- Haskell-Cafe - Haskell.org

Looking for maintainers or comaintainers on my Haskell projects
by Christopher Done 28 Apr '17

28 Apr '17

Hi all, The short version is: I’ve been battling RSI in my fingers for some years. I’m doing various things to mitigate that problem, but I have very limited finger bandwidth these days; enough to work at my usual pace at my job, but not much in the evenings and weekends, and so I can’t manage to do much on my hobby projects. I’m also not as motivated these days to work on my set of open source projects, and am turning my attention to different things. It’s not great, but that’s life. I don’t think that the users of my packages are getting the best maintainership deal. Rather than be “the absentee maintainer”, I’d prefer a straight-forward transition of maintainership or ownership to someone who can put the right energy and time in. In terms of packages, there are really two that have a significant maintenance burden and users aren’t being served very well: - HIndent <https://github.com/chrisdone/hindent> has a significant amount of issues opened for it regularly, and many of them require discussion and debate. If someone would like to become a co-maintainer, let me know. It may (eventually) make sense to move it to a more general GitHub organization like commercialhaskell or haskell. - Intero <https://github.com/commercialhaskell/intero/issues>, which seems to have been a success, has a pretty big maintenance burden on “this doesn’t work” kind of issues which require investigation. There’s some Emacs Lisp work to do on it, and some Haskell work on the intero binary, and a whole lot of platform-specific problems or tooling not working together. On the other hand people really like this project, and there’s a lot of tooling potential. If you want to take xeno <https://github.com/chrisdone/xeno> and make it into a publishable package, please do so. The rest of my projects that are on Stackage are: labels <https://hackage.haskell.org/package/labels>, ace <https://hackage.haskell.org/package/ace>, ical <https://hackage.haskell.org/package/ical>, check-email <https://hackage.haskell.org/package/check-email>, freenect <https://hackage.haskell.org/package/freenect>, frisby <https://hackage.haskell.org/package/frisby>, gd <https://hackage.haskell.org/package/gd>, ini <https://hackage.haskell.org/package/ini>, lucid <https://hackage.haskell.org/package/lucid>, osdkeys <https://hackage.haskell.org/package/osdkeys>, pdfinfo <https://hackage.haskell.org/package/pdfinfo>, present <https://hackage.haskell.org/package/present>, pure-io <https://hackage.haskell.org/package/pure-io>, scrobble <https://hackage.haskell.org/package/scrobble>, shell-conduit <https://hackage.haskell.org/package/shell-conduit>, sourcemap <https://hackage.haskell.org/package/sourcemap>, descriptive <https://hackage.haskell.org/package/descriptive>, wrap <https://hackage.haskell.org/package/wrap>, path <https://hackage.haskell.org/package/path>, weigh <https://hackage.haskell.org/package/weigh>, haskell-docs <https://hackage.haskell.org/package/haskell-docs>, and structured-haskell-mode <https://hackage.haskell.org/package/structured-haskell-mode>. If you’re interested in taking over or co-maintaining any of them, let me know. Some are interesting, others are boring, some are trivial. I have other packages on Hackage, but they’re mostly dead or experiments that don’t need maintenance anyway. I’ve started the process of adding or changing maintainers on my public services: - Haskell News <https://github.com/haskellnews> is now a GitHub organization. Luke Murphy is a co-owner, and has full access to the DigitalOcean account that is running the service. So if you want to work on that project, I’m not in the way. - lpaste <https://github.com/lpaste/lpaste> has been moved to its own DigitalOcean account too. If anyone is interested in taking over the project or co-running it, let me know. - tryhaskell <https://github.com/chrisdone/tryhaskell> doesn’t really require any maintenance, but it’s also on its own DigitalOcean account now too. - IRCBrowse <https://github.com/chrisdone/ircbrowse> is now on its own DigitalOcean account too. It requires maintenance once in a while. If anyone is interested in taking over the project or co-running it, let me know. Cheers!

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Re: [Haskell-cafe] Partial type family application
by Oleg 27 Apr '17

27 Apr '17

If the goal is to write higher-order type families, we can do that already -- and were able to do for a long time. For example, please see http://okmij.org/ftp/Haskell/TTypeable/TTypeable.hs that was written in 2012 for http://okmij.org/ftp/Haskell/typeEQ.html It shows the type-level function that checks for a membership in a type-level using the equality function supplied by a user as the first argument. Incidentally, here is the definition type instance Member f x NIL = HFalse type instance Member f x (h :/ t) = ORELSE (Apply f (x,h)) (CLOS AC_Member (f,x,t)) It was written before the modern syntax for type-level lists and booleans. This is an example of the general technique of defunctionalization.

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[JOB] Summer contracting opportunity for CodeWorld
by Chris Smith 27 Apr '17

27 Apr '17

Hello, Haskellers. I'm happy to announce a summer contracting opportunity helping to create documentation and educational materials for the CodeWorld project. CodeWorld (https://code.world) is a platform (and soon, a curriculum) for teaching mathematics via Haskell programming to children at the U.S. middle school level (ages 11-14). For more information about the CodeWorld project and its motivations, I can refer you to my recent BayHac presentation at https://youtu.be/7CGuI9HcfqQ Start: Early June End: Mid-August (but flexible) Full-time commitment Anticipated compensation: US$1500 / week Working remotely is expected, with the possibility of one week of required travel. As part of this position, you will work closely as a team with two other full-time writers to create detailed educational materials for use with the CodeWorld platform. You will be the team's expert on computer programming and the Haskell programming language. Other team members have expertise in mathematics education, and general and special needs education. The team's over-arching goal will be to produce objectives, instructional video scripts, visual aids, reference documentation (online and offline), pencil-and-paper activities, classroom activity planning, assessments, and any other resources necessary to support the success of this curriculum as a year-long class in schools. You should expect a typical day to include writing, editing and reviewing the content of others, planning objectives and content sequence, brainstorming activities and resources to help with content units, and some debate and consensus-building with the team on important design decisions. All artifacts produced during the job will be released under open source and/or Creative Commons licenses, suitable for use without charge by schools and organizations around the world. Qualifications: - Strong knowledge of Haskell programming language fundamentals. - Excellent writing and communication skills (in English), and in particular, an ability to explain technical ideas to an audience of beginners in a compelling way. - A mathematics and/or education background would be beneficial, but is not required. For this position, you will be a contractor for the New York Haskell User Group. Resumes can be sent to cdsmith(a)gmail.com.

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complex multiplication function in Haskell
by Mahmoud Murad 27 Apr '17

27 Apr '17

Hi there, The number 354162 has 6 digits and contains all digits from 1 to 6, and it can be considered as a multiplication of 3 * 54 = 162. so what I need is a function that will take all the real number and return the number that can be split as above, 354162 .. 3 * 54 = 162 I have no idea how to do such a thing! any help!

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Getting ready for Summer of Haskell 2017
by Niki Vazou 26 Apr '17

26 Apr '17

We are happy to announce that Summer of Haskell 2017 will host at least 8 students, funded from the Haskell community and corporate sponsors. You can find all information (including the timeline) at the Summer of Haskell new webpage: https://summer.haskell.org/ Students can submit applications from April 25th until the May 6th. We recommend that interested students start thinking about their proposals and brainstorm with potential mentors. In case you would like to participate as a student, but you have no idea what to work on, we have a page dedicated to ideas here: https://summer.haskell.org/ideas.html Teachers of FP courses at universities around the world are strongly encouraged to share this announcement with their students. Mentors, as well as everyone from the community, are encouraged to contribute ideas by sending pull requests to the Summer of Haskell repository (or contacting us): https://github.com/haskell-org/summer-of-haskell Sponsors are still welcome, as we can add more slots if the necessary funds become available. Combining our current individual donations with partial sponsors, we only need $2000 more to fund an additional student. Please consider making a small donation towards that goal. If you would like to contribute do not hesitate to contact us or donate directly: https://wiki.haskell.org/Donate_to_Haskell.org We’d like to thank our current sponsors for making this Summer of Haskell possible: haskell.org kicked things off this year by funding a student and organizing the Summer of Haskell 2017 after a successful Summer of Haskell 2016 <https://mail.haskell.org/pipermail/haskell-cafe/2016-December/125702.html>. Asahi Net <http://asahinet.com/> is a Japanese Internet service provider that has been running stable systems for over 25 years. They are a proud sponsor of the Summer of Haskell, and contribute to the Japanese Haskell community. Awake Networks <http://www.awakenetworks.com/> is building a next generation network security and analytics platform. They are a proud sponsor of the Summer of Haskell and contribute broadly to the Haskell community. CodeWorld <http://code.world/> is an educational project that blends mathematics and Haskell programming into a visual playground. Chris Smith has volunteered to fund two students to work on CodeWorld in particular. Facebook <http://facebook.com/> uses Haskell in its anti-abuse infrastructure <https://code.facebook.com/posts/745068642270222/fighting-spam-with-haskell/>, and as part of that effort we open-sourced the Haxl <https://github.com/facebook/Haxl> framework which is being used at scale in production to automatically parallelise data-fetching code. We're delighted to be able to support the Haskell community's efforts by sponsoring a student for this year's Summer of Haskell. Fugue Inc. <http://fugue.co/> radically simplifies cloud operations with its software-defined system for dynamically orchestrating and enforcing cloud infrastructure at scale. Fugue uses Haskell in its product and is proud to sponsor a student to improve the ecosystem. Galois <http://galois.com/> applies cutting-edge computer science and applied mathematics to solve difficult technological problems, delivering practical solutions tailored to our clients’ needs. Haskell and other functional programming languages are key tools we use in providing these solutions. Tweag I/O <http://tweag.io/> is a network of software innovation labs across Europe. We develop novel solutions and products for our clients around the world. Haskell is key to delivering fast, correct and maintainable code. We have shipped Haskell in anything from tiny web services to large high-performance compute clusters with custom hardware. We're particularly keen to help the community grow Haskell into the strongest systems programming language and ecosystem out there. We're very proud to sponsor a student this summer to help make it happen. Finally, Davean has volunteered to fund a student expressly to work on the Hadrian build system for GHC <https://haskell-org.github.io/summer-of-haskell/ideas.html#hadrian-ghc>. Feel free to contact us at (nvazou at cs.umd.edu and m at jaspervdj.be) if want to help or if you have any ideas, questions, or concerns. Best, Niki Vazou & Jasper Van der Jeugt for the Haskell.org Committee

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Senior Lectureships in Computer Science at Chalmers and Gothenburg U
by Andreas Abel 25 Apr '17

25 Apr '17

We are hiring full-time permanent lecturers! http://www.chalmers.se/en/about-chalmers/vacancies/Pages/default.aspx?rmpag… http://www.gu.se/english/about_the_university/job-opportunities/vacancies-d… The positions are focusing on teaching, but some time will be available for research as well. Excerpt from the description: Major responsibilities The scientific area is Computer Science, interpreted broadly. The position is a full-time tenured appointment with focus on education and pedagogical development. You will teach a variety of topics in Computer Science; there may include courses such as programming, data structures, algorithms and databases. You will also supervise bachelor level projects and master’s theses. Besides teaching, you will keep up with the technical and pedagogical development in the areas of the position and introduce new methods in the curriculum. As a faculty member you will share the responsibility of the administration and management of the department and the educational programmes. You will collaborate with industrial, academic or governmental partners, and take part in the research conducted at the department. In addition, you are encouraged to apply for funding of further pedagogical advancement of our programmes, and for research funding. -- Andreas Abel <>< Du bist der geliebte Mensch. Department of Computer Science and Engineering Chalmers and Gothenburg University, Sweden andreas.abel(a)gu.se http://www.cse.chalmers.se/~abela/

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Munich Haskell Meeting, 2017-01-26 @ 19:30
by Christian Neukirchen 25 Apr '17

25 Apr '17

Dear all, This week, our monthly Munich Haskell Meeting will take place again on Thursday, April 27 at Augustiner-Gaststätte Rumpler (Baumstraße 21) at 19h30. For details see here: http://muenchen.haskell.bayern/dates.html If you plan to join, please add yourself to this dudle so we can reserve enough seats! It is OK to add yourself to the dudle anonymously or pseudonymously. https://dudle.inf.tu-dresden.de/haskell-munich-apr-2017/ Everybody is welcome! cu, -- Christian Neukirchen <chneukirchen(a)gmail.com> http://chneukirchen.org

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VSTTE 2017 - Deadline Extension
by Andrei Paskevich 25 Apr '17

25 Apr '17

*** DEADLINE EXTENSION *** 9th Working Conference on Verified Software: Theories, Tools, and Experiments (VSTTE) https://vstte17.lri.fr July 22-23, 2017, Heidelberg, Germany Co-located with the 29th International Conference on Computer-Aided Verification, CAV 2017 Deadline Extension The deadlines for submitting abstracts and full papers have been extended by one week. The new deadlines are firm. Important Dates * Abstract submission (extended): Mon, May 1, 2017 (AoE) * Full paper submission (extended): Mon, May 8, 2017 (AoE) * Notification: Mon, Jun 5, 2017 * VSTTE: Sat-Sun, Jul 22-23, 2017 * Camera-ready: Mon, Aug 21, 2017 Overview The goal of the VSTTE conference series is to advance the state of the art in the science and technology of software verification, through the interaction of theory development, tool evolution, and experimental validation. We welcome submissions describing significant advances in the production of verified software, i.e., software that has been proved to meet its functional specifications. Submissions of theoretical, practical, and experimental contributions are equally encouraged, including those that focus on specific problems or problem domains. We are especially interested in submissions describing large-scale verification efforts that involve collaboration, theory unification, tool integration, and formalized domain knowledge. We also welcome papers describing novel experiments and case studies evaluating verification techniques and technologies. Topics of interest for VSTTE include education, requirements modeling, specification languages, specification/verification/certification case studies, formal calculi, software design methods, automatic code generation, refinement methodologies, compositional analysis, verification tools (e.g., static analysis, dynamic analysis, model checking, theorem proving, satisfiability), tool integration, benchmarks, challenge problems, and integrated verification environments. Paper Submissions We accept both long (limited to 16 pages, references not included) and short (limited to 10 pages, references not included) paper submissions. Short submissions also cover Verification Pearls describing an elegant proof or proof technique. Submitted research papers and system descriptions must be original and not submitted for publication elsewhere. Each submission will be evaluated by at least three members of the Program Committee. We expect that one author of every accepted paper will present their work at the conference. Paper submissions must be written in English using the LNCS LaTeX format (http://www.springer.com/gp/computer-science/lncs/conference-proceedings-gui…) and must include a cogent and self-contained description of the ideas, methods, results, and comparison to existing work. Papers will be submitted via EasyChair at the VSTTE 2017 conference page (https://www.easychair.org/conferences/?conf=vstte2017) The post-conference proceedings of VSTTE 2017 will be published in the LNCS series. Authors of accepted papers will be requested to sign the copyright transfer form. A selection of best papers will be invited for publication in the Journal of Automated Reasoning. Invited Speakers * Christoph Weidenbach (Max Planck Institute for Informatics, Germany) * Santiago Zanella-Beguelin (Microsoft Research, UK) Program Chairs * Andrei Paskevich (Université Paris-Sud, France) * Thomas Wies (New York University, USA) Program Committee * June Andronick (University of New South Wales, Australia) * Christel Baier (TU Dresden, Germany) * Sandrine Blazy (Université de Rennes 1, France) * Arthur Charguéraud (Inria, France) * Ernie Cohen (Amazon Web Services, USA) * Rayna Dimitrova (MPI-SWS, Germany) * Carlo A. Furia (Chalmers University of Technology, Sweden) * Arie Gurfinkel (University of Waterloo, Canada) * Hossein Hojjat (Rochester Institute of Technology, USA) * Marieke Huisman (University of Twente, Netherlands) * Bart Jacobs (KU Leuven, Belgium) * Rajeev Joshi (NASA Jet Propulsion Laboratory, USA) * Zachary Kincaid (Princeton University, USA) * Akash Lal (Microsoft Research, India) * Shuvendu Lahiri (Microsoft Research, USA) * Francesco Logozzo (Facebook, USA) * Peter Müller (ETH Zürich, Switzerland) * Jorge A. Navas (SRI International, USA) * Scott Owens (University of Kent, UK) * Gerhard Schellhorn (Universität Augsburg, Germany) * Peter Schrammel (University of Sussex, UK) * Natarajan Shankar (SRI International, USA) * Mihaela Sighireanu (Université Paris-Diderot, France) * Julien Signoles (CEA LIST, France) * Michael Tautschnig (Queen Mary University of London, UK) * Tachio Terauchi (JAIST, Japan) * Oksana Tkachuk (NASA Ames Research Center, USA) * Mattias Ulbrich (Karlsruhe Institute of Technology, Germany)

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In search for an http/2 server
by Wojtek Narczyński 25 Apr '17

25 Apr '17

Honorable cafe, I'd like to experiment with http/2. The package wai used to contain Network.Wai.HTTP2, but the ChangeLog says it has been removed in 3.2.0, no further explanation given. Where should I look for an http/2 server these days? -- Kind regards, Wojtek Narczynski

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ANN: Compose Unconference and Exchange [NYC, May 20-21]
by Gershom B 25 Apr '17

25 Apr '17

I'm happy to announce that we now have a venue and dates for the affiliated Unconference and Exchange (aka "hackathon") for the Compose conference in NYC. It will take place the weekend immediately following the main conference, featuring improptu tutorials, collaborative coding, and generally be a good informal opportunity to work and discuss with functional programmers of all sorts. Registration (free) is at: https://www.eventbrite.com/e/cmpse-unconference-and-exchange-2017-tickets-3… Registration for the main conference remains at: https://composeconference.eventbrite.com. Early bird tickets are now gone, so get tickets while you can! We're also happy to announce the topic of our invited keynote by Emily Riehl: A Categorical View of Computational Effects * Unconference information: http://www.composeconference.org/2017/unconference/ * Unconference registration: https://www.eventbrite.com/e/cmpse-unconference-and-exchange-2017-tickets-3… * Full conference abstracts: http://www.composeconference.org/2017/program * Conference Registration: http://composeconference.eventbrite.com * Follow @composeconf on twitter for news: https://twitter.com/composeconf * On freenode irc, chat with fellow attendees at #composeconference * Corporate sponsorships are welcome. Current sponsors list forthcoming. * Policies (diversity and anti-harassment): http://www.composeconference.org/conduct * Email us with any questions at info(a)composeconference.org * Please forward this announcement to interested parties and lists.

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