Welcome to the Eighth ACM SIGPLAN Symposium on Scala, 2017! Scala is a general purpose programming language designed to express common programming patterns in a concise, elegant, and type-safe way. It smoothly integrates features of object-oriented and functional languages. The Scala Symposium is the leading forum for researchers and practitioners related to the Scala programming language. We welcome a broad spectrum of research topics and support many submission formats for industry and academia alike. This year’s Scala Symposium is co-located with Splash 2017. Follow @scala_symposium on Twitter for updates. This year we are using Slack to support easy collaboration, discussion and exchange with other participants as well as faciliate the organisation of social events around the Symposium. We invite all participants to register on the Symposium’s Slack instance. Keynote Speakers We are delighted to have two excellent keynote speakers this year: Reynold Xin (Databricks), about Spark and Scala.

Dwayne Reeves (Facebook), about The Hack Programming Language Reynold Xin Reynold Xin is a co-founder and Chief Architect at Databricks. At Databricks, he led the development of Apache Spark and was behind many of the recent efforts, e.g.: DataFrame: a high level DSL in Scala/Java/Python/R for working with big data

Project Tungsten: a new execution engine to achieve 10X to 100X performance using code generation Prior to Databricks, he was pursuing PhD research at the UC Berkeley AMPLab, where he worked on large-scale data processing. Dwayne Reeves Dwayne Reeves is an engineering manager at Facebook, specializing in software design, static analysis and programming languages. In his nearly 6 year career, Dwayne has contributed to and led several initiatives that improved the efficiency and correctness of code at Facebook. He is currently a technical lead manager on the Hack Programming Language team, developing new features and setting the future direction of the language. Dwayne holds a Bachelor’s of Science and a Master’s of Engineering in Computer Science and Engineering from MIT. We are very thankful for the sponsoring of our great partners! Sponsorship money covers registration fees for talented students that have been selected to present Scala projects. Want to help? We are still seeking sponsors to support more young academics. Contact us if you’re interested in sponsoring the future of Scala! Find more information in our call for sponsorship. Student support If you’re a student with an accepted Student Talks, you’re eligible for a grant from us to support attendance (donated by our sponsors), as described in the call for papers. Since the Scala Symposium is sponsored by SIGPLAN, if you’re a student who coauthors a paper accepted for the proceedings (not just a talk), you are typically eligible for a grant from SIGPLAN PAC (if your advisor is a SIGPLAN member). For details, see http://www.sigplan.org/PAC/.

Call for Papers We seek submissions on all topics related to Scala, including (but not limited to): Language design and implementation – language extensions, optimization, and performance evaluation.

Library design and implementation patterns for extending Scala – stand-alone Scala libraries, embedded domain-specific languages, combining language features, generic and meta-programming.

Formal techniques for Scala-like programs – formalizations of the language, type system, and semantics, formalizing proposed language extensions and variants, dependent object types, type and effect systems.

Concurrent and distributed programming – libraries, frameworks, language extensions, programming models, performance evaluation, experimental results.

Big data and machine learning libraries and applications using the Scala programming language.

Safety and reliability – pluggable type systems, contracts, static analysis and verification, runtime monitoring.

Interoperability with other languages and runtimes, such as JavaScript, Java 8 (lambdas), Graal and others.

Tools – development environments, debuggers, refactoring tools, testing frameworks.

Case studies, experience reports, and pearls. No abstract registration

Paper submission deadline extended to : July 20th, 2017

: July 20th, 2017 Paper notification: Aug 20th, 2017

Student talk submission: Aug 30th, 2017

Camera ready: Sep 11th, 2017

Student talk notification: Sep 17th, 2017 All deadlines are at the end of the day, “Anywhere on Earth” (AoE). Submission Format To accommodate the needs of researchers and practitioners, as well as beginners and experts alike, we seek several kinds of submissions, all in acmart/sigplan style, 10pt font. Full papers (at most 10 pages, excluding bibliography)

(at most 10 pages, excluding bibliography) Short papers (at most 4 pages, excluding bibliography)

(at most 4 pages, excluding bibliography) Tool papers (at most 4 pages, excluding bibliography)

(at most 4 pages, excluding bibliography) Student talks (short abstract only, in plain text) Accepted papers (either full papers, short ones or tool papers, but not student talks) will be published in the ACM Digital Library. Detailed information for each kind of submission is given below. Formatting requirements are detailed in Instructions for Authors. Please note that at least one author of each accepted contribution must attend the symposium and present the work. In the case of tool demonstration papers, a live demonstration of the described tool is expected. Full and Short Papers Full and short papers should describe novel ideas, experimental results, or projects related to the Scala language. In order to encourage lively discussion, submitted papers may describe work in progress. Additionally, short papers may present problems and raise research questions interesting for the Scala language community. All papers will be judged on a combination of correctness, significance, novelty, clarity, and interest to the community. In general, papers should explain their original contributions, identifying what has been accomplished, explaining why it is significant, and relating it to previous work (also for other languages where appropriate). Tool Papers Tool papers need not necessarily report original research results; they may describe a tool of interest, report practical experience that will be useful to others, new Scala idioms, or programming pearls. In all cases, such a paper must make a contribution which is of interest to the Scala community, or from which other members of the Scala community can benefit. Where appropriate, authors are encouraged to include a link to the tool’s website. For inspiration, you might consider advice in https://conf.researchr.org/track/POPL-2016/pepm-2016-main#Tool-Paper-Advice, which we however treat as non-binding. In case of doubts, please contact the program chairs. Student Talks In addition to regular papers and tool demos, we also solicit short student talks by bachelor/master/PhD students. A student talk is not accompanied by paper (it is sufficient to submit a short abstract of the talk in plain text). Student talks are about 5-10 minutes long, presenting ongoing or completed research related to Scala. In previous years, each student with an accepted student talk received a grant (donated by our sponsors) covering registration and/or travel costs. Open Source Talks We will also accept a limited number of short talks about open-source projects using Scala presented by contributors. An open-source talk is not accompanied by a paper (it is sufficient to submit a short abstract of the talk in plain text). Open-source talks are about ~10 minutes long and about topics of relevance to the symposium, for instance (but not only) presenting or announcing an open-source project that would be of interest to the Scala community. Submission Website The submission will be managed through HotCRP: https://scala17.hotcrp.com/ For questions and additional clarifications, please contact the conference organizers. Printable version A short, printable version for distribution via notice boards is available as letter size PDF.

Instructions for Authors Submissions should use the ACM acmart template, sigplan subformat, 10 point font, and author-year citation style. The resulting style is similar but not identical to the one used in previous editions. All submissions should be in PDF format. LaTeX and Word templates are available from SIGPLAN resources. For authors using LaTeX, the appropriate template for Scala’17 authors is in the file acmart-sigplanproc-template.tex . As documented in the template, submissions should be prepared using the sigplan and 10pt options and, for authors using double-blind submissions, the anonymous option. The use of the review option is also strongly encouraged but not required (The review option will add line numbers, which will make it easier for reviewers to reference specific parts of your paper in their comments, but should have absolutely no other effect on the typesetting). Details of available technical support for LaTeX-specific questions is available at http://www.acm.org/publications/proceedings-template#h-technical-support. To enable author-year citation style, authors should enable the LaTeX command \citestyle{acmauthoryear} in the provided template. Otherwise, for correct use of author-year citation style please consult advice on citations in OOPSLA’17 instructions for authors. Page Limits Full papers (at most 10 pages, excluding bibliography)

(at most 10 pages, excluding bibliography) Short papers (at most 4 pages, excluding bibliography)

(at most 4 pages, excluding bibliography) Tool papers (at most 4 pages, excluding bibliography)

(at most 4 pages, excluding bibliography) Student talks (short abstract only, in plain text) Concurrent Submissions Papers must describe unpublished work that is not currently submitted for publication elsewhere as described by SIGPLAN’s Republication Policy. Submitters should also be aware of ACM’s Policy and Procedures on Plagiarism. AUTHORS TAKE NOTE: The official publication date is the date the proceedings are made available in the ACM Digital Library. This date may be up to two weeks prior to the first day of the conference. The official publication date affects the deadline for any patent filings related to published work. Single- or Double-blind submissions Scala’17 is a single-blind conference, but offers to authors the option of a double-blind submission. This can be useful, for instance, for anybody submitting distinct but related work concurrently to a double-blind conference. If you decide to do a double-blind submission, please tick the box “Anonymous submission” in the HotCRP submission form.

Attending The Scala Symposium 2017 is co-located with the SPLASH 2017 umbrella event. Together with the other events the symposium will take place at: Hyatt Regency Vancouver

655 Burrard Street

V6C 2R7

Vancouver

Canada For updated details on location and registration, please also refer to the SPLASH website. Registration Fees Due to the co-location with SPLASH, corresponding registration fees of SPLASH apply. If you just want to visit the Scala Symposium the fees will be (updated): Early Bird Registation Standard Registration (also Onsite) (prices in USD) ACM or SIG Non- mem Student ACM|SIG Student Non-mem ACM or SIG Non- mem Student ACM|SIG Student Non-mem 2 days event (Symposium Only) $370 $420 $185 $205 $440 $500 $225 $260

Early bird registration is until Friday 22 September. The registration form allows joining SIGPLAN (for 25$, or 15$ for students) and using the discount right away. Registration for Scala’17 is performed through SPLASH through the following link. Authors of student talk who receive travel support should contact Paolo Giarrusso for registration instructions.