- Haskell-Cafe - Haskell.org

Cognitive dissonance in the Haskell Report
by Douglas McIlroy 08 Nov '25

08 Nov '25

Section 2.4 of the Haskell report defines "identifier" as a lexeme that begins with a letter. A few paragraphs on it says An operator symbol starting with any other character [than :] is an ordinary identifier. In everyday usage, ordinary people are necessarily people, yet this kind of ordinary identifier falls outside the definition of identifier. Section 3.2 says An operator is either an operator symbol, such as + or $$, or is an ordinary identifier enclosed in grave accents. If "either" is taken in the exclusive sense, this implies that operator symbols are *not* ordinary identifiers, in contradiction to Section 2.4. But if either is taken inclusively, then the lexeme +, an ordinary identifier per Section 2.4, can optionally be enclosed in grave accents. The terminology needs some cleaning. Doug McIlroy

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GHC Steering Committee Call for Nominations
by Simon Marlow 07 Nov '25

07 Nov '25

Dear Haskellers, The GHC Steering Committee is seeking nominations for new members. *To nominate yourself *please send an email to Simon Marlow <marlowsd(a)gmail.com> <marlowsd(a)gmail.com>, briefly summarising your background and relevant experience. See below for details on what committee membership involves, and what kind of experience would be useful. DEADLINE: 6 November 2025 *What's the GHC steering committee?* The committee scrutinizes, debates and eventually decides to accept or reject proposals to change the language or major features supported by GHC. Our processes are described in the GitHub repository <https://github.com/ghc-proposals/ghc-proposals> where proposals are submitted. In particular, please have a look at the Committee bylaws <https://github.com/ghc-proposals/ghc-proposals/blob/master/committee.rst>. *Who are we looking for?* We are looking for members who have the ability to: - understand GHC proposals (e.g. for new language extensions), - find holes and missing corner cases in the specifications, - foresee the interaction with other language or compiler features, - comment constructively and improve proposals through engagement with others, - judge the cost/benefit ratio of changes, and - come to a justifiable conclusion. Ideally, committee members should: - have substantial experience of writing or teaching Haskell; - have a track record of active contributions to the Haskell community; or - have expertise in language design and implementation, in either Haskell or related languages. It is our aim that this committee be diverse; by representing different viewpoints, we will make decisions that benefit larger segments of our community. Even if you are uncertain whether your background qualifies you for the role, you are warmly encouraged to apply. The committee's work requires a small, but non-trivial amount of time, especially when you are assigned a proposal for shepherding. We estimate the workload to be around 2 hours per week, and our process works best if members usually respond to technical emails within 1-2 weeks (within days is even better). Please keep that in mind if your email inbox is already overflowing. Committee members serve for 3 years, but are free to re-nominate themselves when their 3-year term expires. Self-nominations are the norm. You can nominate someone else, but please obtain their explicit consent to do so. (We don't want to choose someone who turns out to be unable to serve.) *What happens after nominations?* In accordance with our Committee bylaws <https://github.com/ghc-proposals/ghc-proposals/blob/master/committee.rst>, the committee deliberates nominations *in private* before communicating the decision. The committee doesn't have a fixed size, although we like to have a minimum of 9 members. There are currently two members rotating off, but as the committee currently has 10 members, we will be looking to appoint at least one but possibly (hopefully!) more. On behalf of the committee, Simon Marlow

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GHC 9.14.1-rc2 is now available
by Zubin Duggal 07 Nov '25

07 Nov '25

The GHC developers are very pleased to announce the availability of the second release candidate of GHC 9.14.1. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][]. The changes from the first release candidate are: * Bump the exceptions submodule to 0.10.11 * Bump the os-string submodule to 2.0.8 * Fix a driver regression causing an infinite loop with cyclic imports GHC 9.14 will bring a number of new features and improvements, including: * Significant improvements in specialisation: * The `SPECIALISE` pragma now allows use of type application syntax * The `SPECIALISE` pragma can be used to specialise for expression arguments as well as type arguments. * Specialisation is now considerably more reliable in the presence of `newtype`s * Significant GHCi improvements including: * Correctness and performance improvements in the bytecode interpreter * Features in the GHCi debugger * Support for multiple home units in GHCi * Implementation of the [Explicit Level Imports proposal][levels] * `RequiredTypeArguments` can now be used in more contexts * SSE/AVX2 support in the x86 native code generator backend * A major update of the Windows toolchain and improved compatibility with macOS Tahoe * ... and many more A full accounting of changes can be found in the [release notes][]. Given the many specialisation improvements and their potential for regression, we would very much appreciate testing and performance characterisation on downstream workloads. Note that while this release makes many improvements in the specialisation optimisation, polymorphic specialisation will remain disabled by default in the final release due to concern over regressions of the sort identified in [#26329][T26329]. Users needing more aggressive specialisation can explicitly enable this feature with the `-fpolymorphic-specialisation` flag. Depending upon our experience with 9.14.1, we may enable this feature by default in a later minor release. We would like to thank the Zw3rk stake pool, Well-Typed, Mercury, Channable, Tweag I/O, Serokell, 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 have made the Haskell ecosystem what it is today. As always, do give this release a try and open a [ticket][] if you see anything amiss. [downloads.haskell.org] https://downloads.haskell.org/ghc/9.14.1-rc2 [release notes]: https://downloads.haskell.org/ghc/9.14.1-rc2/docs/users_guide/9.14.1-notes.… [ticket]: https://gitlab.haskell.org/ghc/homepage/-/issues/new [macos]: https://gitlab.haskell.org/ghc/ghc/-/issues/26166 [T26329]: https://gitlab.haskell.org/ghc/ghc/-/issues/26329 [levels]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0682-e…

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Journal of Functional Programming - Call for PhD Abstracts
by Graham Hutton (staff) 06 Nov '25

06 Nov '25

Dear all, If you or one of your students recently completed a PhD (or Habilitation) in the area of functional programming, please submit the dissertation abstract for publication in JFP: simple process, no refereeing, open access, 200+ published to date, deadline 30th November 2025. Please share! Best wishes, Graham Hutton ============================================================ CALL FOR PHD ABSTRACTS Journal of Functional Programming Deadline: 30th November 2025 http://tinyurl.com/jfp-phd-abstracts ============================================================ PREAMBLE: Many students complete PhDs in functional programming each year. As a service to the community, twice per year the Journal of Functional Programming publishes the abstracts from PhD dissertations completed during the previous year. The abstracts are made freely available on the JFP website, i.e. not behind any paywall. They do not require any transfer of copyright, merely a license from the author. A dissertation is eligible for inclusion if parts of it have or could have appeared in JFP, that is, if it is in the general area of functional programming. The abstracts are not reviewed. Please submit dissertation abstracts according to the instructions below. We welcome submissions from both the student and the advisor/supervisor although we encourage them to coordinate. Habilitation dissertations are also eligible for inclusion. ============================================================ SUBMISSION: Please submit the following information to Graham Hutton <graham.hutton(a)nottingham.ac.uk> by 30th November 2025 o Dissertation title: (including any subtitle) o Student: (full name) o Awarding institution: (full name and country) o Date of award: (month and year; depending on the institution, this may be the date of the viva, corrections being approved, graduation ceremony, or otherwise) o Advisor/supervisor: (full names) o Dissertation URL: (please provide a permanently accessible link to the dissertation if you have one, such as to an institutional repository or other public archive; links to personal web pages should be considered a last resort) o Dissertation abstract: (plain text, maximum 350 words; you may use \emph{...} for emphasis, but we prefer no other markup or formatting; if your original abstract exceeds the word limit, please submit an abridged version within the limit) Please do not submit a copy of the dissertation itself, as this is not required. JFP reserves the right to decline to publish abstracts that are not deemed appropriate. ============================================================ PHD ABSTRACT EDITOR: Graham Hutton School of Computer Science University of Nottingham Nottingham NG8 1BB United Kingdom ============================================================ This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.

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Saving Haskellwiki page fails
by X Y 06 Nov '25

06 Nov '25

L.S., When I try to save an edited Haskellwiki page, I get the message: Database error A database query error has occurred. This may indicate a bug in the software. [332be860fb9a0d590251f128] 2025-11-04 03:35:42: Fatal exception of type "Wikimedia\Rdbms\DBQueryError" Can someone solve this? Regards, Henk-Jan van Tuyl

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Full Professor position in Programming Languages at the University of Tartu
by Danel Ahman 05 Nov '25

05 Nov '25

Dear all, The Institute of Computer Science at the University of Tartu in Estonia is currently advertising a Full Professor position in Programming Languages: https://ut.ee/en/job-offer/professor-programming-languages-0 Areas of particular interest include semantics and types, compilers and runtimes, static/dynamic analysis, verification, synthesis, and language-based security. The application deadline is 15.12.2025. Best wishes, Danel Ahman

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[ANN] Ogma 1.10.0
by Ivan Perez 04 Nov '25

04 Nov '25

Hi everyone! I'm thrilled to announce the release of Ogma 1.10.0! NASA's Ogma is a mission assurance tool that generates robotics and flight applications. Use cases supported by Ogma include producing Robot Operating System (ROS 2) packages [3], NASA Core Flight System (cFS) applications [4], and components for FPrime [1] (the software framework used for the Mars Helicopter). Ogma is also one of the solutions recommended for monitoring in Space ROS applications [2]. Ogma is fully written in Haskell, and leverages existing Haskell work, like the Copilot language [5] (also funded by NASA) and BNFC [6]. For more details, including videos of monitors being generated and flown in simulators, see: https://github.com/nasa/ogma * What's changed This major release includes the following improvements: - Ogma is now released under Apache license. - Fix several small errors in cFS template. - Fix bug in ROS 2 template generation when handlers have no arguments. - Install ROS 2 package locally in generated Dockerfile. - Add examples demonstrating ROS 2, cFS. - Add CI action for cFS test. - Fix several other smaller maintenance issues. For details about the release, see: https://github.com/nasa/ogma/releases/tag/v1.10.0 * Releases Ogma is released as a collection of packages in Hackage. The entry point is https://hackage.haskell.org/package/ogma-cli. It is also available in new releases of Ubuntu and Debian (testing), from the official package repositories of those distros; thanks to Scott Talbert and the rest of the Debian Haskell Group. * Code The github repo is located at: https://github.com/nasa/ogma. * What's coming The next release is planned for Nov 21st, 2025. We are currently working on a GUI for Ogma that facilitates collecting all mission data relative to the design, diagrams, requirements and deployments, and help users refine designs and requirements, verify them for correctness, generate monitors and full applications, follow live missions, and produce reports. We also want to remind users that both Ogma and Copilot can now accept contributions from external users, and we are also keen to see students use them for their school projects, their final projects and theses, and other research. If you are interested in collaborating, please reach out to ivan.perezdominguez(a)nasa.gov. We hope that you are as excited as we are and that our work demonstrates that, with the right support, Haskell can reach farther than we ever thought possible. Happy Haskelling! Ivan [1] https://github.com/nasa/fprime [2] https://space.ros.org/ [3] https://www.ros.org/ [4] https://github.com/nasa/cFS [5] https://github.com/Copilot-Language/copilot [6] https://github.com/BNFC/bnfc

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Jeremy Avigad to give this year's LMS/BCS-FACS Evening Seminar -- 6 November 2025, online via Zoom
by Andrei Popescu 03 Nov '25

03 Nov '25

Dear Colleagues, I am delighted to announce that this year’s London Mathematical Society (LMS) / British Computer Society -- Formal Aspects of Computing Science (BCS-FACS) Evening Seminar will feature Jeremy Avigad as the distinguished speaker. Registration is free but required in advance. Date: 6 November 2025 Time: 19:00 (UK time) Format: Online via Zoom Talk title: Mathematics in the Age of AI Jeremy’s website: https://lnkd.in/ep3w-fiB Registration (for access to the Zoom link) is available here: https://lnkd.in/eRE-Bb2A Further details about the talk are included below Best wishes, Andrei Speaker: Jeremy Avigad (Carnegie Mellon University) Title: Mathematics in the Age of AI Abstract: New technologies for reasoning and discovery are bound to have a profound effect on mathematical practice. Proof assistants are already changing the nature of collaboration, communication, and curation of mathematical knowledge. Automated reasoning tools are used to find mathematical objects with specified properties or rule out their existence, and to decide or verify mathematical claims. Machine learning and neural methods can discover patterns in mathematical data, explore complex mathematical spaces, and generate mathematical objects of interest. Neurosymbolic theorem provers, now capable of solving the most challenging competition problems, combine aspects of all of these technologies. It is helpful to keep in mind that the phrase "AI for mathematics" encompasses several distinct technologies that overlap and interact in interesting ways. In this talk, I will survey the landscape, describe a few landmark applications to mathematics, and encourage you to join me in thinking about how mathematicians and computer scientists can collaborate to guide mathematics through this era of technological change. Bio: Jeremy Avigad is a professor in the Department of Philosophy and the Department of Mathematical Sciences at Carnegie Mellon University. He is the director of the Institute for Computer-Aided Reasoning in Mathematics, a new NSF Mathematical Sciences Research Institute, and the director of the Hoskinson Center for Formal Mathematics, a research center at Carnegie Mellon. He has contributed to mathematical logic and the history and philosophy of mathematics, and he is currently working on applications of formal methods and AI to mathematics. He serves on the Lean Community Admin Team and the board of the Lean Focused Research Organization.

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POPL 2026 Call for Participation - Early registration: 12 December
by Ningning Xie 31 Oct '25

31 Oct '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 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 Full details of the conference and co-located events: https: // popl26.sigplan.org/

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2nd Call for Contributions: BOB 2026 (Berlin, March 13 - Deadline Nov 17)
by Michael Sperber 31 Oct '25

31 Oct '25

Haskell is always big at BOB - send us your best! ================================================================================ BOB Conference 2026 "What happens when we use what's best for a change?" https://bobkonf.de/2026/cfc.html Berlin, Mar 13 Call for Contributions Deadline: November 17, 2025 ================================================================================ You are actively engaged in advanced software engineering methods, solve ambitious problem with software and are open to cutting-edge innovation? Attend this conference, meet people that share your goals, and get to know the best software tools and technologies available today. We strive to offer a day full of new experiences and impressions that you can use to immediately improve your daily life as a software developer. If you share our vision and want to contribute, submit a proposal for a talk or tutorial! NOTE: The conference fee will be waived for presenters. Travel expenses will not be covered (for exceptions see "Speaker Grants"). Shepherding ----------- The program committee offers shepherding to all speakers. Shepherding provides speakers assistance with preparing their sessions. Specifically: - advice on structure and presentation - review of talk slides Speaker Grants -------------- BOB has Speaker Grants available to support speakers from groups under-represented in technology. We specifically seek women speakers, speakers of color, and speakers who are not able to attend the conference for financial reasons. Topics ------ We are looking for talks about best-of-breed software technology, e.g.: - functional programming - persistent data structures and databases - event-based modelling and architecture - "fancy types" (dependent types, gradual typing, linear types, ...) - formal methods for correctness and robustness - abstractions for concurrency and parallelism - metaprogramming - probabilistic programming - math and programming - controlled side effects - program synthesis - Ai beyond vibecoding and chatbots - linked data - symbolic AI - next-generation IDEs - effective abstractions for data analytics - ... everything really that isn’t mainstream, but you think should be - ... including rough ideas that are worth discussing. Presenters should provide the audience with information that is practically useful for software developers. Challenges ---------- Furthermore, we seek contributions on successful approaches for solving hard problems, for example: - bias in machine-learning systems - digital transformation in difficult settings - accessibiltity - systems with critical reliability requirements - ecologically sustainable software development We're especially interested in experience reports. Other topics are also relevant, e.g.: - introductory talks on technical background - overviews of a given field - demos and how-tos Requirements ------------ We accept proposals for presentations of 45 minutes (40 minutes talk + 5 minutes questions), as well as 90 minute tutorials for beginners. The language of presentation should be either English or German. Your proposal should include (in your presentation language of choice): - An abstract of max. 1500 characters. - A short bio/cv - Contact information (including at least email address) - A list of 3-5 concrete ideas of how your work can be applied in a developer's daily life - additional material (websites, blogs, slides, videos of past presentations, …) Organisation ------------ - Direct questions to konferenz at bobkonf dot de - Proposal deadline: November 17, 2025 - Notification: December 5, 2025 - Program: December 12, 2025 Submit here: https://pretalx.com/bob-2026/submit/ Program Committee ----------------- (more information here: https://bobkonf.de/2026/programmkomitee.html) - Matthias Fischmann, Wire - Matthias Neubauer, SICK AG - Nicole Rauch, Softwareentwicklung und Entwicklungscoaching - Michael Sperber, Active Group - Stefan Wehr, Hochschule Offenburg Scientific Advisory Board - Annette Bieniusa, TU Kaiserslautern - Torsten Grust, Uni Tübingen - Peter Thiemann, Uni Freiburg

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