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Call for Contributions: Summer BOB 2019 [Aug 21, Berlin, deadline May 17]
by Matthias Fischmann 05 Apr '19

05 Apr '19

[Online version of this email: https://bobkonf.de/2019-summer/cfc.html] Summer BOB Conference 2019 "What happens when we use what's best for a change?" http://bobkonf.de/2019-summer/cfc.html Berlin, August 21 co-located with ICFP 2019 Call for Contributions Deadline: May 17, 2019 You are engaged in software development or software architecture, and have an interesting story to tell about an advanced tools, technique, language or technology that you're using? Or a gnarly problems that these tools fail to address but should? Summer BOB is a one-time-only event, in the spirit of the spectacular Winter BOB. The International Conference on Functional Programming is coming to town, and Summer BOB will be right in the middle of it, on the last day of ICFP proper, prior to all the workshops. Summer BOB will feature two tracks: one from practitioners, and one from researchers, and foster communication and cross-pollination between these communities. If you share our vision and want to contribute, submit a proposal for a talk! NOTE: The conference fee will be waived for presenters. Travel expenses will not be covered (for exceptions see "Speaker Grants"). Topics ------ We are looking for talks about best-of-breed software technology, e.g.: - functional programming - persistent data structures and databases - types - formal methods for correctness and robustness - abstractions for concurrency and parallelism - metaprogramming - probabilistic programming - math and programming - controlled side effects - beyond REST and SOAP - effective abstractions for data analytics - … everything really that isn’t mainstream, but you think should be. Presenters should provide the audience with information that is practically useful for software developers. We're especially interested in experience reports. Other topics are also relevant, e.g.: - demos and how-tos - reports on problems that cutting-edge languages and tools should address but don't - overviews of a given field Requirements ------------ We accept proposals for presentations of 45 minutes (40 minutes talk + 5 minutes questions), as well as 90 minute tutorials for beginners. The language of presentation should be either English. Your proposal should include (in your presentation language of choice): - An abstract of max. 1500 characters. - A short bio/cv - Contact information (including at least email address) - A list of 3-5 concrete ideas of how your work can be applied in a developer's daily life - additional material (websites, blogs, slides, videos of past presentations, …) - Don't be confused: The system calls a submission event. Submit here ----------- https://bobcfc.active-group.de/bob2019-summer/cfp Speaker Grants -------------- BOB has Speaker Grants available to support speakers from groups under-represented in technology. We specifically seek women speakers and speakers who are not be able to attend the conference for financial reasons. Shepherding The program committee offers shepherding to all speakers. Shepherding provides speakers assistance with preparing their sessions, as well as a review of the talk slides. Organisation ------------ - Direct questions to contact at bobkonf dot de - Proposal deadline: May 17, 2019 - Notification: May 31, 2019 - Program: June 14, 2019 Program Committee ----------------- - Matthias Fischmann, zerobuzz UG - Matthias Neubauer, SICK AG - Nicole Rauch, Softwareentwicklung und Entwicklungscoaching - Michael Sperber, Active Group - Stefan Wehr, factis research Scientific Advisory Board - Annette Bieniusa, TU Kaiserslautern - Torsten Grust, Uni Tübingen - Peter Thiemann, Uni Freiburg More information here: http://bobkonf.de/2019-summer/programmkomitee.html

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Hackage Down
by Ara Adkins 04 Apr '19

04 Apr '19

Is anybody else unable to access Hackage? I'm seeing a 502 bad gateway. _ara

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Feedback on plan for checking code requirements in a GHC plugin
by Chris Smith 04 Apr '19

04 Apr '19

Hey everyone, I'm converging on a design for a new feature of CodeWorld, the Haskell-based educational programming environment that I teach with. I'm wondering if anyone has done something like this before. The goal is that when I give an assignment in a class (e.g., "modify this starting code to generalize the repeated pattern using a function"), I want the user to see a checklist of assignment requirements when they run the code. A prototype implementation is here: https://code.world/haskell#PpwpTF1wv3qIvwhohCfvSrQ There are all sorts of possible requirements, such as: "No lines longer than 80 characters", or "there must be a function called foo", or "all top-level definitions must have type signatures", or "your code must define at least 10 top-level variables, and use at least 3 where clauses", or "your definition of var should be equivalent to this one" (see Joachim Breitner's inspection testing work), or even "the function f must satisfy this QuickCheck property". It's been suggested that the requirements language also include the ability to match patterns in the AST, which I think is a good idea. The current prototype uses a pre-compile step that parses the code using haskell-src-exts, and doesn't implement dynamic requirements (runtime-evaluated) at all. My ultimate plan, though, is to send these requirements to GHC via a plugin, then have it evaluate the static ones at compile time, and generate code to check the dynamic ones. Finally, the plugin would add new code to the beginning of main that will invoke a configurable function with the results of the requirement check (hard-coding the static ones, and evaluating dynamic ones on the fly). (In the CodeWorld environment, this function would display the checklist in the web UI, for example.) Has anyone done anything like this before? Any wisdom to share, or ideas to contribute? Thanks, Chris

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MPC 2019 final call for papers - submissions due 3rd May
by Graham Hutton 03 Apr '19

03 Apr '19

====================================================================== *** FINAL CALL FOR PAPERS -- MPC 2019 *** 13th International Conference on Mathematics of Program Construction 7-9 October 2019, Porto, Portugal Co-located with Formal Methods 2019 https://tinyurl.com/MPC-Porto ====================================================================== TIMELINE: Abstract submission 26th April 2019 Paper submission 3rd May 2019 Author notification 14th June 2019 Camera ready copy 12th July 2019 Conference 7-9 October 2019 KEYNOTE SPEAKERS: Assia Mahboubi INRIA, France Annabelle McIver Macquarie University, Australia BACKGROUND: The International Conference on Mathematics of Program Construction (MPC) aims to promote the development of mathematical principles and techniques that are demonstrably practical and effective in the process of constructing computer programs. MPC 2019 will be held in Porto, Portugal from 7-9 October 2019, and is co-located with the International Symposium on Formal Methods, FM 2019. Previous conferences were held in Königswinter, Germany (2015); Madrid, Spain (2012); Québec City, Canada (2010); Marseille, France (2008); Kuressaare, Estonia (2006); Stirling, UK (2004); Dagstuhl, Germany (2002); Ponte de Lima, Portugal (2000); Marstrand, Sweden (1998); Kloster Irsee, Germany (1995); Oxford, UK (1992); Twente, The Netherlands (1989). SCOPE: MPC seeks original papers on mathematical methods and tools put to use in program construction. Topics of interest range from algorithmics to support for program construction in programming languages and systems. Typical areas include type systems, program analysis and transformation, programming language semantics, security, and program logics. The notion of a 'program' is interpreted broadly, ranging from algorithms to hardware. Theoretical contributions are welcome, provided that their relevance to program construction is clear. Reports on applications are welcome, provided that their mathematical basis is evident. We also encourage the submission of 'programming pearls' that present elegant and instructive examples of the mathematics of program construction. SUBMISSION: Submission is in two stages. Abstracts (plain text, maximum 250 words) must be submitted by 26th April 2019. Full papers (pdf, formatted using the llncs.sty style file for LaTex) must be submitted by 3rd May 2019. There is no prescribed page limit, but authors should strive for brevity. Both abstracts and papers will be submitted using EasyChair. Papers must present previously unpublished work, and not be submitted concurrently to any other publication venue. Submissions will be evaluated by the program committee according to their relevance, correctness, significance, originality, and clarity. Each submission should explain its contributions in both general and technical terms, clearly identifying what has been accomplished, explaining why it is significant, and comparing it with previous work. Accepted papers must be presented in person at the conference by one of the authors. The proceedings of MPC 2019 will be published in the Lecture Notes in Computer Science (LNCS) series, as with all previous instances of the conference. Authors of accepted papers will be expected to transfer copyright to Springer for this purpose. After the conference, authors of the best papers from MPC 2019 and MPC 2015 will be invited to submit revised versions to a special issue of Science of Computer Programming (SCP). For any queries about submission please contact the program chair, Graham Hutton <graham.hutton(a)nottingham.ac.uk>. PROGRAM COMMITTEE: Patrick Bahr IT University of Copenhagen, Denmark Richard Bird University of Oxford, UK Corina Cîrstea University of Southampton, UK Brijesh Dongol University of Surrey, UK João F. Ferreira University of Lisbon, Portugal Jennifer Hackett University of Nottingham, UK William Harrison University of Missouri, USA Ralf Hinze University of Kaiserslautern, Germany Zhenjiang Hu National Institute of Informatics, Japan Graham Hutton (chair) University of Nottingham, UK Cezar Ionescu University of Oxford, UK Mauro Jaskelioff National University of Rosario, Argentina Ranjit Jhala University of California, USA Gabriele Keller Utrecht University, The Netherlands Ekaterina Komendantskaya Heriot-Watt University, UK Chris Martens North Carolina State University, USA Bernhard Möller University of Augsburg, Germany Shin-Cheng Mu Academia Sinica, Taiwan Mary Sheeran Chalmers University of Technology, Sweden Alexandra Silva University College London, UK Georg Struth University of Sheffield, UK CONFERENE VENUE: The conference will be held at the Alfândega Porto Congress Centre, a 150 year old former custom's house located in the historic centre of Porto on the bank of the river Douro. The venue was renovated by a Pritzer prize winning architect and has received many awards. LOCAL ORGANISERS: José Nuno Oliveira University of Minho, Portugal For any queries about local issues please contact the local organiser, José Nuno Oliveira <jno(a)di.uminho.pt>. ====================================================================== This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.

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ANN: Haskell Beginners Google+ Community: "Haskell: The Haskell-Beginners Community"
by Benjamin L. Russell 02 Apr '19

02 Apr '19

Since the Google+ social network service is scheduled to be "sunset" (i.e., put out of service) on April 2, 2019, I have created a new Haskell beginners PASHpost community, "Haskell: The Haskell-Beginners Community" (see https://pashpost.com/group/haskell-the-haskell-beginners-community) and migrated a substantial portion of the original posts thereto (sans posts with missing links or irrelevant content). Feel free to join and contribute! -- Benjamin L. Russell

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Generating tagfiles for Vim
by Vanessa McHale 02 Apr '19

02 Apr '19

Hi all, I had been using hasktags for tag generation previously, however, I recently discovered that using GHCi with cabal new-repl λ:> :ctags creates a tags file that actually works with preprocessors (e.g. c2hs or alex or happy). Is there any way to run this semi-automatically? echo ':ctags' | cabal new-repl seems to work in the shell, but I'd like a vim integration if possible (also, it's slow). Cheers, Vanessa McHale

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I fell in love with System.Console.Haskeline.getExternalPrint
by Mario Lang 01 Apr '19

01 Apr '19

Hi. Since I discovered getExternalPrint, I found a ton of use cases for it. In particular, it makes it possible to write background threads that report stuff to the console without disturbing the prompt. I ended up writing a sort of uGHCi with the help of hint and the unreleased master branch of haskeline[1] to make externalPrint available from within the interpreter. Combined with Shh, this opens the door for a lot of useful functionality. Here is a simplified example based on shell programming with the help of Shh: % let watch r p = forkIO . forever $ printProc p >> readIORef r >>= OS.sleep % delay <- newIORef 10 % clock <- watch delay OS.date Sat Mar 2 21:32:28 CET 2019 Sat Mar 2 21:32:38 CET 2019 % writeIORef delay 5 Sat Mar 2 21:32:48 CET 2019 Sat Mar 2 21:32:53 CET 2019 Sat Mar 2 21:32:58 CET 2019 Sat Mar 2 21:33:03 CET 2019 % killThread clock printProc uses externalPrint from haskeline to print the output of a shell command to the console without disturbing the prompt. The OS module in this example simply exports all executables as haskell functions, thanks to the TH magic from Shh. I am relying on a pretty crude hack to make this work: (rFd, wFd) <- liftIO createPipe eprint <- getExternalPrint -- from haskeline liftIO . forkIO . forever $ do (s, bc) <- fdRead rFd 1024 eprint s -- ... -- define a function in the interpreter using hint runStmt $ "let externalPrint s = fdWrite (read " <> show (show wFd) <> ") s >> pure ()" This hack is basically the whole magic of my own hand-rolled uGHCi. I'd love to not reinvent the wheel there, and just be able to use standard GHCi to make use of externalPrint. Question is, would a similar thing be possible to implement in GHCi directly, and if so, what would be required to make this work? I am likely far too much a rooky to get this working on my own, so I am asking for help. What steps should I follow to eventually achieve my goal? I guess submitting a feature request would be a start. However, I want progress, so I am wondering: * The pipe trick is likely too hacky for GHCi. Are there any other portable alternatives for getting data from within the interpreter to the haskell process running it? * Or is there a way to serialize an IO action into the interpreter that I've missed? The problem here is the boundary between the process that runs the interpreter, and the interpreter itself. I am a bit whacky on terminology here, but as I see it, getExternalPrint returns a function that has internal state. So it isn't really possible to make such a function available from within the interpreter. Hence, the pipe hack above, which just sends the *argument* to externalPrint from the interpreter to the process running it. Any insights that might help me make that available in standard GHCi? I really think this is a pretty unique feature that would enable all sorts of interesting interactive code. [1] Haskeline < 0.8.0 doesn't allow to combine IntterpreterT from hint with InputT because of the way exceptions are done. The master branch of haskeline fixes that, so finally you can have a transformer stack that combines both, allowing for pretty simple interactive haskell interpreters with readline functionality. Thanks for that! -- CYa, ⡍⠁⠗⠊⠕

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Compose Second CFP & Keynote Speaker Announcement
by MightyByte 01 Apr '19

01 Apr '19

The April 23 submission deadline for Compose NYC is rapidly approaching, so get your submissions in soon. We are also excited to announce that we now have two confirmed keynote speakers: David Spivak - Compositional Graphical Logic Donya Quick - Making Algorithmic Music Compose is a conference focused specifically on strongly typed functional programming languages. It will be held in New York on Monday and Tuesday, June 24 -25, 2019. Registration will be open shortly. http://www.composeconference.org/2019 To get a sense of Compose, you can check out the great talks from past conferences: https://www.youtube.com/channel/UC0pEknZxL7Q1j0Ok8qImWdQ Below is our call for presentations. http://www.composeconference.org/2019/cfp/ In past years, we have also hosted an unconference over the weekend adjacent to the conference. The unconference details this year have not been finalized yet, but if you’re interested you may want to keep that in mind when making travel plans. *** Compose Conference NYC 2019 Second Call for Presentations June 24 -25, 2019 New York City The audience for Compose is people using Haskell, PureScript, OCaml, F#, SML, and other strongly typed functional programming languages who are looking to increase their skills or learn new technologies and libraries. Presentations should be aimed at teaching or introducing new ideas or tools. We are also interested in presentations aiming at taking complex concepts, such as program derivation, and putting them into productive use. However presentations on anything that you suspect our audience may find interesting are welcome. The following are some of the types of talks we would welcome: *Library/Tool Talks* — Exploring the uses of a powerful toolkit or library, be it for parsing, testing, data access and analysis, or anything else. *Production Systems* — Experience reports on deploying functional techniques in real systems; insights revealed, mistakes made, lessons learned. *Theory made Practical* — Just because it’s locked away in papers doesn’t mean it’s hard! Accessible lectures on classic results and why they matter to us today. Such talks can include simply introducing the principles of a field of research so as to help the audience read up on it in the future; from abstract machines to program derivation to branch-and-bound algorithms, the sky’s the limit. Check out the Compose YouTube channel ( https://www.youtube.com/playlist?list=PLNoHgLVTxtaoolkQo4hLy4ZsA1prUJ51m ) to see videos of talks we've had previously and get an idea of the kinds of topics we usually feature. We also welcome presentations for more formal tutorials. Tutorials should be aimed at a smaller audience of beginner-to-novice understanding, and ideally include hands-on exercises. The due date for submissions is *April 23, 2019*. We will send out notice of acceptance by *April 30th*. We prefer that submissions be via the EasyChair website ( https://easychair.org/conferences/?conf=compose2019 ). Please suggest a title, and describe the topic you intend to speak on. Talks can be either 30 or 45 minutes, please indicate how much time you would prefer to take. You may submit multiple talks if you have several ideas and are unsure which would be the most likely to be accepted. Accepted talks will be asked to submit slides for review prior to the conference. Feel free to include any additional information on both your expertise and interesting elements of your topic that would be appropriate for inclusion in the public abstract. Furthermore, if your abstract doesn't feel "final"—don't worry! We'll work with you to polish it up. If you want to discuss your presentation(s) before submitting, or to further nail down what you intend to speak on, please feel free to contact us at n...@composeconference.org ( n...@composeconference.org ). We're happy to work with you, even if you are a new or inexperienced speaker, to help your talk be great. Diversity We would like to put an emphasis on soliciting a diverse set of speakers - anything you can do to distribute information about this CFP and encourage submissions from under-represented groups would be greatly appreciated. We welcome your contributions and encourage you to apply! Best, Doug Sent via Superhuman ( https://sprh.mn/?vip=mightybyte@gmail.com )

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[Job] Cloudseal seeks Haskell Software Engineers
by Ryan Newton 31 Mar '19

31 Mar '19

Dear fellow Haskellers, We're hiring! See below. -Ryan Newton Cloudseal co-founder, Professor of Computer Science (on leave), Functional programmer for 28 years, Haskeller for 10 *========================================================* We are looking for a Haskell software engineer who is passionate about developer technologies and changing how the world tests and runs software. Cloudseal is an early-stage startup, a spin-out from academic research on reliable (deterministic) software execution. Our core technology is a new containerization mechanism for Linux/x86 programs that enables reproducible builds and functional tests that never flake. You will be joining a growing team with decades of collective experience contributing to developer tools, including the GHC compiler and ecosystem, as well as developer products at Intel and Microsoft. *Skills sought* *-------------------* We are seeking curious and independent people ready to become involved with every part of product development. We are a Haskell+Rust shop, corresponding to the high- and low-level components of our stack, respectively, with this position focused on the former. Familiarity with low-level Linux systems software is not required but would be a positive. Experience with building services (authentication, billing) is a plus for this role. You should be comfortable with modern infrastructure essentials like AWS, Docker, CI, etc. and have passable sysadmin skills. Ability to work independently as part of a distributed development team is essential. This full-time position carries an option for remote work (within the U.S.), but geographic proximity to Philadelphia, Indianapolis, or Bloomington, IN would be preferred. During a ramp-up phase we will work on site together at a higher rate (25-50% travel), after which in-person team meetups will be less frequent. *Benefits* *------------* - Competitive salary & fringe benefits - Significant early-stage stock options - Flexible working hours and vacation time *Applying* *-------------* Email your resume to jobs(a)cloudseal.io. In your message, please share links to your previous work, such as running websites or open source contributions.

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Resources/papers on lazy I/O
by Vanessa McHale 29 Mar '19

29 Mar '19

Hi all, I recently finished up writing streaming facilities via libarchive bindings and lazy bytestrings. It ended up working nicely - reading from a file lazily and then unpacking the archive was more efficient in time + allocations than reading the file all at once. That got me thinking - what exactly is wrong with lazy I/O? I've seen Oleg Kiselyov's paper (http://okmij.org/ftp/Haskell/#lazyIO-not-True) and I've run into issues myself (basically the issue here: https://stackoverflow.com/questions/31342012/read-and-writing-to-file-in-ha…) but none of those seem so pathological - the second issue could be better resolved with linear types! Are the any explanations of why Haskell *does* use lazy I/O? Laziness allows symmetries between values and generators of values - surely it is not *that* immoral to enforce this even in the IO monad? Cheers, Vanessa McHale

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