JVMLangSummit - User contributions [en]

What Kotlin Doesn’t Do and Why

2012-08-01T21:48:56Z

Abreslav:

While working on [http://kotlin.jetbrains.org Kotlin], we had to revise the list of initially planned features, because our experiments showed that in some cases the apparent benefits of this or that feature are not significant enough to outweight the implementation and/or interoperability issues.

In this workshop session we describe the features that we '''dropped''', and our motivation, aiming at provoking fruitful discussions on both feature values and optimal implementation strategies.

The list of Kotlin’s absent features includes:
* Uniform arrays
* Multiple inheritance
** State in traits
** Linearization
* Reified generics
** Type information at runtime
** Specialization
* Full pattern matching
** Tuples
** GADTs
* Multiple constructors

----

Useful links:
* [http://kotlin.jetbrains.org Kotlin docs]
* [http://kotlin-demo.jetbrains.com Kotlin Web Demo]

What Kotlin Doesn’t Do and Why

2012-08-01T21:48:18Z

Abreslav:

While working on [http://kotlin.jetbrains.org Kotlin], we had to revise the list of initially planned features, because our experiments showed that in some cases the apparent benefits of this or that feature are not significant enough to outweight the implementation and/or interoperability issues.

In this workshop session we describe the features that we '''dropped''', and our motivation, aiming at provoking fruitful discussions on both feature values and optimal implementation strategies.

The list of Kotlin’s absent features includes:
* Uniform arrays
* Multiple inheritance
** State in traits
** Linearization
* Reified generics
** Type information at runtime
** Specialization
* Full pattern matching
** Tuples
** GADTs

----

Useful links:
* [http://kotlin.jetbrains.org Kotlin docs]
* [http://kotlin-demo.jetbrains.com Kotlin Web Demo]

A Friend in Need Is a Friend Indeed: Kotlin and Java

2012-08-01T20:58:23Z

Abreslav:

[http://kotlin.jetbrains.org Kotlin] is a modern programming language compiled to JVM byte codes. The project is started by JetBrains and is distributed under the Apache 2 Open Source License.

'''Java interoperability''' is the '''top priority''' for Kotlin, because it is intended to be used in existing projects, where Java and Kotlin code will live side-by-side and frequently talk to each other.

In this session we describe the mechanisms of interaction between Kotlin and Java.

Section 1. '''Enhancing JDK APIs''' for use in Kotlin.

Adding new functions for JDK APIs is easy with Kotlin’s extension functions. A more difficult thing is seamless interoperability with JDK collections: Kotlin has to introduce declaration-site variance to java.util.* interfaces by virtually splitting each of them in two, and then do some compile-time conversions. No runtime overhead, no headache for the user.

Section 2. '''Null-safety''' from the interoperability point of view.

In a Java API, anything may be null, so using it from Kotlin becomes full of null-checks, many of which are pointless (according to the contracts described in the JavaDocs). Kotlin addresses this problem with a number of techniques that allow the user to communicate the knowledge about these contracts to the compiler.

Section 3. '''Packages and Traits'''.

Packages and Traits are two concepts in Kotlin that put the code where Java 7 doesn’t allow it:
into package-level functions and interface methods. To achieve this, Kotlin has to play tricks that appear to be not so straightforward because of binary compatibility issues and requirements of the debugger interface.

----

Resources:
* [[File:JVMLS_12_Ktloin_Java_Interop.pdf]]

Useful links:
* [http://kotlin.jetbrains.org Kotlin docs]
* [http://github.com/abreslav/introduction-to-kotlin Some examples]
* [http://kotlin-demo.jetbrains.com Kotlin Web Demo]

File:JVMLS 12 Ktloin Java Interop.pdf

2012-08-01T20:55:54Z

Abreslav: Slides

Slides

A Friend in Need Is a Friend Indeed: Kotlin and Java

2012-07-28T12:56:45Z

Abreslav:

[http://kotlin.jetbrains.org Kotlin] is a modern programming language compiled to JVM byte codes. The project is started by JetBrains and is distributed under the Apache 2 Open Source License.

'''Java interoperability''' is the '''top priority''' for Kotlin, because it is intended to be used in existing projects, where Java and Kotlin code will live side-by-side and frequently talk to each other.

In this session we describe the mechanisms of interaction between Kotlin and Java.

Section 1. '''Enhancing JDK APIs''' for use in Kotlin.

Adding new functions for JDK APIs is easy with Kotlin’s extension functions. A more difficult thing is seamless interoperability with JDK collections: Kotlin has to introduce declaration-site variance to java.util.* interfaces by virtually splitting each of them in two, and then do some compile-time conversions. No runtime overhead, no headache for the user.

Section 2. '''Null-safety''' from the interoperability point of view.

In a Java API, anything may be null, so using it from Kotlin becomes full of null-checks, many of which are pointless (according to the contracts described in the JavaDocs). Kotlin addresses this problem with a number of techniques that allow the user to communicate the knowledge about these contracts to the compiler.

Section 3. '''Packages and Traits'''.

Packages and Traits are two concepts in Kotlin that put the code where Java 7 doesn’t allow it:
into package-level functions and interface methods. To achieve this, Kotlin has to play tricks that appear to be not so straightforward because of binary compatibility issues and requirements of the debugger interface.

----

Useful links:
* [http://kotlin.jetbrains.org Kotlin docs]
* [http://github.com/abreslav/introduction-to-kotlin Some examples]
* [http://kotlin-demo.jetbrains.com Kotlin Web Demo]

What Kotlin Doesn’t Do and Why

2012-07-28T12:55:40Z

Abreslav: Created page with "While working on [http://kotlin.jetbrains.org Kotlin], we had to revise the list of initially planned features, because our experiments showed that in some cases the apparent ben..."

While working on [http://kotlin.jetbrains.org Kotlin], we had to revise the list of initially planned features, because our experiments showed that in some cases the apparent benefits of this or that feature are not significant enough to outweight the implementation and/or interoperability issues.

In this workshop session we describe the features that we '''dropped''', and our motivation, aiming at provoking fruitful discussions on both feature values and optimal implementation strategies.

The list of Kotlin’s absent features includes:
* Uniform arrays
* Multiple inheritance
** State in traits
** Linearization
* Reified generics
** Type information at runtime
** Specialization
* Full pattern matching
** Tuples
** GADTs
* GWT-compatible JavaScript-backend

----

Useful links:
* [http://kotlin.jetbrains.org Kotlin docs]
* [http://kotlin-demo.jetbrains.com Kotlin Web Demo]

A Friend in Need Is a Friend Indeed: Kotlin and Java

2012-07-28T12:50:58Z

Abreslav: Created page with "[http://kotlin.jetbrains.org Kotlin] is a modern programming language compiled to JVM byte codes. The project is started by JetBrains and is distributed under the Apache 2 Open S..."

Kotlin

2011-07-20T04:48:00Z

Abreslav: The Kotlin Programming Language

'''Title'''

The Kotlin Programming language

'''Speaker'''

Andrey Breslav

'''Resources'''

[http://jetbrains.com/kotlin Kotlin homepage]

'''Abstract'''

We present a new statically typed JVM-targeted programming language developed by JetBrains and intended for industrial use.

We’ve been developing for the Java platform for a long time, and we know how good it is. On the other hand, we know that the Java programming language has certain limitations and problems that are either impossible or very hard to fix due to backward-compatibility issues. We know that Java is going to stand long, but we believe that the community can benefit from a new statically typed JVM-targeted language free of the legacy trouble and having the features so desperately wanted by the developers.

The main design goals behind this project are
* to create a '''Java-compatible''' language,
* that '''compiles as fast as Java''',
* make it '''safer''' than Java, i.e. statically check for common pitfalls such as null pointer dereference,
* make it more '''concise''' than Java by supporting local type-inference, first-class functions (closures), extension functions, mixins and first-class delegation, etc;
* and, keeping the useful level of expressiveness (see above), make it '''way simpler''' than the most mature competitor -- Scala.

User talk:Abreslav

2011-07-20T04:45:21Z

Abreslav: The Kotlin Programming Language

Kotlin

2011-07-20T04:29:01Z

Abreslav: Removing all content from page

Kotlin

2011-07-20T04:28:29Z

Abreslav: New page: '''Speaker''' Andrey Breslav '''Resources''' http://jetbrains.com/kotlin

'''Speaker'''
Andrey Breslav
'''Resources'''
[[http://jetbrains.com/kotlin]]

2012 Main Page

2011-07-19T15:52:37Z

Abreslav: /* Agenda for the 2011 JVM Language Summit */

__NOTOC__
Welcome to the wiki for the 2011 JVM Language Summit, taking place July 18-20, 2011, at the Oracle Santa Clara Campus.

== Links ==

* [http://openjdk.java.net/projects/mlvm/jvmlangsummit JVM Language Summit] main page
* Email contacts: [mailto:brian.goetz-at-oracle.com Brian Goetz] and [mailto:john.r.rose-at-oracle.com John Rose]
* Archived wiki pages: [[2008_Main_Page | 2008]], [[2009_Main_Page | 2009]], [[2010_Main_Page | 2010]]
* [[Logistics]] page for travel tips and requests

== Agenda for the 2011 JVM Language Summit ==

{| border="1"
!
!Monday 7/18
!Tuesday 7/19
!Wednesday 7/20
|-
| 8:30|| align="center" colspan="3" style="background-color:lightpink;" | Breakfast (30 mins) 
|-
| 9:00|| Intro and Welcome || rowspan="2" | Mark Roos [[Porting Smalltalk]] || rowspan="2" | Tobias Ivarsson [[Interface injection]]
|-
| 9:20|| rowspan="2" | Cameron Purdy [[Keynote]]
|-
| 9:40|| rowspan="1" | Jim Laskey [[JavaScript]] || rowspan="1" | Brian Goetz [[Extension methods]]
|-
| 10:20|| align="center" colspan="3" style="background-color:lightpink;" | Break (20 mins) 
|-
| 10:40|| Mads Torgersen [[Async .NET]] || Shashank Bharadwaj [[invokedynamic+Jython]] || Cliff Click TBA
|-
| 11:20|| style="background-color:lightgreen;" | Mads Torgersen (TBA) || style="background-color:lightgreen;" | Ola Bini (Seph) Mark Roos || style="background-color:lightgreen;" | Tom Marble (Jigsaw+Clojure) Tobias Ivarsson
|-
| 12:20|| align="center" colspan="3" style="background-color:lightpink;" | Lunch (60 mins)  
|-
| 1:20|| John Rose [[Method Handles]] || Attila Szegedi [[Dynalink]] || Christine Flood [[Fortress 2011|Fortress]]
|-
| 2:00|| Dan Heidinga [[MethodHandle Impl]] || Georges Saab [[Java SE]] || Thomas Wuerthinger [[Graal]]
|-
| 2:40|| align="center" colspan="3" style="background-color:lightpink;" | Break (20 mins)
|-
| 3:00|| Charlie Nutter TBA || Carson Gross [[Gosu]] || Prashant Deva [[Debugger]]
|-
| 3:40|| Rémi Forax [[JSR-292 Cookbook]] || JetBrains [[Kotlin]] || TBA TBA
|-
| 4:20|| style="background-color:lightgreen;" | Jeroen Frijters (IKVM.NET) John Rose (TBA) || style="background-color:lightgreen;" | Venkat Subramaniam (Language Integration) JetBrains ([[Kotlin]]) || style="background-color:lightgreen;" | Prashant Deva Lukas Stadler ([[Graal]])
|-
| 5:20|| align="center" colspan="3" style="background-color:lightyellow;" |
|-
| 6:00|| || align="center" style="background-color:lightpink;" | Dinner at Faultline ||
|}

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