January 2009 - Haskell

Last CfP: WWV 2009
by demis＠dimi.uniud.it 28 Jan '09

28 Jan '09

[Apologies if you receive multiple copies] *********************************************************** * CALL FOR PAPERS * * * * WWV 2009 * * Automated Specification and Verification of Web Systems * * 5th International Workshop * * * * Castle of Hagenberg, Austria. July 17, 2009 * * http://www.risc.uni-linz.ac.at/conferences/wwv09/ * * * * Part of the RISC Summer 2009 * * http://www.risc.uni-linz.ac.at/conferences/summer2009/ * *********************************************************** IMPORTANT DATES Abstract Submission February 2, 2009 Full Paper Submission February 9, 2009 Acceptance Notification April 20, 2009 Camera Ready June 1, 2009 Workshop July 17, 2009 SCOPE The increased complexity of Web sites and the explosive growth of Web-based applications has turned their design and construction into a challenging problem. Nowadays, many companies have diverted their Web sites into interactive, completely-automated, Web-based applications (such as Amazon, on-line banking, or travel agencies) with a high complexity that requires appropriate specification and verification techniques and tools. Systematic, formal approaches to the analysis and verification can address the problems of this particular domain with automated and reliable tools that also incorporate semantic aspects. We solicit original papers on formal methods and techniques applied to Web sites, Web services or Web-based applications, such as: * rule-based approaches to Web site analysis, certification, specification, verification, and optimization * algebraic methods for verification and certification of Web systems * formal models for describing and reasoning about Web sites * model-checking, synthesis and debugging of Web sites * abstract interpretation and program transformation applied to the semantic Web * intelligent tutoring and advisory systems for Web specifications authoring * Web quality and Web metrics * Web usability and accessibility * Testing and evaluation of Web systems and applications The WWV series provides a forum for researchers from the communities of Rule-based programming, Automated Software Engineering, and Web-oriented research to facilitate the cross-fertilization and the advancement of hybrid methods that combine the three areas. The previous WWV editions were: WWV'08 (Siena, Italy), WWV'07 (Venice, Italy), WWV'06 (Paphos, Cyprus), and WWV'05 (Valencia, Spain). LOCATION WWV'09 will be held at the Research Institute for Symbolic Computation (RISC), which is an institute of the Johannes Kepler University in Linz. It is located in the Castle of Hagenberg, a romantic, medieval castle amidst the lovely, hilly landscape of the Mühlviertel region, 20 km north east of Linz, the provincial capital of Upper Austria, located halfway between Salzburg and Vienna. For more information about RISC, please visit: http://www.risc.uni-linz.ac.at/ The workshop is a part of the RISC Summer 2009 conference series: http://www.risc.uni-linz.ac.at/about/conferences/summer2009/ SUBMISSION PROCEDURE Submissions must be received by February 9, 2009. In addition, an ASCII version of the title and abstract must be submitted by February 2, 2009. Submitted papers should be prepared in LaTeX, formatted according to the Springer llncs style, and should not exceed 15 pages. Submission is web-based via this link: http://www.easychair.org/conferences/?conf=wwv09 PUBLICATION Accepted papers will be published in a preliminary proceedings volume, which will be available during the workshop. After the workshop, a special issue of the Journal of Symbolic Computation on the topic of the WWV workshop is planned. PROGRAM CO-CHAIRS Demis Ballis University of Udine, Italy Temur Kutsia Johannes Kepler University Linz, Austria WORKSHOP CO-CHAIRS Temur Kutsia Johannes Kepler University Linz, Austria Wolfgang Schreiner Johannes Kepler University Linz, Austria INVITED SPEAKERS François Bry Ludwig Maximilian University of Munich, Germany Axel Polleres National University of Ireland, Galway, Ireland PROGRAM COMMITTEE Maria Alpuente Technical University of Valencia, Spain Demis Ballis University of Udine, Italy Wlodzimierz Drabent Linköping University, Sweden, and Institute Of Computer Science, Polish Academy of Sciences, Poland Santiago Escobar Technical University of Valencia, Spain Moreno Falaschi University of Siena, Italy Mário Florido University of Porto, Portugal Temur Kutsia Johannes Kepler University Linz, Austria Massimo Marchiori University of Padova, Italy Mircea Marin University of Tsukuba, Japan Catherine Meadows Naval Research Laboratory, USA Rosario Pugliese University of Florence, Italy I.V. Ramakrishnan Stony Brook University, USA Antonio Vallecillo University of Malaga, Spain

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type inference & instance extensions
by oleg＠okmij.org 27 Jan '09

27 Jan '09

Doug McIlroy wrote: > 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) It is not quite difficult to tell the type checker that if pairs of numbers are numbers, the two components of the pair must have the same type. We say so literally. We first should make the instance more general to permit any pair, of the type (a,b) to match. We next impose the constraint that the types a and b must be in the class Num; furthermore, the types a and b must be the same. Here is the complete solution that should work on GHC 6.4, 6.6, 6.8, and probably of earlier and later versions. > {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, > UndecidableInstances, FlexibleInstances #-} > > module D where > > instance (Num a, Num b, TypeCast b a, TypeCast a b) => Num (a,b) where > (x,y) * (u,v) = (typeCast x * typeCast u - typeCast y * typeCast v, > typeCast x * typeCast v + typeCast y * typeCast u) > (x,y) + (u,v) = (typeCast x + typeCast u, > typeCast y + typeCast v) > (x,y) - (u,v) = (typeCast x - typeCast u, > typeCast y - typeCast v) > fromInteger x = (fromInteger x, 0) > > test1 = (1,1) * (2,2) -- (0.0,4.0) > test2 = (1.1,1) * (2,2) -- (0.20000000000000018,4.2) > test3 = test1 * test2 -- (-16.8,0.8000000000000007) > test4 = (test1 + test3) * (test1 - test3) -- (-297.6,26.880000000000024) > test4' = -16 - test3 * test3 -- (-297.6,26.880000000000024) > > class TypeCast a b | a -> b, b->a where typeCast :: a -> b > class TypeCast' t a b | t a -> b, t b -> a where typeCast' :: t->a->b > class TypeCast'' t a b | t a -> b, t b -> a where typeCast'' :: t->a->b > instance TypeCast' () a b => TypeCast a b where typeCast x = typeCast' () x > instance TypeCast'' t a b => TypeCast' t a b where typeCast' = typeCast'' > instance TypeCast'' () a a where typeCast'' _ x = x As one can see, we added typeCast before every variable, indicating that an application of the equality constraint is needed. We let the GHC figure out what should be `cast' to what. The recent versions of GHC have a nifty equality constraint, so the code can be written simply > {-# LANGUAGE TypeFamilies #-} > > {-# OPTIONS -fglasgow-exts #-} > {-# OPTIONS -fallow-undecidable-instances #-} > > module D where > > instance (Num a, Num b, a ~ b) => Num (a,b) where > (x,y) * (u,v) = (x*u-y*v, x*v+y*u) > > test1 = (1,1) * (2,2) It does typecheck in GHC 6.8.2; alas, running the code produces > ghc-6.8.2: panic! (the 'impossible' happened) > (GHC version 6.8.2 for i386-unknown-freebsd): > nameModule $dNum{v aJiF} I guess one needs to upgrade to GHC 6.10. The solution using TypeCast, however inelegant, works on GHC 6.8 and earlier compilers.

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ANN: Hayoo! beta 0.3
by Timo B. Hübel 25 Jan '09

25 Jan '09

Hello! We are pleased to announce the next beta version 0.3 of Hayoo!, the Haskell API search engine with find-as-you-type and suggestions. Visit Hayoo! here: http://holumbus.fh-wedel.de/hayoo Basically, there is one new major feature available: Hayoo! now works even if your browser does not support JavaScript. Of course, this means that you won't have the find-as-you-type functionality, but everything else will be available. Hence everybody who has been scared away from Hayoo! because of all this crazy AJAX stuff now has no excuse anymore for not using Hayoo! ;-) Along the way we fixed several minor bugs and slightly improved the ranking algorithm as well as the help page. Since the last official announcement we were also able to bring back the source links. Still to come in the next weeks is a major index update to reflect the incredible package growth on Hackage. Please let us know about any problems, hints and suggestions. Happy hacking, Timo

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ANN: filestore 0.1
by Gwern Branwen 25 Jan '09

25 Jan '09

ANN filestore 0.1 We are pleased to announce the first release of a new library, filestore. What is it? filestore provides a uniform, abstract, generic interface for storing versioned files on disk. It allows calling programs to use generic commands to store strings or binary data and perform various queries, such as 'what files are in this repository?' or 'what were the contents of this file at revision XXXXXXX?' or 'give me a diff of this file between revision XXXXXXX and revision YYYYYYY.' Because the interface is abstract, the calling program is insulated from the messy details of the backend (which might be a VCS or a database). What backends are supported? Darcs and Git are fully supported. There are plans for a SQLite backend. What is this good for? Currently it is used by two wikis, Gitit and Orchid. We hope it will see use in other applications as well that need to version data and would like the various advantages of DVCSs (such as easy collaboration, advanced merging, etc.). Where can you get it? Your local cabal-install, Hackage at http://hackage.haskell.org/cgi-bin/hackage-scripts/package/filestore and of course you can do 'darcs get http://johnmacfarlane.net/repos/filestore' for the very latest. filestore was written by John MacFarlane, Gwern Branwen, and Sebastiaan Visser -- gwern

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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/ . 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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. 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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. 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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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