June 2009 - Haskell - Haskell.org

Haskell Weekly News: Issue 121 - June 13, 2009
by Brent Yorgey 13 Jun '09

13 Jun '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090613 Issue 121 - June 13, 2009 --------------------------------------------------------------------------- Welcome to issue 121 of HWN, a newsletter covering developments in the [1]Haskell community. Announcements purely functional lazy non-deterministic programming. Sebastian Fischer [2]announced the [3]explicit-sharing library, which supports lazy functional-logic programming in Haskell. nntp 0.0.1. Maciej Piechotka [4]announced the release of [5]nntp, a library to connect to nntp (i.e. mainly USENET) servers. OpenGLRaw 1.0.0.0. Sven Panne [6]announced the release of [7]OpenGLRaw, a low-level binding for OpenGL. The eventual goal is to make the OpenGL package easier to install, more modular and a bit more flexible. pgm-0.1 on Hackage. Frederick Ross [8]announced [9]pgm, a pure Haskell library to read and write PGM images. It seamlessly handles the divide between 1 and 2 byte per pixel images; reads and writes UArrays; can handle multiple PGMs concatenated one after another in a file; and encodes and decodes all comments in the PGM header, which can be used to drop arbitrary metadata into files in a human readable manner. iteratee-0.2.1 released. John Lato [10]announced the release of [11]iteratee-0.2.1, a major update to the iteratee library. This library provides types and functions for performing enumerator/iteratee based I/O operations in Haskell, as [12]described by Oleg. The new version is a large redesign, including support for resumable exceptions and a greatly simplified interface. testrunner-0.9. Reinier Lamers [13]announced [14]testrunner, a new framework for running unit test. It can run unit tests in parallel; can run QuickCheck and HUnit tests as well as simple boolean expressions; and comes with a ready-made main function for your unit test executable. serial-0.2. Frederick Ross [15]announced version 0.2 of [16]serial, a library for working with line-oriented POSIX serial ports. hunp-0.0. Deniz Dogan [17]announced [18]hunp, a command-line utility which automagically calls the right "unpacker" program for you and works on both files and directories. Nemesis : easy task management. Jinjing Wang [19]announced a new release of [20]nemesis, a simple rake-like task management tool. Data.Reify.CSE. Sebastiaan Visser [21]announced the [22]data-reify-cse module, which implements common sub-expression elimination for graphs generated by the Data.Reify package. This package might especially be useful for optimizing simple compilers for referentially transparent domain specific languages. Hac phi accommodation: register by June 15 for reduced rate! Brent Yorgey [23]reminded anyone interested in attending [24]Hac phi that Monday 15 June is the deadline for getting a special reduced hotel rate. alloy-1.0.0 (generic programming). Neil Brown [25]announced the [26]first release of the [27]Allow generic programming library. It is intended to be a fairly fast blend of several other generics approaches, such as SYB (but without the dynamic typing) and Uniplate (but allowing an arbitrary number of target types), for performing transformations on specific types in large tree structures. StrictBench 0.1 - Benchmarking code through strict evaluation. R.A. Niemeijer [28]announced the release of [29]StrictBench, a library for timing full evaluation of values. haskeem 0.7.0 uploaded to hackage. Uwe Hollerbach [30]announced [31]haskeem, a small scheme interpreter written in Haskell. numtype 1.0 -- Type-level (low cardinality) integers. Bjorn Buckwalter [32]announced the [33]Numeric.NumType module, now released as its own package, which implements a unary type-level representation of integers, supporting addition, subtraction, multiplication, and division. Google Summer of Code Progress updates from participants in the 2008 [34]Google Summer of Code. space profiling. Gergely Patai has some [35]pretty graphs generated by his profiling library. haskell-src-exts. Niklas Broberg is [36]quite close to releasing haskell-src-exts 1.0.0, as soon as he has full and correct support for (almost) everything code-related, with only a few things left to do. He also wrote [37]a post explaining the intricacies of parsing code containing the 'forall' keyword (well, whether it is a keyword depends on which extensions are enabled...) fast darcs. Petr Rockai made a bit less progress this week, with finals and other things interfering, but [38]made some progress on some documentation, tracking down a performance regression, and other things. Discussion Adding an ignore function to Control.Monad. Gwern Branwen [39]proposed adding an 'ignore' function to Control.Monad which explicitly changes an m a into a m (). Bikeshedding (and some useful discussion) ensued. Wiki user accounts. Philippa Cowderoy began a [40]discussion of what to do about the current situation with wiki user accounts (namely, that account creation is disabled due to spam, and the one maintainer of the wiki can't always respond to account creation requests instantly). Lightweight type-level dependent programming in Haskell. Ryan Ingram made an interesting [41]post about implementing lightweight closed type classes in Haskell. who's up for a hackathon? (ICFP, late Aug, early Sept). Eric Kow [42]wanted to know who would be interested in having a hackathon immediately before or after ICFP in Edinburgh. Jobs Galois is hiring functional programmers. Don Stewart [43]announced that [44]Galois is hiring! See the announcement for more details. Blog noise [45]Haskell news from the [46]blogosphere. Blog posts from people new to the Haskell community are marked with >>>, be sure to welcome them! * Niklas Broberg: [47]GSoC status report, week 3. * Joachim Breitner: [48]Introducing L-seed. * Conal Elliott: [49]Memoizing polymorphic functions - part two. * London Haskell Users Group: [50]Next Meeting: Sean Leather, Fun and generic things to do with EMGM. * David Amos: [51]It's on Hackage!. Haskell for Maths is now just a cabal-install away. * Michael Snoyman: [52]Filename encoding issues. * David Amos: [53]Permutation groups. * Edward Kmett: [54]Recursion Schemes: A Field Guide (Redux). * mightybyte: [55]Intro to HAppS-State. * Conal Elliott: [56]Memoizing polymorphic functions - part one. * Lennart Augustsson: [57]More LLVM. * Roman Cheplyaka: [58]Don't play with your monads. * Galois, Inc: [59]Tech Talk: Orc in Haskell. * Petr Rockai: [60]soc progress 3. Progress on Petr's GSoC darcs project. * Magnus Therning: [61]Using msmtp with darcs. * Erik de Castro Lopo: [62]Debian Maintainer. Erik is now a Debian maintainer, and plans to give Haskell on Debian a much-needed facelift! * Niklas Broberg: [63]What's in a forall?. More Haskell parsing fun. * Well-Typed.Com: [64]GHC, primops and exorcising GMP. * Niklas Broberg: [65]What's in a forall?. More than you might expect! * >>> Zsol: [66]Visualizing the graphrewrite process behind Haskell. Work on the [67]visual-graphrewrite package. * Eric Kow (kowey): [68]testrunner for practical quickcheck. * Sebastian Fischer: [69]Explicit sharing of monadic effects. Purely functional, lazy, non-deterministic programming! * LHC Team: [70]New backend. * >>> James McNeill: [71]Messing with Haskell. * Dan Piponi (sigfpe): [72]Hashing Molecules. * Shin-Cheng Mu: [73]Longest Segment Satisfying Suffix and Overlap-Closed Predicates. * David Amos: [74]Simple graphs with Math.Combinatorics.Graph. David shows off his Haskell for Maths library. * Gergely Patai: [75]More colourful graphs. Graphs from Gergely's GSoC project on profiling. * Bryan O'Sullivan: [76]Case conversion and text 0.3. The text module gets solid, standards-compliant case conversion. * Bjorn Buckwalter: [77]numtype 1.0: Type-level (low cardinality) integers. * >>> Jörn Dinkla: [78]Parallelization with Haskell - Easy as can be. Quotes of the Week * sjanssen: in our sub-culture, "considered harmful" means "burn it with fire" * quicksilver: after all, anyone who insists on talking about himself in the third person is clearly someone to be reckoned with. About the Haskell Weekly News New editions are posted to [79]the Haskell mailing list as well as to [80]the Haskell Sequence and [81]Planet Haskell. [82]RSS is also available, and headlines appear on [83]haskell.org. To help create new editions of this newsletter, please see the information on [84]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [85]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.libraries/11265 3. http://sebfisch.github.com/explicit-sharing 4. http://article.gmane.org/gmane.comp.lang.haskell.general/17271 5. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/nntp 6. http://www.haskell.org//pipermail/haskell/2009-June/021402.html 7. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/OpenGLRaw 8. http://article.gmane.org/gmane.comp.lang.haskell.general/17263 9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/pgm 10. http://article.gmane.org/gmane.comp.lang.haskell.general/17262 11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/iteratee 12. http://okmij.org/ftp/Streams.html#iteratee 13. http://article.gmane.org/gmane.comp.lang.haskell.general/17258 14. http://projects.haskell.org/testrunner/ 15. http://article.gmane.org/gmane.comp.lang.haskell.general/17257 16. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/serial 17. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59843 18. http://hackage.haskell.org/package/hunp 19. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59824 20. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/nemesis 21. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59807 22. http://hackage.haskell.org/package/data-reify-cse 23. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59741 24. http://haskell.org/haskellwiki/Hac_%CF%86 25. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59631 26. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/alloy 27. http://twistedsquare.com/Alloy-Tutorial.pdf 28. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59605 29. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/StrictBench 30. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59551 31. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/haskeem 32. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59543 33. http://dimensional.googlecode.com/ 34. http://hackage.haskell.org/trac/summer-of-code/wiki/SoC2008 35. http://just-bottom.blogspot.com/2009/06/more-colourful-graphs.html 36. http://nibrofun.blogspot.com/2009/06/gsoc-status-report-week-3.html 37. http://nibrofun.blogspot.com/2009/06/whats-in-forall.html 38. http://web.mornfall.net/blog/soc_progress_3.html 39. http://thread.gmane.org/gmane.comp.lang.haskell.libraries/11278 40. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/59814 41. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/59749 42. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/59737 43. http://article.gmane.org/gmane.comp.lang.haskell.general/17264 44. http://www.galois.com/ 45. http://planet.haskell.org/ 46. http://haskell.org/haskellwiki/Blog_articles 47. http://nibrofun.blogspot.com/2009/06/gsoc-status-report-week-3.html 48. https://www.joachim-breitner.de/blog/archives/330-Introducing-L-seed.html 49. http://conal.net/blog/posts/memoizing-polymorphic-functions-part-two/ 50. http://www.londonhug.net/2009/06/12/next-meeting-sean-leather-fun-and-gener… 51. http://haskellformaths.blogspot.com/2009/06/its-on-hackage.html 52. http://blog.snoyman.com/2009/06/11/filename-encoding-issues/ 53. http://haskellformaths.blogspot.com/2009/06/permutation-groups.html 54. http://comonad.com/reader/2009/recursion-schemes/ 55. http://softwaresimply.blogspot.com/2008/02/intro-to-happs-state.html 56. http://conal.net/blog/posts/memoizing-polymorphic-functions-part-one/ 57. http://augustss.blogspot.com/2009/06/more-llvm-recently-someone-asked-me-on… 58. http://ro-che.blogspot.com/2009/06/dont-play-with-your-monads.html 59. http://www.galois.com/blog/2009/06/09/tech-talk-orc/ 60. http://web.mornfall.net/blog/soc_progress_3.html 61. http://therning.org/magnus/archives/656 62. http://www.mega-nerd.com/erikd/Blog/CodeHacking/Debian/debian_maintainer.ht… 63. http://nibrofun.blogspot.com/2009/06/whats-in-forall.html 64. http://blog.well-typed.com/2009/06/ghc-primops-and-exorcising-gmp/ 65. http://nibrofun.blogspot.com/2009/06/whats-in-forall.html 66. http://lazybottom.blogspot.com/2009/06/visualizing-graphrewrite-process-beh… 67. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/visual-graphrewr… 68. http://koweycode.blogspot.com/2009/06/testrunner-for-practical-quickcheck.h… 69. http://www-ps.informatik.uni-kiel.de/~sebf/haskell/explicit-sharing.html 70. http://lhc-compiler.blogspot.com/2009/06/new-backend.html 71. http://playtechs.blogspot.com/2009/06/messing-with-haskell.html 72. http://blog.sigfpe.com/2009/06/hashing-molecules.html 73. http://www.iis.sinica.edu.tw/~scm/2009/longest-segment-satisfying-suffix-an… 74. http://haskellformaths.blogspot.com/2009/06/simple-graphs-with-mathcombinat… 75. http://just-bottom.blogspot.com/2009/06/more-colourful-graphs.html 76. http://www.serpentine.com/blog/2009/06/07/case-conversion-and-text-03/ 77. http://flygdynamikern.blogspot.com/2009/06/announce-numtype-10-type-level-l… 78. http://blog.dinkla.net/?p=15 79. http://www.haskell.org/mailman/listinfo/haskell 80. http://sequence.complete.org/ 81. http://planet.haskell.org/ 82. http://sequence.complete.org/node/feed 83. http://haskell.org/ 84. http://haskell.org/haskellwiki/HWN 85. http://code.haskell.org/~byorgey/code/hwn/

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ANNOUNCE: nntp 0.0.1
by Maciej Piechotka 13 Jun '09

13 Jun '09

Nntp is a library to connect to nntp (i.e. mainly USENET) servers. Currently RFC977 is being implemented. It is published on the LGPL v3 license. Currently implemented: Currently all commands from RFC are implemented. However for user interaction other, more generic interface is provided. Currently tested: Automated testing is not available yet. Tested is only *small* subset of commands and it is at an early stage of development.

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FSTTCS 2009 Call for papers
by Piyush P Kurur 12 Jun '09

12 Jun '09

Hi, The deadline for FST TCS 2009 is nearing (July 7 2009). Please do send your interesting results via easychair http://www.easychair.org/conferences/?conf=fsttcs2009 Details: http://www.fsttcs.org/ Hope to see you in Kanpur Regards ppk

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ANNOUNCE: Galois is hiring functional programmers
by Don Stewart 11 Jun '09

11 Jun '09

Galois is hiring. Bringing together mathematicians, researchers and technologists, Galois, based in Portland, Oregon, was founded in 1999 with the mission to apply functional languages and formal methods to solve real world problems. Today, over 30 members strong, we’re living the vision, designing and developing advanced technologies for safety and security-critical systems, networks, and applications. Galois technical staff members play a pivotal role in developing advanced software technology. Members work on one or more projects, and are expected to perform in a variety of roles based upon their talents and organizational needs. Technical staff may be called upon to write proposals, gather requirements, and work in all stages of the software development process, from requirements gathering to testing and validation. Additional duties may include project management, technology research and development, and technical infrastructure development. We’re looking for people who can invent, learn, think, and inspire. We reward creativity and thrive on collaboration. We offer great benefits and perks, including a 401K plan, stock options, paid vacation, family health plan, flexible work schedule, a casual work environment, snacks, espresso and foosball. Galois technical staff members usually work in a small team setting (2-5 members), and must successfully interact with clients, partners, and other employees in a highly cooperative, collaborative, and intellectually challenging environment. A Masters or Ph.D. degree in Computer Science is desirable but not required. Additionally, a strong programming background and experience with Haskell or other functional programming languages is preferred but not required. Must work well with customers, including building rapport, identifying needs, and communicating with strong written, verbal and presentation skills. Must be highly motivated and able to self-manage to deadlines and quality goals. To learn more about us, visit http://www.galois.com and http://www.galois.com/company/careers The types of technology we use are covered in our blog: http://www.galois.com/blog/ We’d like to hear from you! Send your cover letter and resume to us at jobs2009(a)galois.com.

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pgm-0.1 on Hackage
by Frederick Ross 09 Jun '09

09 Jun '09

pgm is a pure Haskell library to read and write PGM images. Points of note: * Seamlessly handles the divide between 1 and 2 byte per pixel images (this is vital for folks doing microscopy, since otherwise we're stuck in tiff hell). * Returns the images as UArrays; writes from UArrays. * Handles multiple PGMs concatenated one after another in a file, provided they are separated only by (optional) whitespace. * Encodes and decodes all comments in the PGM header, which can be used to drop arbitrary metadata into files in a human readable manner. -- Frederick Ross Doctorant, SV/GHI/UPKIN, EPFL Graduate Fellow, The Rockefeller University

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ANN: iteratee-0.2.1 released
by John Lato 09 Jun '09

09 Jun '09

Hello, I would like to announce the release of iteratee-0.2.1, a major update to the iteratee library. This library provides types and functions for performing enumerator/iteratee based I/O operations in Haskell, as described by Oleg at http://okmij.org/ftp/Streams.html#iteratee. This library is intended to be used for incremental, strict I/O and provides high performance and composability. The 0.2 version is a large redesign from the initial release, with many breaking changes. A major new feature is support for resumable exceptions. The interface has been greatly simplified, including the following: -Iteratees that previously returned a result of "Maybe a" will now usually have a result of "a", making it much simpler to combine multiple iteratees. The "bindm" combinator is no longer necessary. Failed operations should now result in a resumable exception. User-defined iteratees may still have results of "Maybe a" of course. -The types IterateeG and IterateeGM have been unified; IterateeGM is no longer necessary or supplied. -The combinators (>>==) and (==<<) are no longer necessary or supplied; the same functionality is provided by (>>=) and ($). -The new combinator "joinIM" simplifies composing multiple enumerations in certain monadic contexts. -The StreamChunk class now depends upon Monoid and ListLike, and defaults are provided for all functions, simplifying the work necessary to create a new StreamChunk instance (although performance can be greatly improved by providing certain custom implementations). -The library depends upon transformers instead of mtl for monadic composition. I made this change because it looks like mtl will be deprecated from HPC in the near future, however it could be reverted if necessary. The only difference between 0.2 and 0.2.1 is that I removed a section on building the test executable from the .cabal file so that test frameworks wouldn't be required of all users. All necessary files for testing are supplied with 0.2.1, they just have to be built manually. The process of updating earlier code to work with this version can be more-or-less straightforward, depending upon style and the particular functionality accessed. I would be happy to provide assistance if anyone is in this situation. Thanks to the following individuals for contributing code to this release: Oleg Kiselyov Bas van Dijk Paulo Tanimoto Thanks to Johan Tibell for comments and ongoing support. Cheers, John Lato

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purely functional lazy non-deterministic programming
by Sebastian Fischer 08 Jun '09

08 Jun '09

[crosspost from Haskell-libraries and Curry mailing list] Dear Haskell and Curry programmers, there is now a Haskell library that supports lazy functional-logic programming in Haskell. It is available from http://sebfisch.github.com/explicit-sharing and can be obtained from Hackage using cabal-install. The project page links to tutorials that explain how to use the library and to an ICFP'09 paper (joint work with Oleg Kiselyov and Chung-chieh Shan) that explains the implemented ideas in depth. Have fun! Sebastian -- Underestimating the novelty of the future is a time-honored tradition. (D.G.)

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LINEARITY 2009 - Call for Papers
by Mário Florido 08 Jun '09

08 Jun '09

Call for Papers LINEARITY 2009 First International Workshop on Linearity http://www.lix.polytechnique.fr/linearity/ Coimbra, Portugal 12 September 2009 A satellite event of CSL 2009, 18th EACSL Annual Conference on Computer Science Logic =================================================================== Important Dates --------------- * 5 July 2009: Abstract deadline * 10 July 2009: Submission deadline * 24 July 2009: Author notification * 1 September 2009: Deadline for final versions of accepted papers * 12 September 2009: Workshop The pre-proceedings and program will be online here before the workshop. Scope ----- Linearity has been the key feature in several lines of research in both theoretical and practical approaches to computer science. In the theoretical side all the work stemming from linear logic dealing with proof technology, complexity classes and more recently quantum computation. In the practical side work on program analysis, expressive operational semantics for programming languages, linear programming languages, program transformation, update analysis and efficient implementation techniques. The aim of this workshop is to bring together researchers who are currently developing theory and applications of linear calculi, in order to foster their interaction, to provide a forum for presenting new ideas and work in progress, and to enable newcomers to learn about current activities in this area. LINEARITY 2009 will be a one-day satellite event of CSL 2009. Topics ------ Topics of interest include foundational calculus, models, applications to programming languages and systems. This includes (but is not limited to): * Linear types: session types, etc * Linear calculi; * Functional calculi: lambda-calculus, rho-calculus, term and graph rewriting; * Object calculi; * Interaction-based systems: interaction nets, games; * Concurrent models: process calculi, action graphs; * Calculi expressing locality, mobility, and active data; * Quantum computational models; * Biological or chemical models of computation; Submission and Publication -------------------------- Authors are invited to submit a short paper (5-7 pages) by 10 July 2009. Preliminary proceedings will be available at the workshop. Papers should be written in English, and submitted in PostScript or PDF format, using the EPTCS style files. Submission is through the Easychair website: http://www.easychair.org/conferences/?conf=linearity2009 After the workshop authors are invited to submit a revised version (12 pages) of their presentation. Accepted contributions will appear in an electronic proceedings Authors and participants will also be invited to submit an article to a special issue of the Journal of Logic and Computation. Programme Committee * Sandra Alves * Ugo Dal Lago * Maribel Fernandez * Simon Gay * Mario Florido (co-chair) * Martin Hofmann * Ian Mackie (co-chair) * Greg Morrisett * Alan Mycroft * Luke Ong * Luca Paolini Contact ------- linearity(a)lix.polytechnique.fr

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ANNOUNCE: testrunner-0.9
by Reinier Lamers 08 Jun '09

08 Jun '09

Dear all, testrunner is a new framework to run unit tests. It has the following distinguishing features: * It can run unit tests in parallel. * It can run QuickCheck and HUnit tests as well as simple boolean expressions. * It comes with a ready-made main function for your unit test executable. * This main function recognizes command-line arguments to select tests by name and replay QuickCheck tests. testrunner was conceived as a part of the darcs project. The home page is http://projects.haskell.org/testrunner/. testrunner can be downloaded from http://projects.haskell.org/testrunner/releases/testrunner-0.9.tar.gz, or with darcs with a "darcs get http://code.haskell.org/testrunner/". Regards, Reinier Lamers (tux_rocker)

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serial-0.2
by Frederick Ross 08 Jun '09

08 Jun '09

serial is a library for working with line-oriented POSIX serial ports. The changes from 0.1 are: * Added a BlockingSerialManager for those devices which have completely ambiguous responses and can't be sorted out nicely to send back to calling functions. Instead, it executes commands one after another, waits until they are done, sends the response back, and moves on to the next command. The magic of MVars makes all this line up properly. * Switched SerialManager to use predicates (String -> Bool) instead of Parsec parsers for sorting out return values. * Turned on -Wall and dealt with everything that appeared. * Decided to use LGPL instead of GPL, at least for now. -- Frederick Ross Doctorant, SV/GHI/UPKIN, EPFL Graduate Fellow, The Rockefeller University

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