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Deadline Extended: 26th Brazilian Symposium on Programming Languages (SBLP 2022)
by Cristiano D. Vasconcellos 07 Jun '22

07 Jun '22

SBLP 2022 is the 26th edition of the Brazilian Symposium on Programming Languages<https://cbsoft2022.facom.ufu.br/sblp.php>. It is promoted by the Brazilian Computer Society (SBC) and constitutes a forum for researchers, students, and professionals to present and discuss ideas and innovations in the design, definition, analysis, implementation, and practical use of programming languages. SBLP's first edition was in 1996. Since 2010, it has been part of CBSoft, the Brazilian Conference on Software: Theory and Practice. The Conference is planned to be held on October 3-7, 2022, fully online. Submission Guidelines Papers can be written in Portuguese or English. Submissions in English are encouraged considering that only accepted papers written in English will appear in the proceedings, usually indexed in the ACM Digital Library (to be confirmed). The acceptance of a paper implies the registration of at least one author in the symposium to present it. Papers must be original and not simultaneously submitted to another journal or conference. No-show of scheduled papers will result in excluding them from the proceedings. SBLP 2022 will use a lightweight double-blind review process. The manuscripts should be submitted for review anonymously (i.e., without listing the author’s names on the paper) and references to own work should be made in the third person. Papers must be submitted electronically (in PDF format) via the EasyChair System.<https://easychair.org/conferences/?conf=sblp2022> The following paper categories are welcome (page limits include figures, references, and appendices): • Full papers: up to 8 pages long in ACM 2-column conference format.<http://www.acm.org/publications/proceedings-template> Full papers can be further specialized, at submission time, as student papers (i.e., as papers describing research conducted mainly by a student at any level). student papers will be subject to the exact same reviewing process and criteria but may be entitled for an award (see below). • Short papers: up to 3 pages in the same format. Short papers can discuss new ideas which are at an early stage of development or can report partial results of on-going dissertations or theses. Each paper can have a maximum of one extra page for references. Active graduate and undergraduate students seeking feedback are invited to submit short papers of their original unpublished and in-progress research work. A set of selected papers, which did not get accepted as full papers, may be accepted as short papers. Awards: Two best paper awards will be attributed, distinguishing full paper submissions of the best: • student paper; • non-student paper. List of Topics (related but not limited to the following): • Programming paradigms and styles, scripting and domain-specific languages and support for real-time, service-oriented, multi-threaded, parallel, distributed, and quantum programming; • Program generation and transformation; • Formal semantics and theoretical foundations: denotational, operational, algebraic, and categorical; • Program analysis and verification, type systems, static analysis, and abstract interpretation; • Programming language design and implementation, programming, language environments, compilation, and interpretation techniques; • Programming languages for the blockchain technology: design and implementation of Smart Contract languages, implementation of consensus protocols, language-based security, and cryptographic primitives. A selection of the best papers appearing in the last editions of SBLP have been invited to be extended and considered for publication in a special issue of the Journal of Computer Languages (COLA), by Elsevier. We will approach COLA for a similar special issue regarding the 2022 edition of SBLP. Important dates: • Abstract submission: 20 June, 2022. • Paper submission: 20 June, 2022. • Author notification: 16 Aug, 2022. • Camera ready deadline: 29 Aug, 2022. Program Committee Program Committee Chair: Cristiano Vasconcellos, UDESC Program Committee Alberto Pardo, Universidad de la República Alcides Fonseca, Universidade de Lisboa Alejandro Díaz-Caro, Universidad Nacional de Quilmes & Universidad de Buenos Aires Alex Kavvos, University of Bristol Anderson Faustino, UEM Andrei Paskevich, Université Paris-Sud, LRI Andre Maidl, Elastic Dalvan Griebler, PUCRS/SETREM Emmanuel Chailloux, University Pierre and Marie Curie Fernando Castor, UFPE & Utrecht University Fernando Pereira, UFMG Francisco Sant'anna, UERJ Karina Roggia, UDESC Leonardo dos Santos, UFJF Liam O'Connor, University of Edinburgh Marcos Viera, Universidad de la República Mário Pereira, Universidade NOVA de Lisboa Mariza Bigonha, UFMG Nuno Macedo, INESC TEC & University of Porto Paul Leger, Universidad Católica del Norte Roberto Bigonha, UFMG Roberto Ierusalimschy PUC-Rio Rodrigo Ribeiro, UFOP Samuel Feitosa, UFFS Sérgio Medeiros, UFRN Simão Sousa, Universidade da Beira Interior Stefania Dumbrava, ENSIIE Paris-Evry Contact: All questions about submissions should be emailed to cristiano.vasconcellos(a)udesc.br

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Re: [Haskell-cafe] Should there be a haskell template for inclusion polymorphism in Haskell?
by Olaf Klinke 05 Jun '22

05 Jun '22

> So my central questions for discussions are: > > - Is inclusion polymorphism something we should use at all in Haskell? > - These boiler plate code maybe better be generated using Haskell template > instead, is there one already, or should > there be one? Maybe one of the authors of a sub-typing library can share a more informed opinion on this. My view as a mathematician: A type being a subtype of another is a relation between types. Relations between types is what multi-parameter type classes is about. Hence it seems that this is how subtypes in Haskell ought to be done. For example, in the attenuation and records-sop package, the latter of which is based on genercis-sop, which depends on Template Haskell. So without having used any of the mentioned packages, I believe your second question can be answered with "yes". Regarding the first question, we should probably ask ourselves how much type-safety we're sacrificing for the convenience we gain. The Num example you gave shows one possible danger: While a subtype relation may hold mathematically, the implementiation details may cause this relation to fail in reality. Example: All floating point numbers are rationals, aren't they? So there should be a subtype relation. But how to convert NaN, -infinity or -0 of type Double to a pair of Integers? Olaf

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cabal 3.8 pre-released!
by Mikolaj Konarski 05 Jun '22

05 Jun '22

Hello! The first 3.8 series cabal release candidate is available. Install via ghcup config add-release-channel \ https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prere…; ghcup install cabal 3.8.0.20220526 or manually from https://downloads.haskell.org/cabal/cabal-install-3.8.1.0-rc1/. We, the cabal team, are completely dependent on our invaluable contributors and collaborators, thanks to whom this pre-release is possible. Therefore, please test extensively and if anything critical is missing or broken that you'd like to see fixed in 3.8.1.0-final, let us know on the bug tracker. There is still a narrow window to change things and the cabal team will try to guide you along and help you implement them. The dynamic list of known grave bugs that could plausibly be solved for 3.8 is at https://github.com/haskell/cabal/issues?q=is%3Aopen+is%3Aissue+label%3A%22p… At the time of writing none of the bugs on the list is blocking the final 3.8 release. Changelogs are at https://github.com/haskell/cabal/blob/Cabal-v3.8.1.0-rc1/release-notes/Caba… https://github.com/haskell/cabal/blob/cabal-install-v3.8.1.0-rc1/release-no… The list of all authors of cabal is the git commit log. You are great. Happy hacking, Mikolaj

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ANN: hledger-1.26
by Simon Michael 05 Jun '22

05 Jun '22

Aloha! I am pleased to announce hledger 1.26: https://github.com/simonmichael/hledger/releases/1.26 https://hledger.org/install https://hledger.org/release-notes.html#hledger-1-26 1.26 is a modest maintenance release; highlights include faster register reports and clearer error messages. Thank you to core contributor Stephen Morgan. What is hledger ? - free, high quality Plain Text Accounting[1] software: - a fast and robust multicurrency double-entry accounting system - built around human-readable, version-controllable plain text files - inspired by and partly compatible with Ledger CLI[2] - convertible to and from Beancount[3] - written in Haskell for correctness and longevity - easy to install on unix, mac and windows. For help getting started, or more info, see https://hledger.org, and join our chat via Matrix or IRC: https://hledger.org/support. Newcomers, experts, contributors, sponsors, feedback are always welcome! Best wishes, -Simon [1] https://plaintextaccounting.org [2] https://ledger-cli.org [3] https://beancount.github.io

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Re: [Haskell-cafe] Hiding type variables from the signature?
by Olaf Klinke 03 Jun '22

03 Jun '22

> λ f = deasilsB . deasilsA > > <interactive>:2:1: error: > • Could not deduce: Dress seed0 peels0 ~ Dress seed peels > ``` > > What is going on? How can I have my `deasils`? > > I tried attaching all kinds of type annotations, but nothing works so far. I do > not even understand the problem. How is it that an expression can be typed, but > cannot be assigned to a name? > > You can see the complete code at the gist [1]. > > [1]: https://gist.github.com/kindaro/6056f753bcf356ced96b817fee72533c/2823ec2792… The given type annotation for desilsA uses forall, which suggests you want to use ScopedTypeVariables here. But for that feature to kick in, you need to actually mention the scoped type variables in the function body, which you don't. :t deasil . first squeeze deasil . first squeeze :: (ForAll peels Functor, Squeezy' left a peels (Strip left a == '[])) => (a, right) -> Squeezed peels (left, right) You must use ScopedTypeVariables to constrain the type variable `a' to the intended (Dress seed peels). Olaf

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Hiding type variables from the signature?
by Ignat Insarov 02 Jun '22

02 Jun '22

Hello café, hope you all doing well! I have this code [1]. Its purpose is to provide an `fmap` that works at any depth. Here is the gist of the gist: ```Haskell fmapz ∷ forall seed fruit seed' fruit' peels recursive. Squeezish seed seed' fruit fruit' peels recursive ⇒ (seed → seed') → fruit → fruit' fmapz function = stretch . fmap @(Squeezed (Strip seed fruit)) function . squeeze ``` As the examples show, it works, and even has some type inference. However, the type signature is unwieldy. It seems like it should have only 4 variables, but I have to also do some type level book-keeping for which the other 2 variables are needed. These book-keeping type variables are determined by type families from the other 4, so surely I can hide them inside a type synonym or something like that? I tried giving a quantified constraint, like so: ```Haskell type Squeezish ∷ ★ → ★ → ★ → ★ → Constraint type Squeezish seed seed' fruit fruit' = forall peels recursive. Squeezish' seed seed' fruit fruit' peels recursive class Squeezish' seed seed' fruit fruit' (peels ∷ [★ → ★]) (recursive ∷ Bool) instance ( peels ~ Strip seed fruit , ForAll peels Functor , Squeezy seed' fruit' peels recursive , Squeezy seed fruit peels recursive ) ⇒ Squeezish' seed seed' fruit fruit' peels recursive ``` — But then the constraints from the context of `Squeezish'` fail to make it to the use site and numerous errors arise. What can I do to solve this problem? Or is it theoretically impossible? [1]: https://gist.github.com/kindaro/6056f753bcf356ced96b817fee72533c

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403 trying to upload hackage package candidate
by ☂Josh Chia (謝任中) 01 Jun '22

01 Jun '22

Hi, After running 'cabal sdist', I tried to upload a package candidate for direct-sqlite and got an inexplicable error. Any idea how I should proceed? You can see that I am one of the maintainers here: https://hackage.haskell.org/package/direct-sqlite/maintainers/ $ cabal upload -u jchia -P 'cat /tmp/pw' /home/jchia/gh/direct-sqlite/dist-newstyle/sdist/direct-sqlite-2.3.27.tar.gz Uploading /home/jchia/gh/direct-sqlite/dist-newstyle/sdist/direct-sqlite-2.3.27.tar.gz... Error uploading /home/jchia/gh/direct-sqlite/dist-newstyle/sdist/direct-sqlite-2.3.27.tar.gz: http code 403 Error: Forbidden No access for this resource.

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Keith Hanna
by chris done 01 Jun '22

01 Jun '22

Hi all, Does anyone know whether Keith Hanna is still active in the Haskell community? He's apparently no longer at the University of Kent (I called and asked) and has no discernible web presence besides research papers that refer to his Kent email address. He was mentioned in the community activities report in 2004 for his work on Vital, which I'd like to get in touch with him about. Cheers, Chris

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ML Family Workshop 2022: DEADLINE EXTENSION
by Benoit Montagu 31 May '22

31 May '22

To increase your chances of submitting your work to the ML workshop, *the submission deadline is extended by a week*. The new deadline is Friday 10th June (AoE). A quick reminder: - The workshop does not have proceedings, making it the perfect venue to run some ideas with the community or present some work in progress within a friendly environment. - The work load as an author is low: submissions are only 3 pages long (excluding references) - YOU have the power to make the ML workshop a success! - You have one more full week to submit to <https://ml2022.hotcrp.com/> (please register your submission early!) - All the details are here: <https://icfp22.sigplan.org/home/mlfamilyworkshop-2022#Call-for-Presentations> - The ML workshop is colocated with ICFP 2022 <https://icfp22.sigplan.org/> -- Benoît Montagu, chair of the ML workshop 2022

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Haskell Symposium 2022: Abstract Deadline Extended to June 1st
by Nadia Polikarpova 29 May '22

29 May '22

The Haskell'22 abstract deadline has been extended to *Wednesday, June 1st*. Please register your submissions by this date! The full submission deadline is still *Friday, June 3rd*. Please find the updated CFP below. Nadia Polikarpova (Haskell'22 chair) ========================================================================= ACM SIGPLAN CALL FOR SUBMISSIONS Haskell Symposium 2022 Ljubljana, Slovenia Thu 15 -- Fri 16 September, 2022 http://www.haskell.org/haskell-symposium/2022/ ========================================================================= The ACM SIGPLAN Haskell Symposium 2022 will be co-located with the 2022 International Conference on Functional Programming (ICFP). Differently from previous years, Haskell'22 will use a single-track submission process (that is, we will only have the regular track and no early track). The Haskell Symposium presents original research on Haskell, discusses practical experience and future development of the language, and promotes other forms of declarative programming. Topics of interest include: * Language design, with a focus on possible extensions and modifications of Haskell as well as critical discussions of the status quo; * Theory, such as formal semantics of the present language or future extensions, type systems, effects, metatheory, and foundations for program analysis and transformation; * Implementations, including program analysis and transformation, static and dynamic compilation for sequential, parallel, and distributed architectures, memory management, as well as foreign function and component interfaces; * Libraries, that demonstrate new ideas or techniques for functional programming in Haskell; * Tools, such as profilers, tracers, debuggers, preprocessors, and testing tools; * Applications, to scientific and symbolic computing, databases, multimedia, telecommunication, the web, and so forth; * Functional Pearls, being elegant and instructive programming examples; * Experience Reports, to document general practice and experience in education, industry, or other contexts; * Tutorials, to document how to use a particular language feature, programming technique, tool or library within the Haskell ecosystem; * System Demonstrations, based on running software rather than novel research results. Regular papers should explain their research contributions in both general and technical terms, identifying what has been accomplished, explaining why it is significant, and relating it to previous work, and to other languages where appropriate. Experience reports and functional pearls need not necessarily report original academic research results. For example, they may instead report reusable programming idioms, elegant ways to approach a problem, or practical experience that will be useful to other users, implementers, or researchers. The key criterion for such a paper is that it makes a contribution from which other Haskellers can benefit. It is not enough simply to describe a standard solution to a standard programming problem, or report on experience where you used Haskell in the standard way and achieved the result you were expecting. Like an experience report and a functional pearl, tutorials should make a contribution from which other Haskellers can benefit. What distinguishes a tutorial is that its focus is on explaining an aspect of the Haskell language and/or ecosystem in a way that is generally useful to a Haskell audience. Tutorials for many such topics can be found online; the distinction here is that by writing it up for formal review it will be vetted by experts and formally published. System demonstrations should summarize the system capabilities that would be demonstrated. The proposals will be judged on whether the ensuing session is likely to be important and interesting to the Haskell community at large, whether on grounds academic or industrial, theoretical or practical, technical, social or artistic. Please contact the program chair with any questions about the relevance of a proposal. If your contribution is not a research paper, please mark the title of your experience report, functional pearl, tutorial or system demonstration as such, by supplying a subtitle (Experience Report, Functional Pearl, Tutorial Paper, System Demonstration). Submission Details ================== Formatting ---------- Submitted papers should be in portable document format (PDF), formatted using the ACM SIGPLAN style guidelines. Authors should use the `acmart` format, with the `sigplan` sub-format for ACM proceedings. For details, see: http://www.sigplan.org/Resources/Author/#acmart-format It is recommended to use the `review` option when submitting a paper; this option enables line numbers for easy reference in reviews. Functional pearls, experience reports, tutorials and demo proposals should be labelled clearly as such. Lightweight Double-blind Reviewing ---------------------------------- Haskell Symposium 2022 will use a lightweight double-blind reviewing process. To facilitate this, submitted papers must adhere to two rules: 1. Author names and institutions must be omitted, and 2. References to authors' own related work should be in the third person (e.g., not "We build on our previous work" but rather "We build on the work of "). The purpose of this process is to help the reviewers come to an initial judgment about the paper without bias, not to make it impossible for them to discover the authors if they were to try. Nothing should be done in the name of anonymity that weakens the submission or makes the job of reviewing the paper more difficult (e.g., important background references should not be omitted or anonymized). In addition, authors should feel free to disseminate their ideas or draft versions of their paper as they normally would. For instance, authors may post drafts of their papers on the web or give talks on their research ideas. A reviewer will learn the identity of the author(s) of a paper after a review is submitted. Page Limits ----------- The length of submissions should not exceed the following limits: Regular paper: 12 pages Functional pearl: 12 pages Tutorial: 12 pages Experience report: 6 pages Demo proposal: 2 pages There is no requirement that all pages are used. For example, a functional pearl may be much shorter than 12 pages. In all cases, the list of references is not counted against these page limits. Deadlines --------- Abstract submission: 1 June 2022 (Wed) Paper submission: 3 June 2022 (Fri) Notification: 1 July 2022 (Fri) Deadlines are anywhere on Earth. Submission ---------- Submissions must adhere to SIGPLAN's republication policy (http://sigplan.org/Resources/Policies/Republication/) and authors should be aware of ACM's policies on plagiarism (https://www.acm.org/publications/policies/plagiarism) Program Committee members are allowed to submit papers, but their papers will be held to a higher standard. The paper submission deadline and length limitations are firm. There will be no extensions, and papers violating the length limitations will be summarily rejected. Papers should be submitted through HotCRP at: https://haskell22.hotcrp.com/ Improved versions of a paper may be submitted at any point before the submission deadline using the same web interface. Supplementary material: Authors have the option to attach supplementary material to a submission, on the understanding that reviewers may choose not to look at it. This supplementary material should not be submitted as part of the main document; instead, it should be uploaded as a separate PDF document or tarball. Supplementary material should be uploaded at submission time, not by providing a URL in the paper that points to an external repository. Authors can distinguish between anonymized and non-anonymized supplementary material. Anonymized supplementary material will be visible to reviewers immediately; non-anonymized supplementary material will be revealed to reviewers only after they have submitted their review of the paper and learned the identity of the author(s). Resubmitted Papers: authors who submit a revised version of a paper that has previously been rejected by another conference have the option to attach an annotated copy of the reviews of their previous submission(s), explaining how they have addressed these previous reviews in the present submission. If a reviewer identifies him/herself as a reviewer of this previous submission and wishes to see how his/her comments have been addressed, the conference chair will communicate to this reviewer the annotated copy of his/her previous review. Otherwise, no reviewer will read the annotated copies of the previous reviews. Proceedings =========== Accepted papers will be included in the ACM Digital Library. Their authors will be required to choose one of the following options: - Author retains copyright of the work and grants ACM a non-exclusive permission-to-publish license (and, optionally, licenses the work with a Creative Commons license); - Author retains copyright of the work and grants ACM an exclusive permission-to-publish license; - Author transfers copyright of the work to ACM. For more information, please see ACM Copyright Policy (http://www.acm.org/publications/policies/copyright-policy) and ACM Author Rights (http://authors.acm.org/main.html) Accepted proposals for system demonstrations will be posted on the symposium website but not formally published in the proceedings. Publication date: The official publication date of accepted papers is the date the proceedings are made available in the ACM Digital Library. This date may be up to two weeks prior to the first day of the conference. The official publication date affects the deadline for any patent filings related to published work. Artifacts ========= Authors of accepted papers are encouraged to make auxiliary material (artifacts like source code, test data, etc.) available with their paper. They can opt to have these artifacts published alongside their paper in the ACM Digital Library (copyright of artifacts remains with the authors). If an accepted paper's artifacts are made permanently available for retrieval in a publicly accessible archival repository like the ACM Digital Library, that paper qualifies for an Artifacts Available badge (https://www.acm.org/publications/policies/artifact-review-badging#available) Applications for such a badge can be made after paper acceptance and will be reviewed by the PC chair. Program Committee ================= Lennart Augustsson Epic Games Jean-Philippe Bernardy University of Gothenburg Iavor Diatchki Galois, Inc Michael Gale Tweag William Hallahan Yale University Makoto Hamana Gumma University Andrew Hirsch MPI SWS John Hughes Chalmers University of Technology Alexis King Tweag James Koppel Massachusets Institute of Technology Rudy Matela Channable Dominic Orchard University of Kent Nadia Polikarpova (chair) University of California, San Diego Eric Seidel Bridgewater Associates Satnam Singh Groq Wouter Swierstra Utrecht University Hiroshi Unno University of Tsukuba Marco Vassena Utrecht University Dimitrios Vytiniotis DeepMind If you have questions, please contact the chair at: npolikarpova(a)ucsd.edu =========================================================================

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