September 2009 - Haskell

ANNOUNCE: OpenGL 2.4.0.0
by Sven Panne 13 Sep '09

13 Sep '09

A new version of the OpenGL package has bee uploaded to Hackage. * Added contextProfile query. * Made a few tiny internal typing changes to make things work with the latest OpenGLRaw package. Cheers, S.

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ANNOUNCE: OpenGLRaw 1.1.0.0
by Sven Panne 13 Sep '09

13 Sep '09

A new version of the OpenGLRaw package has been uploaded to Hackage. * Use opaque newtypes for the basic OpenGL types, adding the common instances for them, too. Note that this might break programs which depend on the concrete representations. Use explicit conversions where necessary, making all assumptions explicit. * Fixed linking issues on Mac OS X, the package should work out of the box without any warnings or additional flags now. * Fall back to GetProcAddress on Windows when WGL doesn't find an API entry. This should fix problems using core functions with some driver/OS combinations. * Added support for OpenGL 3.2 and the latest NV extensions. * All extensions export all their functions/tokens/types, even if they are in the core. This will keep the extension module exports more stable. * Fixed the types of the glPixelMap functions, using GLsizei instead of GLint for the size, following the OpenGL specification. Cheers, S.

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ANNOUNCE: GLURaw 1.1.0.0
by Sven Panne 13 Sep '09

13 Sep '09

A new version of the GLURaw package has been uploaded to Hackage. * Fixed linking issues on Mac OS X, the package should work out of the box without any warnings or additional flags now. * Fixed the type of gluUnProject4, the near and far parameters are of type GLclampd, not GLdouble. This matches the GLU spec. Cheers, S.

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ANNOUNCE: GLUT 2.2.2.0
by Sven Panne 13 Sep '09

13 Sep '09

A new version of the GLUT package has been uploaded to Hackage. * Fixed linking issues on Mac OS X, the package should work out of the box without any warnings or additional flags now. * Handle additional mouse buttons via 'AdditionalButton Int' in the MouseButton type. * Made a few minor typing adjustments, which don't really matter for the type synonyms used for the basic OpenGL types so far, but which do matter for the upcoming datatype renamings for them. * Aesthetic improvements in the brick shader example. Cheers, S.

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Haskell Weekly News: Issue 130 - September 12, 2009
by Joe Fredette 12 Sep '09

12 Sep '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090912 Issue 130 - September 12, 2009 --------------------------------------------------------------------------- Welcome to issue 130 of HWN, a newsletter covering developments in the [1]Haskell community. Welcome to issue 130 of HWN! In the last week, HWN has gotten a new editor, me! I'm Joe Fredette (jfredett on IRC, reddit, and everywhere else), and I'll be taking over for Brent (byorgey) from now on. I think I speak for the whole community when I thank him for his excellent work on the HWN and associated tools. I have a few ideas about how I want to change HWN for the better, and hopefully you'll like them too! So, without further ado, The Haskell Weekly News! Announcements Looking for a new HWN editor. Brent Yorgey [2]went looking for a new editor for the HWN, and that's how you got me! See the editorial for more details. CfPart: FMICS 2009, 2-3 November 2009. Christophe Joubert [3]announced FMICS 2009 - FIRST CALL FOR PARTICIPATION, 14th International Workshop on Formal Methods for Industrial Critical Systems. November 2-3, 2009 Call for Posters: APLAS 2009. Kiminori Matsuzaki [4]announced a CALL FOR POSTER PRESENTATIONS The Seventh ASIAN Symposium on Programming Languages and Systems (APLAS 2009) December 14 - 16, 2009 Seoul National University, Seoul, Korea. hecc-0.1. Marcel Fourn√© [5]announced the first release of hecc, the Elliptic Curve Cryptography Library for Haskell. Implemented are affine, projective, jacobian and modified jacobian point formats with the basic operations. Included as an Example is a basic ECDH as well as a basic speed test. HLint 1.6.8. Neil Mitchell [6]announced HLint 1.6.8. HLint is a tool for suggesting improvements to your source code. It suggests the use of library functions you may have been unaware of, finds patterns of recursion that are really folds/maps, hints about extensions you aren't using and much more. HLint is now one of the top 20 applications on Hackage, and is used by the darcs project to improve and statically check their code base. A Levenberg-Marquardt implementation. Bas van Dijk [7]announced the release of a Haskell binding to Manolis Lourakis's C levmar library. This library implements the Levenberg-Marquardt algorithm which is an iterative technique that finds a local minimum of a function that is expressed as the sum of squares of nonlinear functions. It has become a standard technique for nonlinear least-squares problems and can be thought of as a combination of steepest descent and the Gauss-Newton method. CCA-0.1. Paul L [8]announced that a library for Causal Commutative Arrows (CCA) has been uploaded to Hackage DB. It implements CCA normalization using Template Haskell and a modified arrow pre- processor (based on arrowp) to generate outout that Template Haskell can parse. It's highly experimental since we are still fiddling with several design choices, and by no means we imply Template Haskell is the best choice to implement CCA. Any suggestion or comment is welcome! graphviz-2999.5.0.0. Ivan Lazar Miljenovic [9]announced version 2999.5.0.0 of the graphviz package for Haskell. This is what I like to think of as the 'Hey, this is almost getting to be a decent library!' version. The graphviz package provides bindings to the GraphViz suite of programs by providing the ability to generate and parse GraphViz's Dot language as well as wrappers around the tools themselves. uvector-algorithms 0.2. Dan Doel [10]announced version 0.2 of the uvector-algorithms package. The package so far has implementations of several sorting and selection algorithms for use on the mutable arrays from the uvector library, as well as combinators for applying them to immutable arrays. dbmigrations 0.1. Jonathan Daugherty [11]announced dbmigrations, A library and program for the creation, management, and installation of schema updates (called migrations) for a relational database. In particular, this package lets the migration author express explicit dependencies between migrations and the management tool automatically installs or reverts migrations accordingly, using transactions for safety. This package is written to support any HDBC-supported database, although at present only PostgreSQL is fully supported. Palindromes 0.1. Johan Jeuring [12]announced Palindromes, a package for finding palindromes in files. Visit the [13]homepage The primary features of Palindromes include: A linear-time algorithm for finding exact palindromes, A linear-time algorithm for finding text palindromes, ignoring spaces, case of characters, and punctuation symbols. Discussion Averting QuickCheck Madness. Christopher Lane Hinson Christopher Hinson [14]asked about best practices with regards to QuickCheck, and it's inclusion/exclusion as a dependency for end-user programs. How to customize dyre recompile? Andy Stewart Andy Stewart [15]asked about how to customize Dyre's settings to do a whole-program recompilation. Externally derive instance of Data? Dimitry Golubovsky Dimitry Golubovsky [16]asked about stand-alone deriving for third-party datatypes. Parallel parsing & multicore. Anakim Border Anakim Border [17]talked about parallel parsing, specifically about a parser he had put together, which led to a discussion of Edward Kmett's recent talks at BAHUG. Ph.D position, Utrecht University, the Netherlands. S.Doaitse [18]announced Vacancy PhD student on Realizing Optimal Sharing in the Functional Language Implementations Utrecht University, The Netherlands. Blog noise [19]Haskell news from the [20]blogosphere. Blog posts from people new to the Haskell community are marked with >>>, be sure to welcome them! * Eric Kow (kowey): [21]Cabal-Installing graphical apps on MacOS X. * Don Stewart (dons): [22]Improving Data Structures with Associated Types. * Manuel M T Chakravarty: [23]Haskell Arrays, Accelerated.. * Galois, Inc: [24]Tech Talk: Building Systems That Enforce Measurable Security Goals. * Kevin Reid (kpreid): [25]GSoC conclusion.. * Neil Brown: [26]Boids Simulation: Part 1. * Paul Potts: [27]MacPorts, Snow Leopard, and GHC == Sadness. * Andrew Calleja: [28]Haskell IDEs on Windows. * Sean Leather: [29]"Upwards and downwards accumulations on trees" translated into Haskell. * Xmonad: [30]The Design and Implementation of XMonad. * Galois, Inc: [31]Tech Talk: Constructing a Universal Domain for Reasoning About Haskell Datatypes. * Well-Typed.Com: [32]Slides from the IHG talk at CUFP. * Alex McLean: [33]Hackpact Documentation. This links to part one of a two part series. * Bas van Gijze: [34]Cannibals, Missionaries and the State Monad pt. 1. * Magnus Therning: [35]Wrapping IO. This links to part one of a two part series. * Don Stewart (dons): [36]Stream Fusion for Haskell Arrays. * Tom Schrijvers: [37]EffectiveAdvice: AOP, mixin inheritance, monads, parametricity, non-interference, .... * Johan Jeuring: [38]Finding palindromes. * Neil Brown: [39]Concurrent vs Parallel vs Sequential. * Don Stewart (dons): [40]DEFUN 2009: Multicore Programming in Haskell Now!. * Don Stewart (dons): [41]The Haskell Platform: Status Report: Haskell Symposium 2009. Quotes of the Week * lispy: All haskell lists have less than 400 elements * Jafet: The C preprocessor is purely dysfunctional * edwardk: so the -> is matched on the outside, but the -> and , fail to match on the inside, unification fails, dogs and cats start living together in harmony, general chaos. * yaxu: [about lambdabot] an irc bot that no-one understands the workings of has to be a fine precursor to artificial intelligence * Gracenotes: all in all, you're just another brick in the -Wall About the Haskell Weekly News New editions are posted to [42]the Haskell mailing list as well as to [43]the Haskell Sequence and [44]Planet Haskell. [45]RSS is also available, and headlines appear on [46]haskell.org. To help create new editions of this newsletter, please see the information on [47]how to contribute. Send stories to jfredett . at . gmail . dot . com. The darcs repository is available at darcs get [48]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63133 3. http://article.gmane.org/gmane.comp.lang.haskell.general/17476 4. http://article.gmane.org/gmane.comp.lang.haskell.general/17483 5. http://article.gmane.org/gmane.comp.lang.haskell.general/17482 6. http://article.gmane.org/gmane.comp.lang.haskell.general/17481 7. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63283 8. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63233 9. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63219 10. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63205 11. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63187 12. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63157 13. http://www.jeuring.net/Palindromes/ 14. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63146 15. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63143 16. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63314 17. http://article.gmane.org/gmane.comp.lang.haskell.cafe/63223 18. http://article.gmane.org/gmane.comp.lang.haskell.general/17478 19. http://planet.haskell.org/ 20. http://haskell.org/haskellwiki/Blog_articles 21. http://koweycode.blogspot.com/2009/09/cabal-installing-graphical-apps-on.ht… 22. http://donsbot.wordpress.com/2009/09/11/improving-data-structures-with-asso… 23. http://justtesting.org/post/185173082 24. http://www.galois.com/blog/2009/09/10/jaegermeasurablesecurit/ 25. http://kpreid.livejournal.com/16930.html 26. http://chplib.wordpress.com/2009/09/08/boids-simulation-part-1/ 27. http://praisecurseandrecurse.blogspot.com/2009/09/macports-snow-leopard-and… 28. http://lambdacolyte.wordpress.com/2009/09/08/haskell-ides-on-windows/ 29. http://feedproxy.google.com/~r/splonderzoek/~3/4E8TZPDZ-aM/ upwards-and-downwards-accumulations-on.html 30. http://xmonad.wordpress.com/2009/09/09/the-design-and-implementation-of-xmo… 31. http://www.galois.com/blog/2009/09/08/huffman_universaldomain/ 32. http://blog.well-typed.com/2009/09/slides-from-the-ihg-talk-at-cufp/ 33. http://yaxu.org/hackpact-documentation/ 34. http://adoseoflogic.blogspot.com/2009/07/cannibals-missionaries-and-state-m… 35. http://therning.org/magnus/archives/738 36. http://donsbot.wordpress.com/2009/09/07/stream-fusion-for-haskell-arrays/ 37. http://tomschrijvers.blogspot.com/2009/09/effectiveadvice-aop-mixin-inherit… 38. http://johanjeuring.blogspot.com/2007/08/finding-palindromes.html 39. http://chplib.wordpress.com/2009/09/06/concurrent-vs-parallel-vs-sequential/ 40. http://donsbot.wordpress.com/2009/09/05/defun-2009-multicore-programming-in… 41. http://donsbot.wordpress.com/2009/09/05/the-haskell-platform-status-report-… 42. http://www.haskell.org/mailman/listinfo/haskell 43. http://sequence.complete.org/ 44. http://planet.haskell.org/ 45. http://sequence.complete.org/node/feed 46. http://haskell.org/ 47. http://haskell.org/haskellwiki/HWN 48. http://code.haskell.org/~byorgey/code/hwn/

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ANNOUNCE: A Levenberg-Marquardt implementation
by Bas van Dijk 10 Sep '09

10 Sep '09

Dear all, We like to announce the release of a Haskell binding to Manolis Lourakis's C levmar library at: http://www.ics.forth.gr/~lourakis/levmar/ This library implements the Levenberg-Marquardt algorithm which is an iterative technique that finds a local minimum of a function that is expressed as the sum of squares of nonlinear functions. It has become a standard technique for nonlinear least-squares problems and can be thought of as a combination of steepest descent and the Gauss-Newton method. When the current solution is far from the correct one, the algorithm behaves like a steepest descent method: slow, but guaranteed to converge. When the current solution is close to the correct solution, it becomes a Gauss-Newton method. Our binding consists of three packages: * http://hackage.haskell.org/package/bindings-levmar-0.1 A low-level wrapper around the C library. Note that the C library is lightly patched so that the functions can be safely called inside unsafePerformIO. The patched C library is bundled with this package. * http://hackage.haskell.org/package/levmar-0.1 A high-level wrapper around bindings-levmar. It provides a more familiar Haskell interface. For example, instead of passing a 'Ptr r' to the levmar function you can pass a [r]. levmar also provides some higher-level modules that use some type-level programming to add more type safety. * http://hackage.haskell.org/package/levmar-chart-0.1 Finally levmar-chart is a small package for quickly viewing the output of levmar in a chart. Unfortunately the documentation of these libraries is not available from hackage because bindings-levmar won't configure because of a missing dependency (lapack) on the hackage server. Instead I put the documentation at the following places: http://code.haskell.org/bindings-levmar/bindings-levmar-0.1/doc/html/bindin… http://code.haskell.org/levmar/levmar-0.1/doc/html/levmar/index.html Here follows a quick example: Suppose we have the following model functions: constant :: Num r => Model N1 r r linear :: Num r => Model N2 r r quadratic :: Num r => Model N3 r r cubic :: Num r => Model N4 r r constant a _ = a linear b a x = b * x + constant a x quadratic c b a x = c * x*x + linear b a x cubic d c b a x = d * x*x*x + quadratic c b a x And the jacobians: constantJacob :: Num r => Jacobian N1 r r linearJacob :: Num r => Jacobian N2 r r quadraticJacob :: Num r => Jacobian N3 r r cubicJacob :: Num r => Jacobian N4 r r constantJacob _ _ = 1 ::: Nil linearJacob _ a x = x ::: constantJacob a x quadraticJacob _ b a x = x*x ::: linearJacob b a x cubicJacob _ c b a x = x*x*x ::: quadraticJacob c b a x Now assume we have some sample data. If you call levmar like this: levmar cubic (Just cubicJacob) (-0.05 ::: 0.5 ::: -12 ::: 10 ::: Nil) samples 1000 defaultOpts Nothing Nothing noLinearConstraints Nothing You get the following fit (using levmar-chart): http://code.haskell.org/~roelvandijk/code/levmar-chart/cubicFit.png Note that levmar contains a demo with a lot more examples: http://code.haskell.org/levmar/Demo.hs Happy fitting, Roel and Bas van Dijk

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Call for Posters: APLAS 2009
by Kiminori Matsuzaki 10 Sep '09

10 Sep '09

CALL FOR POSTER PRESENTATIONS The Seventh ASIAN Symposium on Programming Languages and Systems (APLAS 2009) December 14 - 16, 2009 Seoul National University, Seoul, Korea http://ropas.snu.ac.kr/aplas09/ FYI: The list of accepted papers is now on the webpage. APLAS 2009 will include a poster session during the conference. The session aims to give students and researchers an opportunity to present their research to the community, and to get responses from other researchers. SCOPE: Poster presentations describing research advances or experience with non-trivial systems are sought in all areas of programming languages and systems, including (but not limited to): - semantics, logics, foundational theory - type systems, language design - program analysis, optimization, transformation - software security, safety, verification - compiler systems, interpreters, abstract machines - domain-specific languages and systems - programming tools and environments FORMAT: A space of A1 paper size (594 mm wide and 841 mm high) will be provided for each presentation. If you need more space, contact the poster chair (kmatsu AT ipl.t.u-tokyo.ac.jp). To prepare a good poster, search the Web for "poster presentation" and you will find many useful resources. SUBMISSION: Each presenter should e-mail a 1-2 page abstract in PDF or PostScript to the poster chair (Kiminori Matsuzaki; kmatsu AT ipl.t.u-tokyo.ac.jp) by September 30th 2009. The abstract should include the title, author(s), affiliation(s), and summary of the work, and a LaTeX-template will be available at "http://ropas.snu.ac.kr/aplas09/aplas_poster_template.tex". The program of the poster session will be announced by October 10th, 2009. We hope to accommodate every poster, but may restrict presentations (based on relevance and interest to the community) due to space constraints. IMPORTANT DATES: - 1-2 page abstract September 30, 2009 - Notification October 10, 2009 - Conference December 14 - 16, 2009 CONTACT: For questions or requests, please contact the APLAS 2009 poster chair, Kiminori Matsuzaki (kmatsu AT ipl.t.u-tokyo.ac.jp). -- Kiminori MATSUZAKI, Ph.D. Graduate School of Information Science and Technology, University of Tokyo Email: kmatsu(a)ipl.t.u-tokyo.ac.jp

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ANNOUNCE: hecc-0.1
by Marcel Fourné 09 Sep '09

09 Sep '09

Hi, this is the first release of hecc, the Elliptic Curve Cryptography Library for Haskell, to be found at http://hackage.haskell.org/package/hecc Implemented are affine, projective, jacobian and modified jacobian point formats with the basic operations. Included as an Example is a basic ECDH as well as a basic speed test (just a point multiplication on NIST P-256). The code grew out of some finger exercises used during my Master-studies and has been molded into some (arguably) releasable state. The library tries to be fast (achieving the above-mentioned test in just under 10ms on my hardware) but won't compete with a C or assembler-implementation (meaning: it stays more readable). The API is not stable, there may be bugs, you have been warned... Further algorithms may come at a point, but there is no timeframe atm. Please send feedback! Marcel -- Marcel Fourné OpenPGP-Key-ID: 0x74545C72

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ANN: HLint 1.6.8
by Neil Mitchell 09 Sep '09

09 Sep '09

Hi, I am pleased to announce HLint 1.6.8. HLint is a tool for suggesting improvements to your source code. It suggests the use of library functions you may have been unaware of, finds patterns of recursion that are really folds/maps, hints about extensions you aren't using and much more. HLint is now one of the top 20 applications on Hackage, and is used by the darcs project to improve and statically check their code base. HLint is ideal for learning Haskell, but is of use even to experienced developers. I now refuse to code review any Haskell that hasn't had HLint applied, as HLint automates the dull bits allowing people to do the more advanced higher-level reviews. Installation: cabal update && cabal install hlint Hackage: http://hackage.haskell.org/package/hlint Home page: http://community.haskell.org/~ndm/hlint/ Manual: http://community.haskell.org/~ndm/darcs/hlint/hlint.htm HLint 1.6.8 is a _strongly_ recommended upgrade. It fixes quite a few bugs, in particular it requires a newer version of cpphs which doesn't have a very severe bug that could lead to non-termination. == NEW FEATURES (since the last announcement) == * Changelog is now maintained: http://community.haskell.org/~ndm/darcs/hlint/CHANGES.txt * Lots of bugfixes (thanks to everyone who reported bugs) * Add suggestion to replace lambda with operator sections * Hints about redundant imports * Added -threaded flag to Cabal to disable threaded mode * Hints about unused extensions * Hints about functors * Integrates with cpphs to process CPP files * Integrate with HPC, and increase the test coverage (now ~ 70%). I would like to express my thanks to the HPC authors (Andy Gill and Colin Runciman) and encourage everyone to use it in their testing. I welcome any comments/bug reports for HLint, Thanks, Neil

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ANNOUNCE: graphviz-2999.5.0.0
by Ivan Lazar Miljenovic 09 Sep '09

09 Sep '09

I am pleased to announce version 2999.5.0.0 [1] of the graphviz [2] package for Haskell. This is what I like to think of as the "Hey, this is almost getting to be a decent library!" version :p [1] http://hackage.haskell.org/packages/archive/graphviz/2999.5.0.0/graphviz-29… [2] http://hackage.haskell.org/package/graphviz The graphviz package provides bindings to the GraphViz [3] suite of programs by providing the ability to generate and parse GraphViz's Dot [4] language as well as wrappers around the tools themselves. [3] http://www.graphviz.org/ [4] http://www.graphviz.org/doc/info/lang.html This is an almost complete re-write of the previously released version (2999.1.0.2): I do not mean that this version was re-written from scratch, but substantial portions of the library have been improved or replaced. As such, current users of this library will unfortunately have to update their code that uses it. The major changes (becuase there's probably heaps of smaller changes I've forgotten about) are: * Parsing and printing of Dot code was re-written to use the new ParseDot and PrintDot classes rather than the old Parseable class and the Show class. What this means for the end-user is that quotation problems should finally all be resolved (I hope...). In particular, proper quotation of String values is now done automagically: if it is found that the String to be printed requires quoting (because it does not match the format required for non-quoted String values), then quotes within the String are escaped and the entire String is quoted. As part of this, the Data.GraphViz.ParserCombinators module has been moved to Data.GraphViz.Types.Parsing. * Re-write the various Dot* datatypes in Data.GraphViz.Types. Sub-graphs/clusters are now their own entity rather than being part of DotNode and the Node ID type is now a type parameter rather than being just Int. Sub-graphs/clusters can now also be parsed. DotGraph and DotSubGraph now both contain a "DotStatements" value, which in turn contains global attributes, subgraphs, nodes and edges. * The various conversion functions in Data.GraphViz now come in two flavours: the unprimed versions take in a Bool indicating if the graph is directed or not; the primed versions attempt to automatically detect this. Also add cluster support for the graph -> dot -> graph conversion-style functions, as requested by Nikolas Mayr. * Allow custom arrow types as supported by GraphViz; as requested by Han Joosten. * Fixed a bug in HSV-style Color values where Int was used instead of Double; spotted by Michael deLorimier. * Properly resolved the situation initially spotted by Neil Brown: Matthew Sackman was following Dot terminology for an edge `a -> b' when using "head" for `b' and "tail" for `a' (this is presumably because the head/tail of the arrow are at those nodes). DotEdge now uses "from" and "to" avoid ambiguity; the various Attribute values still follow upstream usage. This should hopefully be the last update that is such an intrusive change. The next release will most likely contain updates on how to specify a particular output to use (including variants), with most of the rest remain as-is. -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com IvanMiljenovic.wordpress.com

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