. 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 26
79. New modes for parsing • Original JsonSlurper renamed to JsonSlurperClassic ! • Additional parsing modes: • INDEX_OVERLAY: super fast for <2MB payloads o using a « parsing overlay » technique • CHARACTER_SOURCE: for >2MB payloads o implemented with sliding windows over readers • LAX: beyond the JSON spec, nice for configuration files o support single quotes, / and # comments • CHAR_BUFFER: general purpose 27
80. JsonSlurper for configuration files 28 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
81. JsonSlurper for configuration files 28 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
82. JsonSlurper for configuration files 28 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
83. @glaforge — Groovy in 2014 and beyond Markup template engine </>
84. 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 30
85. 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 30 Spring Boot approved
86. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   }
87. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   } Your template
88. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   } model = [cars: [! new Car(make: 'Peugeot', name: '508'), ! new Car(make: 'Toyota', name: 'Prius’)! ]]
89. Markup template engine — the idea 31 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
90. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   } model = [cars: [! new Car(make: 'Peugeot', name: '508'), ! new Car(make: 'Toyota', name: 'Prius’)! ]] <cars>! <car make='Peugeot' name='508'/>! <car make='Toyota' name='Prius'/>! </cars>
91. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   } model = [cars: [! new Car(make: 'Peugeot', name: '508'), ! new Car(make: 'Toyota', name: 'Prius’)! ]] <cars>! <car make='Peugeot' name='508'/>! <car make='Toyota' name='Prius'/>! </cars> Generate the XML output
92. Markup template engine — the idea 31 cars  {        cars.each  {                car(make:  it.make,  name:  it.name)        }   } model = [cars: [! new Car(make: 'Peugeot', name: '508'), ! new Car(make: 'Toyota', name: 'Prius’)! ]] <cars>! <car make='Peugeot' name='508'/>! <car make='Toyota' name='Prius'/>! </cars>
93. Markup template engine — in action 32 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)
94. Markup template engine — includes 33 //  include  another  template   include  template:  'foo.tpl'           //  include  raw  content   include  unescaped:  'raw.txt'   ! //  escape  &  include   include  escaped:  'to_escape.txt'
95. Markup template engine — static! • Type-checked templates available • use createTypeCheckedModelTemplate() 
 instead of createTemplate() ! • Advantages • get compilation errors o if a variable is not available o if you make mistakes in the code snippets • even faster templates 34
96. Markup template engine — static! • With typed check model creation method ! ! ! ! ! ! ! ! ! • Or declare your model types in the template 35
97. Markup template engine — static! • With typed check model creation method ! ! ! ! ! ! ! ! ! • Or declare your model types in the template 35 def  modelTypes  =  [cars:  "List<Car>"]   ! def  tmpl  =  engine.      createTypeCheckedModelTemplate(
            "page.tpl",  modelTypes)
98. Markup template engine — static! • With typed check model creation method ! ! ! ! ! ! ! ! ! • Or declare your model types in the template 35 def  modelTypes  =  [cars:  "List<Car>"]   ! def  tmpl  =  engine.      createTypeCheckedModelTemplate(
            "page.tpl",  modelTypes) modelTypes  =  {          List<Car>  cars   }   ! cars.each  {  car  -­‐>          p("Car  name:  $car.name")   }
99. Markup template engine — static! • With typed check model creation method ! ! ! ! ! ! ! ! ! • Or declare your model types in the template 35 def  modelTypes  =  [cars:  "List<Car>"]   ! def  tmpl  =  engine.      createTypeCheckedModelTemplate(
            "page.tpl",  modelTypes) modelTypes  =  {          List<Car>  cars   }   ! cars.each  {  car  -­‐>          p("Car  name:  $car.name")   } Works with createTemplate() too
100. Markup template engine — static! • With typed check model creation method ! ! ! ! ! ! ! ! ! • Or declare your model types in the template 35 def  modelTypes  =  [cars:  "List<Car>"]   ! def  tmpl  =  engine.      createTypeCheckedModelTemplate(
            "page.tpl",  modelTypes) modelTypes  =  {          List<Car>  cars   }   ! cars.each  {  car  -­‐>          p("Car  name:  $car.name")   }
101. @glaforge — Groovy in 2014 and beyond Documentation overhaul
102. GroovyDoc 37
103. GroovyDoc 37
104. GroovyDoc 37
105. Groovy GDK documentation 38
106. Groovy GDK documentation 38
107. Brand new documentation 39
108. @glaforge — Groovy in 2014 and beyond Groovy 2.4
109. Beta groovy-lang.org website 41
110. Beta groovy-lang.org website 41
111. Beta groovy-lang.org website 41
112. Beta groovy-lang.org website 41 Notice the « improve this doc » button!
113. Android support • You can use Groovy to code Android apps! • use Groovy 2.4.0-beta-1+ • prefer @CompileStatic ! • Two great posts to get started: • http://melix.github.io/blog/2014/06/grooid.html • http://melix.github.io/blog/2014/06/grooid2.html 42
114. New York Times — Getting Groovy with Android • New York Times Getting Groovy with Reactive Android 43
115. New York Times — Getting Groovy with Android • New York Times Getting Groovy with Reactive Android 43 http://bit.ly/nyt-groovy
116. Android support 44
117. Android support 44 Source code available: https://github.com/melix/gr8confagenda
118. Groovy Macros ! • Sergei Egorov wants to contribute a macro module • https://github.com/groovy/groovy-core/pull/470 ! • Simplify creation of AST transformations • less boilerplate manipulating the Groovy AST API • more powerful and less limited than AstBuilder 45
119. Groovy Macros ! • Authoring AST transformations can be verbose: 46 def  someVariable  =  new  ConstantExpression("xyz")   def  returnStatement  =  new  ReturnStatement(          new  ConstructorCallExpression(                  ClassHelper.make(SomeCoolClass),                  new  ArgumentListExpression(someVariable)          )   )
120. Groovy Macros • With Groovy Macros, it could be simpler: 47 def  someVariable  =  macro  {  "xyz"  }   def  returnStatement  =  macro  {            new  SomeCoolClass($v{  someVariable  })     }
121. Groovy Macros • With Groovy Macros, it could be simpler: 47 def  someVariable  =  macro  {  "xyz"  }   def  returnStatement  =  macro  {            new  SomeCoolClass($v{  someVariable  })     } Special « macro » command
122. Groovy Macros • With Groovy Macros, it could be simpler: 47 def  someVariable  =  macro  {  "xyz"  }   def  returnStatement  =  macro  {            new  SomeCoolClass($v{  someVariable  })     } Special « macro » command Quasi-quotation
123. @glaforge — Groovy in 2014 and beyond Groovy 3.0
125. @glaforge — Groovy in 2014 and beyond New Age Meta-Object Protocol MOP 2
126. 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? 51
127. @glaforge — Groovy in 2014 and beyond Rewriting the Groovy grammar with Antlr v4 Antlr v4 Grammar
128. Antlr v4 grammar • Problems • Groovy still uses Antlr v2! o but version 3 and 4 are out • Groovy’s grammar evolved from a Java grammar o 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! 53
129. Antlr v4 grammar • Problems • Groovy still uses Antlr v2! o but version 3 and 4 are out • Groovy’s grammar evolved from a Java grammar o 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! 53 A « Google Summer of Code » student helped kick start it
130. @glaforge — Groovy in 2014 and beyond Support the new Java 8 language features Java 8 language support
131. 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 55
132. 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 55 Groovy had already: closures, method pointers, mixins, enriched collection & time APIs
133. @glaforge — Groovy in 2014 and beyond Summary
135. Groovy rocks the JVM 
 since 2003!
136. @glaforge — Groovy in 2014 and beyond Q & A
138. Image credits • Big rock • http://wallpaper.preview-reviews.com/12852-red-rocks-in-a-snowstorm • Android robot • http://crackberry.com/sites/crackberry.com/files/styles/large/public/topic_images/2013/ANDROID.png?itok=xhm7jaxS • Modern MOP • http://i933.photobucket.com/albums/ad179/autobin/Wonder%20Mop/wondermop4.jpg • Jason • http://static.comicvine.com/uploads/original/3/32405/1031312-jason_19_inch_figure_l.jpg • Jigsaw • http://www.psdgraphics.com/file/psd-jigsaw-icon.jpg • Many thanks • http://www.trys.ie/wp-content/uploads/2013/06/many-thanks.jpg 60