- Haskell - Haskell.org

Re: arrows
by Ashley Yakeley 12 Dec '02

12 Dec '02

At 2002-12-06 15:57, Wolfgang Jeltsch wrote: >I cannot see how this relatively simple representation can be used to >describe >certain parsers. If I would use Identity for baseMonad, I would have a type >for simple parsers. MyParser Identity would essentially be token -> output. You can't use Identity for baseMonad. You would need to use something that managed a stream. The idea is that your source is something of type "baseMonad token", and by repeatedly calling source, you pull off individual tokens. >Which function of this type should be used to describe, for instance, > (a) a parser reading no tokens and returning () MkMyParser (\_ -> return ()) > (b) a parser reading two tokens and returning the pair of these tokens? MkMyParser (\source -> do { a <- source; b <- source; return (a,b); }) You can then use parsers of type MyParser with all kinds of sources, such as those that read items from a file, or a state transformer that pops items off a list, or whatever. -- Ashley Yakeley, Seattle WA

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GPCE 03
by Akos Ledeczi 12 Dec '02

12 Dec '02

I thought you might be interested in this conference. I apologize if you receive multiple copies of this anouncement. Best regards, Akos Ledeczi Publicity Chair GPCE 2003: Call for Contributions 2nd International Conference on Generative Programming and Component Engineering September 22-25, 2003 Erfurt, Germany Part of NetObjectDays'03 http://gpce.org In Cooperation with ACM SIGPLAN and SIGSOFT Generative and component approaches have the potential to revolutionize software development in a similar way as automation and components revolutionized manufacturing. Generative Programming (developing programs that synthesize other programs), Component Engineering (raising the level of modularization and analysis in application design), and Domain-Specific Languages (elevating program specifications to compact domain-specific notations that are easier to write and maintain) are key technologies for automating program development. GPCE arose as a joint conference, merging the prior conference on Generative and Component-Based Software Engineering (GCSE) and the Workshop on Semantics, Applications, and Implementation of Program Generation (SAIG). The goal of GPCE is to provide a meeting place for researchers and practitioners interested in cutting edge approaches to software development. Thanks to the co-location with NetObjectDays, one of the largest main-stream software development conferences in Germany, the GPCE'03 presentations are expected to have a high attendance by industry practitioners, in addition to regular conference attendees. Important Dates: --------------- Technical paper submission: Apr 6, 2003 Workshop proposal submission: Apr 6, 2003 Practitioner report submission: May 18, 2003 Tutorials proposal submission: May 18, 2003 Demonstration proposal submission: May 18, 2003 Poster proposal submission: Jul 13, 2003 Notification of acceptance for Technical papers: May 25, 2003 Workshop proposals: Apr 20, 2003 Practitioner reports: Jun 1, 2003 Tutorials proposals: Jun 1, 2003 Demonstration proposals: Jun 1, 2003 Poster proposals: Jul 27, 2003 Camera ready copy: Jun 22, 2003 Detailed submission instructions are available at: http://gpce.org Technical Papers ---------------- The GPCE'03 conference invites high quality papers reporting research results and/or experience related to generative programming and component engineering. We seek papers both in software engineering and in programming languages, and especially those that bridge the gap and are accessible to both communities at the same time. The conference solicits submissions related (but not limited) to: * Generative Programming: Reuse, meta-programming, partial evaluation, multi-stage and multi-level languages, * Semantics, type systems, symbolic computation, linking and explicit substitution, in-lining and macros, templates, program transformation * Runtime code generation, compilation, active libraries, synthesis from specifications, development methods, generation of non-code artifacts, formal methods, reflection. * Product Lines and architectures * Industrial Applications * Component-Based Software Engineering: Reuse, distributed platforms, distributed systems, evolution, analysis and design patterns, development methods, formal methods * Integration of Generative and Component-Based Approaches * Domain Engineering, analysis, and languages, domain-specific notations * Separation of Concerns: Aspect-Oriented Programming, Intentional Programming, and Multi-Dimensional Separation of Concerns * Model-driven architecture Reports on applications of these techniques to real-world problems are especially encouraged, as are submissions that relate ideas and concepts from several of these topics, or bridge the gap between theory and practice. Research papers should describe work that advances the current state of the art. The program committee will evaluate each contributed paper based on its relevance, significance, clarity and originality. The program committee is happy to advise on the appropriateness of a particular subject. Authors are invited to submit papers of at most 12 pages in ACM proceedings format, in PDF form, by April 6, 2003. This deadline is firm. Simultaneous submission to other venues and submission of previously published material are not allowed. Electronic submission will be required, except by special arrangement with the program chairs. Practitioner Reports -------------------- GPCE '03 will feature a track geared towards industry and practice, where practitioners will present their experience and insight in applying generative and component-based technologies. We solicit reports in two categories: * Project reports describing successfully completed projects that applied technologies within the scope of GPCE'03. * Experience reports focussing on a particular aspect of technology usage and practice, or describe broad project experiences. The report submissions will be reviewed separately from technical paper submissions by a practitioner report committee. Workshops --------- GPCE workshops provide intensive collaborative environment to explore a specific sub-area of generative and component technology in depth, cover areas that cross the borders of several sub-areas, or focus on the applications and deployment of generative and/or component technology in a particular application domain. Workshops will take place on the first day of the conference. Young Researchers Workshop -------------------------- As in the past year, the conference will feature a one day doctoral symposium, where a panel of experts will review and discuss submissions from graduate students and other young researchers. For more details about submissions, please contact the YRW Chairs Isabel John (john(a)iese.fhg.de) and Matthias Clauss (Matthias.Clauss(a)gmx.de) Tutorials --------- We invite proposals for high-quality tutorials in all areas of generative programming and component-based development. Tutorial levels may be introductory, intermediate, or advanced. Introductory tutorials should seek to educate the participants about the basic concepts and techniques of generative and component-based development. More advanced tutorials may cover advanced development techniques and/or underlying theory. Demonstrations -------------- We invite proposals for demonstrating novel tools, systems, or techniques from both commercial and academic communities. Demonstrations should focus on technical aspects. Demonstrations showing how a specific technology is used in real world scenarios are particularly welcome. Both work in progress or proven techniques are appropriate. Product marketing is inappropriate in this forum. Posters ------- Posters at GPCE provide an excellent forum for authors to present their work in an informal and interactive setting. Posters are ideal for presenting speculative, late-breaking results or for giving an introduction to interesting, innovative work. Exhibits -------- The GPCE '03 exhibits will be held together with the exhibits of NetObjectDays'03, one of the largest main-stream software development conferences in Germany. Therefore, this will be an excellent forum to reach potential customers with news and demonstrations of your latest products, publications or services. If you would like your company to participate as an exhibitor at the conference, please refer to the web site for submission instructions. GPCE'03 Best Contribution Awards -------------------------------- The GPCE'03 audience will elect the best contributions in the following categories: * Best Paper * Best Practitioner Report * Best Commercial Tool * Best Non-Commercial Tool * Best Industrial Project Organizing Committee -------------------- General Chair: (chair03(a)gpce.org) Krzysztof Czarnecki, DaimlerChrysler Research and Technology, Germany. Program Committee Chairs: (pc03(a)gpce.org) Frank Pfenning, Carnegie Mellon University, USA Yannis Smaragdakis, Georgia Institute of Technology, USA Workshop Chair: (workshops03(a)gpce.org) Kasper Osterbye, IT University of Copenhagen, Denmark Tutorial Chair: (tutorials03(a)gpce.org) Gerd Frick, FZI, Karlsruhe, Germany Demonstration Chair: (demos03(a)gpce.org) Markus Voelter, independent consultant, Germany Poster Chair: (posters03(a)gpce.org) Jorn Bettin, SoftMetaWare, New Zealand Industrial Chair: (industrial03(a)gpce.org) Ulrich W. Eisenecker, University of Applied Sciences Kaiserslautern, Germany Publicity Chair: (publicity03(a)gpce.org) Akos Ledeczi, Vanderbilt University, USA Young Researchers Workshop Chairs Isabel John, Fraunhofer IESE, Germany (john(a)iese.fhg.de ) Matthias Clauss, Solutionline CSS, Germany (Matthias.Clauss(a)gmx.de) Program Committee Members (near-final): ------------------------- Giuseppe Attardi, University of Pisa, Italy Don Batory, University of Texas, USA Ira Baxter, Semantic Designs, USA Ted Biggerstaff, softwaregenerators.com, USA Shigeru Chiba, Tokyo Institute of Technology, Japan Rowan Davies, University of Western Australia, Australia Premkumar Devanbu, University of California, Davis, USA Ulrich W. Eisenecker, University of Applied Sciences Kaiserslautern, Germany Robert Glueck, Waseda University, Japan Trevor Jim, AT&T Labs Research, USA Gregor Kiczales, University of British Columbia, Canada Kai Koskimies, Tampere University of Technology, Finland Julia Lawall, DIKU, University of Copenhagen, Denmark Eugenio Moggi, DISI, University of Genova, Italy Jim Neighbors, Bayfront Technologies, USA Calton Pu, Georgia Tech, USA Olin Shivers, Georgia Tech, USA Clemens Szyperski, Microsoft Research, USA Peter Thiemann, University of Freiburg, Germany Eelco Visser, Utrecht University, The Netherlands

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New PhD Positions in Computing Science, Chalmers University of Technology & Göteborg University
by Reiner Haehnle 11 Dec '02

11 Dec '02

Please pass on to interested students. Apologies for multiple copies. --------------------------------------------------------------------- New PhD Positions (DEADLINE 15 February 2003! See "How to apply" below) Department of Computing Science, Chalmers University of Technology & Göteborg University Gothenburg, Sweden http://www.cs.chalmers.se/Cs/ The Department has about 80 researchers, half being faculty members and half PhD students. Our focus is on programming logic, type theory, functional programming, formal methods, distributed and concurrent systems, security, algorithms, bioinformatics, interaction design, and language technology, but research is not restricted to these topics. For more information, see http://www.cs.chalmers.se/Cs/Research. PhD positions are for 5 years. There is no tuition fee. A PhD position is a regular job with social benefits; the salary amounts currently to about 18000 SEK per month in the first year (the exact amount depends on teaching duties, usually 20% of your time). Knowledge of Swedish is not a prerequisite for application. English is our working language for research. Both Swedish and English are used in undergraduate courses. Half of our researchers and PhD students are native Swedes; the rest come from more than 20 different countries. Applicants must have a very good undergraduate degree in Computing Science or in a related subject with a strong Computing Science component. They must also have a strong, documented interest in doing research. You may even apply if you have not yet completed your degree, but expect to do so by 1 September 2003. You are also invited to apply for our new International Master's Programme in Dependable Computer Systems, which can help you to obtain the necessary qualification, if you do not yet have it (see http://www.cs.chalmers.se/Cs/Education/dcs/) The School especially welcomes female applicants. How to apply ------------ First, immediately register your intention to apply using the electronic application form on the WWW via http://www.md.chalmers.se/Jobs/PhD/phd-03-en.thtml The full application should contain 1 A letter of application, listing specific research interests 2 A curriculum vitae 3 Attested copies of degrees and other certificates 4 Copies of relevant work, for example dissertations or articles, that you have authored or co-authored 5 A description of: a previous teaching experience, documented b previous PhD studies, also in other subjects; state financial support obtained for these, if any c previous work experience 6 Letters of recommendation from your teachers or employers If you have financial support of your own (industry job, grant, etc.), please state this fact clearly. It will increase your chances to be accepted considerably, because you need not compete for the limited number of fully financed positions. The reference number of this job opportunity is 3/2003. Send your full application (paper mail) to Department of Computing Science School of Computer Science and Engineering Chalmers University of Technology 412 96 Gothenburg Sweden to arrive by 15 February 2003. You will know the result of your application by 1 May 2003.

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video4linux
by Martin Huschenbett 11 Dec '02

11 Dec '02

Hi all, does anybody know how to read a single image from a video4linux device under Haskell? Thanks for all help, Martin

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RTA'03: call for papers
by Femke van Raamsdonk 10 Dec '02

10 Dec '02

****************************** * * * RTA'03 CALL FOR PAPERS * * * ****************************** http://www.dsic.upv.es/~rdp03/rta The 14th Int. Conf. on Rewriting Techniques and Applications (RTA'03) will be part of the Federated Conf. on Rewriting, Deduction and Programming (RDP'03). IMPORTANT DATES: Jan 15 2003: Deadline electronic submission of title+short abstract Jan 22 2003: Deadline electronic submission of papers Mar 15 2003: Notification of acceptance of papers Apr 7 2003: Deadline for final versions of accepted papers Jun 9-11 '03: Conference. RTA is the major forum for the presentation of research on all aspects of rewriting. Typical areas of interest include (but are not limited to): * APPLICATIONS: case studies; (rule-based) programming; symbolic and algebraic computation; theorem proving; system synthesis and verification; proof checking. * FOUNDATIONS: matching and unification; narrowing; completion techniques; strategies; constraint solving; explicit substitutions. * FRAMEWORKS: string, term, and graph rewriting; lambda-calculus and higher-order rewriting; proof nets; constrained rewriting/deduction; categorical and infinitary rewriting. * IMPLEMENTATION: compilation techniques; parallel execution; rewriting tools. * SEMANTICS: equational logic; rewriting logic. INVITED TALKS will be given at RTA'03 by: * David McAllester Toyota Technological Institute at Chicago Joint invited speaker with TLCA * Jean-Louis Giavitto Universit� d'Evry, France * Pat Lincoln SRI International BEST PAPER AWARDS: A 1000 Euro award wil be given to the best paper or papers as decided by the PC. The award may also totally or partially go to the best paper with a student as main author, according to the submission letter. RTA'03 PROGRAM COMMITEE: * Harald Ganzinger (Max-Planck-Institut) * Claude Kirchner (Nancy) * Salvador Lucas (Valencia) * Chris Lynch (Clarkson) * Jos� Meseguer (Urbana) * Robert Nieuwenhuis (Barcelona, Chair) * Tobias Nipkow (Munich) * Vincent van Oostrom (Utrecht) * Christine Paulin (Paris-sud) * Frank Pfenning (Carnegie Mellon) * Mario Rodr�guez-Artalejo (Madrid) * Sophie Tison (Lille) * Ashish Tiwari (SRI) * Andrei Voronkov (Manchester) * Hantao Zhang (Iowa) RTA'03 SUBMISSIONS: Submissions must be original and not submitted for publication elsewhere. Submission categories include regular research papers and system descriptions. Also problem sets and submissions decribing interesting applications of rewriting techniques will be very welcome. As usual, accepted papers will appear in the Springer-Verlag Lecture Notes in Computer Science series. See the RDP'03 web page <http://www.dsic.upv.es/~rdp03/> for details. For further questions please contact the program chair: RTA'03 PROGRAM CHAIR: Robert Nieuwenhuis Technical University of Catalonia Jordi Girona 1, E-08034 Barcelona, Spain roberto(a)lsi.upc.es

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help
by Suja 10 Dec '02

10 Dec '02

Hi, I want to know how to execute a haskell program that does not contain a main module. I would also like to know the difference between .lhs and .hs extensions.

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Re: How to force recursion
by Cai john 09 Dec '02

09 Dec '02

Thanks for the help everyone,problem solved. Very stupid of me not to see that tree instead of empty would solve the problem. As for the 'other' errors, I wrote too fast and can't find the edit button. My first post contains the better implementation. John __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com

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How to force recursion
by Cai john 09 Dec '02

09 Dec '02

How do I make this work: insertTree tree (x:xs) n = insertTree (insert tree a n) xs n insert -> common insertion into a tree which returns a tree __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com

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ANNOUNCE: GHC version 5.04.2 released
by Simon Marlow 08 Dec '02

08 Dec '02

============================================================== The (Interactive) Glasgow Haskell Compiler -- version 5.04.2 ============================================================== We are pleased to announce a new patchlevel release of the Glasgow Haskell Compiler (GHC), version 5.04.2. This is a bugfix-only release. For all the changes since 5.02.3, see the release notes: http://www.haskell.org/ghc/docs/latest/users_guide/release-5-04.html How to get it ~~~~~~~~~~~~~ The easy way is to go to the WWW page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in the native package format for various flavours of Linux and BSD, and in InstallShield form for Windows folks. Binary builds for other platforms are available as a .tar.gz which can be installed wherever you want. The source distribution is also available from the same place. Once you have the distribution, please follow the pointers in the README file to find all of the documentation about this release. Background ~~~~~~~~~~ Haskell is a standard lazy functional programming language; the current language version is Haskell 98, agreed in December 1998. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces (C, whatever). GHC is distributed under a BSD-style open source license. A wide variety of Haskell related resources (tutorials, libraries, specifications, documentation, compilers, interpreters, references, contact information, links to research groups) are available from the Haskell home page (see below). On-line GHC-related resources ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Relevant URLs on the World-Wide Web: GHC home page http://www.haskell.org/ghc/ Haskell home page http://www.haskell.org/ comp.lang.functional FAQ http://www.cs.nott.ac.uk/~gmh/faq.html System requirements ~~~~~~~~~~~~~~~~~~~ To compile programs with GHC, you need a machine with 64+MB memory, GCC and perl. This release is known to work on the following platforms: * i386-unknown-{linux,*bsd,mingw32} * sparc-sun-solaris2 * alpha-dec-osf3 * powerpc-apple-darwin (MacOS/X) Ports to the following platforms should be relatively easy (for a wunderhacker), but haven't been tested due to lack of time/hardware: * hppa1.1-hp-hpux{9,10} * i386-unknown-solaris2 * mips-sgi-irix{5,6} * {rs6000,powerpc}-ibm-aix The builder's guide on the web site gives a complete run-down of what ports work; it can be found at http://www.haskell.org/ghc/docs/latest/building/building-guide.html Mailing lists ~~~~~~~~~~~~~ We run mailing lists for GHC users and bug reports; to subscribe, use the web interfaces at http://www.haskell.org/mailman/listinfo/glasgow-haskell-users http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs There are several other haskell and ghc-related mailing lists on www.haskell.org; for the full list, see http://www.haskell.org/mailman/listinfo/ Please report bugs using our SourceForge page at http://sourceforge.net/projects/ghc/ or send them to glasgow-haskell-bugs(a)haskell.org. GHC users hang out on glasgow-haskell-users(a)haskell.org. Bleeding edge CVS users party on cvs-ghc(a)haskell.org.

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Re: arrows
by Ashley Yakeley 06 Dec '02

06 Dec '02

At 2002-06-29 14:43, Wolfgang Jeltsch wrote: >To simplify things a bit, let's take a simpler Parser type which doesn't >use monad state transformers but simple state transformers instead. This >makes the type ParserState simpler. You can think of a parser state as >an infinite list of substate-token pairs now. The tokens denote the >input stream. The substates may be used to encapsulate parser states of >a subordinate parsing process. When a token is read, the corresponding >token-substate pair is discarded. Sounds very complicated. Wouldn't a simple stream transformer work? newtype MyParser baseMonad token output = MkMyParser (baseMonad token -> baseMonad output); > (>>=): sequencing of parsers > return: returning values > fail: generation of always failing parsers > mzero: always failing parser > mplus: parsing using alternative parsers > fmap: applying a function to the result of a parser > (>>>): providing high-level tokens and parsing using these tokens > identity: reading a single token > pure: reading a single token and applying a function to it I think I can do all of those for MyParser. There's a one-token look-ahead variant: newtype MyLookaheadParser m t a = MkMyLookaheadParser (m t -> Maybe t -> m (Maybe t,a)); >(I don't allow >finite lists here to make some things a bit easier an more elegant. You >can easily produce an infinite list from a finite one by applying >something like (++ repeat Nothing) . map Just to the finite list.) Wouldn't it be easier to allow finite token lists and have reading past the last token be the same as mzero? -- Ashley Yakeley, Seattle WA

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