- Haskell-Cafe - Haskell.org

Vienna Haskell Meetup on Sep 26th
by Andreas Klebinger 15 Aug '24

15 Aug '24

** *Hello everyone! We are hosting a Haskell meetup in Vienna on the 26th of September! The location will be at TU Vienna Treitlstraße 3, Seminarraum DE0110. The room will open at 18:00.We plan to have 1-2 short talks starting at 19:00 (topics to be announced). Depending on interest there might also be a short Show & Tell session giving people the opportunity to show off or talk about something they work(ed) on for 5-10 Minutes each.There will be time to discuss the presentations with some snacks and non-alcoholic drinks being provided afterwards with an option to acquire beer for a reasonable price.The meetup is open ended but we might have to relocate to a nearby bar as a group if it goes very late..* *There is no entrance fee or mandatory registration, but to help with planning we ask you to let us know in advance if you plan to attend here https://forms.gle/Paiw6D4QJzTKzcmM6 <https://forms.gle/Paiw6D4QJzTKzcmM6>or per email at haskellvienna.meetup(a)gmail.com. We especially encourage you to reach out if you would like to participate in the show&tell or to give a full talk so that we can ensure there is enough time for you to present your topic.We hope to welcome everyone soon, your organizers:Andreas(Andreas PK), Benny, Chris, fendor, VeryMilkyJoe, Samuel*

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no-unused-imports for only one import
by PICCA Frederic-Emmanuel 09 Aug '24

09 Aug '24

Hello, I would like to set -Wno-unused-imports for only one import, is it possible and how to do it ? thanks for your advices. Frederic

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POPL 2025 Call for Tutorials
by Ningning Xie 08 Aug '24

08 Aug '24

POPL 2025 CALL FOR TUTORIALS https://popl25.sigplan.org/track/POPL-2025-tutorials#Call-For-Tutorials The 52nd ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL 2025) will be held in Denver, United States. POPL provides a forum for the discussion of fundamental principles and important innovations in the design, definition, analysis, transformation, implementation, and verification of programming languages, programming systems, and programming abstractions. Tutorials for POPL 2025 are solicited on any topic relevant to the POPL community. We particularly encourage submissions of introductory tutorials that make the research presented at POPL more accessible to the participants. Tutorials will be held on Jan 19–21, 2025. The expected length of a tutorial is 3 hours, including questions and discussion (Q&A). *Submission details* Deadline for submission: October 18th, 2024 Notification of acceptance: November 1st, 2024 A tutorial proposal should provide the following information: - Tutorial title - Presenter(s), affiliation(s), and contact information - 1-3 page description (for evaluation). This should include the objectives, topics to be covered, presentation approach, target audience, prerequisite knowledge, and if the tutorial was previously held, the location (i.e. which conference), date, and number of attendees if available. - 1-2 paragraph abstract suitable for tutorial publicity. - 1-paragraph biography suitable for tutorial publicity. Proposals must be submitted by email to Christoph Matheja (chmat(a)dtu.dk) and Robert Rand (rand(a)uchicago.edu) with the subject line "POPL 2025 Tutorial Proposal: [tutorial name]". The proposal should be attached as a PDF, docx, or txt file. *Further information* Any query regarding POPL 2025 tutorial proposals should be addressed to the co-located events chairs Christoph Matheja (chmat(a)dtu.dk) and Robert Rand ( rand(a)uchicago.edu) or to the general chair Steve Zdancewic ( stevez(a)seas.upenn.edu)

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Mathematics in Programming - a book with Haskell examples
by Xinyu LIU 06 Aug '24

06 Aug '24

Hello, My book 'Mathematics in Programming' in English was published on 7/11/2024. This book uses Haskell as the main tool for examples of mathematics ideas. Springer link: https://link.springer.com/book/10.1007/978-981-97-2432-1 Amazon link: https://www.amazon.com/Mathematics-Programming-Xinyu-Liu/dp/9819724317/ The book presents the mathematical view and tools of computer programming with broad and friendly context. It explains the basic concepts such as recursion, computation model, types, data, and etc. The book serves as an introductory and reference guide to the engineers, students, researchers, and professionals who are interested in functional programming, type system, and computer programming languages. The book covers seven topics. Firstly, it lays out the number system based on Peano Axioms and demonstrates the isomorphic computer data structures. Then, it introduces Lambda calculus as a computing model and recursion, an important programming structure, with the Y-combinator. It next presents the basic abstract algebra, including group and fields, and provides a friendly introduction to Galois theory. After that, it uses category theory as a tool to explain several concepts in computer programming, including the type system, polymorphism, null handler, and recursive data types, then followed by an application of program optimization. In the last two chapters, the author shows how to program with the concept of infinity through stream and lazy evaluation, and then explains the naïve set theory and transfinite numbers, from which the logic paradox arises. Finally, it introduces four historical views of mathematical foundation, as well as Gödel’s incompleteness theorems developed in 1930s, and how they define the boundaries of computer programming. Additionally, the book provides biographies, stories, and anecdotes of 25 mathematicians, along with over 130 exercises and their corresponding answers. Xinyu LIU https://github.com/liuxinyu95 <https://github.com/liuxinyu95/unplugged> *e*^(*π*i)+1 = 0

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IFL 2024 Final call for papers, extended submission deadline.
by Mart Lubbers 05 Aug '24

05 Aug '24

======================================================================= IFL 2024 36rd Symposium on Implementation and Application of Functional Languages venue: Radboud University Nijmegen, The Netherlands August 26 - 28 2024 https://ifl24.cs.ru.nl ======================================================================= ### Scope The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2024 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming. ### Industrial track and topics of interest Topics of interest to IFL include, but are not limited to: - language concepts - type systems, type checking, type inferencing - compilation techniques - staged compilation - run-time function specialisation - run-time code generation - partial evaluation - (abstract) interpretation - meta-programming - generic programming - automatic program generation - array processing - concurrent/parallel programming - concurrent/parallel program execution - embedded systems - web applications - (embedded) domain specific languages - security - novel memory management techniques - run-time profiling performance measurements - debugging and tracing - virtual/abstract machine architectures - validation, verification of functional programs - tools and programming techniques ### Peer-review process Following IFL tradition, IFL 2024 will use a post-symposium review process to produce the formal proceedings. Before the symposium authors submit draft papers. These draft papers will be screened by the program chairs to make sure that they are within the scope of IFL. The draft papers will be made available to all participants at the symposium. Each draft paper is presented by one of the authors at the symposium. After the symposium, a formal review process will take place, conducted by the program committee. Reviewing is single blind. There will be at least 3 reviews per paper. The reviewers have 6 weeks to write their reviews. For the camera-ready version the authors can make minor revisions which are accepted without further reviewing. ### Important dates Submission deadline of draft papers August 6th, 2024 EXTENDED Notification of acceptance for presentation August 6th, 2024 Registration deadline August 19th, 2024 IFL symposium August 26-28, 2024 Submission of papers for proceedings December 1st, 2024 Notification of acceptance February 2nd, 2025 Camera-ready version March 2nd, 2025 ### Submission details All contributions must be written in English. Papers must use the ACM two columns conference format, which can be found at: http://www.acm.org/publications/proceedings-template Submit your paper here: https://easychair.org/conferences/?conf=ifl20240 Register here: https://ifl24.cs.ru.nl/Registration Important note to authors about the new ACM open access publishing model ACM has introduced a new open access publishing model for the International Conference Proceedings Series (ICPS). Authors based at institutions that are not yet part of the ACM Open program and do not qualify for a waiver will be required to pay an article processing charge (APC) to publish their ICPS article in the ACM Digital Library. To determine whether or not an APC will be applicable to your article, please follow the detailed guidance here: https://www.acm.org/publications/icps/author-guidance. Further information may be found on the ACM website, as follows: - Full details of the new ICPS publishing model: https://www.acm.org/publications/icps/faq - Full details of the ACM Open program: https://www.acm.org/publications/openaccess - Please direct all questions about the new model to icps-info(a)acm.org. ### Peter Landin Prize The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honoured article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 Euros. ### Organisation PC Chairs: Mart Lubbers Radboud University, The Netherlands Local Chairs: Peter Achten Radboud University, The Netherlands Sven-Bodo Scholz, Radboud University, The Netherlands ### Program committee: Benoît Montagu, University of Lorraine, Inria, France Christos Dimoulas, Northwestern University, USA Edsko de Vries, Well-typed, The Netherlands Fritz Henglein, University of Copenhagen, Denmark Ian Mackie, University of Sussex, UK Jason Hemann, Seton Hall University, USA João Saraiva, Universidade do Minho, Portugal Jurriaan Hage, Heriot-Watt University, UK Kenichi Asai, Ochanomizu University, Japan Maja Kirkeby, Roskilde University, Denmark Marco Morazán, Seton Hall University, USA Neil Mitchell, Facebook, UK Ralf Laemmel, University of Koblenz Landau, Germany Rinus Plasmeijer, TOP Software/Radboud University, The Netherlands Stephen Chang, UMass Boston, USA Tim Steenvoorden, Open University, The Netherlands Tom Schrijvers, KU Leuven, Belgium Yusuf Moosa Motara, Rhodes University, South Africa ### Venue IFL 2024 will be held physically in Nijmegen, the Netherlands. See the website for more information. https://ifl24.cs.ru.nl ### Acknowledgments This call-for-papers is an adaptation and evolution of content from previous instances of IFL. We are grateful to prior organisers for their work, which is reused here.

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Haskell Implementors' Workshop - Change of date
by Matthew Pickering 29 Jul '24

29 Jul '24

This year the decision has been taken to combine together Haskell Implementors' Workshop and Haskell Symposium. Therefore the workshop will now take place on the dates September 6/7 (the dates of the Haskell Symposium). Please email me if you have any questions. Cheers, Matt

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[ANN] streamly-0.10 with fast binary serialization
by Harendra Kumar 29 Jul '24

29 Jul '24

Streamly is a concurrent stream and array library supporting a wide range of functionality. Important features in the new release include: (1) fast binary serialization to arrays with an option to serialize record field names; (2) the array type can now represent pinned as well unpinned memory, unifying the representations used by bytestring, text and vector; and (3) concurrency support for folds. For more details, see this post: https://blog.composewell.com/v0/posts/streamly-release-0.10.0.html . -harendra

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Call for Participation, Functional Software Architecture (Sep 6, Milan)
by Michael Sperber 29 Jul '24

29 Jul '24

====================================================================== *** FUNARCH 2024 -- CALL FOR PARTICIPATION *** The Second ACM SIGPLAN Workshop on Functional Software Architecture - FP in the Large 6th September 2024, Milan, Italy Co-located with ICFP 2024 https://www.functional-architecture.org/events/funarch-2024/ ====================================================================== BACKGROUND: The ACM SIGPLAN Workshop on Functional Software Architecture - FP in the Large aims to disseminate and enable the use of functional programming in the large and long-lived software projects. We specifically want: - To assemble a community interested in software architecture techniques and technologies specific to functional programming; - To identify, categorize, and document topics relevant to the field of functional software architecture; - To connect the functional programming community to the software architecture community to cross-pollinate between the two. We'd love for you to be part of this effort. Whatever your background, you're welcome at FUNARCH - to listen to talks, report on your experience, and interact with others that share our goals. See you at FUNARCH! REGISTRATION: You can register for the workshop via the registration page for the ICFP conference, but there's no need to also register for the conference. Reduced fees are available until 5th August. http://icfp24.sigplan.org/attending/registration KEYNOTE: Architecting Functional Programs Marco Sampellegrini ACCEPTED SUBMISSIONS: F3: A Compiler For Feature Engineering Weixi Ma, Arnaud Venet, Junhua Gu, Subbu Subramanian, Siyu Wang, Rocky Liu (Meta) Daniel Friedman, Yafei Yang (Indiana University) Design and implementation of a verified interpreter for additive manufacturing programs Matthew Sottile, Mohit Tekriwal (Lawrence Livermore National Laboratory) Applying Continuous Formal Methods to Cardano James Chapman, Arnaud Bailly, Polina Vinogradova (IOHK) Continuations: what have they ever done for us? Marc Kaufmann (Austriae Central European University), Bogdan Popa Bidirectional Data Transformations Marcus Crestani, Markus Schlegel, Marco Schneider (Active Group) PROGRAM CHAIRS: Mike Sperber (Active Group, Germany) Perdita Stevens (University of Edinburgh, UK) PROGRAM COMMITTEE: Annette Bieniusa (University of Kaiserslautern) Jeffrey Young (IOG) Will Crichton (Brown University) Isabella Stilkerich (Schaeffler Technologies AG) Kiko Fernandez-Reyes (Ericsson) Ryan Scott (Galois) Satnam Singh (Groq) Facundo Dominguez (Tweag) Ilya Sergey (University of Singapore) Martin Elsman (University of Copenhagen) Benjamin Pierce (University of Pennsylvania) Matthew Flatt (University of Utah) Nada Amin (Harvard University) Richard Eisenberg (Jane Street) WORKSHOP VENUE: The workshop will be co-located with the ICFP 2024 conference at the Milano Convention Centre, Milan, Italy. ======================================================================

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Functional Conf 2024 - Bengaluru, India
by John Sinclair 26 Jul '24

26 Jul '24

===================================================================== Call for Proposals Functional Conf 2024 21-23 November Bengaluru, India https://functionalconf.com <https://igafnl.com/click?redirect=https%3A%2F%2Ffunctionalconf.com&dID=1721…> ===================================================================== You are invited to join us for 3 days in-person for Functional Conf, Asia's Premier Functional Programming Conference. Immerse yourself in thought-provoking sessions led by top-notch speakers, engage in hands-on workshops to elevate your coding skills, and network with like-minded professionals. Whether you’re a seasoned pro or a curious beginner, this conference promises to ignite your passion for Functional Programming and revolutionize the way you approach software development. Don’t miss out on this exciting opportunity to be a part of the future of technology. *Call for Proposals is currently open* The stage is set for you to showcase your expertise at our upcoming event through our Call for Proposals. Whether you’re eager to deliver a captivating talk, lead a dynamic demonstration, present a compelling case study, offer an insightful tutorial, share an experience report, or facilitate an engaging workshop of Functional Programming in action, we welcome your submissions with open arms. * Submit a Proposal (deadline: 1 September 2024) https://confengine.com/conferences/functional-conf-2024/proposals <https://igafnl.com/click?redirect=https%3A%2F%2Fconfengine.com%2Fconference…> * Registration: https://confengine.com/conferences/functional-conf-2024/register/selection <https://igafnl.com/click?redirect=https%3A%2F%2Fconfengine.com%2Fconference…> Early bird tickets still available! We hope to see you there!

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Strange kind error when using Lens.traverseOf
by Henning Thielemann 23 Jul '24

23 Jul '24

I have this simplified module: module Ganeti.LensPlain where import Control.Lens (LensLike, traverseOf) import Data.Functor.Compose (Compose(..)) traverseOf2 :: LensLike (Compose f g) s t a b -> (a -> f (g b)) -> s -> f (g t) traverseOf2 k f = getCompose . traverseOf k (Compose . f) With ghc-9.2 and later I get this kind error: src/Ganeti/LensPlain.hs:8:32: error: [GHC-25897] • Couldn't match kind ‘k2’ with ‘*’ When matching types Compose f g0 :: * -> * Compose f g :: k2 -> * Expected: s -> Compose f g t Actual: s -> Compose f g0 t0 ‘k2’ is a rigid type variable bound by the type signature for: traverseOf2 :: forall {k1} {k2} (f :: k1 -> *) (g :: k2 -> k1) s (t :: k2) a (b :: k2). LensLike (Compose f g) s t a b -> (a -> f (g b)) -> s -> f (g t) at src/Ganeti/LensPlain.hs:7:1-79 • In the second argument of ‘(.)’, namely ‘traverseOf k (Compose . f)’ In the expression: getCompose . traverseOf k (Compose . f) In an equation for ‘traverseOf2’: traverseOf2 k f = getCompose . traverseOf k (Compose . f) • Relevant bindings include f :: a -> f (g b) (bound at src/Ganeti/LensPlain.hs:8:15) k :: LensLike (Compose f g) s t a b (bound at src/Ganeti/LensPlain.hs:8:13) traverseOf2 :: LensLike (Compose f g) s t a b -> (a -> f (g b)) -> s -> f (g t) (bound at src/Ganeti/LensPlain.hs:8:1) | 8 | traverseOf2 k f = getCompose . traverseOf k (Compose . f) | ^^^^^^^^^^^^^^^^^^^^^^^^^^ GHC-9.0 accepts the code. Also GHC-9.2 accepts it when the module is compiled as part of a larger Cabal project! I thought that (.) would cause the problem, but manually inlining it does not help. I compiled with: $ ghc-9.6.6 -package lens -c src/Ganeti/LensPlain.hs

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