March 2022 - Haskell-Cafe

Accessing a MinGW/MSYS2 shell from Setup.hs
by Hécate 26 Mar '22

26 Mar '22

Hi everyone, I am writing a custom Setup.hs to do an Autotools build for a bundled library. This is easy everywhere with `process` _except_ Windows, because I can't get a shell with the Autotools in them, despite there definitely being one. `process` gives me a cmd.exe shell, which wouldn't know about the Autotools, and on Windows, _any_ GHC installation has to have certain POSIX stuff available, which is why it bundles MinGW. Is the shell I get from that accessible from Setup.hs, via `process` or otherwise? Cheers, Hécate -- Hécate ✨ 🐦: @TechnoEmpress IRC: Hecate WWW:https://glitchbra.in RUN: BSD

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Call for Talks: Haskell Implementors' Workshop 2022
by Alejandro Serrano Mena 23 Mar '22

23 Mar '22

(apologies for multiple copies of this message) ACM SIGPLAN Haskell Implementors' Workshop https://icfp22.sigplan.org/home/hiw-2022 Ljubljana, Slovenia, 11 September 2022 Co-located with ICFP 2022 https://icfp22.sigplan.org/ Important dates --------------- Deadline: 11 July, 2022 (AoE) Notification: 11 August, 2022 Workshop: 11 September, 2022 The 14th Haskell Implementors' Workshop is to be held alongside ICFP 2022 this year in Ljubljana. It is a forum for people involved in the design and development of Haskell implementations, tools, libraries, and supporting infrastructure, to share their work and discuss future directions and collaborations with others. Talks and/or demos are proposed by submitting an abstract, and selected by a small program committee. There will be no published proceedings. The workshop will be informal and interactive, with open spaces in the timetable and room for ad-hoc discussion, demos, and lightning short talks. Scope and target audience ------------------------- It is important to distinguish the Haskell Implementors' Workshop from the Haskell Symposium which is also co-located with ICFP 2022. The Haskell Symposium is for the publication of Haskell-related research. In contrast, the Haskell Implementors' Workshop will have no proceedings -- although we will aim to make talk videos, slides and presented data available with the consent of the speakers. The Implementors' Workshop is an ideal place to describe a Haskell extension, describe works-in-progress, demo a new Haskell-related tool, or even propose future lines of Haskell development. Members of the wider Haskell community encouraged to attend the workshop -- we need your feedback to keep the Haskell ecosystem thriving. Students working with Haskell are specially encouraged to share their work. The scope covers any of the following topics. There may be some topics that people feel we've missed, so by all means submit a proposal even if it doesn't fit exactly into one of these buckets: * Compilation techniques * Language features and extensions * Type system implementation * Concurrency and parallelism: language design and implementation * Performance, optimisation and benchmarking * Virtual machines and run-time systems * Libraries and tools for development or deployment Talks ----- We invite proposals from potential speakers for talks and demonstrations. We are aiming for 20-minute talks with 5 minutes for questions and changeovers. We want to hear from people writing compilers, tools, or libraries, people with cool ideas for directions in which we should take the platform, proposals for new features to be implemented, and half-baked crazy ideas. Please submit a talk title and abstract of no more than 300 words. Submissions can be made via HotCRP at https://icfphiw22.hotcrp.com until July 11th (anywhere on earth). We will also have lightning talks session. These have been very well received in recent years, and we aim to increase the time available to them. Lightning talks be ~7mins and are scheduled on the day of the workshop. Suggested topics for lightning talks are to present a single idea, a work-in-progress project, a problem to intrigue and perplex Haskell implementors, or simply to ask for feedback and collaborators. Program Committee ----------------- * Pepe Iborra (Meta) * Gabrielle Keller (Utrecht University) * Emily Pilmore (Kadena) * Vladislav Zavialov (Serokell) * Alejandro Serrano (Tweag) Contact ------- * Alejandro Serrano <trupill at gmail.com>

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Retro/indie Haskell to appreciate
by Rishiyur Nikhil 21 Mar '22

21 Mar '22

> I’m looking to appreciate “retro” Haskell projects, things from before stabilization/company use. > Such as: > ... > BlueSpec compiler https://github.com/B-Lang-org/bsc Note, the Bluespec compiler, though written in "retro" Haskell, remains in daily production use (as it has been, for 2 decades). Another project, written a few years ago but in totally "retro" style is Forvis, a complete executable spec for the RISC-V instruction set: https://github.com/rsnikhil/Forvis_RISCV-ISA-Spec Covers RV32 and RV64; unprivileged and privileged: unprivileged ISA: I (basic integer) M (integer multiply/divide) A (atomics) F, D (single and double precision floating point) C (compressed) privileged ISA: M (machine), S (supervisor) and U (user modes) Sv32, Sv39 and Sv48 virtual memory and has successfully booted a Linux kernel. Rgds, Nikhil

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[announce] Stackage LTS 19 (ghc-9.0) & Nightly moved to ghc-9.2
by Jens Petersen 20 Mar '22

20 Mar '22

The Stackage Team is happy to announce the first release of the stable LTS 19 series of package sets over GHC 9.0.2: https://www.stackage.org/lts-19.0 We are also excited to announce that Nightly has been updated to use ghc-9.2.2 (thanks to heroic work by Adam Bergmark)! You can find a few more details in the short accompanying post: https://www.stackage.org/blog/2022/03/announce-lts-19-nightly-ghc9.2 Thank you to everyone in the Haskell community who contributed to make these new releases possible!

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Haskell internships with Standard Chartered Bank in the UK
by José Pedro Magalhães 20 Mar '22

20 Mar '22

All details at https://discourse.haskell.org/t/haskell-internships-with-standard-chartered… Cheers, Pedro

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Re: [Haskell-cafe] Retro/indie Haskell to appreciate
by Johannes Waldmann 19 Mar '22

19 Mar '22

> I’m looking to appreciate “retro” Haskell projects, If "retro" = "old", then look at this from 1997 https://github.com/jwaldmann/rx (state at first commit) And, I second what others have suggested: Paul Hudak: Haskore, https://web.archive.org/web/19970206084830/http://haskell.cs.yale.edu:80/ha… Peter Thiemann: Wash, http://www2.informatik.uni-freiburg.de/~thiemann/haskell/WASH/ The pinnacle of Haskell retrocomputing certainly is https://downloads.haskell.org/~ghc/0.29/ > ... things from before stabilization/company use. Haskell(98,2010) does have stability: language and core libraries adhere to the report. It's the companies that are destroying it :-) But you're right, they also spend effort on stabilization. When I cabalized my project in/around 2014, I was pleasantly surprised how little change it needed. Basically, just build-depend: haskell98. Don't read the actual source too closely - it's full of Lists and Ints, because, well .. little did I know at the time. On the other hand: naive means of expression, combined with absence, or ignorance, of libraries - makes future-proof software. Will you tell us the results of your appreciations? Are you "just" collecting sources? (already that is worthwhile) Compiling them? Running? Benchmarking? Writing a paper? I'd love to read that. - J.W.

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Functional Conf 2022 - March 24-26 online - registrations closing soon
by John Sinclair 17 Mar '22

17 Mar '22

Hey Haskellers, It is just a week until Functional Conf 2022 kicks off online. We hope you will be among the 400+ attendees we expect at the conference. Learn more and register: https://confng.in/cHeBoXDf We have an exciting lineup of speakers for you this year including a keynote from Bartosz Milewski a guru of Haskell and Category Theory. You can check the full schedule here: https://confng.in/WCrltlIO This year, we are pleased to present Haskell talks by: - Bartosz Milewski (Author of "Category Theory for Programmers") - Tony Morris (Software Engineer @ Simple Machines) - Michael Snoyman (VP, Engineering @ FP Complete) - Curtis D'Alves (Ph.D Candidate @ McMaster University) - Evie Ciobanu (Senior Haskell Engineer @ Hasura) - Christopher Anand (Associate Professor @ McMaster University) - Siddharth Bhat (Student @ IIIT Hyderabad) - Saurabh Nanda (Founder @ Vacation Labs) - Quy Dai Nhan Thai (Software Engineer @ Google) - Auke Booij (Haskell Engineer @ Hasura) The conference is broader than just Haskell talks and offers an excellent opportunity to expand your understanding of what is happening in the world of functional programming. There will be opportunities for networking and socialising with other attendees in video hangouts, who knows who you might meet? The talks will be streamed via Zoom on the confengine.com platform. You can check out the talks from the last (in-person) Functional Conf on YouTube: https://confng.in/niusPTYB With exceptional speakers, enthusiastic learners and a supportive community of functional programmers you don't want to miss this! Register now to save your place: https://confng.in/_3SLI-9u

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[ANNOUNCE] GHC 9.2.2 is not available
by Ben Gamari 16 Mar '22

16 Mar '22

The GHC developers are very happy to at announce the availability of GHC 9.2.2. Binary distributions, source distributions, and documentation are available at downloads.haskell.org: https://downloads.haskell.org/ghc/9.2.2 This release includes many bug-fixes and other improvements to 9.2.1 including: * A number of bug-fixes in the new AArch64 native code generator * Fixes ensuring that the `indexWord8ArrayAs*#` family of primops is handled correctly on platforms lacking support for unaligned memory accesses (#21015, #20987). * Improvements to the compatibility story in GHC's migration to the XDG Base Directory Specification (#20684, #20669, #20660) * Restored compatibility with Windows 7 * A new `-fcompact-unwind` flag, improving compatibility with C++ libraries on Apple Darwin (#11829) * Introduction of a new flag, `-fcheck-prim-bounds`, enabling runtime bounds checking of array primops (#20769) * Unboxing of unlifted types (#20663) * Numerous improvements in compiler performance. * Many, many others. See the [release notes] for a full list. As some of the fixed issues do affect correctness users are encouraged to upgrade promptly. Finally, thank you to Microsoft Research, GitHub, IOHK, the Zw3rk stake pool, Tweag I/O, Serokell, Equinix, SimSpace, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Moreover, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do open a [ticket][] if you see anything amiss. Happy compiling, - Ben [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [release notes]: https://downloads.haskell.org/ghc/9.2.2/docs/html/users_guide/9.2.2-notes.h…

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JOB | Developers (Edinburgh)
by James Tobin 15 Mar '22

15 Mar '22

Hello, I'm working with a global fintech company looking to hire for their new office in Edinburgh. Should there be frontend or backend people that work with the likes of Core Java, Javascript, Typescript, React, RxJS interested in forming a small development squad do get in touch. I can be reached using "JamesBTobin (at) Gmail (dot) Com". Kind regards, James

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bracket and type family
by PICCA Frederic-Emmanuel 14 Mar '22

14 Mar '22

Hello I try to have a generic way to open and close ressources for my software class DataResource a where data OpenedDataResource a :: * acquireDataResource :: a -> IO (OpenedDataResource a) releaseDataResource :: OpenedDataResource a -> IO () the idea is to have a generic method like this withDataResource :: DataResource a => a -> (OpenedDataResource a -> IO r) -> IO r withDataResource r = bracket (acquireDataResource r) releaseDataResource and later another one for the bracket of Pipes. So I try with something simple -- File newtype H5FilePath = H5FilePath FilePath instance DataResource H5FilePath where data OpenedDataResource H5FilePath = File acquireDataResource (H5FilePath f) = openFile (pack f) [ReadOnly] Nothing releaseDataResource = closeFile but I end up with this sort of error src/Hkl/H5.hs:231:40: error: • Couldn't match type ‘File’ with ‘OpenedDataResource H5FilePath’ Expected type: IO (OpenedDataResource H5FilePath) Actual type: IO File • In the expression: openFile (pack f) [ReadOnly] Nothing In an equation for ‘acquireDataResource’: acquireDataResource (H5FilePath f) = openFile (pack f) [ReadOnly] Nothing In the instance declaration for ‘DataResource H5FilePath’ | 231 | acquireDataResource (H5FilePath f) = openFile (pack f) [ReadOnly] Nothing | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ src/Hkl/H5.hs:232:25: error: • Couldn't match type ‘OpenedDataResource H5FilePath’ with ‘File’ Expected type: OpenedDataResource H5FilePath -> IO () Actual type: File -> IO () • In the expression: closeFile In an equation for ‘releaseDataResource’: releaseDataResource = closeFile In the instance declaration for ‘DataResource H5FilePath’ | 232 | releaseDataResource = closeFile | ^^^^^^^^^ cabal: Failed to build hkl-0.1.0.0 (which is required by exe:binoculars-ng from hkl-0.1.0.0). I do not understand why ? and more seriously, I do not know how to fix this. thanks for your help Frederic

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