- Haskell-Cafe - Haskell.org

Re: [Haskell-cafe] Announcing the Haskell Error Index
by Douglas McIlroy 21 Oct '22

21 Oct '22

(comment mostly for entertainment) The announcement of the Haskell error index conjured memories of the Fortran I stop book. On an error, the original Fortran compiler executed a halt instruction. To find the cause, one would read the memory address of the halt from the console lights and manually look the address up in the stop book, a thick 11"x17" computer printout. In the Haskell error index, the codes are permanent identifiers for evolving diagnostic explanations. In contrast, Fortran stop numbers varied with compiler version, while the explanations were essentially static. The stop book was indispensable, but far from user-friendly. If reasonably curated, the error index could be a big advance in the latter respect. Doug McIlroy

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Bogotá Functional Programming Interest Group
by Jeffrey Brown 20 Oct '22

20 Oct '22

I imagine people who read Haskell Cafe and live in Colombia might be interested in this new group. It's the closest thing I'm aware of to a Haskell user group in the country. https://www.meetup.com/functional-programming-interest-group-at-puj/ -- Jeff Brown | Jeffrey Benjamin Brown LinkedIn <https://www.linkedin.com/in/jeffreybenjaminbrown> | Github <https://github.com/jeffreybenjaminbrown> | Twitter <https://twitter.com/carelogic> | Facebook <https://www.facebook.com/mejeff.younotjeff>

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Announcing the Haskell Error Index
by David Christiansen 20 Oct '22

20 Oct '22

The Haskell Error Index (https://errors.haskell.org/) is a community-driven web site for improving the documentation of Haskell tooling. In the upcoming release of GHC, each error message or warning includes a unique code. This code can be looked up on the index to find user-contributed explanations and examples. As the specific phrasing of messages in GHC is improved over time, the codes will remain constant, which allows the documentation on the site to retain its value and its search-engine usefulness. The site is run off of a Git repo full of Markdown files and example programs at https://github.com/haskellfoundation/error-message-index/ , so you don't need to be an expert to contribute. Contributions of documentation as well as technical improvements to the site generator, HTML, and CSS are all very welcome. Most of the current content and infrastructure was contributed by volunteers at Zurihac this year. Right now, it only covers an unreleased version of GHC, but the system is set up to also work with other tools. If you're an author of Haskell-related tooling and would like to have it included, please write to me at david(a)haskell.foundation. The site is inspired by the Rust error index and by the excellent user-contributed sections in the PHP documentation. It's part of the Haskell Foundation's technical agenda, arising from a Haskell Foundation Technical Proposal ( https://github.com/haskellfoundation/tech-proposals/blob/main/proposals/acc…) If you'd like to have influence on what we at the HF do, please submit a proposal! All the best, David Thrane Christiansen Executive Director The Haskell Foundation

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PhD positions at Binghamton University
by William Hallahan 19 Oct '22

19 Oct '22

Dear all, I am a new faculty member at Binghamton University, looking for PhD students (starting in Spring 2023 or Fall 2023) to work on formal verification, analysis, and/or synthesis. A common aim of my work is to ease the process of verifying programs, either by improving the debugging experience when verification fails, or by automating the verification process. Much of my work revolves around functional languages, with a particular focus on debugging and verifying Haskell programs. I am also interested in verification and synthesis of systems in domains such as networking and machine learning. You can find more information about me on my website: https://billhallahan.github.io <https://billhallahan.github.io/> Please reach out if you are interested or if you have any questions. Best, William Hallahan

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Haskell language model
by Jorrit Willaert 19 Oct '22

19 Oct '22

Dear all, For my thesis, I will try to offer Haskell coding assignments for a course in a more dynamic way, where the next assignment is based on the knowledge gap of the learner. For this, I will use a neural network, which will have to process a submission of a learner. Therefore, I want to use a language model that extracts features from the submission. I was planning to use BERT in a first phase, since this model creates embeddings from a document. However, this model is not trained on any programming language, so this may turn out to be insufficient. Moreover, models such as CodeBERT are trained on source code, but only on very well known programming languages. I was wondering if someone had an idea if there already exists a language model that can create meaningful representations for Haskell. More general models such as Codex (paying API) or GPT-Code-Clippy (free and opensource) could also be tried out, but if there exists a model that has been trained on Haskell specific data, that would of course be the most beneficial option. If you want to read more about my thesis, you can read more about it in the attachment. Thanks in advance! Kind regards, Jorrit Willaert https://www.linkedin.com/in/jorrit-willaert-166a64198/ https://github.com/JorritWillaert

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What's different about quantified constraints since GHC 9.2?
by Li-yao Xia 19 Oct '22

19 Oct '22

Dear Café, There's a trick [1] involving quantified constraints (and usually type families) where a function has a quantified constraint (forall a. CF a) and which is explicitly instantiated with a well-placed type annotation (_ :: CF x => ...). Since GHC 9.2, this trick works without that type annotation. How did GHC get smarter at instantiating this quantified constraint? Below is a minimized example which compiles on GHC 9.2.1 but not 9.0.1 (haven't tested 9.0.2), unless you uncomment the last line. Cheers, Li-yao [1]: an Iceland_jack trick https://gitlab.haskell.org/ghc/ghc/-/issues/14860#note_151394 {-# LANGUAGE TypeFamilies, FlexibleInstances, FlexibleContexts, QuantifiedConstraints, ScopedTypeVariables #-} module A where type family F a class C a class C (F a) => CF a f :: C (F a) => a f = undefined g :: (forall a. CF a) => a g = f -- :: forall a. CF a => a -- needed until GHC 9.0.1 but not GHC 9.2.1 (and later)

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FOSDEM 2023 Haskell devroom proposal - co-organiser needed!
by Fraser Tweedale 19 Oct '22

19 Oct '22

Greetings, I decided to propose a Haskell devroom (like a one/half-day specialist track or miniconf) for FOSDEM 2023, to be held February 4--5 in Brussels. It would be great to promote Haskell among this audience and hopefully attract new contributors / community members. Unfortunately I left it quite late (deadline submission is today). I only just realised I need a secondary contact (i.e. co-organiser) to submit the proposal. So... any volunteers? Ideally you are located in Europe or definitely planning to attend FOSDEM. If you are willing, please reply! I think I all need right now is your name and email address (and enthusiasm). The text of my proposal may be found at https://github.com/frasertweedale/talks/blob/master/2022-02-xx-fosdem-haske…. I have experience organising and host FP miniconfs at linux.conf.au including running the CFP etc. I expect FOSDEM will be similar, except y'know, the other side of the world from Australia, where I live. Thanks, Fraser

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Package takeover request: utf8-light
by Francesco Ariis 18 Oct '22

18 Oct '22

Hello list, I would like to take over `utf8-light`: https://hackage.haskell.org/package/fgl as it currently breaks compilation for a game I wrote: https://github.com/haskell-infra/hackage-trustees/issues/347 There is no repository, I contacted the maintainer via email on october 2, without receiving any answer —F

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Call for Contributions: BOB 2023 [March 17, Deadline Nov 21]
by Stefan Wehr 18 Oct '22

18 Oct '22

================================================================================ BOB Conference 2023 "What happens when we use what's best for a change?" https://bobkonf.de/2023/cfc.html Berlin, Mar 17 Call for Contributions Deadline: November 21, 2022 ================================================================================ You are actively engaged in advanced software engineering methods, solve ambitious problem with software and are open to cutting-edge innovation? Attend this conference, meet people that share your goals, and get to know the best software tools and technologies available today. We strive to offer a day full of new experiences and impressions that you can use to immediately improve your daily life as a software developer. If you share our vision and want to contribute, submit a proposal for a talk or tutorial! NOTE: The conference fee will be waived for presenters. Travel expenses will not be covered (for exceptions see "Speaker Grants"). Online or Onsite ---------------- We expect we'll be able to hold BOB 2023 in Berlin. Note that we intend to provide a safe environment for all participants. There will be space outside to eat and chat. We may ask you to wear a mask indoors when not presenting or eating, and may also ask you to take a COVID test on-site before the event. If an on-site BOB is not possible, we'll make BOB a successful online event, like BOB 2021 and BOB 2022. Should BOB happen online, we will likely ask for pre-recorded talks to make room for questions and social interactions during the actual conference day. (Of course, we'll provide assistance making those recordings.) Tutorials will likely happen as a live-session. Shepherding ----------- The program committee offers shepherding to all speakers. Shepherding provides speakers assistance with preparing their sessions. Specifically: - advice on structure and presentation - review of talk slides - assistance with recording - review of recording, if applicable Speaker Grants -------------- BOB has Speaker Grants available to support speakers from groups under-represented in technology. We specifically seek women speakers, speakers of color, and speakers who are not able to attend the conference for financial reasons. Topics ------ We are looking for talks about best-of-breed software technology, e.g.: - functional programming - persistent data structures and databases - event-based modelling and architecture - "fancy types" (dependent types, gradual typing, linear types, ...) - formal methods for correctness and robustness - abstractions for concurrency and parallelism - metaprogramming - probabilistic programming - math and programming - controlled side effects - program synthesis - next-generation IDEs - effective abstractions for data analytics - … everything really that isn’t mainstream, but you think should be - … includeing rough ideas worth discussing. Presenters should provide the audience with information that is practically useful for software developers. Challenges ---------- Furthermore, we seek contributions on successful approaches for solving hard problems, for example: - bias in machine-learning systems - digital transformation in difficult settings - accessibiltity - systems with critical reliability requirements - ecologically sustainable software development We're especially interested in experience reports. Other topics are also relevant, e.g.: - introductory talks on technical background - overviews of a given field - demos and how-tos 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 or German. 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. Organisation ------------ - Direct questions to konferenz at bobkonf dot de - Proposal deadline: November 21, 2022 - Notification: December 5, 2022 - Program: December 12, 2022 Submit here: https://pretalx.com/bob-2023/submit/ Program Committee ----------------- (more information here: https://bobkonf.de/2023/programmkomitee.html) - Matthias Fischmann, Wire - Matthias Neubauer, SICK AG - Nicole Rauch, Softwareentwicklung und Entwicklungscoaching - Michael Sperber, Active Group - Stefan Wehr, Hochschule Offenburg Scientific Advisory Board - Annette Bieniusa, TU Kaiserslautern - Torsten Grust, Uni Tübingen - Peter Thiemann, Uni Freiburg

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Haskell merchandise
by Borys Kopeć 14 Oct '22

14 Oct '22

Hey all, Do you know where to find official (if there is one) merch on Haskell? I'm talking stickers, clothes and gadgets. Regards Borys

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