Dotty & Scala: Status report

Dmitry Petrashko

About me:

https://github.com/darkdimius/
doing PhD at EPFL
previously worked on ScalaBlitz (up to 24x faster collections)
since March 2014 building on Dotty under supervision of Martin.
since March 2015 working on Dotty Linker and supervising students working on Dotty.

Dotty contributor stats:

git ls-tree -r -z --name-only HEAD -- | egrep -z -Z -E '\.(scala)$'\
| xargs -0 -n1 git blame --line-porcelain | grep "^author "| sort | uniq -c | sort -nr

author	commits	additions	deletions	blame lines
Martin Odersky	2,280	146,133	85,391	66,698
Dmitry Petrashko	628	158,249	50,201	83,713
Samuel Gruetter	19	62,324	12,510	36,615
Ondrej Lhotak	29	2,009	340	1,874
Guillaume Martres	77	2,197	1,190	1,171
Vera Salvisberg	17	1,109	364	819
Jason Zaugg	16	213	149	153
Alexander Myltsev	5	275	65	144
Vlad Ureche	13	255	77	51

Past of Scala

How old are those languages?

Java: 1990;
Python: 1991;
Ruby: 1995;
Pizza: 2001;
Lisp: 1958;
Scheme: 1975;
Haskell: 1990;
Scala: 2004;

History of Scala

Funnel, Pizza
Generic Java
Scala 1.0, Scala 2.0-2.7, Scala 2.8

Scala Today

I can honestly say if someone had shown me the Programming Scala book by by Martin Odersky, Lex Spoon & Bill Venners back in 2003 I'd probably have never created Groovy.

— James Strachan (Creator of Groovy language)

Red Monk language rankings

StackOverflow survey: salaries

StackOverflow survey: enjoyment

Scalac today

Stability, stability and more stability.
Long lifetime of releases.

Future of Scala.

DOT today

Developed by Amin, Grutter, Stucki, Rompf and Odersky
A minimal, core calculus for scala.
Proven sound.
Has structural subtyping but can encode Nominal subtyping.
Long term foundation for Dotty.

Dotty today

a third compiler for Scala language.
simpler design, more fundamental approach.
more predictable behavior and easier to evolve.
foundation for future Scala.

Dotty ecosystem:

Libraries: Modularization
TASTY: Solving binary compatibility.
Link time optimization: -lto
Meta: basis for tooling and metaprograming
Backends: JVM, JS.
Simpler collections?

Unrelated picture. Please ignore

Dotty status:

Opensource: https://github.com/lampepfl/dotty
Recently bootstrapped itself
Currently compiled stdlib
Runs faster
Not ready for production use yet

Who's behind all this?

EPFL: LAMP

Research.
Projects: Miniboxing, macros, pickling, Dotty.

EPFL: LARA

Automated Reasoning and Analysis.
Validation and gerenation of Scala code.
Projects: Leon.

Typesafe Lightbend

Founded in 2011.
Projects: Akka. Play. Slick. Sbt.
Enterprise + stability

Typelevel

Founded in 2014.
Projects: Shapeless. Cats. Spire.
Different vision of what Scala should be.