- Haskell-Cafe - Haskell.org

Intanciate data type
by Corentin Dupont 09 Jul '16

09 Jul '16

Hi all, I have a data type looking like this: data Foo e a where Foo :: e → Foo e a I would like to instantiate it to make it equivalent to: data Bar a where A :: String → Bar Int B :: Maybe a → Bar a How can I do that? With a functional dependency? I probably need to change the definition of Foo.

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Re: [Haskell-cafe] Haskell-Cafe Digest, Vol 155, Issue 8
by Alexander Granin 09 Jul '16

09 Jul '16

Hi Anton! My first thought is to blame Russian letters and/or spaces. Try to move your programs and libraries to plain English path. No guarantees it would help, though. Best, Alexander 2016-07-08 18:00 GMT+06:00 <haskell-cafe-request(a)haskell.org>: > Send Haskell-Cafe mailing list submissions to > haskell-cafe(a)haskell.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > or, via email, send a message with subject or body 'help' to > haskell-cafe-request(a)haskell.org > > You can reach the person managing the list at > haskell-cafe-owner(a)haskell.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Haskell-Cafe digest..." > > > Today's Topics: > > 1. Strange error with cabal install on windows: (Anton Kholomiov) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 8 Jul 2016 12:06:07 +0400 > From: Anton Kholomiov <anton.kholomiov(a)gmail.com> > To: Haskell Cafe <haskell-cafe(a)haskell.org> > Subject: [Haskell-cafe] Strange error with cabal install on windows: > Message-ID: > < > CADDxdqOVLzBe%2BKYiPKieZzjfeZJEkqAHsr1jcdM4pcvfiJ8Qzg(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > I've got an error that I don't know how to fix with cabal install. > Has anyone experienced such a thing? It installs fine on ubuntu but > fails to install on windows 7. It's my own package called `sharc-timbre`: > > ~~~ > Building sharc-timbre-0.1... > Preprocessing library sharc-timbre-0.1... > C:\Program Files\Haskell Platform\8.0.1\bin\ghc.exe: createProcess: does > not > exist (No such file or directory) > cabal: Leaving directory > 'C:\Users\антон\AppData\Local\Temp\cabal-tmp-4484\sharc-timbre-0.1' > ~~~ > > Thanks, > Anton >

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Chair in Information/Computer Security (Sheffield, UK)
by Achim D. Brucker 08 Jul '16

08 Jul '16

(Apologies for duplicates) Dear all, The Computer Science Department of The University Of Sheffield has an open position for a Chair in Computer and Information Security. The new chair will lead a new research group in the Department of Computer Science and establish an agenda for security and privacy research across the wider university. Applications are welcome in all areas of computer and/or information security, including * Human factors and secure systems * Security aspects of distributed and autonomous systems Internet of things, cloud computing * Applications of secure systems Manufacturing, health, transport, robotics * Security analysis Intrusion monitoring, threat detection, links with machine learning and language processing * Secure software engineering (Both empirical and theoretical approaches) * Applied cryptography Applications in IT systems, homomorphic encryption For more information about the position and the Department, please visit http://www.sheffield.ac.uk/dcs/research/groups/security/index Or apply directly at https://goo.gl/FSfk5P, application deadline is 27th July, 2016. Best, Achim -- Dr. Achim D. Brucker | Software Assurance & Security | University of Sheffield https://www.brucker.uk/ | https://logicalhacking.com/blog

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3rd Call for Papers: OCL and Textual Modeling Tools and Textual Model Transformations (OCL 2016) - Less Than 10 Days Left To Submit Your Paper!
by Achim D. Brucker 08 Jul '16

08 Jul '16

(Apologies for duplicates) Less than 10 days until the deadline! CALL FOR PAPERS 16th International Workshop on OCL and Textual Modeling Co-located with ACM/IEEE 19th International Conference on Model Driven Engineering Languages and Systems (MODELS 2016) October 2, 2016, Saint-Malo, France http://oclworkshop.github.io Modeling started out with UML and its precursors as a graphical notation. Such visual representations enable direct intuitive capturing of reality, but some of their features are difficult to formalize and lack the level of precision required to create complete and unambiguous specifications. Limitations of the graphical notations encouraged the development of text-based modeling languages that either integrate with or replace graphical notations for modeling. Typical examples of such languages are OCL, textual MOF, Epsilon, and Alloy. Textual modeling languages have their roots in formal language paradigms like logic, programming and databases. The goal of this workshop is to create a forum where researchers and practitioners interested in building models using OCL or other kinds of textual languages can directly interact, report advances, share results, identify tools for language development, and discuss appropriate standards. In particular, the workshop will encourage discussions for achieving synergy from different modeling language concepts and modeling language use. The close interaction will enable researchers and practitioners to identify common interests and options for potential cooperation. Topics of interest include (but are not limited to) =================================================== - Mappings between textual modeling languages and other languages or formalisms - Algorithms, evaluation strategies and optimizations in the context of textual modeling languages for -- validation, verification, and testing, -- model transformation and code generation, -- meta-modeling and DSLs, and -- query and constraint specifications - Alternative graphical/textual notations for textual modeling languages - Evolution, transformation and simplification of textual modeling expressions - Libraries, templates and patterns for textual modeling languages - Tools that support textual modeling languages (e.g., verification of OCL formulae, runtime monitoring of invariants) - Complexity results for textual modeling languages - Quality models and benchmarks for comparing and evaluating textual modeling tools and algorithms - Successful applications of textual modeling languages - Case studies on industrial applications of textual modeling languages - Experience reports -- usage of textual modeling languages and tools in complex domains, -- usability of textual modeling languages and tools for end-users - Empirical studies about the benefits and drawbacks of textual modeling languages - Innovative textual modeling tools - Comparison, evaluation and integration of modeling languages - Correlation between modeling languages and modeling tasks This year, we particularly encourage submissions describing tools that support - in a very broad sense - textual modeling languages (if you have implemented OCL.js to run OCL in a web browser, this is the right workshop to present your work) as well as textual model transformations. Venue ===== The workshop will be organized as a part of MODELS 2016 Conference in Saint-Malo, France. It continues the series of OCL workshops held at UML/MODELS conferences: York (2000), Toronto (2001), San Francisco (2003), Lisbon (2004), Montego Bay (2005), Genova (2006), Nashville (2007), Toulouse (2008), Denver (2009), Oslo (2010), Zurich (2011, at the TOOLs conference), 2012 in Innsbruck, 2013 in Miami, 2014 in Valencia, Spain, and 2015 in Ottawa, Canada. Similar to its predecessors, the workshop addresses both people from academia and industry. The aim is to provide a forum for addressing integration of OCL and other textual modeling languages, as well as tools for textual modeling, and for disseminating good practice and discussing the new requirements for textual modeling. Workshop Format =============== The workshop will include short (about 15 min) presentations, parallel sessions of working groups, and sum-up discussions. Submissions =========== Two types of papers will be considered: * short contributions (between 6 and 8 pages) describing new ideas, innovative tools or position papers. * full papers (between 12 and 16 pages) in LNCS format. Submissions should be uploaded to EasyChair (https://easychair.org/conferences/?conf=ocl16) The program committee will review the submissions (minimum 2 reviews per paper, usually 3 reviews) and select papers according to their relevance and interest for discussions that will take place at the workshop. Accepted papers will be published online in a post-conference edition of CEUR (http://www.ceur-ws.org) Important Dates =============== Submission of papers: July 17, 2016 Notification: August 14, 2016 Workshop date: October 2, 2016 Organizers ========== Achim D. Brucker, The University of Sheffield, UK Jordi Cabot, ICREA - Open University of Catalonia, Spain Adolfo Sánchez-Barbudo Herrera, University of York, UK Programme Committee (TBC) ========================= Thomas Baar, University of Applied Sciences Berlin, Germany Mira Balaban, Ben-Gurion University of the Negev, Israel Tricia Balfe, Nomos Software, Ireland Domenico Bianculli, University of Luxembourg Dan Chiorean, Babes-Bolyai University, Romania Robert Clariso, Universitat Oberta de Catalunya, Spain Tony Clark, Middlesex University, UK Manuel Clavel, IMDEA Software Institute, Spain Birgit Demuth, Technische Universitat Dresden, Germany Marina Egea, Indra Sistemas S.A., Spain Geri Georg, Colorado State University, USA Martin Gogolla, University of Bremen, Germany Shahar Maoz, Tel Aviv University, Israel Istvan Rath, Budapest University of Technology and Economics, Hungary Bernhard Rumpe, RWTH Aachen, Germany Massimo Tisi, Mines de Nantes, France Frederic Tuong, Univ. Paris-Sud - IRT SystemX - LRI, France Edward Willink, Willink Transformations Ltd., UK Burkhart Wolff, Univ. Paris-Sud - LRI, France Steffen Zschaler, King's College, UK -- Dr. Achim D. Brucker | Software Assurance & Security | University of Sheffield https://www.brucker.uk/ | https://logicalhacking.com/blog

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Strange error with cabal install on windows:
by Anton Kholomiov 08 Jul '16

08 Jul '16

I've got an error that I don't know how to fix with cabal install. Has anyone experienced such a thing? It installs fine on ubuntu but fails to install on windows 7. It's my own package called `sharc-timbre`: ~~~ Building sharc-timbre-0.1... Preprocessing library sharc-timbre-0.1... C:\Program Files\Haskell Platform\8.0.1\bin\ghc.exe: createProcess: does not exist (No such file or directory) cabal: Leaving directory 'C:\Users\антон\AppData\Local\Temp\cabal-tmp-4484\sharc-timbre-0.1' ~~~ Thanks, Anton

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Resumable applicative parsing from tail end?
by martin 07 Jul '16

07 Jul '16

Hello all, in my attempt to write a simulation program, I am facing the following problem: as the simulation progresses, I collect "primary" log entries, each one associated with a timestamp. These entries carry the information I am interested in (and not so much the final state). Currently I am using a simple list to collect log entries. Since (:) is so much easier than (++) I prepend new entries to the head of the list. So my log runs backwards in time with the oldest entries at the tail end. Because the log-entries are typically too fine-grained to be useful, I want to aggregate several of them into a single log entry in a secondary log. I want to do this "as I go" and discard primary log entries which are already aggregated. Thus I can keep the primary log reasonably small. I thought that aggregation is just a special case of parsing. And indeed, I could write an applicative parser PrimaryLog -> (PrimaryLog, SecondaryLog) which does the trick, except I had to reverse the ordering of the primary log. This is because the parser/aggregator must parse from past to future, because there may be new log entries coming up in the future. I need to be able to resume parsing where I left off whenever new primary log entries are entered, becuase I may then have just enough unconsumed primary log entries to create another secondary entry. Currently I'm trying Data.Sequence to let the primary log grow to the left and let parsing to begin at the far-right. But I have a bad feeling about it. Particularly, I don't have any hard reasons why a simple List wouldn't be sufficient. But I just wasn't able to write the code. What do you think? How would you parse a list from the tail end? Or how else would you deal with this problem?

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[ANN] processing-for-haskell. New graphics and animation package
by Anton Kholomiov 06 Jul '16

06 Jul '16

I'd like to announce a graphics libary processing-for-haskell (available on Hackage). It tries to implement Processing language with Haskell. Processing is an imperative DSL for graphics and animation. It's very easy and fun to use. Intended to be used by non-programmers it has very small but powerful core of functions. It's a shallow EDSL. The Processing is implemented with OpenGL and GLUT. That gives us an opportunity to use all Haskell IO-functions inside the animation loop. Enjoy! github: https://github.com/anton-k/processing-for-haskell hackage: http://hackage.haskell.org/package/processing-for-haskell

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Haskell in Leipzig 2016: Another Call for Papers (deadline extended)
by Joachim Breitner 06 Jul '16

06 Jul '16

Haskell in Leipzig September 14-15, 2016 HTKW Leipzig, Germany http://hal2016.haskell.org/ We have received good and interesting proposals, but our schedule still has room for more. So whether you wanted to submit, but just did not make the first deadline, or whether you only now decide to come to Leipzig, this is your chance: Please submit your short abstract until Friday, July 15th. Do you need ideas? Here some possible directions: * Very fancy type tricks using all of GHC’s extensions. * Very fancy type tricks using none of GHC’s extensions. * Getting Haskell to run really really fast. * Using Haskell to make real money, in real life. * Showing how this one odd Haskell library make doing something appear rally simple. * Stuff that is really horrible with Haskell (and how to do it better) * What is cool in other functional programming language right now. We are particularly interested in good tutorials. These could range from impressing beginners with what you can do with Haskell to teaching new tricks to the experts. So if you think you have something useful to teach, please submit a proposal. Please share this CfP with whoever might be interested. == About HaL == The workshop series “Haskell in Leipzig”, now in its 11th year, brings together Haskell developers, Haskell researchers, Haskell enthusiasts and Haskell beginners to listen to talks, take part in tutorials, and join in interesting conversations. Everything related to Haskell is on topic, whether it is about current research, practical applications, interesting ideas off the beaten track, education, or art, and topics may extend to functional programming in general and its connections to other programming paradigms as well. This year, HaL is colocated with two related conferences, * the Workshop on Functional and (Constraint) Logic Programming (WFLP) and * the Workshop on (Constraint) Logic Programming (WLP), to form the Leipzig Week of Declarative Programming (L-DEC): http://nfa.imn.htwk-leipzig.de/LDEC2016/ In order to accommodate and welcome a more international audience, this year’s HaL will be held in English. == Invited Speaker == Unsure about whether HaL is interesting to you? No need to worry: Alejandro Russo (from Chalmers) is our keynote speaker and will talk about his work on information-flow control (i.e. SecLib, LIO, MAC, HLIO) – a great topic that is of interest to researchers, practitioners and beginners alike. == Submissions == Contributions can take the form of * talks (about 30 minutes), * tutorials (about 90 minutes), * demonstrations, artistic performances, or other extraordinary things. Please submit an abstract that describes the content and form of your presentation, the intended audience, and required previous knowledge. We recommend a length of 2 pages, so that the PC and the audience get a good idea of your submission, but this is not a hard requirement. You can submit your abstract, as an PDF document, at https://easychair.org/conferences/?conf=hal2016 until Friday, July 15, 2016. You will be notified by July 30, 2016. == Program committee == * Andreas Abel, Chalmers and Gothenburg University, Sweden * Heinrich Apfelmus, Leipzig, Germany * Joachim Breitner, Karlsruhe Institute of Technology, Germany (Chair) * Matthias Fischmann, Zerobuzz, Germany * Petra Hofstedt, BTU Cottbus-Senftenberg, Germany * Wolfgang Jeltsch, Institute of Cybernetics at Tallinn University of Technology, Estonia * Andres Löh, Well-Typed LLP, Germany * Alejandro Serrano Mena, Universiteit Utrecht, Netherlands * Neil Mitchell, Standard Chartered Bank, UK * Katie Ots, Facebook, UK * Peter Stadler, University of Leipzig, Germany * Henning Thielemann, Freelancer, Germany * Niki Vazou, University of California, San Diego, USA If you have any questions, please do not hesitate to contact Joachim Breitner <breitner(a)kit.edu>. -- Dr. rer. nat. Joachim Breitner Wissenschaftlicher Mitarbeiter http://pp.ipd.kit.edu/~breitner

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2nd CfP: IFL 2016 (28th Symposium on Implementation and Application of Functional Languages)
by publicityifl＠gmail.com 05 Jul '16

05 Jul '16

Hello, Please, find below the second call for papers for IFL 2016. Please forward these to anyone you think may be interested. Apologies for any duplicates you may receive. best regards, Jurriaan Hage Publicity Chair of IFL --- IFL 2016 - 2nd Call for papers 28th SYMPOSIUM ON IMPLEMENTATION AND APPLICATION OF FUNCTIONAL LANGUAGES - IFL 2016 KU Leuven, Belgium In cooperation with ACM SIGPLAN August 31 - September 2, 2016 https://dtai.cs.kuleuven.be/events/ifl2016/ Scope The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2016 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming. Peer-review Following the IFL tradition, IFL 2016 will use a post-symposium review process to produce the formal proceedings. All participants of IFL 2016 are invited to submit either a draft paper or an extended abstract describing work to be presented at the symposium. At no time may work submitted to IFL be simultaneously submitted to other venues; submissions must adhere to ACM SIGPLAN's republication policy: http://www.sigplan.org/Resources/Policies/Republication The submissions will be screened by the program committee chair to make sure they are within the scope of IFL, and will appear in the draft proceedings distributed at the symposium. Submissions appearing in the draft proceedings are not peer-reviewed publications. Hence, publications that appear only in the draft proceedings are not subject to the ACM SIGPLAN republication policy. After the symposium, authors will be given the opportunity to incorporate the feedback from discussions at the symposium and will be invited to submit a revised full article for the formal review process. From the revised submissions, the program committee will select papers for the formal proceedings considering their correctness, novelty, originality, relevance, significance, and clarity. The formal proceedings will appear in the International Conference Proceedings Series of the ACM Digital Library. Important dates August 1: Submission deadline draft papers August 3: Notification of acceptance for presentation August 5: Early registration deadline August 12: Late registration deadline August 22: Submission deadline for pre-symposium proceedings August 31 - September 2: IFL Symposium December 1: Submission deadline for post-symposium proceedings January 31, 2017: Notification of acceptance for post-symposium proceedings March 15, 2017: Camera-ready version for post-symposium proceedings Submission details Prospective authors are encouraged to submit papers or extended abstracts to be published in the draft proceedings and to present them at the symposium. All contributions must be written in English. Papers must use the new ACM two columns conference format, which can be found at: http://www.acm.org/publications/proceedings-template For the pre-symposium proceedings we adopt a 'weak' page limit of 12 pages. For the post-symposium proceedings the page limit of 12 pages is firm. Authors submit through EasyChair: https://easychair.org/conferences/?conf=ifl2016 Topics IFL welcomes submissions describing practical and theoretical work as well as submissions describing applications and tools in the context of functional programming. If you are not sure whether your work is appropriate for IFL 2016, please contact the PC chair at tom.schrijvers(a)cs.kuleuven.be. Topics of interest include, but are not limited to: - language concepts - type systems, type checking, type inferencing - compilation techniques - staged compilation - run-time function specialization - run-time code generation - partial evaluation - (abstract) interpretation - metaprogramming - generic programming - automatic program generation - array processing - concurrent/parallel programming - concurrent/parallel program execution - embedded systems - web applications - (embedded) domain specific languages - security - novel memory management techniques - run-time profiling performance measurements - debugging and tracing - virtual/abstract machine architectures - validation, verification of functional programs - tools and programming techniques - (industrial) applications Peter Landin Prize The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honored article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 Euros. Programme committee Chair: Tom Schrijvers, KU Leuven, Belgium - Sandrine Blazy, University of Rennes 1, France - Laura Castro, University of A Coruña, Spain - Jacques, Garrigue, Nagoya University, Japan - Clemens Grelck, University of Amsterdam, The Netherlands - Zoltan Horvath, Eotvos Lorand University, Hungary - Jan Martin Jansen, Netherlands Defence Academy, The Netherlands - Mauro Jaskelioff, CIFASIS/Universidad Nacional de Rosario, Argentina - Patricia Johann, Appalachian State University, USA - Wolfram Kahl, McMaster University, Canada - Pieter Koopman, Radboud University Nijmegen, The Netherlands - Shin-Cheng Mu, Academia Sinica, Taiwan - Henrik Nilsson, University of Nottingham, UK - Nikolaos Papaspyrou, National Technical University of Athens, Greece - Atze van der Ploeg, Chalmers University of Technology, Sweden - Matija Pretnar, University of Ljubljana, Slovenia - Tillmann Rendel, University of Tübingen, Germany - Christophe Scholliers, Universiteit Gent, Belgium - Sven-Bodo Scholz, Heriot-Watt University, UK - Melinda Toth, Eotvos Lorand University, Hungary - Meng Wang, University of Kent, UK - Jeremy Yallop, University of Cambridge, UK Venue The 28th IFL will be held in association with the Faculty of Computer Science, KU Leuven, Belgium. Leuven is centrally located in Belgium and can be easily reached from Brussels Airport by train (~15 minutes). The venue in the Arenberg Castle park can be reached by foot, bus or taxi from the city center. See the website for more information on the venue.

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Packaging a library with a separate shared object
by Bryan Gardiner 05 Jul '16

05 Jul '16

Hi folks! I'm working on packaging Qtah (my Qt bindings) for upload to Hackage. This is somewhat complicated, as I have some C++ glue code that I build into a shared library that the Haskell library needs. Currently, my build hooks are as follows, in: https://gitlab.com/khumba/qtah/blob/packaging/qtah/Setup.hs - postConf: Generate Haskell code in src/ and C++ code in cpp/. - preBuild: Add cpp/ to HookedBuildInfo.extraLibDirs because the build phase needs this needs this. - buildHook: Run make to build the C++ code into libqtah.so before the Haskell code builds. - copyHook and instHook: Copy libqtah.so into InstallDirs.libdir (~/.cabal/lib/.../qtah-*/). This installs successfully, but ultimately doesn't work because the Haskell libHSqtah*.so that gets built can't find libqtah.so. The installation directory ~/cabal/lib/.../qtah-*/ isn't on libHSqtah*.so's RUNPATH (which makes sense, it's not known at link time). I could create a separate package for the C++ bits, but I'd rather not do that unless necessary (there's already a qtah-generator package as well). I can't see how I can avoid doing this though. Are there any Cabal experts that could point me in the right direction, or confirm that I'll need to split the package? Many thanks, Bryan

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