- Haskell-Cafe - Haskell.org

Supporting Haskell.org
by Tikhon Jelvis 06 Jan '20

06 Jan '20

A significant part of the Haskell community infrastructure—including the haskell.org website, Hackage, Hoogle and the build infrastructure for GHC—runs on donations from the Haskell community administered by Haskell.org. Haskell.org also organizes Haskell's participation in the Google Summer of Code program. We had 18 projects this year, 15 of which were completed successfully, a solid completion ratio. If you would like to support Haskell.org, you can donate via several methods including PayPal and check: https://wiki.haskell.org/Donate_to_Haskell.org Haskell.org can also accept donations through employers via Benevity using the unique ID 475236502. Haskell.org is a 501(c)(3) non-profit, so donations may be tax-deductible in your jurisdiction. We look forward to continuing this work with your support in 2020 as well as exploring new projects to improve the Haskell community infrastructure. Best wishes, Tikhon Jelvis on behalf of the haskell.org committee.

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separate compilation for library profiling
by Henning Thielemann 05 Jan '20

05 Jan '20

Why does GHC start a separate compilation when I build with cabal --enable-library-profiling? At least parsing and type-checking should be the same as in the non-profiling compilation. Why aren't these steps shared between profiling and non-profiling compilation? I remember that in the past GHC also started a separate compilation for shared object generation. However, starting with GHC-7.8 dyn-files are just generated along with static compilation.

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Lift data from IO to Validation
by Debasish Ghosh 04 Jan '20

04 Jan '20

Hi - I am not an experienced Haskell programmer and would like to have some help with the following problem .. I am trying to validate a bunch of inputs and found the package Data.Validation. I am also using Data.Time for date and time. I have a function like this .. validateOpenDate :: ZonedTime -> Validation [String] ZonedTime It's supposed to validate a date for which I need to fetch the current date and time. I can do that with getZonedTime :: IO ZonedTime. I want to check if the current time is less than the date time I pass to the function and return an appropriate Validation. The question is how do I lift the result from IO into the Validation ? Or is there any alternative strategy that I should consider for this validation ? I have a number of other validations which follow the same strategy but don't have the IO. My final goal is to be able to compose all these validations applicatively to prepare a final ADT in a smart constructor. Any help will be appreciated .. regards. -- Debasish Ghosh

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[ANN] rdf4h-4.0.0 released - working with RDF in Haskell
by Rob Stewart 03 Jan '20

03 Jan '20

Hi, rdf4h-4.0.0 has been released. This library [1,2] is for working with semantic web RDF data. It includes multiple graph representations, RDF parsers/serialisers, and an API for querying and modifying RDF graphs. Version 4.0.0 is significant because it is the first release of the rdf4h library to be 100% compliant [3] with the parser unit tests defined by the W3C RDF Test Suite Curation Community Group [4] for parsing NTriple, Turtle and XML RDF formats. [1] https://hackage.haskell.org/package/rdf4h-4.0.0 [2] https://github.com/robstewart57/rdf4h [3] https://travis-ci.org/robstewart57/rdf4h [4] https://www.w3.org/community/rdf-tests/ Special thanks to Slava Kravchenko, Pierre Le Marre and Renzo Carbonara whose efforts contributed to this milestone. -- Rob Stewart

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WST 2020 Call for Papers
by Samir Genaim 02 Jan '20

02 Jan '20

========================================================================== WST 2020 - Call for Papers 17th International Workshop on Termination http://costa.fdi.ucm.es/wst2020 July 4-5, 2020, Paris, France co-located with IJCAR and FSCD 2020. ========================================================================== The Workshop on Termination (WST) traditionally brings together, in an informal setting, researchers interested in all aspects of termination, whether this interest be practical or theoretical, primary or derived. The workshop also provides a ground for cross-fertilization of ideas from the different communities interested in termination (e.g., working on computational mechanisms, programming languages, software engineering, constraint solving, etc.). The friendly atmosphere enables fruitful exchanges leading to joint research and subsequent publications. The workshop is co-located with IJCAR and FSCD 2020. https://ijcar2020.org/ https://fscd2020.org/ IMPORTANT DATES: * submission deadline: April 12, 2020 * notification: May 10, 2020 * final version due: May 31, 2020 * workshop: July 4-5, 2020 TOPICS: The 17th International Workshop on Termination welcomes contributions on all aspects of termination. In particular, papers investigating applications of termination (for example in complexity analysis, program analysis and transformation, theorem proving, program correctness, modeling computational systems, etc.) are very welcome. Topics of interest include (but are not limited to): * abstraction methods in termination analysis * certification of termination and complexity proofs * challenging termination problems * comparison and classification of termination methods * complexity analysis in any domain * implementation of termination methods * non-termination analysis and loop detection * normalization and infinitary normalization * operational termination of logic-based systems * ordinal notation and subrecursive hierarchies * SAT, SMT, and constraint solving for (non-)termination analysis * scalability and modularity of termination methods * termination analysis in any domain (lambda calculus, declarative programming, rewriting, transition systems, etc.) * well-founded relations and well-quasi-orders COMPETITION: Since 2003, the catalytic effect of WST to stimulate new research on termination has been enhanced by the celebration of the Termination Competition and its continuously developing problem databases containing thousands of programs as challenges for termination analysis in different categories, see http://termination-portal.org/wiki/Termination_Competition In 2020, the Termination Competition will run shortly before WST and the main venues (IJCAR-FSCD), and the results will be presented at IJCAR or FSCD. PROGRAM COMMITTEE: Martin Avanzini - INRIA Sophia, Antipolis Florian Frohn - Max-Planck-Institut für Informatik, Saarbrücken Carsten Fuhs - Birkbeck, U. of London Samir Genaim (chair) - U. Complutense de Madrid Jürgen Giesl - RWTH Aachen Matthias Heizmann - U. of Freiburg Cynthia Kop - Radboud U. Nijmegen Salvador Lucas - U. Politècnica de València Étienne Payet - U. de La Réunion Albert Rubio - U. Complutense de Madrid René Thiemann - U. of Innsbruck Johannes Waldmann - HTWK Leipzig INVITED SPEAKERS: tba SUBMISSION: Submissions are short papers/extended abstracts which should not exceed 5 pages. There will be no formal reviewing. In particular, we welcome short versions of recently published articles and papers submitted elsewhere. The program committee checks relevance and provides additional feedback for each submission. The accepted papers will be made available electronically before the workshop. Papers should be submitted electronically via the submission page: https://easychair.org/conferences/?conf=wst2020 Please, use LaTeX and the LIPIcs style file http://drops.dagstuhl.de/styles/lipics/lipics-authors.tgz to prepare your submission.

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SBLP 2020 - first call for papers
by Simon Thompson 31 Dec '19

31 Dec '19

Call for Papers - XXIV Brazilian Symposium on Programming Languages (SBLP 2020) Natal, Brazil, September 21-25, 2020 Submission link: https://easychair.org/conferences/?conf=sblp2020 SBLP 2020 is the 24th edition of the Brazilian Symposium on Programming Languages. 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 is part of CBSoft, the Brazilian Conference on Software: Theory and Practice. Submission Guidelines ________________________________________________________________________________ Papers can be written in Portuguese or English. Submissions in English are encouraged because the proceedings will be indexed in the ACM Digital Library. The acceptance of a paper implies that at least one of its authors will register for the symposium to present it. Papers must be original and not simultaneously submitted to another journal or conference. SBLP 2020 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 third person. Papers must be submitted electronically (in PDF format) via the Easychair System: http://www.easychair.org/conferences/?conf=sblp2020 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, available at http://www.acm.org/publications/proceedings-template 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. 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, and distributed 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 Publication ________________________________________________________________________________ SBLP proceedings will be published in ACM's digital library. As in previous editions, authors of selected regular papers will be invited to submit an extended version of their work to be considered for publication in a journal's special issue. Since 2009, selected papers of each SBLP edition are being published in a special issue of Science of Computer Programming, by Elsevier. Important dates ________________________________________________________________________________ Abstract submission: 31 May, 2020 Paper submission: 7 June, 2020 (strict) Author notification: 24 July, 2020 Camera ready deadline: 9 August 2020 Program Committee ________________________________________________________________________________ Alex Garcia Instituto Militar de Engenharia Alvaro Moreira Universidade Federal do Rio Grande do Sul Anamaria Moreira Universidade Federal do Rio de Janeiro André Murbach Maidl Pontifícia Universidade Católica do Paraná Bernhard Scholz The University of Sydney Beta Ziliani Universidad Nacional de Córdoba Christiano Braga Universidade Federal Fluminense Cristiano Vasconcellos Universidade do Estado de Santa Catarina Fernando Castor Universidade Federal de Pernambuco Fernando Pereira Universidade Federal de Minas Gerais Francisco Sant'Anna Unversidade Estadual do Rio de Janeiro Hans-Wolfgang Loidl Heriot-Watt University Henrique Rebêlo Universidade Federal de Pernambuco João Paulo Fernandes University of Coimbra Krishna Nandivada IIT Madras Laure Gonnord University of Lyon Leonardo Reis Universidade Federal de Juiz de Fora Lucilia Figueiredo Universidade Federal de Ouro Preto Marisa Bigonha Universidade Federal de Minas Gerais Martin Musicante Universidade Federal do Rio Grande do Norte Pavlos Petoumenos University of Manchester Renato Cerqueira IBM Research Roberto Ierusalimschy PUC-Rio Rodrigo Ribeiro Universidade Federal de Ouro Preto Sandro Rigo Universidade de Campinas Sérgio Medeiros Universidade Federal do Rio Grande do Norte (Chair) Simon Thompson University of Kent Tomofumi Yuki INRIA Contact ________________________________________________________________________________ All questions about submissions should be emailed to Sérgio Medeiros (sergiomedeiros(a)ect.ufrn.br) Simon Thompson | Professor of Logic and Computation School of Computing | University of Kent | Canterbury, CT2 7NF, UK s.j.thompson(a)kent.ac.uk | M +44 7986 085754 | W www.cs.kent.ac.uk/~sjt

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A Generic Ordering over Types
by Justin Paston-Cooper 29 Dec '19

29 Dec '19

Hello, I've defined a module which defines a Data.Type.Ordering over types which are instances of Generic: https://github.com/jpcooper/generic-type-ordering/blob/master/src/Data/Type…. I was considering submitting it to Hackage if anyone finds this useful. I am using it in conjunction with Data.Type.Set (type-level-sets), which requires an ordering over the used types. The ordering works by first comparing the package, then the module, then the type name. I take it that the ordering as defined is correct over all types which are an instance of Generic. I wanted to check first whether this is done anywhere else, or in a different, better way. Can anyone advise? Cheers, Justin

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Re: [Haskell-cafe] Which is easier to ship on windows, a gi-gtk or fltk-hs project?
by Ruben Astudillo 25 Dec '19

25 Dec '19

On 25-12-19 02:13, Patrick Chilton wrote: > Hi, maybe you could host it somewhere and give it a web interface? > Google Compute Engine has a pretty generous free tier and you can > install Nix on it, which would take care of the packaging issues. I would prefer to not. Conceptually that is a harder sell as there is not a good technical reason to depend on webstuff apart of inconvenience. Also TeX compilation should be done on a web service if it's on the web (I think). This is a side project, which for me it's a opportunity to learn something new. That is right now shipping programs to windows that use bindings and depend on other programs. -- -- Rubén -- pgp: 4EE9 28F7 932E F4AD

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Which is easier to ship on windows, a gi-gtk or fltk-hs project?
by Ruben Astudillo 25 Dec '19

25 Dec '19

Dear list Currently for work I am doing a technical document generator using HaTex. The user primarily uses windows so I would like to ship to it. He is not a technical user, so a GUI is a must. FLTK is lighter than gtk but it seems the community has less experience shipping haskell GUIs with it on windows than with gi-gtk. So which toolkit binding would you use for a windows project? Also how would you ship such a project, which depends on a toolkit and TeX-engine on windows? I am used to a nix world-view. -- -- Rubén -- pgp: 4EE9 28F7 932E F4AD

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[ANN] ascii-holidays
by amindfv＠gmail.com 24 Dec '19

24 Dec '19

For those of you celebrating Christmas this week, I've just uploaded an early version of the ascii-holidays package to Hackage. At the moment it's a reimplementation of two ASCII art Christmas tree animations, one originally written in Bash and the other in Perl. Over time I plan to add animations for other holidays as well. You can install it with cabal install, then run it like: ascii-holidays xmas-1 I hope this adds a bit of Haskelly Christmas cheer to a few homes, and happy holidays to all! Tom

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