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Haskell Summers of Code retrospective (updated for 2011)
by Gwern Branwen 17 Jan '12

17 Jan '12

The Wheel turns, and months come and pass, leaving blog posts that fade into 404s; a wind rose in Mountain View, whispering of the coming Winter... Tonight I sat down and finally looked into the 2011 SoCs to see how they turned out and judge them according to my whimsically arbitrary and subjective standards: http://www.gwern.net/Haskell%20Summer%20of%20Code#results-1 They turned out pretty much as I predicted - but then I *would* say that, wouldn't I? (Also submitted to /r/haskell for those who swing that way: http://www.reddit.com/r/haskell/comments/n82ln/summer_of_code_2011_retrospe… ) -- gwern http://www.gwern.net

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ICFP 2012 Call for papers
by Wouter Swierstra 17 Jan '12

17 Jan '12

===================================================================== ICFP 2012: International Conference on Functional Programming Copenhagen, Denmark, September 9 - 15, 2012 http://www.icfpconference.org/icfp2012 ===================================================================== Important Dates ~~~~~~~~~~~~~~~ Submissions due: Monday Mar 12, 2012 14:00 UTC Author response: Monday May 07, 2012 14:00 UTC - May 9 14:00 UTC Notification: Monday May 28, 2012 Final copy due: Monday Jul 02, 2012 Scope ~~~~~ ICFP 2012 seeks original papers on the art and science of functional programming. Submissions are invited on all topics from principles to practice, from foundations to features, and from abstraction to application. The scope includes all languages that encourage functional programming, including both purely applicative and imperative languages, as well as languages with objects, concurrency, or parallelism. Topics of interest include (but are not limited to): * Language Design: concurrency and distribution; modules; components and composition; metaprogramming; interoperability; type systems; relations to imperative, object-oriented, or logic programming * Implementation: abstract machines; virtual machines; interpretation; compilation; compile-time and run-time optimization; memory management; multi-threading; exploiting parallel hardware; interfaces to foreign functions, services, components, or low-level machine resources * Software-Development Techniques: algorithms and data structures; design patterns; specification; verification; validation; proof assistants; debugging; testing; tracing; profiling * Foundations: formal semantics; lambda calculus; rewriting; type theory; monads; continuations; control; state; effects; program verification; dependent types * Analysis and Transformation: control-flow; data-flow; abstract interpretation; partial evaluation; program calculation * Applications and Domain-Specific Languages: symbolic computing; formal-methods tools; artificial intelligence; systems programming; distributed-systems and web programming; hardware design; databases; XML processing; scientific and numerical computing; graphical user interfaces; multimedia programming; scripting; system administration; security * Education: teaching introductory programming; parallel programming; mathematical proof; algebra * Functional Pearls: elegant, instructive, and fun essays on functional programming * Experience Reports: short papers that provide evidence that functional programming really works or describe obstacles that have kept it from working If you are concerned about the appropriateness of some topic, do not hesitate to contact the program chair. Abbreviated instructions for authors ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * By March 12 2012, 14:00 UTC, submit a full paper of at most 12 pages (6 pages for an Experience Report), including bibliography and figures. The deadlines will be strictly enforced and papers exceeding the page limits will be summarily rejected. * Authors have the option to attach supplementary material to a submission, on the understanding that reviewers may choose not to look at it. * Each submission must adhere to SIGPLAN's republication policy, as explained on the web at http://www.acm.org/sigplan/republicationpolicy.htm * Authors of resubmitted (but previously rejected) papers have the option to attach an annotated copy of the reviews of their previous submission(s), explaining how they have addressed these previous reviews in the present submission. If a reviewer identifies him/herself as a reviewer of this previous submission and wishes to see how his/her comments have been addressed, the program chair will communicate to this reviewer the annotated copy of his/her previous review. Otherwise, no reviewer will read the annotated copies of the previous reviews. Overall, a submission will be evaluated according to its relevance, correctness, significance, originality, and clarity. It should explain its contributions in both general and technical terms, clearly identifying what has been accomplished, explaining why it is significant, and comparing it with previous work. The technical content should be accessible to a broad audience. Functional Pearls and Experience Reports are separate categories of papers that need not report original research results and must be marked as such at the time of submission. Detailed guidelines on both categories are on the conference web site. Proceedings will be published by ACM Press. Authors of accepted submissions are expected to transfer the copyright to the ACM. Presentations will be videotaped and released online if the presenter consents. Formatting: Submissions must be in PDF format printable in black and white on US Letter sized paper and interpretable by Ghostscript. If this requirement is a hardship, make contact with the program chair at least one week before the deadline. Papers must adhere to the standard ACM conference format: two columns, nine-point font on a ten-point baseline, with columns 20pc (3.33in) wide and 54pc (9in) tall, with a column gutter of 2pc (0.33in). A suitable document template for LaTeX is available: http://www.acm.org/sigs/sigplan/authorInformation.htm Submission: Submissions will be accepted only online via the ICFP website. Improved versions of a paper may be submitted at any point before the submission deadline using the same web interface. Author response: Authors will have a 48-hour period, starting at 14:00 UTC on Monday May 7th 2012, to read reviews and respond to them. Special Journal Issue: There will be a special issue of the Journal of Functional Programming with papers from ICFP 2012. The program committee will invite the authors of select accepted papers to submit a journal version to this issue. Conference Chair: Peter Thiemann, University of Freiburg Program Chair: Robby Findler, Northwestern University Program Committee: Andreas Rossberg, Google Andrew Tolmach, Portland State University Brigitte Pientka, McGill University Colin Runciman, University of York Eijiro Sumii, Tohoku University Jan Midtgaard, Aarhus University John Hughes, Chalmers University of Technology and Quviq AB Lars Birkedal, IT University of Copenhagen Manuel Fähndrich, Microsoft Research Mariangiola Dezani-Ciancaglini, University of Turin Matthias Blume, Google R. Kent Dybvig, Cisco and Indiana University Sam Tobin-Hochstadt, Northeastern University Satnam Singh, Google Research Simon Marlow, Microsoft Research Zena M. Ariola, University of Oregon

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Second CfP --- 75 Years of the Lambda Calculus
by Conor McBride 16 Jan '12

16 Jan '12

[posted on behalf of Patricia Johann] [Please note that the submission deadline is 27 January. Flyer attached below. -patty] International Workshop on 75 Years of Lambda-Calculus University of St Andrews, Scotland 15th June, 2012 Call for papers http://msp.cis.strath.ac.uk/lambda2012 Sponsored by Scottish Informatics & Computer Science Alliance (SICSA) Overview -------- In 1936, Alonzo Church?s foundational 'An unsolvable problem of elementary number theory' introduced the Lambda-calculus which, with Turing machines, now underpins contemporary theoretical and practical Computer Science. To celebrate the 75th anniversary of the publication of this seminal work, papers are invited for presentation at a one day International Workshop, to be held in St Andrews on 15th June 2012, immediately following the International Symposium on Trends in Functional Programming (TFP). Topics ------ Church's life & work Origins/history Computability Programming language design & implementation Logic, proof & reasoning Guest Speakers -------------- Henk Barendregt, University of Nijmegen Chris Hankin, Imperial College Roger Hindley, University of Swansea Fairouz Kamareddine, Heriot-Watt University Workshop Chairs --------------- Greg Michaelson, Heriot-Watt University Patricia Johann, University of Strathclyde Programme Committee ------------------- Robert Atkey, University of Strathclyde Dan Dougherty, WPI Maribel Fernandez, Kings College London Philip Scott, University of Ottawa Dates (2012) ------------ 27th January: submission 2nd March: notification of acceptance for Workshop 18th May: deadline for draft proceedings 15th June: Workshop 31st August: deadline for HOSC special issue 30th November: notification of acceptance for HOSC Submissions ----------- Submissions will be 'light touch' refereed for relevance before the Workshop, and will appear in the draft proceedings, with full refereeing thereafter for publication in a special issue of Higher Order and Symbolic Computation. Submissions should be of 16 pages maximum length in the Springer format from http://cs.au.dk/~hosc/ Submission ---------- https://www.easychair.org/conferences/?conf=75ylc Registration ------------ There will be an attendance charge of around ?50 for refreshments, lunch, and proceedings. There will be no charge for PhD students from SICSA affiliated Universities. Registration will be through TFP: http://www.cs.st-andrews.ac.uk/~kh/TFP2012/TFP_2012/Home.html

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Patch combinators
by Emil Axelsson 16 Jan '12

16 Jan '12

Hi all! Based on ideas by Koen Claessen, I have made a small module for what might be called patch combinators: http://hpaste.org/56501 Examples are found as comments. Before I push this to Hackage, I just wanted to check if there is any package that already provides this sort of functionality. (We're planning to use this module for expressing compile-time constraints on Feldspar functions.) Thanks for any feedback! / Emil

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named pipe interface
by Serge D. Mechveliani 16 Jan '12

16 Jan '12

People, (I wonder: is this for beginners(a)haskell.org ?) I need to organize a string interface for a Haskell function Main.axiom and a C program fifoFromA.c via a pair of named pipes (in Linux, UNIX). The pipes are created before running, by the commands > mkfifo toA > mkfifo fromA Main.axiom outputs a string to toA and inputs the respond string from fromA as the result. fifoFromA inputs a string from toA, converts it to the string resStr, outputs resStr to fromA. Main.axiom must be able to be applied in a loop, and there must be avoided repeated opening of a file/channel in a loop. As an example, the string conversion in fifoFromA.c is put the conversion of each character to the lower case: -------------------------- fifoFromA.c ------------------------------ #include <string.h> #include <stdio.h> #include <fcntl.h> #define BOUND 64 int main() { int toA, fromA, i, numread; char buf[BOUND]; toA = open("toA", O_RDONLY); fromA = open("fromA", O_WRONLY); for (;;) { numread = read(toA, buf, BOUND); buf[numread] = '\0'; // printf("A: Read from toA: %s\n", buf); i = 0; // convert the string to the lower case while (i < numread) {buf[i] = tolower(buf[i]); i++;} write(fromA, buf, strlen(buf)); } } ----------------------------------------------------------------------- For the "to-A" part writen in C (instead of Haskell), this interface loop works all right. With Haskell, I manage to process only a single string in the loop, and then it ends with an error. Main.hs is given below. I never dealt with such an IO in Haskell. Can you, please, fix the code or give comments? Please, copy the response to mechvel(a)botik.ru (I am not in the list). Thank you in advance for your notes, ------ Sergei mechvel(a)botik.ru ------------------------------------------------------------------- import System.IO (IOMode(..), IO(..), Handle, openFile, hPutStr, hGetLine, hFlush) import System.IO.Unsafe (unsafePerformIO) dir = showString "/home/mechvel/ghc/axiomInterface/byLowerLevel/" toA_IO = openFile (dir "toA") WriteMode :: IO Handle fromA_IO = openFile (dir "fromA") ReadMode -- used as global values toA = unsafePerformIO toA_IO -- fromA = unsafePerformIO fromA_IO -- axiomIO :: String -> IO String axiomIO str = do hPutStr toA str hFlush toA hGetLine fromA axiom :: String -> String -> String axiom str = showString (unsafePerformIO $ axiomIO str) -- Examples of usage -------------------------------------------- -- main = putStr (axiom "ABC1" "\n") -- I -- putStr (axiom "ABC1" $ showChar '\n' $ axiom "ABC2" "\n") -- II {- III: putStr (shows resPairs "\n") where n = 9000 str0 = "ABC" strings = [str0 ++ (show i) | i <- [1 .. n]] resPairs = [(str, axiom str "") | str <- strings] -} ----------------------------------------------------------------- I use Glasgow Haskell ghc-7.01. Build: > gcc -o fifoFromA fifoFromA.c > ghc --make Main Running: first, command > ./fifoFromA on terminal-2, then command > ./Main on terminal-1. Now, the example (I) works -- in the sense that terminal-1 shows the result "abc1" after the program on terminal-2 is interrupted. II and III do not work. And the aim is the examples like III.

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Functor0?
by Evan Laforge 16 Jan '12

16 Jan '12

Often when I define some type that wraps something else, I find myself writing a function like the following: newtype Thing = Thing X liftThing f (Thing x) = Thing (f x) It's like a Functor, but I can't make it an instance because Functor requires that the type be parametric. So I've been using type families to make a kind of "0 argument functor": class Functor0 a where type Elem a :: * fmap0 :: (Elem a -> Elem a) -> a -> a instance Functor0 Thing where type Elem Thing = X fmap0 = liftThing Is there a name for this? A better way to do it?

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porting feed to xml-enumerator
by Simon Michael 16 Jan '12

16 Jan '12

Hi Sigbjorn (and Don), I'm back for another reason. feed leaks and uses a lot of memory due to the xml package. Rather than fix xml I ported feed to xml-enumerator, which is used by yesod and more actively maintained than xml. This seems to have fixed the problem so I'm thinking of uploading this version to hackage as feed-1.0 (which I'll use for rss2irc and hackagebot.) Please let me know whether you agree. Also you might be interested in moving your repo (http://code.galois.com/cgi-bin/gitweb?p=feed.git;a=summary) to github ? This would make it easier to publish my changes, either to the main repo or a branch or fork. Otherwise I'll need to get them to your repo somehow. Thanks again, -Simon On Feb 21, 2011, at 5:14 PM, Simon Michael wrote: > thanks for feed. I'm just investigating a bug with rss2irc, and I think I'm seeing problems in the current feed on hackage. It lookas as if there's no way to get item updated date as opposed item published date, and getItemPublishDate actually gets the updated date in the case of an atom feed (http://hackage.haskell.org/packages/archive/feed/0.3.8/doc/html/src/Text-Fe…) > > I'd like to contribute a fix. Would you be able to make feed's repo public, eg on darcsden.com or github ?

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HaskellWiki upload failed
by Henk-Jan van Tuyl 16 Jan '12

16 Jan '12

L.S., I am trying to upload a file of about 12 Mbyte to the HaskellWiki; the upload fails without error message. Is the file too big? Regards, Henk-Jan van Tuyl -- http://Van.Tuyl.eu/ http://members.chello.nl/hjgtuyl/tourdemonad.html Haskell programming --

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hackage trac broken
by Joachim Breitner 16 Jan '12

16 Jan '12

Hi, a Debian user tried to report a bug against cabal-install (http://bugs.debian.org/655752) but the trac instance linked from the Cabal homepage seems to be down: http://hackage.haskell.org/trac/hackage/ Internal Server Error TracError: IOError: [Errno 13] Permission denied: '/srv/trac/hackage/VERSION' Is this known and will it be fixed? Thanks, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata(a)debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata(a)joachim-breitner.de | http://people.debian.org/~nomeata

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SBLP - call for papers
by Simon Thompson 16 Jan '12

16 Jan '12

============================================================ CALL FOR PAPERS 16th BRAZILIAN SYMPOSIUM ON PROGRAMMING LANGUAGES Natal, Rio Grande do Norte, Brazil September 24-28, 2012 http://www.cbsoft.dimap.ufrn.br ============================================================ IMPORTANT DATES Paper abstract submission (15 lines): April 20nd, 2012 Full paper submission: April 27th, 2012 Notification of acceptance: May 28th, 2012 Final papers due: June 29th, 2012 INTRODUCTION The 16th Brazilian Symposium on Programming Languages, SBLP 2012, will be held in Natal, Brazil, on September 24-28, 2012. SBLP provides a venue for researchers and practitioners interested in the fundamental principles and innovations in the design and implementation of programming languages and systems. The symposium will be part of the 3nd Brazilian Conference on Software: Theory and Practice, CBSoft 2012, http://www.cbsoft.dimap.ufrn.br, which will host four traditional, well-established symposia: * XXVI Brazilian Symposium on Software Engineering (SBES) * XVI Brazilian Symposium on Programming Languages (SBLP) * XV Brazilian Symposium on Formal Methods (SBMF) * VI Brazilian Symposium on Components, Software Architecture and Software Reuse (SBCARS) SBLP 2012 invites authors to contribute with technical papers related (but not limited) to: * Program generation and transformation, including domain- specific languages and model-driven development in the context of programming languages. * Programming paradigms and styles, including functional, object-oriented, aspect-oriented, scripting languages, real-time, service-oriented, multithreaded, parallel, and distributed programming. * Formal semantics and theoretical foundations, including denotational, operational, algebraic and categorical. * Program analysis and verification, including type systems, static analysis and abstract interpretation. * Programming language design and implementation, including new programming models, programming language environments, compilation and interpretation techniques. SUBMISSIONS Contributions should be written in Portuguese or English. We solicit papers that should fall into one of two different categories: full papers, with at most 15 pages, or short papers, with at most 5 pages. All papers should be prepared using the SBC template. In particular, we encourage the submission of short papers reporting on partial results of on-going master dissertations or doctoral theses. All accepted papers will be published in the conference proceedings. Submissions should be done using SBLP 2012 installation of the EasyChair conference mangement system at http://www.easychair.org/conferences/?conf=sblp2012. As in previous editions, a journal special issue, with selected papers from accepted contributions, is anticipated. GENERAL CO-CHAIRS Nélio Cacho, UFRN Gibeon Aquino, UFRN Martin Musicante, UFRN PROGRAMME CHAIRS Francisco Heron de Carvalho Junior, UFC Luis Soares Barbosa, Univ. do Minho PROGRAMME COMMITTEE * Alberto Pardo, Univ. de La Republica * Alex Garcia, IME * Alvaro Freitas Moreira, UFRGS * André Rauber Du Bois, UFPel * Andre Santos, UFPE * Carlos Camarao, UFMG * Christiano Braga, UFF * Fernando Castor Filho, UFPE * Fernando Quintão Pereira, UFMG * Francisco Heron de Carvalho Junior, UFC (co-chair) * Joao Saraiva, Universidade do Minho * João F. Ferreira, Teeside University * Jonathan Aldrich, Carnegie Mellon Univ. * Jose Luiz Fiadeiro, Univ. of Leicester * Lucilia Figueiredo, UFOP * Luis Soares Barbosa, Univ. do Minho * Manuel António Martins, Univ. de Aveiro * Marcelo A. Maia, UFU * Marcello Bonsangue, Leiden Univ/CWI * Marcelo d'Amorim, UFPE * Marco Tulio Valente, UFMG * Mariza A. S. Bigonha, UFMG * Martin A. Musicante, UFRN * Noemi Rodriguez, PUC-Rio * Paulo Borba, UFPE * Peter Mosses, Swansea University * Qiu Zongyang, Beijing University * Rafael Dueire Lins, UFPE * Renato Cerqueira, PUC-Rio * Ricardo Massa, UFPE * Roberto S. Bigonha, UFMG * Roberto Ierusalimschy, PUC-Rio * Sandro Rigo, UNICAMP * Sergio Soares, UFPE * Simon Thompson, Univ. of Kent * Varmo Vene, Univ. de Tartu Simon Thompson | Professor of Logic and Computation School of Computing | University of Kent | Canterbury, CT2 7NF, UK s.j.thompson(a)kent.ac.uk | M +44 7986 085754 | W www.cs.kent.ac.uk/~sjt

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