Java is Dead, Long Live Ceylon, Kotlin, etc.

Slides from my DevoxxUK 2015 presentation. Compare and contrast of JVM-based strongly-typed, statically compiled languages: Java, Ceylon, Kotlin, Scala, Frege, Groovy.

Code is on GitHub: https://github.com/russel/Pi_Quadrature

Transcript

1. Copyright © 2015 Russel Winder 1 Java is Dead Long Live Ceylon, Kotlin, etc. Dr Russel Winder email: russel@winder.org.uk twitter: @russel_winder Web: http://www.russel.org.uk
2. Copyright © 2015 Russel Winder 2 Java is Dead
3. Copyright © 2015 Russel Winder 3 Java is Dying
4. Copyright © 2015 Russel Winder 4 What are the symptoms? • Java is seriously verbose. • Java has poor type inference. • Java has only low-level support for concurrency and parallelism. • Java generates a dependency hell . “ ” • Java is a 1990s imperative language that isn't really object-oriented. • …
5. Copyright © 2015 Russel Winder 5 Is there a cure? • Can Java: • Be less verbose. • Have better type inferencing. • Do concurrency and parallelism better. (Doug Lea, Brian Goetz and others have been doing great work on this for a while, but ) … • Have a reasonable module system, cf. Jigsaw vs. OSGi. • Be a real object-oriented language.
6. Copyright © 2015 Russel Winder 6 Prognosis: not great
7. Copyright © 2015 Russel Winder 7 Trust me I'm a doctor.
8. Copyright © 2015 Russel Winder 8 Alternatives?
9. Copyright © 2015 Russel Winder 9 Create a new language • Java is a statically typed, compiled language, so create a new statically typed compiled language: • Kotlin, Ceylon • Scala, Frege • Fantom • Gosu • ?
10. Copyright © 2015 Russel Winder 10 Gross oversimplifications…
11. Copyright © 2015 Russel Winder 11 Scala • Integrates functional and object-oriented. • Very declarative style of expression. • Strong support for data parallelism. Also Akka for actors and such-like. • Strong static type checking with inferencing and reified generic type parameters.
12. Copyright © 2015 Russel Winder 12 Kotlin • Top-level functions. • Object-oriented, with functional elements • Strong static type checking with inferencing. • Has modules. • Allows extension methods. • Compiles to JavaScript or JVM to support end- to-end Web applications development. • Runs on Android.
13. Copyright © 2015 Russel Winder 13 Ceylon • Top-level functions. • Object oriented with functional features. • Strong static typing with inference. • Explicit module system. • JavaScript and JVM backends so as to be end-to-end for Web applications development.
14. Copyright © 2015 Russel Winder 14 Frege • Pure functional language based on Haskell. • Completely declarative. • Strong static type checking.
15. Copyright © 2015 Russel Winder 15 Fantom • Top-level functions. • Object-oriented. • Integrated modules system via pods. • Targets JVM and CLR.
16. Copyright © 2015 Russel Winder 16 Gosu • Top-level functions. • Object-oriented. • Scripts.
17. Copyright © 2015 Russel Winder 17 ? The identity of this statically typed, object-oriented (with functional bits) language for the JVM will remain unnamed at this time to preserve an air of mystery and suspense.
18. Copyright © 2015 Russel Winder 18
19. Copyright © 2015 Russel Winder 19 Code!
20. Copyright © 2015 Russel Winder 20
21. Copyright © 2015 Russel Winder 21 
22. Copyright © 2015 Russel Winder 22
23. Copyright © 2015 Russel Winder 23 What is the value of ?
24. Copyright © 2015 Russel Winder 24 Well that's easy, it's…
25. Copyright © 2015 Russel Winder 25 
26. Copyright © 2015 Russel Winder 26 Exactly.
27. Copyright © 2015 Russel Winder 27 It's simples. Александр Орлов 2009
28. Copyright © 2015 Russel Winder 28 But is it irrational?
29. Copyright © 2015 Russel Winder 29 Approximating  • What is it's value represented as a floating point number? • We can only obtain an approximation. • A plethora of possible algorithms to choose from, a popular one is to employ the following integral equation. π 4 =∫ 0 1 1 1+x2 dx
30. Copyright © 2015 Russel Winder 30 One possible algorithm • Use quadrature to estimate the value of the integral which is the area under the curve. – π= 4 n ∑ i=1 n 1 1+( i−0.5 n ) 2 With n = 3 not much to do, but potentially lots of error. Use n = 107 or n = 109? Embarrassingly parallel.
31. Copyright © 2015 Russel Winder 31 Code!
32. Copyright © 2015 Russel Winder 32 Java Ceylon Kotlin Scala Frege
33. Copyright © 2015 Russel Winder 33 Because addition is commutative and associative, expression can be decomposed into sums of partial sums.
34. Copyright © 2015 Russel Winder 34 a + b + c + d + e + f = ( a + b ) + ( c + d ) + ( e + f )
35. Copyright © 2015 Russel Winder 35 Scatter Gather — map reduce data parallel
36. Copyright © 2015 Russel Winder 36 Code!
37. Copyright © 2015 Russel Winder 37 Java Ceylon Kotlin Scala
38. Copyright © 2015 Russel Winder 38 ?
39. Copyright © 2015 Russel Winder 39 Surprise time…
40. Copyright © 2015 Russel Winder 40 JVM is a Groovy place
41. Copyright © 2015 Russel Winder 41 Groovy • Top-level functions. • Object-oriented with functional features. • Extension methods. • Compiles to JVM bytes codes or JavaScript, cf. GrooScript. • Runs on Android. • Scripts. • A dynamic language with a run time meta-object protocol.
42. Copyright © 2015 Russel Winder 42 Groovy A statically typed, compiled language.
43. Copyright © 2015 Russel Winder 43 @TypeChecked @CompileStatic
44. Copyright © 2015 Russel Winder 44 Groovy • @TypeChecked: • Traditional dynamic Groovy but with full static (compile-time) type checking. • @CompileStatic: • Full static typechecked, compilation to bytecode at compile time. • No dynamic meta- object protocol.
45. Copyright © 2015 Russel Winder 45 Code!
46. Copyright © 2015 Russel Winder 46
47. Copyright © 2015 Russel Winder 47 Code!
48. Copyright © 2015 Russel Winder 48 Java is not the future programming language for the Java Platform.
49. Copyright © 2015 Russel Winder 49 Kotlin, Ceylon, Groovy, Scala, Frege, … are the future of static languages on the Java Platform.
50. Copyright © 2015 Russel Winder 50 2014-03-18
51. Copyright © 2015 Russel Winder 51 Java 8 Released
52. Copyright © 2015 Russel Winder 52 Java 8 has been the biggest revolution in Java since 1994. Bigger than Java 5.
53. Copyright © 2015 Russel Winder 53 Has Java revived? Is this a new lease of life?
54. Copyright © 2015 Russel Winder 54 What's Interesting in Java 8? • G1 garbage collector. • Nashorn. • JavaFX. • Lambda expressions. • Default methods in interfaces (traits). • Enhanced collections. • Method references.
55. Copyright © 2015 Russel Winder 55 G1 garbage collector is now the standard: no more PermGen.
56. Copyright © 2015 Russel Winder 56 Nashorn comes as standard: Server-side JavaScript without Rhino.
57. Copyright © 2015 Russel Winder 57 JavaFX in the distribution: you will want to use GroovyFX though. Use Griffon
58. Copyright © 2015 Russel Winder 58 Lambda expressions, method references default methods in interfaces, associated collections enhancements.
59. Copyright © 2015 Russel Winder 59 Code!
60. Copyright © 2015 Russel Winder 60 Java is Dead Long Live Kotlin, Ceylon, etc. Russel Winder email: russel@winder.org.uk twitter: @russel_winder Web: http://www.russel.org.uk
61. Copyright © 2015 Russel Winder 61 Java is Dead Long Live Java Russel Winder email: russel@winder.org.uk twitter: @russel_winder Web: http://www.russel.org.uk
62. Copyright © 2015 Russel Winder 62 Java is Dead Long Live Groovy Russel Winder email: russel@winder.org.uk twitter: @russel_winder Web: http://www.russel.org.uk
63. Copyright © 2015 Russel Winder 63 Java is Dead Long Live Kotlin, Ceylon, etc. Russel Winder email: russel@winder.org.uk twitter: @russel_winder Web: http://www.russel.org.uk