- Haskell-Cafe - Haskell.org

[ANNOUNCE] GHC 9.8.1-alpha3 is now available
by Ben Gamari 23 Aug '23

23 Aug '23

The GHC developers are very pleased to announce the availability of the third alpha prerelease of GHC 9.8.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.8.1-alpha3 GHC 9.8 will bring a number of new features and improvements, including: * Preliminary support the `TypeAbstractions` language extension, allowing types to be bound in type declarations [TypeAbstractions]. * Support for the `ExtendedLiterals` extension, providing syntax for non-word-sized numeric literals in the surface language [extended-literals] * Improved rewrite rule matching behavior, allowing limited matching of higher-order patterns * Better support for user-defined warnings by way of the `WARNING` pragma [warnings] * The introduction of the new `GHC.TypeError.Unsatisfiable` constraint, allowing more predictable user-defined type errors [unsatisfiable] * Implementation of the export deprecation proposal, allowing module exports to be marked with `DEPRECATE` pragmas [deprecated-exports] * The addition of build semaphore support for parallel compilation; with coming support in `cabal-install` this will allow better use of parallelism in multi-package builds [jsem] * More efficient representation of info table provenance information, reducing binary sizes by over 50% in some cases when `-finfo-table-map` is in use A full accounting of changes can be found in the [release notes]. This alpha includes roughly a dozen changes relative to alpha 2, including what we believe should be nearly the last changes to GHC's boot libraries. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. Happy compiling, ~ Ben [TypeAbstractions]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0425-d… [extended-literals]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0451-s… [unsatisfiable]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0433-u… [warnings]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0541-w… [deprecated-exports]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0134-d… [jsem]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0540-j… [release notes]: https://downloads.haskell.org/ghc/9.8.1-alpha3/docs/users_guide/9.8.1-notes…

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[ANNOUNCE] GHC 9.8.1-alpha2 is now available
by Ben Gamari 23 Aug '23

23 Aug '23

The GHC developers are very pleased to announce the availability of the second alpha prerelease of GHC 9.8.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.8.1-alpha2 GHC 9.8 will bring a number of new features and improvements, including: * Preliminary support the `TypeApplications` language extension [type-binders], allowing types to be bound in type declarations. * Support for the `ExtendedLiterals` extension, providing syntax for non-word-sized numeric literals in the surface language [extended-literals] * Improved rewrite rule matching behavior, allowing limited matching of higher-order patterns * Better support for user-defined warnings by way of the `WARNING` pragma [warnings] * The introduction of the new `GHC.TypeError.Unsatisfiable` constraint, allowing more predictable user-defined type errors [unsatisfiable] * Implementation of the export deprecation proposal, allowing module exports to be marked with `DEPRECATE` pragmas [deprecated-exports] * The addition of build semaphore support for parallel compilation; with coming support in `cabal-install` this will allow better use of parallelism in multi-package builds [jsem] * More efficient representation of info table provenance information, reducing binary sizes by over 50% in some cases when `-finfo-table-map` is in use A full accounting of changes can be found in the [release notes]. This alpha includes around two dozen bug-fixes relative to alpha 1. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. Happy compiling, ~ Ben [type-binders]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0425-d… [extended-literals]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0451-s… [unsatisfiable]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0433-u… [warnings]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0541-w… [deprecated-exports]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0134-d… [jsem]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0540-j… [release notes]: https://downloads.haskell.org/ghc/9.8.1-alpha2/docs/users_guide/9.8.1-notes… [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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Re: [Haskell-cafe] Can I get 'forall (a :: k). Typeable a => Dict (Typeable k)'?
by Ryan Scott 23 Aug '23

23 Aug '23

To respond to your original point: > Morally I think that > > class Typeable (a :: k) > > should have been > > class Typeable k => Typeable (a :: k) > > This has been considered before, although it is not entirely straightforward to implement. See [1] and [2], which track the idea of having GHC solve these constraints automatically, without the need for users to explicitly reach for `typeRepKind`. Best, Ryan ----- [1] https://gitlab.haskell.org/ghc/ghc/-/issues/14190 [2] https://gitlab.haskell.org/ghc/ghc/-/issues/16627

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Can I get 'forall (a :: k). Typeable a => Dict (Typeable k)'?
by Tom Ellis 23 Aug '23

23 Aug '23

Morally I think that class Typeable (a :: k) should have been class Typeable k => Typeable (a :: k) If I'm wrong, could someone please elaborate why? If I'm right, please read on ... That would be a breaking change, but could we at least get kindable :: forall (a :: k). Typeable a => Dict (Typable (a :: k)) in the meantime? Tom

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[ANN] avif - libavif bindings on Hackage
by Vanessa McHale 12 Aug '23

12 Aug '23

Hello all, I have release avif, a Haskell wrapper around libavif compatible with JuicyPixels. https://hackage.haskell.org/package/avif Cheers, Vanessa McHale

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[ANNOUNCE] mig - new library to write composable web-servers
by Anton Kholomiov 09 Aug '23

09 Aug '23

I'm happy to announce the release of a new library for web-servers. It offers simple and concise functions to build servers from small parts. Servers are monoids, and we can aggregate them with functions like `mconcat`. Main features: * lightweight library * expressive DSL to compose servers * type-safe handlers * handlers are encoded with generic haskell functions * built on top of WAI and warp server libraries. For DSL design I wanted to touch the middle ground between scotty (being small and simple, but imperative) and servant (being composable, but somewhat advanced on type-level features) I like scotty for being very simple and servant for being composable, type-safe and how functions are used as handlers which provides decoupling of Web-handlers from application logic. But sometimes scotty feels too imperative and lacks a servant's composability. And servant with type-level magic and huge errors can feel too complicated. So I wanted to create something in the middle. Something composable and simple at the same time. And be able to use arbitrary haskell functions as handlers. There are only two functions to combine servers. And types of inputs and outputs are encoded with newtype-wrpappers with phantom types which provide type-safety. It's very first release. So feedback is welcome and I'm sure there are places to improve. I hope that you will enjoy the lib. links: * [github](https://github.com/anton-k/mig) * [hackage](https://hackage.haskell.org/package/mig-0.1.0.1) * [examples]( https://github.com/anton-k/mig/tree/main/examples/mig-example-apps) * [example of a handle pattern app]( https://github.com/anton-k/handle-pattern-mig-app) * [example of a reader pattern app]( https://github.com/anton-k/reader-pattern-mig-app) Cheers, Anton

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[Call for submissions TFPiE 2024] Trends in Functional Programming in Education - January 9 2024, Seton Hall University, USA
by Peter Achten 08 Aug '23

08 Aug '23

TFPIE 2024 Call for papers https://wiki.tfpie.science.ru.nl/TFPIE2024 (January 9th 2024, West Orange, NJ, USA, co-located with TFP 2024 at Seton Hall University) TFPIE 2024 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=tfpie2024 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 26th 2023, Anywhere on Earth Notification: by December 30th 2023 (Note: submissions will be evaluated on a rolling basis, so earlier submissions will receive an earlier response) TFPIE Registration Deadline: TBA Workshop: January 9th 2024 Submission for formal review: April 19th 2024, Anywhere on Earth. Notification of full article: May 24th 2024 Camera ready: June 28th 2024 Program Committee - TBD Stephen Chang (Chair) - UMass Boston, USA Registration information See https://wiki.tfpie.science.ru.nl/TFPIE2024 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.

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[ANN] Yampa 0.14.4
by Ivan Perez 08 Aug '23

08 Aug '23

Hi everyone, I'm very happy to announce the release of Yampa 0.14.4 and yampa-test 0.14.4. Yampa is a fast, elegant Functional Reactive Programming implementation. Yampa prides itself in being a long-standing community project. It has now been around for 20 years!!! See https://github.com/ivanperez-keera/yampa#features for details on Yampa's features. This release introduces a benchmark that can be used to evaluate the performance of a proposed change to Yampa, as well as to compare different ways of writing the same expressions. We hope that the benchmarks will improve and grow over time, and that they will help speed up the process of evaluating pull requests submitted to the project. Performance can be tricky to evaluate precisely, so no eyes are too many. We invite everyone to go to the Github repo and discuss ways to make the benchmarks more reliable, representative, and useful. This release also introduces version bounds for dependencies that did not have them, which will make Yampa easier to install. The current release has been tested with all major GHC versions from 7.6 to 9.6. Special thanks go to @johannes-riecken for a regular contribution to support the Yampa project. For details, see: - https://github.com/ivanperez-keera/Yampa/releases/tag/v0.14.4 The Yampa ecosystem comprises many projects. You can explore the current versions at: - https://hackage.haskell.org/package/Yampa - https://hackage.haskell.org/package/yampa-test - https://hackage.haskell.org/package/yampa-gloss - https://hackage.haskell.org/package/simple-affine-space - https://hackage.haskell.org/package/SpaceInvaders - https://hackage.haskell.org/package/haskanoid # Code The github repos are located at: - https://github.com/ivanperez-keera/Yampa/ - https://github.com/ivanperez-keera/yampa-gloss/ - https://github.com/ivanperez-keera/simple-affine-space/ - https://github.com/ivanperez-keera/SpaceInvaders/ - https://github.com/ivanperez-keera/haskanoid/ # What's coming This release comes exactly 2 months after the last release. The next release is planned for Oct 7, 2023. There are several issues open that you can contribute to. Following our roadmap, we plan to: - Create demos and examples using GHC's web backends. - Remove unnecessarily exposed elements from the interface (e.g., FRP.Yampa.Arrow.arr3) that are not used and belong in other libraries. This topic is open to discussion. - Switch from the old mailing list to a new discussion method. We will in the future lose access to Yale's CS department-based mailman list, and are thinking of the best place to move to. For now, the Discussions tab on Github has been enabled. # Other news I'm also happy to report that the paper "The Beauty and Elegance of Functional Reactive Animation" has been accepted for presentation at FARM 2023. The paper discusses different animations that can easily be created using Yampa. I invite you all to download the paper once it's published, and to stop by FARM 2023 if you are at ICFP next month! # Donations Our project is seeking donations to help continue developing Yampa, create new open source libraries, new material, and give talks. No donation is too small. Any contribution will absolutely help. See https://github.com/sponsors/ivanperez-keera for details. If you can help, please come forward. All the best, Ivan

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Haskell GitLab abuse
by aeiouaeiouaeiouaeiouaeiouaeiou 03 Aug '23

03 Aug '23

Spam detection software, running on the system "mail.haskell.org", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Hi everyone, I don't know where the best place to post about this issue is, so here goes. Recently I found that some Google results are bloated with malicious links from Haskell GitLab fork repositories. You can see for yourself: https://gitlab.haskell.org/search?repository_ref=master&scope=blobs&search=… [...] Content analysis details: (5.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 3.0 SINGLE_HEADER_3K A single header contains 3K-4K characters 1.3 HK_RANDOM_FROM From username looks random 0.0 HK_RANDOM_ENVFROM Envelope sender username looks random -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% [score: 0.5000] 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid The original message was not completely plain text, and may be unsafe to open with some email clients; in particular, it may contain a virus, or confirm that your address can receive spam. If you wish to view it, it may be safer to save it to a file and open it with an editor.

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ICFP 2023: Call for Participation
by ICFP Publicity 03 Aug '23

03 Aug '23

===================================================================== Call for Participation The 28th ACM SIGPLAN International Conference on Functional Programming (ICFP 2023) and affiliated events https://icfp23.sigplan.org Seattle, USA; Sep 4-9, 2023 ===================================================================== ICFP is a celebration of the art and science of functional programming, providing a forum for researchers and developers to engage on a variety of topics, from foundations to features, and from abstraction to application. You are invited to participate in a full week dedicated to functional programming, featuring the ICFP main conference as well as several other related events. * Accepted Papers: https://icfp23.sigplan.org/track/icfp-2023-papers#event-overview * Registration: https://icfp23.sigplan.org/attending/registration The early-bird deadline is August 5, 2023 * Hotel: The Westin Seattle https://icfp23.sigplan.org/venue/icfp-2023-venue Conference hotel reservation cutoff: August 11, 2023 There are several events affiliated with ICFP: September 4 Erlang - https://icfp23.sigplan.org/home/erlang-2023 FHPN - https://icfp23.sigplan.org/home/FHPNC-2023 HIW - https://icfp23.sigplan.org/home/hiw-2023 HOPE - https://icfp23.sigplan.org/home/hope-2023 PLMW - https://icfp23.sigplan.org/track/plmw-icfp-2023 TyDe - https://icfp23.sigplan.org/home/TyDe-2023 September 5-7 ICFP - Main conference September 8 Haskell - https://icfp23.sigplan.org/home/haskellsymp-2023 FARM - https://icfp23.sigplan.org/home/farm-2023 FUNARCH - https://icfp23.sigplan.org/home/FUNARCH-2023 ML - https://icfp23.sigplan.org/home/mlworkshop-2023 miniKanren - https://icfp23.sigplan.org/home/minikanren-2023 Tutorial: Vehicle, A Specification Language for Neural Network Properties Tutorial: Porting Lwt applications to OCaml 5 and Eio September 9 Haskell - https://icfp23.sigplan.org/home/haskellsymp-2023 Scheme - https://icfp23.sigplan.org/home/scheme-2023 OCaml - https://icfp23.sigplan.org/home/ocaml-2023 DeclMed - https://icfp23.sigplan.org/home/declmed-2023 Tutorial: Teaching and Learning Compilers Incrementally Tutorial: Teaching functional programming Conference organizers: https://icfp23.sigplan.org/committee/icfp-2023-organizing-committee =====================================================================

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