January 2010 - Haskell

ANNOUNCE: Updates and a new member of the Monadic Regions family
by Bas van Dijk 23 Jan '10

23 Jan '10

Hello, I released updates of all the members of the Monadic Regions family: * http://hackage.haskell.org/package/regions-0.3 - Export the 'Dup' and 'ParentOf' classes from 'Control.Monad.Trans.Region'. - Add: 'mapInternalHandle ∷ (Handle resource1 → Handle resource2) → (RegionalHandle resource1 r → RegionalHandle resource2 r)'. - Internal refactoring. * http://hackage.haskell.org/package/regions-monadsfd-0.3 * http://hackage.haskell.org/package/regions-monadstf-0.3 * http://hackage.haskell.org/package/usb-safe-0.5.1 - No major changes in these packages just internal refactoring and support for regions-0.3.*. * http://hackage.haskell.org/package/safer-file-handles-0.3 - 'File' is turned into a GADT, it's parameterized with the IOMode and its constructors are exported. - Added support for bytestring IO. - Internal refactoring. * http://hackage.haskell.org/package/explicit-iomodes-0.2 This package is not a member of the family but it is required for 'safer-file-handles'. I released an update which: - Added support for bytestring IO. - Internal refactoring. Additionally I would like to announce a new member of the family: * http://hackage.haskell.org/package/regional-pointers-0.1 to quote the description: "The library allows you to allocate memory in a region yielding a regional pointer to it. When the region terminates all pointers are automatically freed. Most importantly, a pointer can't be returned from the region. So it's impossible to reference unallocated memory." This package need some more work (primarily documentation and testing) so I consider it a beta release. Note that the darcs repositories for all packages are not updated because I can't seem to get a SSH connection with code.haskell.org :-( Happy Haskell Hacking, Bas

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{darcs,hackage,cvs}.haskell.org, monk.galois.com
by Ian Lynagh 22 Jan '10

22 Jan '10

Hi all, As you may be aware, the server monk.galois.com has had hardware problems recently, and has now been replaced with a new server abbot.galois.com (thanks to the summer of code people for buying the replacement, to Galois for hosting it, and for Galois's sysadmin Paul for setting it up). The names darcs.haskell.org hackage.haskell.org cvs.haskell.org now point at abbot instead of monk. When SSHing to any of these names, you will be told that the SSH key has changed. The new key is 97:f2:f1:55:a8:2d:c0:13:28:df:03:95:f8:f2:f1:2d The major services should already have been moved to abbot. However, we are taking the opportunity to do some housekeeping, so haven't moved absolutely everything across. In particular, some things may be better hosted on http://community.haskell.org/ but have been on darcs.haskell.org for historical reasons. monk will be taken offline in a month's time, so before then can you please: If you have an account on monk.galois.com, log in and copy anything you wish to keep from your home directory. If you need an account on abbot and don't already have one, e-mail me saying what you need it for. If you are responsible for anything in http://old-darcs.well-typed.com/ then: If you think it should stay on darcs.haskell.org, e-mail me saying why. Otherwise, please take a copy of it (you can also access it by SSHing to monk.galois.com and changing to the /home/darcs directory) and let me know so that I can mark it as dealt with. If you see any other problems with the new server, or anything else missing from it, let me know. Thanks Ian

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ZuriHac registration deadline on February 14, 2010
by Johan Tibell 19 Jan '10

19 Jan '10

Hi all, Due to budget and security constraints, we need to know the final number of attendees a bit in advance. We've therefore set a registration deadline on February 14, 2010. To register please follow the instructions on the registration page: http://www.haskell.org/haskellwiki/ZuriHac/Register Cheers, Johan & Christophe

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CfP: PPDP 2010
by Temur Kutsia 19 Jan '10

19 Jan '10

====================================================================== Call for Papers PPDP 2010 12th International ACM SIGPLAN Symposium on Principles and Practice of Declarative Programming Hagenberg, Austria, 26-28 July 2010 (co-located with LOPSTR 2010) http://www.risc.uni-linz.ac.at/conferences/ppdp2010/ ====================================================================== PPDP 2010 aims to bring together researchers from the declarative programming communities, including those working in the logic, constraint and functional programming paradigms, but also embracing a variety of other paradigms such as visual programming, executable specification languages, database languages, AI languages and knowledge representation languages used, for example, in the semantic web. The goal is to stimulate research in the use of logical formalisms and methods for specifying, performing, and analysing computations, including mechanisms for mobility, modularity, concurrency, object-orientation, security, and static analysis. Papers related to the use of declarative paradigms and tools in industry and education are especially solicited. The conference will take place in July 2010 in the Castle of Hagenberg, Austria, colocated with the 20th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2010), organised by the Research Institute for Symbolic Computation (RISC) of the Johannes Kepler University Linz. Topics: * Logic, Constraint, and Functional Programming * Database, AI and Knowledge Representation Languages * Visual Programming * Executable Specification Languages * Applications of Declarative Programming * Methodologies: Program Design and Development * Declarative Aspects of Object-Oriented Programming * Concurrent Extensions to Declarative Languages * Declarative Mobile Computing * Integration of Paradigms * Proof Theoretic and Semantic Foundations * Type and Module Systems * Program Analysis and Verification * Program Transformation * Abstract Machines and Compilation * Programming Environments The list above is not exhaustive - submissions describing new and interesting ideas relating broadly to declarative programming are encouraged. Submission guidelines: Papers should be submitted via the Easychair submission website for PPDP 2010: http://www.easychair.org/conferences/?conf=ppdp2010 Papers should consist of the equivalent of 12 pages under the ACM formatting guidelines. These guidelines are available online, along with formatting templates or style files. Submitted papers will be judged on the basis of significance, relevance, correctness, originality, and clarity. They should include a clear identification of what has been accomplished and why it is significant. They must describe original, previously unpublished work that has not been simultaneously submitted for publication elsewhere. Authors who wish to provide additional material to the reviewers beyond the 12-page limit can do so in clearly marked appendices: reviewers are not required to read such appendices. No simultaneous submission to other publication outlets (either a conference or a journal) is allowed. Proceedings: The proceedings will be published by ACM Press. Authors of accepted papers will be required to sign a copyright form. Camera ready papers for accepted papers should be prepared and submitted according to the final instructions that will be sent by the publisher after notification of acceptance. Invited Speakers: As in previous years, we are planning to include invited talks in the programme. Important Dates: # Submission: title and abstract: 15 March 2010 full paper: 21 March 2010 # Notification: 23 April 2010 # Final version: 12 May 2010 # Symposium: 26-28 July 2010 Programme Committee: Elvira Albert (Spain) Sergio Antoy (US) Frederic Blanqui (China) Michele Bugliesi (Italy) Giuseppe Castagna (France) Mariangiola Dezani (Italy) Francois Fages (France) Maribel Fernandez (UK), chair Joxan Jaffar (Singapore) Andy King (UK) Temur Kutsia (Austria) Francisco Lopez Fraguas (Spain) Ian Mackie (France) Henrik Nilsson (UK) Albert Rubio (Spain) Kazunori Ueda (Japan) Philip Wadler (UK) Symposium Chairs: Temur Kutsia and Wolfgang Schreiner (Austria) For more information, please contact the chairs: Maribel Fernandez King's College London, UK Email: Maribel.Fernandez(a)kcl.ac.uk Temur Kutsia and Wolfgang Schreiner Research Institute for Symbolic Computation Johannes Kepler University Linz Email: kutsia(a)risc.uni-linz.ac.at

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Presentation about ICFP'09 programming contest
by Janis Voigtländer 17 Jan '10

17 Jan '10

Hi Haskell folk, If you are in Madrid tomorrow (Monday), you will likely not want to miss the video presentation by Andy Gill and his group about the techniques behind their running the ICFP'09 programming contest: http://www.program-transformation.org/PEPM10/SpecialFeature The presentation is scheduled to start 17:15, in the PEPM workshop room. Ciao, Janis. -- Jun.-Prof. Dr. Janis Voigtländer http://www.iai.uni-bonn.de/~jv/ mailto:jv@iai.uni-bonn.de

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Haskell Weekly News: Issue 146 - January 17, 2010
by jfredett＠gmail.com 17 Jan '10

17 Jan '10

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20100117 Issue 146 - January 17, 2010 --------------------------------------------------------------------------- Welcome to issue 146 of HWN, a newsletter covering developments in the [1]Haskell community. This has been a pretty light week in terms of discussion and announcments, but even in this comparative news lull we have the release of several new versions of packages. Inlcluding the start of a new IDE, some new job and graduate program openings, and some really excellent blog noise. Until next week, Haskellers, your Haskell Weekly News. Announcements haskell-src-exts 1.7.0. Niklas Broberg [2]announced a new release of haskell-src-exts Lite Haskell IDE. Mambo Banda [3]announced a new Haskell IDE, as part of his effort to learn Haskell. Functional Programming Bibliography. James Russell [4]announced the Functional Programming Bibliography, a new resource for the FP community. It, though in it's early stages, contains oer 1500 references (most of which are Haskell-related) to resources within the Functional Programming World. hakyll-1.0. Jasper Van der Jeugt [5]announced the release of version 1.0 of his static site generation tool, hakyll. From all (one) of us at the HWN, contragulations on the big 1.0! afv-0.0.0. Tom Hawkins [6]announced the initial release of 'Atom's Formal Verifier', a tool for verifying C code generated by Atom chp-2.0.0, chp-plus-1.0.0. Neil Brown [7]announced released new versions of his Comminicating Haskell Processes (CHP) packages. CHP is a message-passing concurrency library for Haskell. The major change in this version is a split of CHP into two packages, one containing core functionality, and one containing additional capabilities. Update for type-level library (0.2.4). Seyed Hosein Attarzadeh Niaki [8]announced a new version of his type-level library for type-level programming. This is a minor update to fix compatibility issues with dependencies. Two PhD positions in theoretical computer science. Alexandra Silva [9]announced vacancies for PhD positions in theoretical computer science at Leiden University. HaXml-1.20.1. Malcolm Wallace [10]announced a new, stable release of HaXml AST 2010 reminder--call for papers and presentations. John Hughes [11]reminded us of the AST 2010 call for papers and presentations. The submission deadline is only one week away. Job at Mylife. Julien Verlaguet [12]announced an availabiity for an OCaml developer at MyLife. Open Position (PhD student or Postdoc), U Tubingen, Germany. Torsten Grust [13]announced an open PhD/Postdoc position at the University of Tubingen in Germany. (ED: Apologies for the improper 'u' -- it should have an umlaut, but the compilation software is not cooperating) Palindromes 0.2. Johan Jeuring [14]announced a new release of the Palindromes package, including many new features and upgrades. Discussion From records to a type class. Taru Karttunen [15]asked about turning records into type classes, in an effort to make his bindings for Fuse more elegant. AlternativePrelude extension. Sjur Gjostein Karevoll [16]suggested a language pragma for alternative preludes. (ED: Again, apologies for the look-alike, but improper character). Blog noise [17]Haskell news from the [18]blogosphere. Blog posts from people new to the Haskell community are marked with >>>, be sure to welcome them! * Holumbus: [19]Linking Hayoo! Search Results. * Jeff Heard: [20]SPDE, Semi-functional programming for Processing. * Neil Mitchell: [21]Using .ghci files to run projects. * Neil Mitchell: [22]Better .ghci files. * Neil Brown: [23]Darcs. * Neil Brown: [24]Splitting CHP. * Darcs: [25]darcs weekly news #50. * Bryan O'Sullivan: [26]Progress on GHC's I/O manager. * Michael Snoyman: [27]New blog address. * Conal Elliot: [28]Exact Numeric Integration. I had missed this one last week (amidst the myriad, I failed to see it), so it is presented in this week's edition. Quotes of the Week * Jafet: <gwern> closures are a poor man's object <ddarius> objects are a poor man's closure <Berengal> objects are a rich man's structs <Jafet> Poor programmers should start unions * monochrom: Time flies like an Arrow. Space leaks like a Monad. * monochrom: Haskell already has natural language support. Just switch your natural language to simple-typed lambda calculus. * edwardk: @remember Baugn @remember lambdabot fasta says: I think the @remember command is way overused. * Berengal: data Neither a b = Left | Right * Cale: Removing monad comprehensions was actually the snowball which caused the avalanche of fail in Haskell 98 About the Haskell Weekly News New editions are posted to [29]the Haskell mailing list as well as to [30]the Haskell Sequence and [31]Planet Haskell. [32]RSS is also available, and headlines appear on [33]haskell.org. To help create new editions of this newsletter, please see the information on [34]how to contribute. Send stories to jfredett . at . gmail . dot . com. The darcs repository is available at darcs get [35]http://patch-tag.com/r/jfredett/HWN2/pullrepo HWN2 . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/69197 3. http://article.gmane.org/gmane.comp.lang.haskell.cafe/69176 4. http://article.gmane.org/gmane.comp.lang.haskell.cafe/69153 5. http://article.gmane.org/gmane.comp.lang.haskell.cafe/69106 6. http://article.gmane.org/gmane.comp.lang.haskell.cafe/68995 7. http://article.gmane.org/gmane.comp.lang.haskell.cafe/68943 8. http://article.gmane.org/gmane.comp.lang.haskell.cafe/68940 9. http://article.gmane.org/gmane.comp.lang.haskell.general/17727 10. http://article.gmane.org/gmane.comp.lang.haskell.general/17725 11. http://article.gmane.org/gmane.comp.lang.haskell.general/17724 12. http://article.gmane.org/gmane.comp.lang.haskell.general/17723 13. http://article.gmane.org/gmane.comp.lang.haskell.general/17722 14. http://article.gmane.org/gmane.comp.lang.haskell.general/17721 15. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/69207 16. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/69194 17. http://planet.haskell.org/ 18. http://haskell.org/haskellwiki/Blog_articles 19. http://holumbus.fh-wedel.de/blog/?p=30 20. http://vis.renci.org/jeff/2010/01/15/spde-semi-functional-programming-for-p… 21. http://neilmitchell.blogspot.com/2010/01/using-ghci-files-to-run-projects.h… 22. http://neilmitchell.blogspot.com/2010/01/better-ghci-files.html 23. http://chplib.wordpress.com/2010/01/14/darcs/ 24. http://chplib.wordpress.com/2010/01/11/splitting-chp/ 25. http://blog.darcs.net/2010/01/darcs-weekly-news-50.html 26. http://www.serpentine.com/blog/2010/01/11/progress-on-ghcs-io-manager/ 27. http://snoyberg.wordpress.com/2010/01/10/new-blog-address/ 28. http://conal.net/blog/posts/exact-numeric-integration/ 29. http://www.haskell.org/mailman/listinfo/haskell 30. http://sequence.complete.org/ 31. http://planet.haskell.org/ 32. http://sequence.complete.org/node/feed 33. http://haskell.org/ 34. http://haskell.org/haskellwiki/HWN 35. http://patch-tag.com/r/jfredett/HWN2/pullrepo%20HWN2

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ANNOUNCE: nntp 0.0.3
by Maciej Piechotka 17 Jan '10

17 Jan '10

Rather a 'bug-fix' release. Intended to add additional symbols to group names. I'd like to add support for explicit fetching some headers only and giving the message a more MIME-like behaviour but I'm afraid there is nowhere written how XHDR/HDR would behave with multiline headers nor I found a suitable package (mime[1] seems to not include even parsing the headers only and mime-string[2] does not take into account comments which may or may not be a problem with Message-ID comparaison). Regards [1] http://hackage.haskell.org/package/mime [2] http://hackage.haskell.org/package/mime-string

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Spring School in Generic and Indexed Programming
by Jeremy.Gibbons＠comlab.ox.ac.uk 16 Jan '10

16 Jan '10

SPRING SCHOOL ON GENERIC AND INDEXED PROGRAMMING Wadham College, Oxford, 22nd to 26th March 2010 TOPIC "Generic programming" is about making programs more widely applicable via exotic kinds of parametrization - not just along the dimensions of values or of types, but of things such as the shape of data, algebraic structures, strategies, computational paradigms, and so on. "Indexed programming" is a lightweight form of dependently typed programming, constraining flexibility by allowing one to state and check relationships between parameters: that the shapes of two arguments agree, that an encoded value matches to some type, that values transmitted along a channel conforms to some protocol, and so on. The two forces of genericity and indexing balance each other nicely, simultaneously promoting and controlling generality. The EPSRC-funded Generic and Indexed Programming project at Oxford has been exploring their interaction over the period 2006 - 2010; this school is the closing activity of the project. LECTURERS Six lecturers from the Programming Languages community, each an acknowledged expert in their specialism, will cover various aspects of generic and indexed programming. Each will give about four hours' lectures, distributed throughout the week. Nate Foster (Princeton University) "Bidirectional Programming" Ralf Hinze (University of Oxford) "Generic Programming with Adjunctions" Oleg Kiselyov (Fleet Numerical Meteorology and Oceanography Center) "Typed Tagless Interpreters" Simon Peyton Jones (Microsoft Research Cambridge) "Type Functions" Jeremy Siek (University of Colorado at Boulder) "Concepts in C++" Stephanie Weirich (University of Pennsylvania) "Generic Programming with Dependent Types" PREREQUISITES The school is aimed at doctoral students in programming languages and related areas; however, researchers and practitioners will be very welcome, as will strong masters students with the support of a supervisor. It will be assumed that participants have a good understanding of typed functional programming, as in Haskell or O'Caml. DATES Registration deadline: 19th February School: 22nd March (0900) to 26th March (lunchtime) VENUE Lectures will be held and accommodation provided in Wadham College in the centre of Oxford. The college celebrates its 400th anniversary in 2010; notable past members include Sir Christopher Wren, the founder of the Royal Society, and notable present ones Marcus du Sautoy, the mathematician and TV presenter. COSTS Costs will be kept low, thanks to support from EPSRC. There will be a nominal registration fee, and B&B accommodation in college will be about £55 per night. (Precise costs are yet to be determined.) FURTHER INFORMATION Further information, including instructions on how to register, will be available soon at the website: http://www.comlab.ox.ac.uk/projects/gip/school.html

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ANN: haskell-src-exts 1.7.0
by Niklas Broberg 15 Jan '10

15 Jan '10

Fellow Haskelleers, As I was asked to start spamming again, I'm hereby pleased to announce the release of haskell-src-exts-1.7.0! * On hackage: http://hackage.haskell.org/package/haskell-src-exts * Via cabal: cabal install haskell-src-exts * Darcs repo: http://code.haskell.org/haskell-src-exts For users of hsx, this version works fine with hsx-0.6.1. Since I haven't sent out one of these announcements in a while, here's the complete CHANGELOG since the previous announcement: ** 1.7.x 1.6.1 --> 1.7.0 =============== * Operators defined on the form (a `op` b) c = ... could not be handled by the (annotated) AST, nor the parser. I had to change the definition of the AST node for InfixMatch to allow a list of right-hand subpatterns, i.e. InfixMatch l (Pat l) (Name l) (Pat l) ... has become InfixMatch l (Pat l) (Name l) [Pat l] ... I also had an epiphany and fixed the issue that would arise with exact printing of prefix definitions including parentheses (e.g. (foo x) y = ...), so that now works too! ** 1.6.x 1.6.0 --> 1.6.1 =============== * UnicodeSyntax now works not only for identifiers, but also for ->, <- and =>, as well as Arrows arrows and kind stars. (And before you send me bug reports for this one, do check that your version of readFile is Unicode aware, i.e. you use GHC 6.12 or the utf8-string version). 1.5.3 --> 1.6.0 =============== * (=~=) turns out to be too general at Functor (for intuitive and not technical reasons), so is specialised to Annotated to closer mirror the original intention. * applyFixities is hoisted to a monad, and now fails on ambiguous infix expressions. ** 1.5.x 1.5.2 --> 1.5.3 =============== * Several small bug fixes in the exact printer, and fail more gracefully if the number of srcInfoPoints doesn't match the needs of the node. 1.5.1 --> 1.5.2 =============== * Fix a bug in the exact printer that made it always print the first token at position (0,0). * In fixing the above, Annotated is now a superclass of ExactP. It was already a superclass in spirit, and nothing can break from this since ExactP is only exported abstractly. 1.5.0 --> 1.5.1 =============== * The pretty printer now introduces parentheses for non-atomic arguments to function application. Note that infix applications are left untouched, no parentheses will be inserted there, as it is assumed that fixities are already properly resolved. * Fix a bug in the pretty printer where view patterns and n+k patterns were not properly parenthesised. 1.4.0 --> 1.5.0 =============== * Add support for acting on LINE pragmas while parsing, i.e. updating the source position according to info given in LINE pragmas. This is done conditionally based on a new flag ignoreLinePragmas in the ParseMode, hence the need to increase the major version. ** 1.4.x 1.3.5 --> 1.4.0 =============== * The AST node for Proc in the simple AST is changed to include a SrcLoc argument, to make it consistent with similar nodes e.g. Lambda. This is specifically needed for transformation of patterns in HSX. ** 1.3.x 1.3.4 --> 1.3.5 =============== * Added an entry point in the parser for statements, and an instance Parseable Stmt to go with it. * Ensured that .Annotated exports all relevant parseXXX(WithYYY) functions. 1.3.3 --> 1.3.4 =============== * Operator fixities are now resolved in patterns. 1.3.2 --> 1.3.3 =============== * Fixes a bug where qualified keywords are rejected even if the extension that enables the keyword in question is not turned on. 1.3.0 --> 1.3.2 =============== (Let's forget 1.3.1 ever existed.) * Fix a bug where declarations of infix operators were not properly merged as FunBinds.

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ANNOUNCE: Functional Programming Bibliography
by James Russell 15 Jan '10

15 Jan '10

I am pleased to announce the Functional Programming Bibliography at http://www.catamorphism.net/ The functional programming bibliography was created in the hope that it will be a useful resource to the functional programming community. The site is still in an early stage of development, and is pretty raw, and incomplete in a number of ways. Keyword categorization, in particular, is still fairly spotty. It currently contains in excess of 1500 references, heavily slanted toward Haskell-related topics, and contains links to publicly available versions of many papers, as well as links to gated versions of some papers. I am eager for suggestions as to how the site could be made more useful. Regards, James Russell

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