August 2026 - Haskell-Cafe

Haskell.org is not feeling well
by X Y 28 Aug '26

28 Aug '26

L.S., I am trying to update the Haskellwiki; I keep getting 503 errors and one 502 error. The most recent message is: ---------------------------------------------------- Error 503 Backend is unhealthy Backend is unhealthy Error 54113 Details: cache-rtm-ehrd2290036-RTM 1787867570 777577883 Varnish cache server ---------------------------------------------------- Can someone do something about this? Regards, ಹೆಂಕ್-ಜಾನ್ ವ್ಯಾನ್ ಟುಯ್ಲ್ Henk-Jan van Tuyl

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IFL 2026 - Second call for draft papers
by Mart Lubbers 28 Aug '26

28 Aug '26

======================================================================= IFL 2026 38th Symposium on Implementation and Application of Functional Languages venue: Aspenäs Herrgård, Gothenburg, Sweden October 28 - 30 2026 https://ifl26.cse.chalmers.se/ ======================================================================= ### 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 2026 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. ### 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 2026 will use a post-symposium review process for the formal proceedings. Authors are invited to submit draft papers before the symposium. The program chairs will screen submissions for relevance to IFL, and accepted drafts will be shared with all participants. Each accepted paper must be presented at the symposium by at least one author. If submissions exceed capacity, selection will be based on quality, maturity, and relevance. Authors of accepted presentations will have the opportunity to revise their work in response to symposium feedback and submit a full paper to the post-proceedings. These submissions will be reviewed by the program committee for correctness, novelty, originality, relevance, significance, and clarity. The post-symposium review process is single-blind, with at least three reviews per paper. Camera-ready versions may include minor revisions without further review. ### Important dates Submission of draft papers September 4, 2026 Draft papers notification September 11, 2026 Deadline for early registration September 18, 2026 Deadline for late registration September 25, 2026 IFL symposium October 28-30, 2026 Submission of papers for proceedings November 25, 2026 Notification of acceptance February 12, 2027 Camera-ready version March 12, 2027 Deadlines are end of day Anywhere on Earth (UTC-12). ### 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=ifl26 Register here: https://ifl26.cse.chalmers.se/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: ICPS publishing model FAQ: https://www.acm.org/publications/icps/faq ACM Open program details: https://www.acm.org/publications/openaccess Questions: 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: - Alex Gerdes, Chalmers and University of Gothenburg, Sweden - Koen Claessen, Chalmers and University of Gothenburg, Sweden Publicity Chair: - Mart Lubbers, Radboud University, The Netherlands Local Chairs: - Alex Gerdes, Chalmers and University of Gothenburg, Sweden - Koen Claessen, Chalmers and University of Gothenburg, Sweden Please direct any questions you may have towards alexg(a)chalmers.se. ### Program committee - Abhiroop Sarkar, ETH Zurich - Andres Löh, Well-Typed LLP - Daan Leijen, Microsoft - Dominic Orchard, University of Kent - Fritz Henglein, DIKU - Graham Hutton, University of Nottingham - Guillaume Allais, University of Strathclyde - Jesper Cockx, Delft University of Technology - Mart Lubbers, Radboud University - Nachiappan Valliappan, University of Edinburgh - Nicolas Wu, Imperial College London - Niki Vazou, IMDEA Software Institute The program committee is still being finalized and may be updated. ### Venue IFL 2026 will be held at Aspenäs Herrgård, just outside Gothenburg, Sweden. Aspenäs Herrgård is a residential conference center by Lake Aspen in Lerum, approximately 20 minutes from central Gothenburg. See the website for more information: https://ifl26.cse.chalmers.se/venue/ ### 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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LEFUNK 2026 (Leipzig, Germany, September 29-30) - register now
by Johannes Waldmann 24 Aug '26

24 Aug '26

register now for: Leipziger Workshop Funktionale Programmierung, September 29-30 https://www.imn.htwk-leipzig.de/LFUNK2026/ program includes talks, tutorials, and music live coding performances. we are looking for sponsors: buy extra “industry tickets” and advertise your company at the workshop. - J.W.

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like "deriving Read" but faster?
by Johannes Waldmann 23 Aug '26

23 Aug '26

Dear Cafe, I could use a parser that is equivalent to the one produced by "deriving Read" but ... A) faster, and using less space (Data.Text(.Lazy) instead of String) B) streaming (parse a long list literal "[0,1,2, ... ]" in constant space, produce the first cons of the result right after reading "[0") C) with some minimal error reporting (e.g., some prefix of not-consumed input) perhaps attoparsec with some form of early-commited choice? I do have something (only for A) at https://codeberg.org/jwaldmann/text-read (attoparsec on lazy text) and it seems twice as fast as "deriving Read" in my tests. NB: I was quite shocked to see that "deriving Read" accepts "Just Foo { foo = 42 }" (no parentheses around the record literal) (while "deriving Show" produces them). - J.W.

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HExpat
by Ivan Perez 20 Aug '26

20 Aug '26

Hi, Does anyone have a valid email address to contact a current maintainer of HExpat? https://hackage.haskell.org/package/hexpat The ones I tried (including the one listed on the package page on Hackage) all bounced. Thanks, Ivan

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Accessing haskell.org returns 503 errors
by Ivan Perez 19 Aug '26

19 Aug '26

Hi, I just tried to access https://wiki.haskell.org/Base_package and got the following messages: Error 503 Backend is unhealthy and Error 503 first byte timeout It also happens when I try to access https://downloads.haskell.org/ghc/latest/docs/users_guide/. Ivan

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Errors downloading packages from Hackage in CI job on Github
by Ivan Perez 16 Aug '26

16 Aug '26

Hi, My Github actions have been failing all day with messages like: Unexpected response 404for http://objects-us-east-1.dream.io/hackage-mirror/package/StateVar-1.2.2.tar… Error: Process completed with exit code 1. It's not always the same package. If I keep insisting, they may eventually succeed, but it can take dozens of attempts over several hours. Is this a problem of Github or Hackage? Thanks, Ivan

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The Leksah (Haskell) IDE for Windows, Linux & macOS
by Andrew Goh 14 Aug '26

14 Aug '26

Dear Haskell Cafe, There was the Leksah (Haskell) IDE about 10 to 12 years ago. I wonder if you chaps can bring it back for the Windows, Linux and maybe macOS platform. I have the GHCup toolchain installed after a few mistries, and set up VS Code for Haskell programming, but I still would really prefer the Leksah IDE (this time in native mode) instead. As for the macOS platform, there is a Haskell Mac for IDE that can be brought for under US$10. Lastly, why don't you allow Haskell users to subscribe to all Haskell mailing lists rather than go individaully to each one to do that. - Andrew

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re-implementing gracefulClose in the network library
by Kazu Yamamoto 14 Aug '26

14 Aug '26

Hello, I'm going to change the implementation of "gracefulClose" in the network library. If you have opinions, please speak up. https://github.com/haskell/network/pull/617 --Kazu

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Type-level Programming and Extensibility at The MCG! - Melbourne Compose Group - Thurs 20th of August
by John Walker 12 Aug '26

12 Aug '26

This month we are looking forward to **Viktor Dukhovni** taking us into the realm of practical type level programming. *The Talk* *Viktor Dukhovni - Types, Nats, and Wire Formats - Type-level Programming and Extensibility in the Haskell dnsbase Stub Resolver Library * The dnsbase stub resolver library, written in Haskell, is a modernised revision of Kazu Yamamoto's "dns" library (GHC 7.x 2010-06). The "dns" library modelled DNS records via an ADT, with discrete constructors for each support RR type. In "dnsbase" existential quantification replaces the fixed form ADT and additional type-level machinery is used to make the library's set of supported DNS types extensible at runtime. This talk will highlight some of the techniques that make this possible. *When and Where* Format: Strictly IRL When: Thursday 20th Aug 2026, 6:00pm – 8:00pm Where: Kathleen Syme Centre, Activity Room 2, Carlton (Melbourne Victoria, Australia) Arrive from 6:00 for chat and socialising, talks start start at 6:30pm. [Please RSVP via Luma](https://luma.com/8eywg8ed) . As always, newcomers welcome. *About Melbourne Compose Group* Melbourne Compose Group is the monthly in-person meetup for functional programmers in Melbourne, every 3rd Thursday of the month in Carlton. Hope to see you there :) -Ben Hutchison & John Walker

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