January 2020 - Haskell-Cafe

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.

1 0

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

5 6

[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

1 0

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.

1 0