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Haskell Weekly News: Issue 102 - January 24, 2009
by Brent Yorgey 24 Jan '09

24 Jan '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090124 Issue 102 - January 24, 2009 --------------------------------------------------------------------------- Welcome to issue 102 of HWN, a newsletter covering developments in the [1]Haskell community. Announcements Monoids and fingertrees. Heinrich Apfelmus posted a [2]nice tutorial explaining the monoid magic behind 2-3 fingertrees. STM-IO-Hooks-0.0.1. Peter Robinson [3]announced the [4]stm-io-hooks library, which provides an STM monad with commit and retry IO hooks. A retry-action is run (once) in a separate thread if the transaction retries, while commit-actions are executed iff the transaction commits. The code is based on the [5]AdvSTM monad by Chris Kuklewicz, but in addition also ensures some atomicity guarantees for commit-actions. 1000 libraries. Don Stewart [6]announced that Hackage has now [7]reached 1000 packages! HTTP-4000.0.4 released. Sigbjorn Finne [8]announced that a new release of [9]HTTP, version 4000.0.4, is now available. The main change is the addition of registering a Browser event handler for capturing state changes to the request-response processing pipeline. Blog noise [10]Haskell news from the [11]blogosphere. * Luke Palmer: [12]Existential Memoization. * Luke Palmer: [13]The Third Virtue. Luke has a Grand Vision (TM)! * Darcs: [14]darcs weekly news #14. * Magnus Therning: [15]More sensible comments on cabal-debian. * GHC / OpenSPARC Project: [16]Wait and perform. * LHC Team: [17]Typeclasses are working, now we're missing a bunch of instances.... * Andy Gill: [18]Memoization in GHC. A cool tutorial on how to memoize a pure function with GHC, without changing the function's definition. * Magnus Therning: [19]Experience with cabal-debian. * Joachim Breitner: [20]darcswatch uploaded to hackage. * GHC / OpenSPARC Project: [21]The Strap. * Real-World Haskell: [22]Bryan O'Sullivan on the Power of Haskell. * Jeff Heard: [23]Visualizing groundwater nitrate concentration. * Don Stewart (dons): [24]Open source releases and growth. * Lennart Augustsson: [25]Performance update on LLVM. * Arch Haskell News: [26]Piet implementation for Arch. * Mark Jason Dominus: [27]Triples and Closure. Did you know that monads are like closure operators? If not, read on. * GHC / OpenSPARC Project: [28]The Grind. * LHC Team: [29]Functions in Haskell.. * Magnus Therning: [30]Building Debian packages of (cabalised) Haskell packages. * Xmonad: [31]xmonad cheatsheet. * Xmonad: [32]xmonad on twitter. * Jeff Heard: [33]A random note on programming with Gtk2Hs.. * Xmonad: [34]xmonad 0.8.1 : GHC 6.10 maintenance release. * Jonathan Tang: [35]Some observations on Kinds. * Martijn van Steenbergen: [36]Type Synonym Families. Quotes of the Week * Jonathan Cast: [on advertising for Haskell programmers and informing them that the codebase is actually in Perl at the interview] <Andrew Wagner> That's......evil. <Jonathan> I know. I'm evil too, though. So it's cool. * rwbarton: A type class is not a type just like a dog house is not a dog. * SPJ: [This is] clearly not a bug in GHC; but it would be more felicitous if it gave you a warning... * Gracenotes: > let o_o = 0.0 ;o' =(, ); ;o (*)=(*) ;( lol, xD :p )= o' o' $o.o$ (:[]) $o.o$ (:[]) o_o in (:[]) o_o :p * Cale: I plan on forming a symbiotic relationship with sandtrout, which, as they merge with my body, will sustain me as I slowly turn into a sandworm, and make use of my billions of other memories and prescience to rule over everyone and everything for millenia. * quicksilver: or in Java, we'd make it more generic by using a PolynomialDivisionOperatorFactory. * roconnor: I was going to read about laziness, but I decided to do it later, when I need to understand it. About the Haskell Weekly News New editions are posted to [37]the Haskell mailing list as well as to [38]the Haskell Sequence and [39]Planet Haskell. [40]RSS is also available, and headlines appear on [41]haskell.org. To help create new editions of this newsletter, please see the information on [42]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [43]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://apfelmus.nfshost.com/monoid-fingertree.html 3. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51249 4. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/stm-io-hooks 5. http://www.haskell.org/haskellwiki/New_monads/MonadAdvSTM 6. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51186 7. http://hackage.haskell.org/cgi-bin/hackage-scripts/stats 8. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51165 9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HTTP 10. http://planet.haskell.org/ 11. http://haskell.org/haskellwiki/Blog_articles 12. http://lukepalmer.wordpress.com/2009/01/24/existential-memoization/ 13. http://lukepalmer.wordpress.com/2009/01/24/the-third-virtue/ 14. http://blog.darcs.net/2009/01/darcs-weekly-news-14.html 15. http://therning.org/magnus/archives/485 16. http://ghcsparc.blogspot.com/2009/01/wait-and-perform.html 17. http://lhc-compiler.blogspot.com/2009/01/typeclasses-are-working-now-were.h… 18. http://blog.unsafeperformio.com/?p=34 19. http://therning.org/magnus/archives/476 20. https://www.joachim-breitner.de/blog/archives/317-darcswatch-uploaded-to-ha… 21. http://ghcsparc.blogspot.com/2009/01/strap.html 22. http://www.realworldhaskell.org/blog/2009/01/21/bryan-osullivan-on-the-powe… 23. http://vis.renci.org/jeff/?p=63 24. http://donsbot.wordpress.com/2009/01/21/open-source-releases-and-growth/ 25. http://augustss.blogspot.com/2009/01/performance-update-ive-continued.html 26. http://archhaskell.wordpress.com/2009/01/20/piet-now-packaged/ 27. http://blog.plover.com/math/monad-closure.html 28. http://ghcsparc.blogspot.com/2009/01/grind.html 29. http://lhc-compiler.blogspot.com/2009/01/functions-in-haskell.html 30. http://therning.org/magnus/archives/458 31. http://xmonad.wordpress.com/2009/01/19/xmonad-cheatsheet/ 32. http://xmonad.wordpress.com/2009/01/19/xmonad-on-twitter/ 33. http://vis.renci.org/jeff/?p=24 34. http://xmonad.wordpress.com/2009/01/19/xmonad-081-ghc-610-maintainance-rele… 35. http://eve-language.blogspot.com/2009/01/some-observations-on-kinds.html 36. http://martijn.van.steenbergen.nl/journal/2009/01/11/type-synonym-families/ 37. http://www.haskell.org/mailman/listinfo/haskell 38. http://sequence.complete.org/ 39. http://planet.haskell.org/ 40. http://sequence.complete.org/node/feed 41. http://haskell.org/ 42. http://haskell.org/haskellwiki/HWN 43. http://code.haskell.org/~byorgey/code/hwn/

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(CfP) WGP'09: Workshop on Generic Programming Call for Papers
by Patrik Jansson 22 Jan '09

22 Jan '09

Interested Haskellers are encouraged to submit by 090510. The scope is generic programming in a broad sense (not limited to datatype-generic programming) so almost any Haskell development fits subjectwise! /Patrik --------------------------- ACM SIGPLAN Workshop on Generic Programming 2009 Edinburgh, UK, August 30, 2009 http://wiki.portal.chalmers.se/cse/WGP09 Goals of the workshop Generic programming is about making programs more adaptable by making them more general. Generic programs often embody non-traditional kinds of polymorphism; ordinary programs are obtained from them by suitably instantiating their parameters. In contrast with normal programs, the parameters of a generic program are often quite rich in structure; for example they may be other programs, types or type constructors, class hierarchies, or even programming paradigms. Generic programming techniques have always been of interest, both to practitioners and to theoreticians, and for at least 20 years generic programming techniques have been a specific focus of research in the functional and object-oriented programming language communities. Generic programming has gradually spread to more and more mainstream languages and is today widely used also in industry. This workshop will bring together leading researchers and practitioners in generic programming from around the world, and feature papers capturing the state of the art in this important area. We welcome contributions on all aspects, theoretical as well as practical, of * adaptive object-oriented programming, * aspect-oriented programming, * concepts (as in the STL / C++ sense) * component-based programming, * generic programming, * meta-programming, * polytypic programming, * programming with modules, * and so on. Organisers: Chair Patrik Jansson, CSE.Chalmers.se co-Chair Sibylle Schupp, STS.TUHH.de Programme Committee: Edwin Brady, U. of St Andrews, Peter Gottschling, TU Dresden Patrik Jansson, Chalmers Chair Barry Jay, U. of T., Sydney Jaakko Järvi, Texas A&M Oleg Kiselyov, FNMOC Andres Löh, Utrecht U. Fritz Ruehr, Willamette U. Sibylle Schupp, TU Hamburg Harburg, Co-Chair Marcin Zalewski, Chalmers, We plan to have formal proceedings, published by the ACM. Submission details Deadline for submission: Sunday 090510 Notification of acceptance: Monday 090601 Final submission due: Tuesday 090616 Workshop: Sunday 090830 Authors should submit papers, in postscript or PDF format, formatted for A4 paper, to the WGP09 EasyChair instance by 10th of May 2009. The length should be restricted to 12 pages in standard (two-column, 9pt) ACM format. Accepted papers are published by the ACM and will additionally appear in the ACM digital library. History of the Workshop on Generic Programming This year: * Edinburgh, UK 2009 (affiliated with ICFP09) Earlier Workshops on Generic Programming have been held in * Victoria, BC, Canada 2008 (affiliated with ICFP), * Portland 2006 (affiliated with ICFP), * Utrecht 2005 (informal workshop), * Dagstuhl 2002 (IFIP WG2.1 Working Conference), * Nottingham 2001 (informal workshop), * Ponte de Lima 2000 (affiliated with MPC), * Marstrand 1998 (affiliated with MPC). There were also (closely related) DGP workshops in Oxford (June 3-4 2004), and a Spring School on DGP in Nottingham (April 24-27 2006, which had a half-day workshop attached). Additional information: The WGP steering committee consists of J Gibbons, R Hinze and J Jeuring.

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HaskellWiki Update
by Ashley Yakeley 21 Jan '09

21 Jan '09

There has been a lot of spam on HaskellWiki. Since anonymous edits have been switched off, a spammer tactic has been to create hundreds of accounts to evade individual account blocks. To combat this, I have 1. deleted all user accounts that have made no edits; 2. switched off account creation; 3. blocked at least some of the remaining spam accounts. This is obviously not ideal, as there is now no way for new users to edit the wiki. I will investigate appropriate ways to allow account creation. -- Ashley Yakeley

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FMICS 2009: Second Call for Papers
by FMICS 2009 workshop chair 20 Jan '09

20 Jan '09

FMICS 2009 - 2ND CALL FOR PAPERS Please visit: http://www.dsic.upv.es/workshops/fmics2009 ************************************************************ * 14th International Workshop on * * Formal Methods for Industrial Critical Systems * * FMICS 2009 * * * * November 2-3, 2009 * * Eindhoven, The Netherlands * ************************************************************ * ** NEWS ** * * * * >> LNCS proceedings * * Springer has confirmed that the proceedings * * will be published in their Lecture Notes in * * Computer Science series. * ************************************************************ IMPORTANT DATES --------------- Deadline for abstracts: 1st April Deadline for papers: 7 April Accept/Reject notification: 15 June Camera-ready version: 15 July Workshop: 2-3 November SCOPE OF THE WORKSHOP --------------------- The aim of the ERCIM FMICS workshop series is to provide a forum for researchers who are interested in the development and application of formal methods in industry. In particular, these workshops bring together scientists and engineers that are active in the area of formal methods and interested in exchanging their experiences in the industrial usage of these methods. These workshops also strive to promote research and development for the improvement of formal methods and tools for industrial applications. Topics include, but are not restricted to: - Design, specification, code generation and testing based on formal methods. - Methods, techniques and tools to support automated analysis, certification, debugging, learning, optimization and transformation of complex, distributed, real-time systems and embedded systems. - Verification and validation methods that address shortcomings of existing methods with respect to their industrial applicability (e.g., scalability and usability issues). - Tools for the development of formal design descriptions. - Case studies and experience reports on industrial applications of formal methods, focusing on lessons learned or identification of new research directions. - Impact of the adoption of formal methods on the development process and associated costs. - Application of formal methods in standardization and industrial forums. INVITED SPEAKERS ---------------- To be announced CO-CHAIRS --------- Maria Alpuente Tech. University Valencia, Spain Byron Cook Microsoft Research, UK PROGRAM COMMITTEE ------------------- Hassan Ait-Kaci Ilog, Canada Maria Alpuente Tech. University Valencia, Spain Thomas Arts IT-Univ. i Goteborg, Sweden Demis Ballis Universita Udine, Italy Josh Berdine Microsoft Research, UK Lubos Brim Masarykova Univ., Czech Republic Darren Cofer Rockwell Collins, USA Byron Cook Microsoft Research, UK Patrick Cousot Ecole Normale Superieure, France Santiago Escobar Tech. University Valencia, Spain Azadeh Farzan University of Toronto, Canada Hubert Garavel INRIA Rhone-Alpes, France Stefania Gnesi ISTI-CNR, Italy Alexey Gotsman University of Cambridge, UK Holger Hermanns Universitat Saarlandes, Germany Christophe Joubert Tech. University Valencia, Spain Daniel Kroening ETH Zurich, Switzerland Michael Leuschel Universitat Dusseldorf, Germany Pedro Merino Universidad de Malaga, Spain Juan Jose Moreno-Navarro Univ. Politecnica Madrid, Spain Corina Pasareanu NASA Ames Research Center, USA Jaco van de Pol Univ. Twente, The Netherlands Murali Rangarajan Honeywell, USA Jakob Rehof Tech. Univ. Dortmund, Germany Andrey Rybalchenko Max-Planck-Gesellschaft, Germany Marcel Verhoef Chess, The Netherlands Martin Wirsing Universitat Munchen, Germany Hongseok Yang University of London, UK Greta Yorsh IBM Watson Research Center, USA ERCIM FMICS WG COORDINATOR -------------------------- Alessandro Fantechi Univ. Firenze, ISTI-CNR, Italy WORKSHOP CHAIR -------------- Christophe Joubert Tech. University Valencia, Spain PAPER SUBMISSIONS ----------------- Submissions must be made electronically through the EasyChair system. Papers should be up to 16 pages in LNCS format, with the names and affiliations of the authors and a clear and informative abstract. Additional details may be included in a clearly marked appendix, which will be read at the discretion of the program committee. All submissions must report on original research. Submitted papers must not have previously appeared in a journal or conference with published proceedings and must not be concurrently submitted to any other peer-reviewed workshop, symposium, conference or archival journal. Any partial overlap with any such published or concurrently submitted paper must be clearly indicated. Case study papers should identify lessons learned, validate theoretical results (such as scalability of methods), or provide specific motivation for further research and development. The workshop proceedings will be published in the Springer series Lecture Notes in Computer Science (LNCS). CO-LOCATION ----------- FMICS 2009 is part of the first Formal Methods Week (FMweek), which will bring together a choice of events in the area, including TESTCOM/FATES (Conference on Testing of Communicating Systems and Workshop on Formal Approaches to Testing of Software), FACS (Formal Aspects of Component Software), PDMC (Parallel and Distributed Methods of verifiCation), FM2009 (Symposium of Formal Methods Europe), CPA (Communicating Process Architectures), FAST (Formal Aspects of Security and Trust), FMCO (Formal Methods for Components and Objects), and the REFINE Workshop. For the latest information on FMweek, see http://www.win.tue.nl/fmweek. ************************************************************ * * * +============================================+ * * | | * * | ** FMweek ** | * * | | * * +============================================+ * * | CPA | FACS | FAST | * * +--------------------------------------------+ * * | FM2009 | FMCO | FMICS | * * +--------------------------------------------+ * * | PDMC | REFINE | TESTCOM/FATES | * * +--------------------------------------------+ * * | http://www.win.tue.nl/fmweek | * * +============================================+ * * * ************************************************************

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Haskell Weekly News: Issue 101 - January 19, 2009
by Brent Yorgey 19 Jan '09

19 Jan '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090119 Issue 101 - January 19, 2009 --------------------------------------------------------------------------- Welcome to issue 101 of HWN, a newsletter covering developments in the [1]Haskell community. Gee whiz, people, stop being so darn productive or you're going to burn me out. Seriously. Announcements curl-1.3.4. Sigbjorn Finne [2]announced that a new version of [3]curl, a complete Haskell binding to the libcurl API, is now available and have been uploaded to Hackage. The most notable change is the overloading of representation of response buffers (and headers), allowing for the use of ByteStrings. Turbinado V0.4. Alson Kemp [4]announced the release of version 0.4 of [5]Turbinado, an easy to use Model-View-Controller-ish web framework for Haskell. Highlights for the 0.4 release include a dramatically improved ORM which handles foreign keys, and improved documentation. Hackage about to reach 1000 releases. Don Stewart [6]announced that Hackage is about to reach the 1000 release mark, 2 years after it went live. Some pretty charts [7]can be seen here. leapseconds-announced-2009. Bjorn Buckwalter [8]announced the release of the [9]leapseconds-announced package, which contains a single module and a single function implementing the Data.Time.Clock.TAI.LeapSecondTable interface. zipper-0.1. Andres Loeh [10]announced [11]zipper-0.1, a library offering a generic zipper for systems of recursive datatypes. multirec-0.2. Andres Loeh [12]announced [13]multirec-0.2, a library which provides a mechanism to talk about fixed points of systems of datatypes that may be mutually recursive. On top of these representations, generic functions such as the fold or the Zipper can then be defined. ghci-haskeline 0.1. Judah Jacobson [14]announced the first release of [15]ghci-haskeline. This package uses the GHC API to reimplement ghci with the [16]Haskeline library as a backend. Haskeline is a library for line input in command-line programs, similar to readline or editline, which is written in Haskell and thus (hopefully) more easily integrated into other Haskell programs. The Monad.Reader (13) - Call for copy. Wouter Swierstra [17]announced a Call for Copy for Issue 13 of [18]The Monad.Reader. The submission deadline is February 13, 2009. Please get in touch with Wouter if you intend to submit something. Cabal 2.0. Duncan Coutts [19]announced that he has started a [20]wiki page to collect ideas for Cabal 2. The basic idea for Cabal 2 is to learn lessons from our how the existing design has fared and how we can make a better design to tackle an expanded set of goals. Announcing Haskell protocol-buffers 1.4.0 (the smashing recursive edition). Chris Kuklewicz [21]announced version 1.4.0 (the smashing recursive edition) of [22]protocol-buffers, a Haskell interface to Google's "..language-neutral, platform-neutral, extensible way of serializing structured data for use in communications protocols, data storage, and more." Haskell WikiProject. Robin Green [23]asked: is anyone else interested in forming a Haskell WikiProject on Wikipedia, to collaborate on improving and maintaining the coverage and quality of articles on Haskell-related software and topics (broadly defined)? darcs 2.2.0. Petr Rockai [24]announced the release of darcs 2.2.0, with both a [25]source tarball and a [26]cabalized tarball available. This version features many improvements and bug fixes; see Petr's original announcement for a list. hledger 0.3. Simon Michael [27]announced the release of [28]hledger 0.3, a partial haskell clone of John Wiegley's "ledger" text-based accounting tool. It generates transaction and balance reports from a plain text ledger file, and demonstrates a functional implementation of ledger. language-sh-0.0.3.1. Stephen Hicks [29]announced the [30]language-sh package, a set of modules for parsing, manipulating, and printing sh-style shell scripts. It's being developed alongside shsh, the [31]Simple Haskell Shell. Coadjute 0.0.1, generic build tool. Matti Niemenmaa [32]announced version 0.0.1 of [33]Coadjute, a generic build tool intended as an easier to use and more portable replacement for make. dataenc 0.12. Magnus Therning [34]announced version 0.12 of [35]dataenc, a data encoding library currently providing Uuencode, Base64, Base64Url, Base32, Base32Hex, Base16, Base85, and (new in 0.12) yEncoding. 3 applications of "indexed composition" as a language design principle. Greg Meredith [36]announced that he has found a way to generalize the LogicT transformer, and calculated it's [37]application to three fairly interesting examples. HTTPbis / HTTP-4000.x package available. Sigbjorn Finne [38]announced the availability of a modernization of the venerable and trusted [39]HTTP package. The headline new feature of this version is the parametrization of the representation of payloads in both HTTP requests and responses; two new representations are supported, strict and lazy ByteStrings. monad-interleave 0.1. Patrick Perry [40]announced the [41]monad-interleave package, which provides a type class generalizing his two favorite functions in Haskell, "unsafeInterleaveIO" and "unsafeInterleaveST". hs-dotnet, version 0.3.0. Sigbjorn Finne [42]announced the [43]first public release of [44]hs-dotnet, a pragmatic take on interoperating between Haskell (via GHC) and .NET. HEADS UP: finalizer changes coming in GHC 6.10.2. Simon Marlow [45]announced that, by popular demand, GHC 6.10.2 will support finalizers that are actually guaranteed to run, and run promptly. However, there's a catch. If you want to know what the catch is, read his message. split-0.1.1 (doc bugfix; new functions wordsBy and linesBy). Brent Yorgey [46]announced version 0.1.1 of the [47]split library. This version fixes some Haddock bugs, and adds two new convenience functions suggested by Neil Mitchell, wordsBy and linesBy. json-0.4.1. Sigbjorn Finne [48]announced a new release (0.4.1) of the [49]json package. New in this release is a generic JSON encoder contributed by Lennart Augustsson along with a number of other, smaller changes. haskell-platform mailing list. Duncan Coutts [50]announced that anyone interested in helping out with the haskell platform project is invited to subscribe to the [51]haskell-platform mailing list. This mailing list is for discussing practical stuff; policy questions will be discussed on the libraries mailing list. bytestring-trie 0.1.4. wren ng thornton [52]announced version 0.1.4 of the [53]bytestring-trie package. This release fixes a number of bugs, adds functions such as keys, toListBy, fromList{L,R,S}, and separated Data.Trie (the main module for users) from Data.Trie.Internal (gritty details, and core implementation). HLint 1.2. Neil Mitchell [54]announced [55]HLint version 1.2, a lint-like tool for Haskell that detects and suggests improvements for your code. The biggest new feature is list recursion suggestions. Working with HLint from Emacs. Alex Ott [56]announced an [57]emacs module for integration with [58]HLint. Discussion An Alternative Data.List.Zipper. Jeff Wheeler [59]posted [60]an improved version of Data.List.Zipper, and requested feedback or constructive criticism. Comments from OCaml Hacker Brian Hurt. John Goerzen [61]posted a link to a [62]blog post by Brian Hurt, along with some thoughts about naming things in the standard libraries, spawning the longest ML thread in recent history. Blog noise [63]Haskell news from the [64]blogosphere. * Jeff Heard: [65]The Docuverse.. Cool search query visualization for massive numbers of documents. * Ben Moseley: [66]The Category Theory of Appendages. * Galois, Inc: [67]Galois at POPL. * Colin Ross: [68]Does your IDE define you or support you?. * Alson Kemp: [69]ANNOUNCE: Turbinado V0.4. * Jeff Heard: [70]ProteinVis: Visualizing a large tree in Haskell and OpenGL. * ezekiel smithburg: [71]what to do when you can't solve a problem with a hackage library you need?. * Jeff Heard: [72]Simple Futures in Haskell. * Dan Piponi (sigfpe): [73]Haskell Monoids and their Uses. A nice introductory tutorial on Monoids in Haskell. * Real-World Haskell: [74]John Goerzen on Why You Should Learn Haskell. * LHC Team: [75]LLVM is great.. * Jeff Heard: [76]iBiblio traffic, search engine hits, and cross-traffic. * Luke Palmer: [77]Use MonadRandom!. * LHC Team: [78]Why LLVM probably won't replace C--.. * Magnus Therning: [79]Series of posts on testing Haskell code. * Magnus Therning: [80]Useful thing when adopting test-framework after already using HUnit. * Magnus Therning: [81]dataenc 0.12 posted to HackageDB. * Jeff Heard: [82]The new HTTP library. * Jeff Heard: [83]Beautiful Code, Compelling Evidence. * LHC Team: [84]The case against C/LLVM.. * Manuel M T Chakravarty: [85]Some nice code examples showing how to use type families.. * Manuel M T Chakravarty: [86]Enforcing a relation between independent type families.. * Nick Mudge: [87]Zunes, Year 2038 Problem, Real World Haskell, Why, Potion, Games. * Darcs: [88]darcs 2.2.0 is released!. * GHC / OpenSPARC Project: [89]Info tables. * LHC Team: [90]What is LHC?. * LHC Team: [91]Resources.. * LHC Team: [92]Typeclass Blues. * GHC / OpenSPARC Project: [93]Liveness lies. * Galois, Inc: [94]Real World Haskell: Intel Parallel Programming Podcast. * Real-World Haskell: [95]Intel Parallel Programming Podcast: Real World Haskell. * Brent Yorgey: [96]Abstraction, intuition, and the "monad tutorial fallacy". * Luke Palmer: [97]Ha! I can't even get Events right. * GHC / OpenSPARC Project: [98]Bootstrapping 7. * Colin Ross: [99]Finding a member of an infinite list. * LHC Team: [100]The mess with variable ids.. * Luke Palmer: [101]Ridding ourselves of IO before there is a good replacement. * GHC / OpenSPARC Project: [102]Bootstrapping 7. * Colin Ross: [103]Notes on working with finite sorted lists. * Bryan O'Sullivan: [104]Fun with Haskell view patterns. * Conal Elliott: [105]3D rendering as functional reactive programming. Quotes of the Week * luqui: sigh: mathematicians. can't live with 'em, can't prove 'em wrong. * mauke: YO DAWG I HEARD YOU LIKE METACIRCULARITY SO WE PUT AN INTERPRETER IN YOUR INTERPRETER SO YOU CAN RUN CODE WHILE YOU RUN CODE * lament: tuples are proof that haskell is inherently broken and will never work. * roconnor: [after a long -cafe thread on the suckiness of using math terms in Haskell] we don't use Integer anymore. Too abstract. It is now called CountingThingy. * quicksilver: partially applied type synonym = type lambdas = unrestricted type functions = can of pants * ddarius: In the spirit of that article on monoids, we should drop the term "tree" and replace it with the term "free pointed magma" * ski_: unique among types, 'Void -> X' has its own charm. tourists should definitely pay a visit. * pao: Cale: thanks ... I really think you deserve a statue ... or, at least, a portrait in ascii art on haskell.org :-) * byorgey: TDD replaces a type checker in Ruby in the same way that a strong drink replaces sorrows. About the Haskell Weekly News New editions are posted to [106]the Haskell mailing list as well as to [107]the Haskell Sequence and [108]Planet Haskell. [109]RSS is also available, and headlines appear on [110]haskell.org. To help create new editions of this newsletter, please see the information on [111]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [112]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.general/16792 3. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/curl 4. http://article.gmane.org/gmane.comp.lang.haskell.general/16788 5. http://www.turbinado.com/ 6. http://article.gmane.org/gmane.comp.lang.haskell.general/16782 7. http://archhaskell.wordpress.com/2009/01/18/open-source-haskell-releases-an… 8. http://article.gmane.org/gmane.comp.lang.haskell.general/16770 9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/leapseconds-anno… 10. http://article.gmane.org/gmane.comp.lang.haskell.general/16756 11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/zipper 12. http://www.haskell.org//pipermail/haskell/2009-January/020925.html 13. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/multirec 14. http://article.gmane.org/gmane.comp.lang.haskell.general/16751 15. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ghci-haskeline 16. http://trac.haskell.org/haskeline 17. http://article.gmane.org/gmane.comp.lang.haskell.general/16750 18. http://www.haskell.org/haskellwiki/The_Monad.Reader 19. http://article.gmane.org/gmane.comp.lang.haskell.libraries/10568 20. http://hackage.haskell.org/trac/hackage/wiki/Cabal-2 21. http://article.gmane.org/gmane.comp.lang.haskell.libraries/10497 22. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/protocol-buffers 23. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51037 24. http://www.haskell.org//pipermail/haskell-cafe/2009-January/053732.html 25. http://www.darcs.net/darcs-2.2.0.tar.gz 26. http://hackage.haskell.org/packages/archive/darcs/2.2.0/darcs-2.2.0.tar.gz 27. http://www.haskell.org//pipermail/haskell-cafe/2009-January/053843.html 28. http://joyful.com/hledger 29. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50907 30. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/language-sh 31. http://code.haskell.org/shsh/ 32. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50896 33. http://iki.fi/matti.niemenmaa/coadjute/ 34. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50831 35. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/dataenc 36. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50756 37. http://biosimilarity.blogspot.com/2009/01/3-applications-of-indexed-composi… 38. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50748 39. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HTTP 40. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50648 41. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/monad-interleave 42. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50548 43. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hs-dotnet 44. http://haskell.forkIO.com/dotnet 45. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50477 46. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50421 47. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/split 48. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50362 49. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/json 50. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50336 51. http://projects.haskell.org/cgi-bin/mailman/listinfo/haskell-platform 52. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50292 53. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/bytestring-trie 54. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50283 55. http://www-users.cs.york.ac.uk/~ndm/hlint/ 56. http://article.gmane.org/gmane.comp.lang.haskell.cafe/50264 57. http://xtalk.msk.su/~ott/common/emacs/hs-lint.el 58. http://www-users.cs.york.ac.uk/~ndm/hlint/ 59. http://thread.gmane.org/gmane.comp.lang.haskell.general/16771 60. http://hpaste.org/14030 61. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/50590 62. http://enfranchisedmind.com/blog/2009/01/15/random-thoughts-on-haskell/ 63. http://planet.haskell.org/ 64. http://haskell.org/haskellwiki/Blog_articles 65. http://vis.renci.org/jeff/?p=66 66. http://nattermorphisms.blogspot.com/2009/01/category-theory-of-appendages.h… 67. http://www.galois.com/blog/2009/01/18/galois-at-popl/ 68. http://vcolin.com/2009/01/18/ide-define-support/ 69. http://www.alsonkemp.com/haskell/announce-turbinado-v04/ 70. http://vis.renci.org/jeff/?p=52 71. http://tehgeekmeister.wordpress.com/2009/01/17/what-to-do-when-you-cant-sol… 72. http://vis.renci.org/jeff/?p=27 73. http://sigfpe.blogspot.com/2009/01/haskell-monoids-and-their-uses.html 74. http://www.realworldhaskell.org/blog/2009/01/17/john-goerzen-on-why-you-sho… 75. http://lhc-compiler.blogspot.com/2009/01/llvm-is-great.html 76. http://vis.renci.org/jeff/?p=33 77. http://lukepalmer.wordpress.com/2009/01/17/use-monadrandom/ 78. http://lhc-compiler.blogspot.com/2009/01/why-llvm-probably-wont-replace-c.h… 79. http://therning.org/magnus/archives/436 80. http://therning.org/magnus/archives/437 81. http://therning.org/magnus/archives/434 82. http://vis.renci.org/jeff/?p=8 83. http://vis.renci.org/jeff/?p=4 84. http://lhc-compiler.blogspot.com/2009/01/case-against-cllvm.html 85. http://justtesting.org/post/70895924 86. http://justtesting.org/post/70893530 87. http://nickmudge.info/?post=103 88. http://blog.darcs.net/2009/01/darcs-220-is-released.html 89. http://ghcsparc.blogspot.com/2009/01/info-tables.html 90. http://lhc-compiler.blogspot.com/2009/01/what-is-lhc.html 91. http://lhc-compiler.blogspot.com/2009/01/resources.html 92. http://lhc-compiler.blogspot.com/2009/01/typeclass-blues.html 93. http://ghcsparc.blogspot.com/2009/01/liveness-lies.html 94. http://www.galois.com/blog/2009/01/13/real-world-haskell-intel-parallel-pro… 95. http://www.realworldhaskell.org/blog/2009/01/13/intel-parallel-programming-… 96. http://byorgey.wordpress.com/2009/01/12/abstraction-intuition-and-the-monad… 97. http://lukepalmer.wordpress.com/2009/01/13/ha-i-cant-even-get-events-right/ 98. http://ghcsparc.blogspot.com/2009/01/bootstrapping-7.html 99. http://vcolin.com/2009/01/12/finding-member-infinite-list/ 100. http://lhc-compiler.blogspot.com/2009/01/mess-with-variable-ids.html 101. http://lukepalmer.wordpress.com/2009/01/12/ridding-ourselves-of-io-before-t… 102. http://ghcsparc.blogspot.com/2009/01/bootstrapping-7.html 103. http://vcolin.com/2009/01/11/notes-working-finite-sorted-lists/ 104. http://www.serpentine.com/blog/2009/01/11/fun-with-haskell-view-patterns/ 105. http://conal.net/blog/posts/3d-rendering-as-functional-reactive-programming/ 106. http://www.haskell.org/mailman/listinfo/haskell 107. http://sequence.complete.org/ 108. http://planet.haskell.org/ 109. http://sequence.complete.org/node/feed 110. http://haskell.org/ 111. http://haskell.org/haskellwiki/HWN 112. http://code.haskell.org/~byorgey/code/hwn/

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type inference & instance extensions
by Doug McIlroy 19 Jan '09

19 Jan '09

A fragment of an attempt to make pairs serve as complex numbers, using ghc/hugs extensions: instance Num a => Num (a,a) where (x,y) * (u,v) = (x*u-y*v, x*v+y*u) Unfortunately, type inference isn't strong enough to cope with (1,1)*(1,1) Why shouldn't it be strengthened to do so? Or is there a declarative trick (perhaps with dependent classes) that will accomplish the goal? Doug McIlroy

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ANN: curl-1.3.4
by Sigbjorn Finne 19 Jan '09

19 Jan '09

Hi, a new version 'curl', a complete Haskell binding to the libcurl API, is now available and have been uploaded to Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/curl Git repo at git://code.galois.com/curl.git Appended is the list of changes since the previous release. Most notable is the overloading of representation of response buffers (and headers), allowing for the use of ByteStrings. Speedups might be had as a result... enjoy --sigbjorn Version 1.3.4: released 2009-01-18; changes from 1.3.3 * Overloaded Network.Curl operations over response representation of payloads and headers. Controlled via CurlBuffer and CurlHeader classes. New actions: - curlGetString_, curlGetResponse_, perform_with_response_, do_curl_, curlHead_ * Provided ByteString instances (strict and lazy) * No modification in calling interface to existing exports, so backwards compatible. * Added Show instance for Network.Curl.Opts.CurlOption * curl_version_string, curl_version_number now gives you access to version info of underlying lib you _compiled_ the package with. * Sync'ed wrt libcurl-7.19.2, so bunch of new options added to Network.Curl.Opts. Use version functions to determine if they are supported though.

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ANNOUNCE: Turbinado V0.4
by Alson Kemp 18 Jan '09

18 Jan '09

Turbinado (http://www.turbinado.com) is an easy to use Model-View-Controller-ish web framework for Haskell. The source for the framework can be found at: http://github.com/alsonkemp/turbinado The source for the website turbinado.org can be found at: http://github.com/alsonkemp/turbinado-website (see the /App directory for the code for www.turbinado.org) Release 0.4 contains: * A dramatically improved ORM (or Type-Relation Mapper) which handles foreign keys. Still PostgreSQL only at this point. * All dependencies in tmp/dependencies to ease building the application. * In code documentation (not complete, but starting). * Documentation (see http://turbinado.org/Architecture) Release 0.5 will focus on: * Ease of installation! * Moving to GHC 6.10 (whenever Debian shifts). Diego Eche provided a port from plugins to ghc-api. * Additional functionality (e.g. sessions, authentication, etc). * Tutorials.

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ICLP 2009: Call for workshop proposals
by cfp＠clip.dia.fi.upm.es 18 Jan '09

18 Jan '09

*** CALL FOR WORKSHOP PROPOSALS *** ICLP 2009 25th International Conference on Logic Programming Pasadena, California, USA July 14-17, 2009 URL: http://www.ist.unomaha.edu/iclp2009/ ICLP 2009, the 25th International Conference on Logic Programming, will be held in Pasadena (USA), from July 14 to 17, 2009. Workshops co-located with international conferences are one of the best venue for the presentation and discussion of preliminary work, novel ideas, and new open problems to a wide and interested audience. Co-located workshops also provide an opportunity for presenting specialized topics and opportunities for intensive discussions and project collaboration. The topics of the workshops co-located with ICLP 2009 can cover any areas related to logic programming, (e.g., theory, implementation, environments, language issues, alternative paradigms, applications), including cross-disciplinary areas. However, any workshop proposal will be considered. The format of the workshop will be decided by the workshop organizers, but ample time must be allowed for general discussion. Workshops can vary in length, but the optimal duration will be half a day or a full day. Workshop Proposal: ================== Those interested in organizing a workshop at ICLP 2009 are invited to submit a workshop proposal. Proposals should be in English and about two pages in length. They should contain: * The title of the workshop. * A brief technical description of the topics covered by the workshop. * A discussion of the timeliness and relevance of the workshop. * A list of some related workshops held in the last years. * The (preliminary) required number of half-days allotted to the workshop and an estimate of the number of expected attendees. * The names, affiliation, and contact details (email, web page, phone, fax) of the workshop organizer(s) together with a designated contact person. * The previous experience of the workshop organizing committee in workshop/conference organization. Proposals are expected in ASCII or PDF format. All proposals should be submitted to the Workshop Chair (Manuel Carro) by email by February 9th, 2009. Reviewing Process: ================== Each submitted proposal is reviewed by the Workshops Chair and the Conference Program Chairs. Proposals that appear well-organized and that fit the goals and scope of ICLP will be selected. The decision will be notified by email to the responsible organizer by February 23rd, 2009. The definitive length of the workshop will be planned according to the number of submissions received by the different workshops. For every accepted workshop, the ICLP local organizers will prepare a meeting place and arrange the distribution of the workshop proceedings, whose preparation is however in charge to the workshop organizers. The workshop registration fees will be handled together with the conference fees. Workshop Organizers' Tasks: =========================== * Producing a "Call for Papers" for the workshop and posting it on the net and/or other means. Please provide a web page URL which can be linked into the ICLP 2009 home page by March 9th, 2009. * Providing a brief description of the workshop for the conference program. * Reviewing/accepting submitted papers. * Scheduling workshop activities in collaboration with the local organizers and the workshop chair. * Sending workshop program and workshop proceedings in pdf format to the workshop chair for distribution at the conference. * The use of the Computing Research Repository (CoRR) for the workshop proceedings is strongly suggested. See http://www.logicprogramming.org/ for guidelines. We encourage reading these instructions in advance so that you can ask paper authors to prepare accordingly the final versions of their papers. Location: ========= All workshops will take place in Pasadena at the site of the main conference. See the ICLP 2009 web site for location details. Important Dates: ================ February 9, 2009: Proposal submission deadline. February 23, 2009: Notification. March 9, 2009: Deadline to receive the CFP and URL for the web page of the workshop June 1, 2009: Deadline for preliminary proceedings. July 14-17, 2009: ICLP 2009 workshops. Workshop Chair: =============== Manuel Carro [mcarro AT fi dot upm dot es] (www.clip.dia.fi.upm.es/~mcarro)

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How to define gunfold on List?
by haihualin 18 Jan '09

18 Jan '09

Hi, Does some one know how to define gunfold on recursive data struction like List? The ghc doc only give the example for non-recursive data like below. data T a b = C1 a b | C2 deriving (Typeable, Data) GHC will generate an instance that is equivalent to instance (Data a, Data b) => Data (T a b) where gfoldl k z (C1 a b) = z C1 `k` a `k` b gfoldl k z C2 = z C2 gunfold k z c = case constrIndex c of 1 -> k (k (z C1)) 2 -> z C2 toConstr (C1 _ _) = con_C1 toConstr C2 = con_C2 dataTypeOf _ = ty_T con_C1 = mkConstr ty_T "C1" [] Prefix con_C2 = mkConstr ty_T "C2" [] Prefix ty_T = mkDataType "Module.T" [con_C1, con_C2]

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