- Haskell-Cafe - Haskell.org

Call for Participation: BOB 2026 (Berlin, Mar 13)
by Stefan Wehr 19 Dec '25

19 Dec '25

there's quite a bit of Haskell material at BOB 2026. Come along! ========================================================================= BOB 2026 Conference “What happens if we simply use what’s best?” March 13, 2026, Berlin https://bobkonf.de/2026/ Program: https://bobkonf.de/2026/program.html Registration: https://bobkonf.de/2026/registration.html ========================================================================= BOB conference is a place for developers, architects, and decision-makers to explore technologies beyond the mainstream in software development and to find the best tools available to software developers today. Our goal is for all participants of BOB to return home with new insights that enable them to improve their own software development experience. The program features 16 talks and 8 tutorials on current topics: https://bobkonf.de/2026/program.html Talk subjects includes functional programming, software architecture, formal methods, accessibility, UI programming, reactive systems, and domain-driven design. BOB tutorial include sessions on TypeScript, OCaml, Haskell, Agda, accessibility, and reactive systems. Stefan Kaufmann will give the keynote talk on digital sovereignty. Registration is open - many discount options - including limited early-bird discounts - are available, as are grants for members of groups underrepresented in tech. https://bobkonf.de/2026/registration.html

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Call for Participation: BOB 2026 (Berlin, Mar 13)
by Michael Sperber 15 Dec '25

15 Dec '25

BOB 2026 has lots of exciting content on functional programming, type systems and formal methods! ========================================================================= BOB 2026 Conference “What happens if we simply use what’s best?” March 13, 2026, Berlin https://bobkonf.de/2026/ Program: https://bobkonf.de/2026/program.html Registration: https://bobkonf.de/2026/registration.html ========================================================================= BOB conference is a place for developers, architects, and decision-makers to explore technologies beyond the mainstream in software development and to find the best tools available to software developers today. Our goal is for all participants of BOB to return home with new insights that enable them to improve their own software development experience. The program features 16 talks and 8 tutorials on current topics: https://bobkonf.de/2026/program.html Talk subjects includes functional programming, software architecture, formal methods, accessibility, UI programming, reactive systems, and domain-driven design. BOB tutorial include sessions on TypeScript, OCaml, Haskell, Agda, accessibility, and reactive systems. Stefan Kaufmann will give the keynote talk on digital sovereignty. Registration is open - many discount options - including limited early-bird discounts - are available, as are grants for members of groups underrepresented in tech. https://bobkonf.de/2026/registration.html

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TFPiE 2026, Call for Submissions
by Mart Lubbers 15 Dec '25

15 Dec '25

TFPIE 2026 Call for papers https://wiki.tfpie.science.ru.nl/TFPIE2026 (January 26th 2026, Odense, Denmark, co-located with TFP 2026 at University of Southern Denmark) TFPIE 2026 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/my/conference?conf=tfpie26 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 2025, Anywhere on Earth Notification: by December 30th 2025 (Note: submissions will be evaluated on a rolling basis, so earlier submissions will receive an earlier response) TFPIE Registration Deadline: TBA Workshop: January 26th 2026 Submission for formal review: April 22nd 2026, Anywhere on Earth Notification of full article: May 27th 2026 Camera ready: June 24th 2026 ## Program Committee Mart Lubbers, Radboud University, Nijmegen, Netherlands (PC Chair) Tim Steenvoorden, Open Universiteit, Heerlen, Netherlands Marco T. Morazán, Seton Hall University, South Orange, NJ, USA Guannan Wei, Tufts University, Medford, MA, USA Marcos Viera, Universidad de la República, Montevideo, Uruguay Johannes Åman Pohjola, Chalmers University of Technology, Gothenburg, Sweden ## Registration information See https://wiki.tfpie.science.ru.nl/TFPIE2026 for updated information and see https://trendsfp.github.io/ for info on registration Registration and attendance are mandatory for at least one author of every paper that is presented at the workshop. Only papers that have been presented at TFPIE may be submitted to the post-reviewing process.

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Soundness of forall mixed with Coercible
by Tom Ellis 12 Dec '25

12 Dec '25

Is it sound to define forallCoercible :: forall f g. (forall a. Coercible (f a) (g a)) => Coercion (Forall f) (Forall g) forallCoercible = unsafeCoerce (Coercion @(f Any) @(g Any)) I'm having trouble coming up with a reason why it is not, but my intuition for these things is not very good. Thanks, Tom

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Re: State of Haskell 2025
by Olaf Klinke 12 Dec '25

12 Dec '25

> Because I haven't tried to upgrade: the risk of breaking something > exceeds any 'benefit' from new 'features', none of which do I want to > use. If you did not try to upgrade, how did you find out that upgrading would break your code? Indeed, only offering "yes" and "no" as options is not enough for this question. "Bottom" would be the appropriate answer in your case, and I'd have chosen that, too. Olaf

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GHC 9.12.3-rc3 is now available
by Zubin Duggal 11 Dec '25

11 Dec '25

The GHC developers are very pleased to announce the availability of the third release candidate for GHC 9.12.3. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][] and via [GHCup](https://www.haskell.org/ghcup/). GHC 9.12.3 is a bug-fix release fixing several issues of a variety of severities and scopes. A full accounting of these fixes can be found in the [release notes][]. As always, GHC's release status, including planned future releases, can be found on the GHC Wiki [status][]. This release candidate will have a two-week testing period. If all goes well the final release will be available the week of 22 December 2025. The changes from the first release candidate are - Fix use after free on windows due to a linker optimisation introduced in an earlier RC (#26613) - A fix for a bug in the configure script which result in the LLVM toolchain not being detected in certain situations (#26564) - Fixes for the WASM backend GHC development is sponsored by: * [Juspay](https://juspay.com/) * [QBayLogic](https://qbaylogic.com/) * [Channable](https://www.channable.com/) * [Haskell Foundation](https://haskell.foundation/) * [Serokell](https://serokell.io/) * [Well-Typed](https://well-typed.com/) * [Tweag](https://www.tweag.io/) * [Dotcom-Monitor](https://www.dotcom-monitor.com/) * [LoadView](https://www.loadview-testing.com/) * [Web Hosting Buddy](https://webhostingbuddy.com/) * [Find My Electric](https://www.findmyelectric.com/) * [Standard Chartered](https://www.sc.com) * [UpCloud](https://upcloud.com) We would like to that these sponsors 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. [release notes]: https://gitlab.haskell.org/ghc/ghc/-/blob/ghc-9.12/docs/users_guide/9.12.3-… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.3-rc3 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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State of Haskell 2025
by Jose Calderon 11 Dec '25

11 Dec '25

Hello everyone! The Haskell Foundation is reviving Taylor Fausak's State of Haskell Survey. It's been a few years and so we're doing it a bit differently, but the plan is to start doing this yearly again so that we can collect longitudinal data on the Haskell community and ecosystem. Please take the ~10 minutes to fill this out and share it with friends/colleagues/coworkers, whether or not they are users of Haskell. https://www.surveymonkey.com/r/6M3Z6NV Thanks! -Jose

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ICFP 2026: Call for Workshops, Tutorials, and Co-Located Events
by ICFP Publicity 09 Dec '25

09 Dec '25

ICFP 2026: Call for Workshops, Tutorials, and Co-located Events The 31st ACM SIGPLAN International Conference on Functional Programming (ICFP) invites proposals for workshops, tutorials, and co-located events. ICFP will be held in Indianapolis, IN, United States from *Monday, August 24 to Saturday, August 29, 2026*. ICFP provides a forum for researchers and developers to hear about the latest work on the design, implementation, principles, and uses of functional programming. Proposals are invited for: - *Workshops* (and other co-located events, such as symposiums and side meetings) to be affiliated with ICFP 2026 and sponsored by SIGPLAN. We welcome proposals for events that facilitate discussions, presentations, hands-on activities, and other engaging formats to foster the exchange of new ideas and community building. These events should be less formal and more focused than ICFP itself, include sessions that enable interaction among the attendees, and foster the exchange of new ideas. The preference is for one-day events, but other schedules may be possible. - *Tutorials* (or panels, discussions, etc.), lasting approximately 3 hours each, to be presented during ICFP and its co-located workshops and other events. Tutorials may focus either on a concrete technology or on a theoretical or mathematical tool. Tutorials may be intended primarily for researchers or for practitioners. Ideally, tutorials will have a concrete result, such as “Learn to do X with Y” rather than “Learn language Y”. The workshops, tutorials, etc. may occur on August 24th (the day before ICFP) and August 28-29th (the two days after ICFP). *Submission Portal*: https://icfp26events.hotcrp.com/ *All co-located events* must submit a proposal — workshops, tutorials, symposiums, or side meetings. Submission Details <https://icfp26.sigplan.org/track/icfp-2026-icfp-tutorials#submission-details> - Deadline for Workshop Proposal Submission: January 15, 2026 - Notification of Acceptance: January 29, 2026 - Deadline for Tutorial Proposal Submission: June 21, 2026 - Notification of Acceptance: June 28, 2026 Prospective organizers of workshops, symposia, or co-located events with PCs should submit proposals before the Workshop deadline. Proposals should outline the objectives, intended audience, and planned activities. Workshops that plan to have proceedings in the ACM DL will need SIGPLAN approval of their proposed PC list. The workshop chairs will solicit approval and send any feedback to workshop organizers. Workshops without proceedings still need conference approval from ICFP. See the Submission Portal for details. The selection committee will review proposals. Successful workshops may be asked to prepare a summary report suitable for publication in SIGPLAN Notices. Prospective organizers of tutorials, panels, or discussions should submit proposals by the Tutorial deadline. Proposals should outline the objectives, intended audience, and planned activities. See the Submission Portal for details. Selection Committee <https://icfp26.sigplan.org/track/icfp-2026-icfp-tutorials#selection-committ…> Event proposals will be evaluated by a committee comprising members from the ICFP 2026 organizing committee, in collaboration with the SIGPLAN executive committee. Sponsorship and Reimbursement <https://icfp26.sigplan.org/track/icfp-2026-icfp-tutorials#sponsorship-and-r…> ACM-sponsored workshops are permitted to have additional sponsors (i.e., getting donations specifically for the workshop, not for the main conference). Funds go to the ACM. Workshop organizers can request reimbursement using this form: https://app.hubspot.com/documents/5374542/view/900008676?accessId=a07c28 Further information about SIGPLAN sponsorship is available at: http://www.sigplan.org/Resources/Proposals/Sponsored/ Contact Information <https://icfp26.sigplan.org/track/icfp-2026-icfp-tutorials#contact-informati…> For inquiries, please contact the workshop co-chairs: Ben Greenman: blg(a)cs.utah.edu Jiasi Shen: sjs(a)cse.ust.hk We look forward to your proposals and to creating a vibrant and engaging workshop program at ICFP 2026!

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CGO 2026 - Call for Participation
by Luisa Cicolini 09 Dec '25

09 Dec '25

CGO 2026<https://2026.cgo.org/> registration is now open! The IEEE/ACM International Symposium on Code Generation and Optimization (CGO) provides a premier venue to bring together researchers and practitioners working at the interface of hardware and software on a wide range of optimization and code generation techniques and related issues. The conference spans the spectrum from purely static to fully dynamic approaches, and from pure software-based methods to specific architectural features and support for code generation and optimization. CGO will be held in Sydney, Australia from 31st January – 4th February 2026 and will be co-located as part of HPCA/CGO/PPoPP/CC 2026. The early-bird registration deadline<https://2026.cgo.org/attending/registration> is December 31st. For more information, please visit the CGO conference website at https://2026.cgo.org/. We hope to see you there! Luisa Cicolini

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POPL 2026 Second Call for Participation - Early registration: 12 December
by Ningning Xie 08 Dec '25

08 Dec '25

======================================= Call for Participation ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2026) January 11-17, 2026, Rennes, France. https://popl26.sigplan.org/ ======================================= - Early registration deadline: ** 12 December 2025 ** - Register here: https://popl26.sigplan.org/attending/registration - The POPL program: https://popl26.sigplan.org/track/POPL-2026-popl-research-papers ======================================= The 53rd ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2026) is a forum for the discussion of all aspects of programming languages and programming systems. Location: le Couvent des Jacobins, 20 place Saint-Anne, 35000 Rennes, France Dates: - Main conference: Wed 14 - Fri 16 January - Workshops, tutorials, co-located events: Sun 11, Mon 12, Tue 13 and Sat 17 January Keynote Speakers: - Damien Pous, CNRS, Medium-scale automation for proof assistants - Caroline Trippel, Stanford University, Hardware-Software Contracts for High Assurance with Applications to Side-Channel Security Organizers: - General Chair: Sandrine Blazy, University of Rennes - PC Chair: Suresh Jagannathan, Purdue University Full details of the conference and co-located events: https://popl26.sigplan.org/

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