Post on 29-Nov-2014
description
Copyright © 2014 Russel Winder 1
Java is DeadLong Live Scala, Kotlin, Ceylon,
etc.
Russel Winder
email: russel@winder.org.ukxmpp: russel@winder.org.uk
twitter: @russel_winderWeb: http://www.russel.org.uk
Copyright © 2014 Russel Winder 2
Java is Dead
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Java is Dying
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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.
● …
Copyright © 2014 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 actually been doing this for a while.)
● Have a reasonable module system, cf. Jigsaw vs. OSGi.
● Be a real object-oriented language.
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Prognosis: not great
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Alternatives?
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Create a new language
● Java is a statically typed, compiled language, so create a new statically typed compiled language:
● Scala
● Kotlin
● Ceylon
● Fantom
● ?
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Gross oversimplifications…
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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.
Copyright © 2014 Russel Winder 11
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.
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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.
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Fantom
● Top-level functions.
● Object-oriented.
● Integrated modules system via pods.
● Targets JVM and CLR.
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?
The identity of this statically typed, object-oriented (with functional bits) language for the JVM will remain unnamed at this time to preserve the air of mystery and suspense.
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Code!
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What is the value of ?
Easy, it's known exactly.
It's .
Obviously.
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It's simples Александр Орлов 2009
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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.
4=∫0
1 1
1x2dx
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One possible algorithm
● Use quadrature to estimate the value of the integral which is the area under the curve.–
=4n∑i=1
n 1
1i−0.5n
2
With n = 3 not much to do, but potentially lots of error. Use n = 107 or n = 109?
Embarrassingly parallel.
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Because addition is commutative andassociative, expression can be
decomposed into sums of partial sums.
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a + b + c + d + e + f
=
( a + b ) + ( c + d ) + ( e + f )
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Scatter Gather—
map reduce
data parallel
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Code!
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ScalaKotlinCeylonFantom
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?
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Surprise time…
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JVM is a Groovy place
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Groovy
● Top-level functions
● Object-oriented with functional features.
● Extension methods.
● Compiles to JVM bytes codes or JavaScript (cf. GrooScript)
● A dynamic language with a run time meta-object protocol.
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Groovy
A statically typed,compiled language.
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@TypeChecked
@CompileStatic
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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.
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Code!
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Code!
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Did I mention invokedynamic?
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Code!
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Java is Dead!
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Groovy(or Scala, Kotlin, Ceylon, Fantom, )…is the future of static languages
on the JVM.
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2014-03-18
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Java 8Released
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Java 8 is the biggest revolution in Java since 1994.
Bigger than Java 5.
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Has Java revived?
Is this a new lease of life?
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What's Interesting in Java 8?
● G1 garbage collector.
● Nashorn.
● JavaFX.
● Lambda expressions.
● Default methods in interfaces (traits).
● Enhanced collections.
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G1 garbage collector is now the standard: no more PermGen.
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Nashorn comes as standard:Server-side JavaScript without Rhino.
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JavaFX in the distribution:you will want to use GroovyFX though.
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Lambda expressions,default methods in interfaces,
associated collections enhancements.
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Code!
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Copyright © 2014 Russel Winder 54
Code!
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Java is DeadLong Live Scala, Kotlin, Ceylon,
etc.
Russel Winder
email: russel@winder.org.ukxmpp: russel@winder.org.uk
twitter: @russel_winderWeb: http://www.russel.org.uk
Copyright © 2014 Russel Winder 56
Java is DeadLong Live Java
Russel Winder
email: russel@winder.org.ukxmpp: russel@winder.org.uk
twitter: @russel_winderWeb: http://www.russel.org.uk
Copyright © 2014 Russel Winder 57
Java is DeadLong Live Groovy
Russel Winder
email: russel@winder.org.ukxmpp: russel@winder.org.uk
twitter: @russel_winderWeb: http://www.russel.org.uk