April 2012 - Haskell - Haskell.org

ANNOUNCE: ioctl 0.0.1
by Maciej Piechotka 13 Sep '15

13 Sep '15

A package for type-safe I/O control. Currently only ioctl is supported. Currently simply a extract from my tuntap fork TODO: - Return the integer as well as structure (will break the API) - Port for Windows Network.Socket.IOCtl (as soon as I manage to setup some sane environment on this platform) - Wrapping around DeviceIoControl Example (in hsc): data NotRead = NotRead instance NotRead Int where ioctlReq _ = #const FIONREAD notRead s = ioctlsocket' s NotRead Regards

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CFP: Term and Graph rewriting, special issue of MSCS
by Rachid Echahed 13 Feb '14

13 Feb '14

-------------------------------------------------------------------------- First Call for Papers Special Issue of Mathematical Structures in Computer Science (MSCS) on "TERM and GRAPH Rewriting" -------------------------------------------------------------------------- Scope -------------------------------------------------------------------------- Rewriting techniques constitute a foundational theory of computing science. They are being investigated for several structures such as lambda-terms, first-order terms or graphs and have been successfully used in many areas such as programming languages, automated reasoning, program verification, security, etc. This is witnessed by the leading international events ICGT, RTA or TLCA among others. During the last decade, a particular interest has been devoted to the study of the impact of shared structures in term and graph rewriting through the international editions of TERMGRAPH series of workshops. Sharing is indeed ubiquitous in several research areas, for instance: the modelling of first- and higher-order term rewriting by (acyclic or cyclic) graph rewriting, the modelling of biological or chemical abstract machines, the implementation techniques of programming languages. Term and graph rewriting are also used in automated theorem proving and symbolic computation systems working on shared structures... This special issue is devoted to recent developments in all aspects of TERM and GRAPH rewriting. This includes (but is not limited to): term rewriting, graph transformation, proof methods, programming languages, infinitary rewriting, rewrite strategies, semantics, properties of rewriting ... -------------------------------------------------------------------------- Submissions -------------------------------------------------------------------------- Submitted papers must be original and not submitted for publication elsewhere, and will be subject to the standard journal refereeing process of the Mathematical Structures in Computer Science (MSCS) journal. Submissions should be in pdf format following the MSCS instruction for contributors (http://assets.cambridge.org/MSC/MSC_ifc.pdf) and should be submitted electronically via the following easy-chair web site: https://www.easychair.org/conferences/?conf=mscsrewriting2012 -------------------------------------------------------------------------- Important Dates -------------------------------------------------------------------------- January 20, 2012 : Abstract submission February 20, 2012: Paper submission June 15, 2012 : Notification of acceptance -------------------------------------------------------------------------- Guest Editor: -------------------------------------------------------------------------- Rachid Echahed, CNRS LIG Lab., Grenoble, France echahed(a)imag.fr --------------------------------------------------------------------------

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ANNOUNCE: planar-graph-1.0
by Ivan Lazar Miljenovic 28 Apr '12

28 Apr '12

I uploaded this [1] yesterday, posted the blog article [2] about it... but forgot to send a message to the lists! [1]: http://hackage.haskell.org/package/planar-graph [2]: http://ivanmiljenovic.wordpress.com/2012/04/27/announcing-planar-graph/ planar-graph is an implementation of, strangely enough, planar graphs (that is, a graph that contains an embedding on a surface, can be drawn with no edge crossings and has a specific ordering of edges). It handles graphs on planes and spheres, but I'm not sure about other surfaces (and there seems to be little demand for such). This probably won't be of many use to people, but as I described in the blog post, I've been using this as a test bed for graph library design (specifically usage of abstract node/edge identifiers, using half-edges and the serialisation/encoding setup). -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com http://IvanMiljenovic.wordpress.com

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Re: [Haskell] ANN: Portackage - a hackage portal
by Andrew Seniuk 27 Apr '12

27 Apr '12

Hi Derek, Thanks for your comments. Yes, I am probably going to focus on making it work as a web service and stay away from platform-specific mobile apps. Not been thinking mobile much at all, since the quantities of data are taxing even to my laptop, and also I'm inclined to believe people are mostly at a laptop or desktop when coding Haskell. However, I'm planning to try server-side sorting and filtering, and compare performance. No DB is used on the server yet, but it would be simple enough I suppose -- all this is quite new territory for me. Also my shared hosting resource limits may become a problem if this gets a lot of use. On the other hand, was planning to use persistence (cookies i guess?) to save the data on the client, so that patches based on Hackage RSS could be applied incrementally. Also, I think the sorting could be faster by sending per-column lists of indices. But maybe it is just the browser rendering which is taking all the time? I'll take this opportunity to announce a few improvements: - shift-click a row to see the Hackage page (bare click does nothing) - per-column filtering widgets Presently working on getting the "last updated" column, this information is not in a .cabal file but I'm hoping it is in the TAR metadata... The link again: http://www.fremissant.net/portackage A.

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ANN: Portackage - a hackage portal
by Andrew Seniuk 27 Apr '12

27 Apr '12

Hello, This is to announce a provisional webpage to summarise hackage.haskell.org. http://www.fremissant.net/portackage It is a lot of data, so will be a bit slow to load. Columns can be sorted by clicking the headers, but this will also take some seconds on a typical client. The initial sort is by module name. Clicking a table row links to the project page on hackage. Although I believe this is a complete list of all packages/modules in hackage, it is probably still buggy, so if you see anything amiss please let me know. Also, a subsequent version in the near future will update automatically based on the http://hackage.haskell.org/packages/archive/recent.rss RSS feed, but for now it's based on a recent snapshot. Haskell code which prepares the page will be released after a few more days testing and refinement. Some previous work [1] provided a list of all modules, but is not being maintained, and I was unable to rearouse the author's interest. Feature requests and suggestions are welcome! Kind Reg'ds, Andrew Seniuk [1] http://folk.ntnu.no/hammar/explore-hackage/

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CHR 2012: Call for Papers
by Jon Sneyers 27 Apr '12

27 Apr '12

========================================================================= Call for Papers Ninth International Workshop on Constraint Handling Rules CHR 2012 http://dtai.cs.kuleuven.be/CHR/CHR2012/ Budapest (Hungary), September 4th, 2012 (co-located with ICLP 2012) ========================================================================= Introduction The CHR 2012 Workshop will be held on September 4th, 2012 in Budapest, Hungary, at the occasion of the 28th International Conference on Logic Programming (ICLP 2010), the premier international venue for presenting research in logic programming. More information on the venue and the co-located conference and workshops can be found on the ICLP website (http://www.cs.bme.hu/iclp2012/) The Constraint Handling Rules (CHR) language has become a major declara- tive specification formalism and implementation language for constraint reasoning algorithms and applications. Algorithms specified using infe- rence rules, rewrite rules, sequents, proof rules, or logical axioms can often be directly written in CHR. Its clean semantics facilitates pro- gram design, analysis, and transformation. For more information, please visit the CHR website (http://dtai.cs.kuleuven.be/CHR/) The aim of the CHR workshop series is to stimulate and promote interna- tional research and collaboration on topics related to the CHR language. The workshop is a lively, friendly forum for presenting and discussing new results, interesting applications, and work in progress. Previous Workshops on Constraint Handling Rules were organized in 2004 in Ulm (Germany), in 2005 in Sitges (Spain) at ICLP, in 2006 in Venice (Italy) at ICALP, in 2007 in Porto (Portugal) at ICLP, in 2008 in Hagen- berg (Austria) at RTA, in 2009 in Pasadena (California, US) at ICLP, in 2010 in Edinburgh (Scotland, UK) at ICLP, and in 2011 in Cairo (Egypt), at the 2nd CHR summer school. Topics of Interest The workshop calls for full papers and short papers describing ongoing work on any aspect of CHR and related approaches. The following topics are relevant (this list is non-exhaustive): - (Logical) Algorithms - Applications - Comparisons with Related Approaches - Constraint Solvers - Critical Assessment - Expressiveness and Complexity - Implementations and Optimization - Language Extensions (Types, Modules,...) - Program Analysis - Program Transformation and Generation - Programming Environments (Debugging) - Programming Pearls - Programming Tools - Retractable Constraints - Semantics - System Descriptions Important dates - Paper submission deadline: July 2nd, 2012 - Notification of acceptance: August 1st, 2012 - Final version due: August 17, 2012 (tentative) - Workshop date: September 4th, 2012 Submission Information The four broad categories for submissions are: 1. technical papers for describing technically sound, innovative ideas that can advance the state of the art of CHR 2. application papers, where the emphasis will be on the use of CHR in the application, on the impact on the application domain, and the lessons learned from this application 3. system and tool papers, emphasising the novelty, practicality, usability and general availability of the systems and tools described 4. short papers, for ongoing work not yet ready for full publication and research project overviews. All papers must describe original, previously unpublished research, and must not simultaneously be submitted for publication elsewhere. They must be written in English. Technical papers must not exceed 15 pages. The limit for short papers is 8 pages, as is the standard page limit for application papers, and system and tool papers. However, particularly strong contributions in the latter two areas may be submitted as technical paper as well. All papers must be in the Springer LNCS format. General information about the Springer LNCS series and the LNCS authors' instructions are available at the Springer LNCS home page (http://www.springer.com/computer/lncs?SGWID=0-164-7-72376-0) Submissions must be made via the EasyChair submission system, available at http://www.easychair.org/conferences/?conf=chr2012 Programme Committee - Henning Christiansen, Roskilde University, Denmark - Veronica Dahl, Simon Fraser University, Canada - François Fages, INRIA Paris-Rocquencourt, France - Thom Frühwirth, Ulm University, Germany (co-chair) - Maurizio Gabbrielli, Universita' di Bologna, Italy - Rémy Haemmerlé, Universidad Politecnica de Madrid, Spain - Thierry Martinez, INRIA Paris-Rocquencourt, France - Eric Monfroy, Université de Nantes, France - Tom Schrijvers, University of Ghent, Belgium - Jon Sneyers, KU Leuven, Belgium (co-chair) - Armin Wolf, Fraunhofer FIRST, Germany Workshop Coordinators Contact: chr2012(a)easychair.org Jon Sneyers Department of Computer Science, KU Leuven Leuven, Belgium http://people.cs.kuleuven.be/~jon.sneyers/ Thom Frühwirth Programmiermethodik und Compilerbau, Ulm University Ulm, Germany http://www.informatik.uni-ulm.de/pm/mitarbeiter/fruehwirth/

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Re: [Haskell] ANN: Portackage - a hackage portal
by Andrew Seniuk 26 Apr '12

26 Apr '12

Jonathan, On Thu, Apr 26, 2012 at 4:13 PM, Jonathan Daugherty <jtd(a)galois.com> wrote: >> Although I believe this is a complete list of all packages/modules in >> hackage, it is probably still buggy, so if you see anything amiss >> please let me know. > > It might not be showing the most recent releases of everything. As an > example, it shows a much older version of my vty-ui library (1.0) and > its metadata, instead of the latest version, 1.5. As a result the > version, module list, description, homepage, etc., are not current. Thank-you, I'd realised this issue but forgot to address it. It is due to a false assumption on my part that the .cabal entries in the 00-index.tar file were in increasing version order. I'll address this problem today. Cheers, Andrew

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Full-time Haskell position
by Carl Baatz 26 Apr '12

26 Apr '12

Erudify is an early-stage technology firm building tools that help individuals learn. We are based in Zurich, funded, not yet seeking publicity, and intent on solving this the right way. On the Haskell side, our team consists of two full-time programmers, both with 5+ years of Haskell experience. The team is growing, and we are looking for the right person to come and join us. We have a range of interesting problems to work on and are keen to speak with programmers with expertise and experience in any of a number of fields. In addition to being a productive Haskell programmer, we will look for the following in applicants: - Focus - Grit - Rationality - Curiosity - Intelligence To apply, please email us at jobs(a)erudify.ch with - a short description of what you think matters in life - why you program - your view about the world today (what scares you? what excites you?) - a CV / the inline equivalent We look forward to hearing from you soon. Carl Baatz Erudify AG

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Haskell Weekly News: Issue 224
by Daniel Santa Cruz 26 Apr '12

26 Apr '12

Welcome to issue 224 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of April 15 to 21, 2012. Announcements Some of these announcements are a bit behind, for which I apologize. Better late than never... The long awaited version of cabal-install is out! [1] http://goo.gl/LlO7s Janis Voigtlander is looking for contributors for the May 2012 edition of the Haskell Comunities and Activities Report. If you have anything Haskell related that you have been working on, make sure to send Janis a note. The deadline is May 1st. [2] http://goo.gl/AW3gR Jeremy O'Donoghue announced the release of wxHaskell 0.90. "his release represents a significant milestone for us as it includes support for wxWidgets 2.9.x." [3] http://goo.gl/vTYTp Janis Voigtlander also issued a call for papers for the Haskell Symposium 2012, Copenhagen, Denmark on 13th September, 2012, directly after ICFP. [4] http://goo.gl/fR2hB Eric Kow released the 9th edition of the Parallel Haskell Digest. [5] http://goo.gl/gBIhK Quotes of the Week * TSC: The type families might have little type children * mm_freak: i'd love to have an embeddable Agda type checker and evaluator mm_freak: that would make a great scripting language for haskell programs * shachaf: You can't spell "-funsafe" without "fun" and "safe". * elliott: By the way, I find the inclusion of a package named "colour" in a section titled "Color" offensive :) * elliott: I don't think Haskell can ever hope to enter the enterprise if we can't model non-standard colourblind observers with it. * danharaj:oh hey this looks nice. Mathnerd314: every open-source math library under the sun glued together into a Python framework danharaj: nevermind o_o * elliott: What do we do with people who paste code blocks on IRC? We yell at them. * acowley: I am a bull in a math shop * elliott: I like how edwardk's answer to every question always goes "most abstract solution to the problem possible --> microoptimisation details". elliott: I swear I've seen him go from category theory to unboxed types and unsafeCoerce in a single line of IRC. * shachaf: It is a sobering thought that by the time Galois was my age, he had been dead for almost two months. Top Reddit Stories * Why do Monads Matter? (or it's Monad tutorial season again) Domain: cdsmith.wordpress.com, Score: 64, Comments: 27 On Reddit: [6] http://goo.gl/DCJYV Original: [7] http://goo.gl/8glhF * Ur/Web records: can we apply lessons from them to Haskell? Domain: blog.ezyang.com, Score: 53, Comments: On Reddit: [8] http://goo.gl/9m3Sw Original: [9] http://goo.gl/dNcET * Blank Canvas - a new Haskell graphics library based on HTML5 and <canvas> Domain: ittc.ku.edu, Score: 42, Comments: 10 On Reddit: [10] http://goo.gl/H3SMB Original: [11] http://goo.gl/if7kG * Client Side Yesod, an FRP-inspired approach Domain: yesodweb.com, Score: 41, Comments: 44 On Reddit: [12] http://goo.gl/gECTq Original: [13] http://goo.gl/Rn0LS * Understanding Haskell Kinds Domain: softwaresimply.blogspot.com, Score: 38, Comments: 18 On Reddit: [14] http://goo.gl/XxiwQ Original: [15] http://goo.gl/xaqDM * Adding SIMD Support to Data Parallel Haskell Domain: ghc-simd.blogspot.co.uk, Score: 35, Comments: 8 On Reddit: [16] http://goo.gl/R8M9L Original: [17] http://goo.gl/ZeJ7e * Working With HTML In Haskell Domain: adit.io, Score: 31, Comments: 24 On Reddit: [18] http://goo.gl/4NMBc Original: [19] http://goo.gl/EOvM1 * Descending the level ladder Domain: monoidal.blogspot.com, Score: 26, Comments: 13 On Reddit: [20] http://goo.gl/9IYZL Original: [21] http://goo.gl/TJm0D * Why is Haskell so large? Domain: self.haskell, Score: 25, Comments: 29 On Reddit: [22] http://goo.gl/KQnbj Original: [23] http://goo.gl/KQnbj * Parallel Haskell Digest 9: GSoC, STM, SIMD, and the Downfall of Imperative Programming? Domain: well-typed.com, Score: 25, Comments: 1 On Reddit: [24] http://goo.gl/Z5bF3 Original: [25] http://goo.gl/eLnVs * blaze-html 0.5 released Domain: jaspervdj.be, Score: 25, Comments: 3 On Reddit: [26] http://goo.gl/7XtMD Original: [27] http://goo.gl/RkbR7 * Four Tips for New Haskell Programmers Domain: softwaresimply.blogspot.com, Score: 22, Comments: 72 On Reddit: [28] http://goo.gl/GQ4O1 Original: [29] http://goo.gl/Ye57L * Check for interest - an argument/option parser using type level strings Domain: self.haskell, Score: 22, Comments: 13 On Reddit: [30] http://goo.gl/eOtE5 Original: [31] http://goo.gl/eOtE5 * New Cabal feature: cabal bench Domain: blog.johantibell.com, Score: 22, Comments: 3 On Reddit: [32] http://goo.gl/ClkjJ Original: [33] http://goo.gl/sA3aD Top StackOverflow Questions * The Pause monad votes: 20, answers: 5 Read on SO: [34] http://goo.gl/DNIo1 * To what extent are macros “functions in reverse?” votes: 15, answers: 6 Read on SO: [35] http://goo.gl/ZoEht * Curry-Howard isomorphism votes: 13, answers: 3 Read on SO: [36] http://goo.gl/1pzKd * How does Djinn work? votes: 12, answers: 3 Read on SO: [37] http://goo.gl/RnEny * How is co-recursion handled? votes: 12, answers: 2 Read on SO: [38] http://goo.gl/DXtj1 * Distinction between typeclasses MonadPlus, Alternative, and Monoid? votes: 11, answers: 1 Read on SO: [39] http://goo.gl/4LZd7 * Why can't Existential Types use record syntax? votes: 11, answers: 2 Read on SO: [40] http://goo.gl/4Gn96 * Given a Haskell type signature, is it possible to generate the code automatically? votes: 11, answers: 4 Read on SO: [41] http://goo.gl/7Xff3 * Is it possible to force a type to a class in Haskell? votes: 10, answers: 6 Read on SO: [42] http://goo.gl/SeFpb * Haskell concurrency - is forkIO really nondeterministic? votes: 10, answers: 2 Read on SO: [43] http://goo.gl/z2q9Y * Where to find programming exercises for applicative functors? votes: 9, answers: 4 Read on SO: [44] http://goo.gl/CXOYU Until next time, Daniel Santa Cruz References 1. http://permalink.gmane.org/gmane.comp.lang.haskell.general/19239 2. http://www.haskell.org/pipermail/haskell/2012-April/023244.html 3. http://permalink.gmane.org/gmane.comp.lang.haskell.wxhaskell.general/1178 4. http://permalink.gmane.org/gmane.comp.science.types.announce/2949 5. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/97851 6. http://cdsmith.wordpress.com/2012/04/18/why-do-monads-matter/ 7. http://www.reddit.com/r/haskell/comments/sfvbu/why_do_monads_matter_or_its_… 8. http://blog.ezyang.com/2012/04/how-urweb-records-work-and-what-it-might-mea… 9. http://www.reddit.com/r/haskell/comments/sjoh5/urweb_records_can_we_apply_l… 10. http://ittc.ku.edu/csdl/fpg/Tools/BlankCanvas 11. http://www.reddit.com/r/haskell/comments/seppr/blank_canvas_a_new_haskell_g… 12. http://www.yesodweb.com/blog/2012/04/client-side 13. http://www.reddit.com/r/haskell/comments/sm72n/client_side_yesod_an_frpinsp… 14. http://softwaresimply.blogspot.com/2012/04/less-travelled-monad-tutorial-pa… 15. http://www.reddit.com/r/haskell/comments/scagx/understanding_haskell_kinds/ 16. http://ghc-simd.blogspot.co.uk/2012/04/adding-simd-support-to-data-parallel… 17. http://www.reddit.com/r/haskell/comments/sfxck/adding_simd_support_to_data_… 18. http://adit.io/posts/2012-04-14-working_with_HTML_in_haskell.html 19. http://www.reddit.com/r/haskell/comments/sbxhb/working_with_html_in_haskell/ 20. http://monoidal.blogspot.com/2012/04/descending-level-ladder.html 21. http://www.reddit.com/r/haskell/comments/scq1q/descending_the_level_ladder/ 22. http://www.reddit.com/r/haskell/comments/sb80y/why_is_haskell_so_large/ 23. http://www.reddit.com/r/haskell/comments/sb80y/why_is_haskell_so_large/ 24. http://www.well-typed.com/blog/65 25. http://www.reddit.com/r/haskell/comments/sjbgv/parallel_haskell_digest_9_gs… 26. http://jaspervdj.be/posts/2012-04-21-blaze-html-0.5.html 27. http://www.reddit.com/r/haskell/comments/sl6ps/blazehtml_05_released/ 28. http://softwaresimply.blogspot.com/2012/04/four-tips-for-new-haskell-progra… 29. http://www.reddit.com/r/haskell/comments/sarkz/four_tips_for_new_haskell_pr… 30. http://www.reddit.com/r/haskell/comments/sbpmz/check_for_interest_an_argume… 31. http://www.reddit.com/r/haskell/comments/sbpmz/check_for_interest_an_argume… 32. http://blog.johantibell.com/2012/04/cabal-bench.html 33. http://www.reddit.com/r/haskell/comments/sfhv3/new_cabal_feature_cabal_benc… 34. http://stackoverflow.com/questions/10236953/the-pause-monad 35. http://stackoverflow.com/questions/10249110/to-what-extent-are-macros-funct… 36. http://stackoverflow.com/questions/10212660/curry-howard-isomorphism 37. http://stackoverflow.com/questions/10217931/how-does-djinn-work 38. http://stackoverflow.com/questions/10257326/how-is-co-recursion-handled 39. http://stackoverflow.com/questions/10167879/distinction-between-typeclasses… 40. http://stackoverflow.com/questions/10192663/why-cant-existential-types-use-… 41. http://stackoverflow.com/questions/10205793/given-a-haskell-type-signature-… 42. http://stackoverflow.com/questions/10211664/is-it-possible-to-force-a-type-… 43. http://stackoverflow.com/questions/10247555/haskell-concurrency-is-forkio-r… 44. http://stackoverflow.com/questions/10239630/where-to-find-programming-exerc…

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ANN: Language module for the BBEdit text editor
by Nicolas Godbout 25 Apr '12

25 Apr '12

I am pleased to announce the first release of a language module for editing Haskell source code from within the BBEdit text editor, available at http://code.google.com/p/bbedit-haskell/ The module implements these features: * color highlighting of keywords and comment, including nested comments * color syntax for characters and strings, including multi-line strings * scanning of function names; they appear in a drop-down menu in the editing window * automatic detection of .hs suffix * support for Un/Comment command available in BBEdit 10.1 and above BBEdit is a commercial text editor available for the MacOS X platform. Nicolas Godbout.

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