October 2022 - Haskell-Cafe

Munich Haskell Meeting, 2022-10-25 @ 19:30
by Leah Neukirchen 23 Oct '22

23 Oct '22

Dear all, Next week, our monthly Munich Haskell Meeting will take place again on Tuesday, October 25 at Cafe Puck 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://nuudel.digitalcourage.de/haskell-munich-oct-2022 Everybody is welcome! cu, -- Leah Neukirchen <leah(a)vuxu.org> https://leahneukirchen.org/

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

21 Oct '22

David, the Haskell error index is an awesome idea and the existing entries of high quality. Are there plans to tap the already quite enormous online resources about GHC errors, e.g. this mailing list, reddit and stackoverflow? One can imagine there are numerous brilliant explanations to be found. How did the other languages you mentioned handle the initial populatuion with content? (A general problem knowledge bases suffer: To be useful, a critical mass of knowledge must be accumulated, otherwise users won't be likely to contribute.) Regards, Olaf

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TFPIE 2023 call for submissions (deadline Dec 27th)
by Elena Machkasova 21 Oct '22

21 Oct '22

Please consider submitting and spread the word! TFPIE 2023 Call for papers https://wiki.tfpie.science.ru.nl/TFPIE2023 (January 12th 2023, Boston, MA, USA, co-located with TFP 2023 and POPL 2023) TFPIE 2023 welcomes submissions describing techniques used in the classroom, tools used in and/or developed for the classroom and any creative use of functional programming (FP) to aid education in or outside Computer Science. Topics of interest include, but are not limited to: FP and beginning CS students FP and Computational Thinking FP and Artificial Intelligence FP in Robotics FP and Music Advanced FP for undergraduates FP in graduate education Engaging students in research using FP FP in Programming Languages FP in the high school curriculum FP as a stepping stone to other CS topics FP and Philosophy The pedagogy of teaching FP FP and e-learning: MOOCs, automated assessment etc. Best Lectures - more details below In addition to papers, we are requesting best lecture presentations. What's your best lecture topic in an FP related course? Do you have a fun way to present FP concepts to novices or perhaps an especially interesting presentation of a difficult topic? In either case, please consider sharing it. Best lecture topics will be selected for presentation based on a short abstract describing the lecture and its interest to TFPIE attendees. The length of the presentation should be comparable to that of a paper. In addition, the speaker can provide commentary on effectiveness or student feedback. Submissions Potential presenters are invited to submit an extended abstract (4-6 pages) or a draft paper (up to 20 pages) in EPTCS style. The authors of accepted presentations will have their preprints and their slides made available on the workshop's website. Papers and abstracts can be submitted via easychair at the following link: https://easychair.org/conferences/?conf=tfpie2023 After the workshop, presenters are invited to submit (a revised version of) their article for the formal review. The PC will select the best articles for publication in the Electronic Proceedings in Theoretical Computer Science (EPTCS). Articles rejected for presentation and extended abstracts will not be formally reviewed by the PC. Important Dates Submission deadline: December 27th 2022, Anywhere on Earth. Notification: December 30th 2022 (Note: earlier submissions will receive earlier response) TFPIE Registration Deadline: TBA Workshop: January 12th 2023 Submission for formal review: April 19th 2023, Anywhere on Earth. Notification of full article: May 24th 2023 Camera ready: July 1st 2023 Program Committee Christopher Anand - McMaster University, Canada Attila Egri-Nagy - Akita International University, Japan Jason Hemann - Seton Hall University, USA Kevin Kappelmann - Technical University of Munich, Germany Elena Machkasova (Chair) - University of Minnesota Morris, USA Kristina Sojakova - INRIA, France Jørgen Villadsen - Technical University of Denmark, Denmark Registration information See https://wiki.tfpie.science.ru.nl/TFPIE2023 for updated information. Registration and attendance are mandatory for at least one author of every paper that is presented at the workshop. Presenters will have their registration fee waived. Only papers that have been presented at TFPIE may be submitted to the post-reviewing process. Best regards, Elena Machkasova (program committee chair) -- Dr. Elena Machkasova Associate Professor of Computer Science Division of Science and Mathematics University of Minnesota, Morris Office: Sci 2325 (320) 589-6308 http://cda.morris.umn.edu/~elenam/ Pronouns: she/her/hers or any other

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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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