April 2004 - Haskell - Haskell.org

Mixing monadic and non-monadic functions
by Sean E. Russell 17 Sep '05

17 Sep '05

Hello, I posted this question to comp.lang.functional, and someone suggested that I try this group instead. I'm struggling with monads. Well, not monads themselves, but mixing them with non-monadic functions. Here's my base case: someFunc :: String -> IO [a] ... ax <- someFunc a bx <- someFunc b assertBool "fail" $ length ax == length bx I don't like the assignments; the typing is redundant, if I have a lot of asserts like this, and the "variables" are temporary. What I'd much rather have is: ... assertBool "fail" $ (length $ someFunc a) == (length $ someFunc b) which is more readable, to my eye. The only solution which has been suggested that may work is liberal use of the liftM variants, but this gets *really* tedious and obtuse. Is there an elegant way to do what I want to do, or am I stuck with procedural-style assignments and bunches of temp vars? Thanks! -- ### SER ### Deutsch|Esperanto|Francaise|Linux|XML|Java|Ruby|Aikido ### http://www.germane-software.com/~ser jabber.com:ser ICQ:83578737 ### GPG: http://www.germane-software.com/~ser/Security/ser_public.gpg

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WS-FM 2004 Call For Participation
by Mario Bravetti 20 Jul '05

20 Jul '05

---------------------------------------------------------------------- We apologize if you receive multiple copies of this announcement. ---------------------------------------------------------------------- ====================================================================== 1st International Workshop on Web Services and Formal Methods (WS-FM 2004) February 23-24, 2004, Pisa, Italy Workshop affiliated to COORDINATION 2004, February 24-27, 2004 WS-FM 2004 homepage: http://www.cs.unibo.it/~lucchi/ws-fm04/ ====================================================================== - The technical program is available at: http://www.cs.unibo.it/~lucchi/ws-fm04/ - Information about registration, travel and accomodation can be found at the COORDINATION 2004 web site: http://www.di.unipi.it/Coordination2004/ If you intend to participate, we recommend you to register and book the hotel as soon as possible. The Coordination 2004 Organizing Committee informed us that hotels are going to be fully booked in short time.

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CfP: SNPD'03 Workshop on High-Level Approaches to Parallel and Distributed Computing
by Clemens Grelck 08 Jul '04

08 Jul '04

Please apologize in case you receive multiple copies of this information. ========================================================================== CALL FOR PAPERS Workshop on High-Level Approaches to Parallel and Distributed Computing held in the context of the Fourth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing (SNPD'03) October 16th - 18th, 2003 Luebeck, Germany http://www.isp.uni-luebeck.de/snpd03/Workshop/ws02/index.htm ========================================================================== Scope and Topics: ================== Today parallel and distributed computing systems are readily available and provide a continuously improving price/performance ratio. However, this technological breakthrough in hardware is not accompanied by similar progress in software technology. Parallel and distributed programming is still dominated by low-level techniques such as explicit message passing. This low level of abstraction makes programming these systems exceedingly difficult, time-consuming, and error-prone. Hence, parallel and distributed computing requires new programming models which liberate programmers from low-level concerns and increase programming productivity while maintaining reasonable trade-offs between level of abstraction and runtime performance. Topics of interest include, but are not limited to - methodologies for high-level parallel programming, - parallel programming languages, - high-level libraries for parallel computing, - compilers and runtime systems for parallel computing, - implementation aspects of high-level parallel programming environments, - compiler-based optimization and parallelization, - experience with high-level parallel programming environments, - support for debugging and performance analysis, - concurrent array programming, - programming concepts for the grid. This workshop provides a forum for researchers and practitioners interested in the design, implementation, and evaluation of high-level parallel programming concepts. It aims at creating some focus within the otherwise broad spectrum of the SNPD'03 conference. Workshop Chair and Organizer: ============================== Clemens Grelck University of Luebeck Institute of Software Technology and Programming Languages Seelandstr. 1A 23569 Luebeck, Germany E-Mail: grelck(a)isp.uni-luebeck.de Papers and Publication: ======================== Original, unpublished papers in English not exceeding 8 pages in ACIS double column format are solicited. For detailed formatting instructions see the SNPD'03 conference web site at http://www.isp.uni-luebeck.de/snpd03/index.htm Please send your papers as PDF documents by electronic mail directly to the workshop chair: grelck(a)isp.uni-luebeck.de Please indicate your paper submission by the subject SNPD03 WORKSHOP SUBMISSION Accepted papers will be published in the conference proceedings with ISBN. A selection of excellent papers presented at the conference including its workshops will be published in a special issue of the International Journal of Computer and Information Science. Important Deadlines: ===================== Full paper submission due: August, 30th Notification of acceptance: September, 10th Camera-ready papers due: September, 24th

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NEW DEADLINE: MKM 2004 - CFP (Bialowieza, Poland)
by Roman Matuszewski 25 Jun '04

25 Jun '04

Please post - apologies for multiple copies. ============================================ *** NEW DEADLINE: May 15, 2004 *** MKM 2004 Third International Conference on MATHEMATICAL KNOWLEDGE MANAGEMENT http://mizar.org/MKM2004 September 19 - 21, 2004 Bialowieza - Poland (organized by University of Bialystok) CALL FOR PAPERS Mathematical Knowledge Management is a new field in the intersection of mathematics and computer science. We need new techniques for managing the enormous volume of mathematical knowledge available in current mathematical sources and making it available through the new developments in information technology. A list of topics (to be understood as specialized to the realm of mathematical information) comprises but is not restricted to: Knowledge representation Repositories of formalized mathematics Metadata Deduction systems Datamining Computer Algebra Systems Digital libraries Authoring languages and tools Searching and retrieving Interactive learning Languages of mathematics Web presentation of mathematics Math assistants MathML- and XML-based standards SUBMISSION To submit your paper go to MKM 2004 electronic submission site: http://mizar.uwb.edu.pl/CyberChairMKM/ The deadline for submissions is May 15, 2004. Submitted papers should not exceed 15 pages, must be original and not submitted for publication elsewhere. All papers submitted to the Conference will be reviewed. Accepted papers will appear in the proceedings before the Conference. PROCEEDINGS We plan to publish the proceedings of the Conference in the Springer-Verlag Lecture Notes in Computer Science series (http://www.springer.de/comp/lncs/) Submitted papers must be prepared according to "Authors Instructions of LNCS" (http://www.springer.de/comp/lncs/authors.html) We strongly encourage the author(s) to use LaTeX. Authors of accepted papers are expected to present their work at the conference. IMPORTANT DATES NEW Submission Deadline: May 15, 2004 Notification of acceptance/rejection: June 10, 2004 Camera ready copies: July 1st, 2004 Conference: September 19 - September 21, 2004 AFFILIATED WORKSHOPS - September 18, 2004 - Mathematical User-Interfaces, organized by Paul Libbrecht, - 30 Years of Mizar, organized by Grzegorz Bancerek. PROGRAM COMMITTEE Andrzej Trybulec, Univ. of Bialystok, Poland (Chair) Andrew A. Adams, University of Reading, U.K. Andrea Asperti, University of Bologna, Italy Bruno Buchberger, RISC Linz, Austria Roy McCasland , U. of Edinburgh, U.K. James Davenport, University of Bath, U.K. William M.Farmer, McMaster University, Canada Herman Geuvers, Katholieke U. Nijmegen, NL Therese Hardin, Pierre & Marie Curie U., France Fairouz Kamareddine, Heriot-Watt U., U.K. Michael Kohlhase, Internat. U. Bremen, Germany Paul Libbrecht, Saarland University, Germany Bengt Nordstrom, Chalmers U. of Techn., Sweden Renaud Rioboo, Pierre & Marie Curie U., France Bernd Wegner, Technical U. of Berlin, Germany RELATED LINKS MKM Consortium, http://monet.nag.co.uk/mkm/consortium.html MKM 2001, http://www.risc.uni-linz.ac.at/institute/conferences/MKM2001/ MKM 2003, http://www.cs.unibo.it/MKM03/ MKM NET, http://monet.nag.co.uk/mkm/ MKM Symposium 2003, http://www.macs.hw.ac.uk/~fairouz/mkm-symposium03/ NA-MKM 2002, http://imps.mcmaster.ca/na-mkm-2002/ NA-MKM 2004, http://imps.mcmaster.ca/na-mkm-2004/ ================================================================== Questions should be sent to Conference Chair: Roman Matuszewski, mailto:romat@mizar.org http://mizar.org/people/romat/

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ICFP Poster Session
by Amr A Sabry 17 Jun '04

17 Jun '04

The 2004 ICFP Poster Session http://abstract.cs.washington.edu/~djg/icfp-poster.html Part of the 2004 International Conference on Functional Programming http://www.cs.indiana.edu/icfp04/ The 2004 International Conference on Functional Programming (ICFP) will include a poster session during the first day of the conference. The poster session aims to give students and professionals an opportunity to gain experience presenting technical material to the research community, and to get technical advice from leading researchers in the field. PARTICIPANT OBLIGATIONS: * Sign-up via the on-line form below by June 30, 2004. * Submit a one-page abstract summarizing the poster topic by July 15, 2004. * Register for ICFP 2004. (There is no separate poster registration beyond the on-line sign-up form.) * Prepare a poster and attend the session on September 19, 2004. In addition, participants are strongly encouraged to prepare a short article (roughly 2 or 3 pages) for peer feedback and to provide feedback for some other participants' articles. This process should improve the quality of the posters. Articles should be submitted by August 1, 2004. NUMBER OF PARTICIPANTS: * We hope to accomodate everyone wishing to participate, but may restrict participation (based on relevance and interest to the community) in the case of unmanageably high interest. * We may need to cancel the session if there is too little interest, roughly fewer than ten participants. * To ensure we know there is interest, please sign-up promptly. Somebody has to be first and there is no danger you will be the sole participant. POSTER PRESENTATIONS: In the poster session, each participant will be provided with a space for posting their diagrams and short descriptions of their research (approximately 3x6 feet, or 1x2 meters). Contact with your audience happens through casual conversation. Count on only a reasonable attention span when describing your work. Over five minutes is usually overdoing it. Prepare a list of questions that you would like help getting answered. Please feel free to direct any questions that you might have to: Dan Grossman, ICFP2004 Poster Session Chair http://www.cs.washington.edu/homes/djg

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[Haskell] Programming language shootout (completing the Haskell entry)
by Sean E. Russell 14 Jun '04

14 Jun '04

Hiya, I know it is silly, but I'm interested in helping to complete the Haskell entry in the Programming Language Shootout page[1] (http://www.bagley.org/~doug/shootout/craps.shtml) The Haskell entry is missing 5 (out of 13) entries, and since no points are "scored" for missing entries, this skews Haskell's rank downwards. Since I'm not the worlds Best Haskell Programmer -- and I'm certainly not adept at optimizing, and since I'd like to provide the fastest Haskell code that I can, I thought I'd run it through my code through this list and see if anybody would like to suggest improvements. The implementations for this particular test must be written in the "same way"; this is defined to be that the submissions "use the same logic and data structures", the goal being to "try to measure languages doing the same operations, as closely as possible." The "description" of the test is: "In this test, we create 10000 hash entries, then add them into a new hash N times. " The correct output for this code where N=10 must be: 1 9999 10 99990 I chose to use (lookup) and associative arrays. I create a *bunch* of hashes, rather than just two that I re-use because, honestly, I'm such a novice I don't know how to do it otherwise. Anyway, as I said, any suggestions for optimization are appreciated. This is just for fun. ===== BEGIN hash2.hs module Main where import System (getArgs) import Numeric (readDec) import Maybe main = do argv <- getArgs let h1 = hash1 9999 [] h2 = hash2 (fst $ head $ readDec $ argv!!0) h1 [] print h1 h2 where hash1 0 x = x hash1 n xs = hash1 (n-1) ((mkentry n):xs) mkentry y = ( "foo_"++(show y), y ) hash2 0 _ x2 = x2 hash2 n x1 x2 = hash2 (n-1) x1 [ (k1, v1+(get k1 x2)) | (k1, v1) <- x1 ] print x1 x2 = putStrLn ( (show $ get "foo_1" x1)++" "++ (show $ get "foo_9999" x1)++" "++ (show $ get "foo_1" x2)++" "++ (show $ get "foo_9999" x2) ) get :: String -> [(String, Int)] -> Int get key hash = fromMaybe 0 $ lookup key hash ===== END hash2.hs [1] The page is entirely tounge-in-cheek, but I find it interesting, nonetheless. -- ### SER ### Deutsch|Esperanto|Francaise|Linux|XML|Java|Ruby|Aikido ### http://www.germane-software.com/~ser jabber.com:ser ICQ:83578737 ### GPG: http://www.germane-software.com/~ser/Security/ser_public.gpg

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CFP: Haskell Workshop 2004
by Henrik Nilsson 28 May '04

28 May '04

Please find enclosed the Call For Papers for the 2004 Haskell Workshop, to be held on 22 September in Snowbird, Utah, USA in association with ICFP'04. The submission deadline is 4 June: just a little more than a month away! See http://www.cs.nott.ac.uk/~nhn/HW2004/ for further details, including Call For Papers in PDF/HTML format. My apologies for multiple copies. Best regards, /Henrik -- Henrik Nilsson School of Computer Science and Information Technology The University of Nottingham nhn(a)cs.nott.ac.uk 2004 Haskell Workshop Snowbird, Utah, USA, 22 September, 2004 http://www.cs.nott.ac.uk/~nhn/HW2004 Call For Papers The Haskell Workshop 2004 is an ACM SIGPLAN sponsored workshop affiliated with the 2004 International Conference on Functional Programming (ICFP). Previous Haskell Workshops have been held in La Jolla (1995), Amsterdam (1997), Paris (1999), Montreal (2000), Firenze (2001), Pittsburgh (2002), and Uppsala (2003). ******************** Scope ******************** The purpose of the Haskell Workshop is to discuss experience with Haskell, and possible future developments for the language. The scope of the workshop includes all aspects of the design, semantics, theory, application, imple- mentation, and teaching of Haskell. Topics of interest include, but are not limited to, the following: Language Design with a focus on possible extensions and modifications of Haskell as well as critical discussions of the status quo; Theory in the form of a formal treatment of the semantics of the present language or future extensions, type systems, and foundations for program analysis and transformation; Implementation Techniques including program analysis and transformation, static and dynamic compilation for sequential, parallel, and distributed architectures, memory management as well as foreign function and component interfaces; Tool Support in the form of profilers, tracers, debuggers, pre-processors, and so forth; Applications, Practice, and Experience with Haskell for scientific and symbolic computing, database, multimedia and Web applications, and so forth as well as general experience with Haskell in education and industry; Functional Pearls being elegant, instructive examples of using Haskell. Papers in the latter two categories need not necessarily report original research results; they may instead, for example, report practical experience that will be useful to others, re-usable programming idioms, or elegant new ways of approaching a problem. The key criterion for such a paper is that it makes a contribution from which other practitioners can benefit. It is not enough simply to describe a program! The programme committee welcomes short papers and may accept them for brief presentation at the workshop. ******************** Submission Details ******************** Deadline for submission: 4 June, 2004 Notification of acceptance: 5 July, 2004 Final submission due: 30 July, 2004 (tentative) Haskell Workshop: 22 September, 2004 Authors should submit papers in postscript format, formatted for A4 paper, to Henrik Nilsson (nhn(a)cs.nott.ac.uk) by 4 June 2004. The length should be restricted to the equivalent of 5000 words (which is approximately 12 pages in ACM format). The papers will be published by the ACM and will appear in the ACM Digital Library. If you are interested in demonstrating a Haskell-related system or tool, please send a brief demo proposal to Henrik Nilsson (nhn(a)cs.nott.ac.uk) ******************** Programme Committee ******************** Jörgen Gustavsson Chalmers Thomas Hallgren OGI Jerzy Karczmarczuk Université de Caen Daan Leijen Universiteit Utrecht Henrik Nilsson (chair) University of Nottingham Colin Runciman University of York Martin Sulzmann National University of Singapore Valery Trifonov Yale University

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return?
by Ben_Yu＠asc.aon.com 30 Apr '04

30 Apr '04

Hi, While writing monad programs, I sometimes want to do a return as it is in imperative program. i.e., do{return 1; return 2} is same as return 1 This seems useful to me when I need to do something like do mwhen cond $ return 1 ...... -- subsequent actions I know I can do if cond then return 1 else ( ...--subsequent actions ) However, that syntax does not look very pleasant to me due to this extra indentation and the pair of parens. Is this possible at all? Ben.

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Re: [Haskell] return?
by Graham Klyne 30 Apr '04

30 Apr '04

>Is this possible at all? I don't think so, in the form that you suggest. Ultimately, it all comes down to function applications, for which there is no such "bail out". Rather, I think something like this is required: do { ... ; if cond then return 1 else do (the rest) } Here's an example from some real (tested) code: [[ -- Open and read file, returning its handle and content, or Nothing -- WARNING: the handle must not be closed until input is fully evaluated repOpenFile :: String -> RepStateIO (Maybe (Handle,String)) repOpenFile fnam = do { (hnd,hop) <- lift $ if null fnam then return (stdin,True) else do { o <- try (openFile fnam ReadMode) ; case o of Left e -> return (stdin,False) Right h -> return (h,True) } ; hrd <- lift $ hIsReadable hnd ; res <- if hop && hrd then do { ; fc <- lift $ hGetContents hnd ; return $ Just (hnd,fc) } else do { lift $ hClose hnd ; repError ("Cannot read file: "++fnam) 3 ; return Nothing } ; return res } ]] #g -- >Hi, >While writing monad programs, I sometimes want to do a return as it is in >imperative program. i.e., >do{return 1; return 2} is same as return 1 > >This seems useful to me when I need to do something like >do > mwhen cond $ return 1 > ...... -- subsequent actions > > >I know I can do >if cond then return 1 else ( > ...--subsequent actions > ) > > > However, that syntax does not look very pleasant to me due to this extra >indentation and the pair of parens. > > >Is this possible at all? > >Ben. > >_______________________________________________ >Haskell mailing list >Haskell(a)haskell.org >http://www.haskell.org/mailman/listinfo/haskell ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact

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how to print the Report in CM fonts?
by Boyko Bantchev 30 Apr '04

30 Apr '04

Hello all, The Haskell98 Report, in its printed form, uses Times and Courier fonts. I would like to have the Report printed in the TeX-standard cm family of fonts (including the tt font which I like much more than Courier as a `computer font'). Some time ago, I tried to do this from the sources in the CVS repository but failed. Could someone please explain how to achieve this, i.e. what changes should be applied to the files before tex-ing? And what is the set of files needed for a current version? Thank you. Best regards, Boyko Bantchev ----------------------------- КРАДЕЦ НА ЖИВОТИ Психологически трилър, в който Анджелина Джоли е ФБР агентката в преследване на престъпник-маниак http://movies.mail.bg/takinglives/

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