November 2005 - Haskell

RE: [Haskell] [ANNOUNCE] yhc - York Haskell Compiler
by Simon Marlow 16 Nov '05

16 Nov '05

On 15 November 2005 10:37, Lennart Augustsson wrote: > Simon Peyton-Jones wrote: >>> I am aware of some experiments with alternative back-ends for ghc, >>> but I don't know of any work on a ghc back-end generating portable >>> bytecode. A few years ago some work was done towards a ghc-hugs >>> fusion, but in the end hugs remained separate and the ghc people >>> developed ghci. Perhaps ghc and/or hugs developers can comment >>> further? >> >> GHCi does indeed generate byte code, but we have never gotten around >> to trying to dump it into files and reload it. That might be an >> interesting project -- but it only gives a constant performance >> factor over loading the source files in the first place, so it's not >> clear that it's a major win. > > The major win with having the byte code in a file is that you could > have a stand alone byte code interpreter (and runtime system). > That would make bootstrapping GHC a much less daunting task. This would be nice, but for a couple of reasons it isn't entirely straightforward to do. - our byte code doesn't include primitives, because we rely on the base package always being compiled. If we were to interpret the base package, then we have to implement 200+ primitives in the byte code. Maybe we could cleverly map them to FFI calls and auto-generate the C implementations, or something. - to get portable byte code, the original Haskell code has to be platform-independent. Lots of Haskell code in GHC and the base package has #ifdefs. There was a thread a few months back on glasgow-haskell-users in which we counted the #ifdefs with a view to improving portability, you might want to look it up. The upshot was that the vast majority of #ifdefs were Windows-vs-Unix, so restricting portability to just Unix would be much easier than complete platform-independence. Cheers, Simon

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Making Haskell more open
by Victor Blomqvist 15 Nov '05

15 Nov '05

"Tomasz Zielonka" <tomasz.zielonka at gmail.com> writes: > On Fri, Nov 11, 2005 at 03:12:40PM +0000, Duncan Coutts wrote: >> I would tend to disagree. I think the combination of the mailing lists, >> a wiki and the IRC channel cover most of our communication needs. > > Personally I prefer to use mailing lists, but they have one disadvantage > - if you don't set up filters to split incoming mail into multiple > folders, you can be flooded with messages. > >> I don't think that yet another variant would help us much. Web boards >> tend to be harder to use than email since it requires a web browser. >> Having too many differnt types of communication channel would reduce the >> readership of any one of them. "...most of our communication needs" Yes, I can agree on that, everyone here are obviosly happy (more or less) with the mailinglists, and also I agree that a forum would not be of any use if it was only me there. :) But I think that especially outside the *nix/academic world, most people like web forums better than mailing lists. Actually, I heard the same arguments when disucssing webforum vs news at my institution, most old *nix-hackers prefered the news, and newer (non *nix-hacker) students liked web forum better. Just recently a forum was opened, but I wasn't active in the news at the time so I don't know what tipped it over. But I definatly think it will be more used than the news system once everything is moved there. My suggestion was aimed outside the haskell community of today, even if I now see that some of the other points in Simons message was more about how to get the users already here contribute more and better. For example, a very large part of the users that answered Johns survey had connections to the academic world (37% Students and 29% Working in a university) and from my experience, those intrested in programming languages are also more used to mailing lists than the rest of the group (at least at my university). But maybe the rest (such Algorithm or Human Interaction students) is not intrested in Haskell anyway, so theres no point with a forum.. > > How about a forum integrated with mailing lists? An integrated forum is not a bad idea. As we all agree, it is not a good idea to split the readers in 2 and I don't think its possible to get you all to switch over at once ;) Or just a link to gmane/google/whatever where its possible to read the mailinglist in a good way from your web browser if such a thing already exists. But as it is now, at least I have trouble browsing the archive compared to forums I visit. /vb

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RE: [Haskell] [ANNOUNCE] yhc - York Haskell Compiler
by Simon Peyton-Jones 15 Nov '05

15 Nov '05

| I am aware of some experiments with alternative back-ends for ghc, but I | don't know of any work on a ghc back-end generating portable bytecode. | A few years ago some work was done towards a ghc-hugs fusion, but in the | end hugs remained separate and the ghc people developed ghci. Perhaps | ghc and/or hugs developers can comment further? GHCi does indeed generate byte code, but we have never gotten around to trying to dump it into files and reload it. That might be an interesting project -- but it only gives a constant performance factor over loading the source files in the first place, so it's not clear that it's a major win. GHC is available now as a Haskell library (just say "import GHC"). The idea is to make it possible for people to import GHC, use it to parse and typecheck the program, and then process the result in whatever way they want. The interface is still evolving, but that evolution will be strongly guided by what people want. It's in the HEAD only at the moment, not any released compiler, but I do encourage interested parties to give it a whirl. | So far as debugging back-ends for ghc are concerned, Robert Ennals and | Simon PJ did a stop-and-look style debugger using speculative evaluation | which perhaps is still distributed? It's still available in Rob's CVS branch, but definitely not supported. The entire speculative evaluation thing was tremendously interesting and provocative, but it was just a bit too complicated to fold into the main GHC head. As Simon mentioned, though, another thing we'd like to see done is to modify GHCi so that it always does cost-centre profiling. That way, every thunk would record who built it, and that would give quite a powerful jumping off point for building a quick-and-dirty debugger. There'd be a perf cost, but the effect would be muffled by the fact that GHCi is an interpreter anyway. Anyone? Simon

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PSI 2006: 2nd CFP
by PSI06 Conference 15 Nov '05

15 Nov '05

************************************************** <our apologies for cross-posting> ************************************************** SECOND CALL FOR PAPERS Sixth International Andrei Ershov Memorial Conference PERSPECTIVES OF SYSTEM INFORMATICS 27-30 June 2006, Novosibirsk, Akademgorodok, Russia http://www.iis.nsk.su/PSI06 [AIMS AND SCOPE] The conference is held to honor the 75th anniversary of academician Andrei Ershov (1931-1988) and his outstanding contributions towards advancing informatics. The first five conferences were held in 1991, 1996, 1999, 2001 and 2003, respectively, and proved to be significant international events. Andrei Ershov was one of the early Russian pioneers in the field of the theory of programming and systems programming, a founder of the Siberian Computer Science School. In 1974 he was nominated as a Distinguished Fellow of the British Computer Society. In 1981 he received the Silver Core Award for services rendered to IFIP. Andrei Ershov's brilliant speeches were always in the focus of public attention. Especially notable was his lecture on "Aesthetic and human factor in programming" presented at the AFIPS Spring Joint Computer Conference in 1972. Andrei Ershov was not only an extremely gifted scientist, teacher and fighter for his ideas, but also a bright and many-sided personality. He wrote poetry, translated the works of R. Kipling and other English poets, and enjoyed playing guitar and singing. Everyone who had the pleasure of knowing Andrei Ershov and working with him will always remember his great vision, eminent achievements, and generous friendship. The aim of the conference is to provide a forum for the presentation and in-depth discussion of advanced research directions in computer science. For a developing science, it is important to work out consolidating ideas, concepts and models. Movement in this direction is another aim of the conference. Improvement of the contacts and exchange of ideas between researchers from the East and West are further goals. [CONFERENCE CHAIR] Alexander Marchuk A. P. Ershov Institute of Informatics Systems Novosibirsk, Russia [STEERING COMMITTEE] Dines Bjorner Institute of Informatics and Mathematical Modelling Denmark Manfred Broy Institut fur Informatik Technische Universitat Munchen Germany Alexandre Zamulin A. P. Ershov Institute of Informatics Systems Novosibirsk, Russia [PROGRAM COMMITTEE CO-CHAIRS] Irina Virbitskaite A. P. Ershov Institute of Informatics Systems Novosibirsk, Russia Andrey Voronkov Microsoft Research Redmond, USA [CONFERENCE SECRETARY] Natalia Cheremnykh A. P. Ershov Institute of Informatics Systems 6, Acad. Lavrentjev pr. 630090 Novosibirsk, Russia tel.: +7-383-3307352 fax: +7-383-3323494 e-mail: psi06(a)iis.nsk.su [CONFERENCE TOPICS] Conference topics include: 1. Foundations of Program and System Development and Analysis - specification, validation, and verification techniques, - program analysis, transformation and synthesis, - semantics, logic and formal models of programs, - partial evaluation, mixed computation, abstract interpretation, compiler construction, - theorem proving and model checking, - concurrency theory, - modeling and analysis of real-time and hybrid systems, - computer models and algorithms for bioinformatics. 2. Programming Methodology and Software Engineering - object-oriented, aspect-oriented, component-based and generic programming, - programming by contract, - program and system construction for parallel and distributed computing, - constraint programming, - multi-agent technology, - system re-engineering and reuse, - integrated programming environments, - software architectures, - software development and testing, - model-driven system/software development, - agile software development, - tools for software engineering, - program understanding and visualization. 3. Information Technologies - data models, - database and information systems, - knowledge-based systems and knowledge engineering, - ontologies and semantic Web, - digital libraries, collections and archives, Web publishing, - peer-to-peer data management. In addition to papers in the above list of topics, papers both bridging the gap between different directions and promoting mutual understanding of researchers are welcome. Papers defining the general prospects in Computer Science are also encouraged. [PROGRAM COMMITTEE MEMBERS] Scott W. Ambler, Ambysoft Inc., Toronto, Canada Egidio Astesiano, Univ. Genova, Italy Janis Barzdins, Univ. Latvia, Riga, Latvia Frederic Benhamou, Univ. Nantes, France Stefan Brass, Univ. Halle, Germany Ed Brinksma, Univ. Twente, The Netherlands Kim Bruce, Pomona College, California, USA Mikhail Bulyonkov, IIS SB RAS, Novosibirsk, Russia Albertas Caplinskas, IMI, Vilnius, Lithuania Sung-Deok Cha, KAIST, Taejon, South Korea Gabriel Ciobanu, Inst. Comp. Sc. RA, Iasi, Romania Paul C. Clements, Carnegie-Mellon Univ., USA Miklos Csuroes, Univ. Montreal, Canada Serge Demeyer, Univ. of Antwerp, Belgium Alexander Dikovsky, Univ. Nantes, France Javier Esparza, Univ. Stuttgart, Germany Jean Claude Fernandez, Univ. J. Fourier, Grenoble, France Chris George, UNU/ IIST, Macau Ivan Golosov, Intel, Novosibirsk, Russia Jan Friso Groote, Eindhoven Univ. of Technology, The Netherlands Alan Hartman, IBM Haifa Research Lab., Israel Victor Ivannikov, IPS RAS, Moscow, Russia Victor Kasyanov, IIS SB RAS, Novosibirsk, Russia Joost-Pieter Katoen, RWTH Aachen Univ., Germany Alexander Kleschev, IACP RAS, Vladivostok, Russia Nikolay Kolchanov, ICiG, Novosibirsk,, Russia Gregory Kucherov, INRIA/LORIA, Nancy, France Johan Lilius, Abo Akademi Iniv. Turku, Finland Dominique Mery, Univ. Henri Poincare, Nancy, France Torben Mogensen, Univ. Copenhagen, Denmark Bernhard Moeller, Univ. Augsburg, Germany Hanspeter Moessenboeck, JK Univ. Linz, Austria Peter Mosses, Univ. Wales, Swansea, UK Ron Morrison, St Andrews Univ., UK Peter Mueller, ETH Zurich, Switzerland Fedor Murzin, IIS SB RAS, Novosibirsk, Russia Valery Nepomniaschy, IIS SB RAS, Russia Nikolaj Nikitchenko, Nat. Univ. Kiev, Ukraine Jose R. Parama, Univ. A Coruna, Spain Francesco Parisi-Presicce, GM Univ., Virginia, USA Wojciech Penczek, Inst. Comp. Sci., Warsaw, Poland Jaan Penjam, Tallinn Tech. Univ., Estonia Peter Pepper, Tech. Univ. Berlin, Germany Alexander Petrenko, IPS RAS, Moscow, Russia Jaroslav Pokorny, Charles U., Prague, Czech Republic Wolfgang Reisig, Tech. Univ. Berlin, Germany Viktor Sabelfeld, Univ. Karlsruhe, Germany Timos Sellis, Nation. Tech. Univ. Athens, Greece Alexander Semenov, Intel, Novosibirsk, Russia Klaus-Dieter Schewe, Massey Univ, PN, New Zealand David Schmidt, Kansas State Univ., Manhattan, USA Sibylle Schupp, Chalmers Univ. Tech., Sweden Nikolay Shilov, IIS SB RAS, Novosibirsk, Russia Alexander Tomilin, IPS RAS, Moscow, Russia Enn Tyugu, Inst. Cybernetics, Tallinn, Estonia Alexander L. Wolf, Univ. Colorado at Boulder, USA Tatyana Yakhno, Dokuz Eylul Univ., Izmir, Turkey Wang Yi, Uppsala Univ., Sweden [INVITED SPEAKERS] 1. Amir Pnueli (Weizmann Inst. Science, Rehovot, Israel) 2. Eike Best (Univ. Oldenburg, Germany) 3. Robert Harper (Carnegie Mellon Univ., Pittsburgh, USA) 4. Rustan Leino (Microsoft Research, Redmond, USA) 5. Alexander Letichevsky (Inst. Cybernetics, Kiev, Ukraine) 6. Gordon Plotkin (Univ. Edinburgh, UK (unconfirmed)) [LOCATION] The conference will be held in Akademgorodok (Academy town), 30 km South from Novosibirsk, the largest city of Siberia. Akademgorodok is located in a picturesque place near the Ob lake. It is surrounded with birch and pine forests and pleasant not only for work but for recreation as well. Silence, beautiful landscape, and pure air are the factors promoting scientific activity and creativity. [SUBMISSIONS] Submissions for extended abstracts must: - Contain original contributions that have not been published or submitted to other conferences/journals in parallel with this conference. - Clearly state the problem being addressed, the goal of the work, the results achieved, and the relation to other work. - Be in PS or PDF and formatted according to Springer LNCS Information for Authors: http://www.springeronline.com - Have a length that does not exceed 10 pages for a regular talk and 5 pages for a short talk. - Be in English and in a form that can be immediately included in the proceedings without major revision. - Be sent electronically (as a PostScript or PDF file) using website http://www.easychair.org/PSI2006/submit/ not later than January 23, 2006 [CONFERENCE PROCEEDINGS] A book of extended abstracts of invited and accepted talks will be available at the conference. The full versions of the papers presented at the conference (roughly, 14 pages long for a regular talk and 7 pages long for a short talk) will be published by Springer-Verlag in the Lecture Notes in Computer Science series after the conference. One can find the proceedings of the previous four conferences in LNCS, Vol. 1181, 1755, 2244 and 2890, respectively. A report on the previous conference can be found in EATCS Bulletin, No 81 (2003) 267-271, and also at the conference site: www.iis.nsk.su/PSI03/ [TRAVELLING] You can fly to Novosibirsk via Moscow by Aeroflot, Transaero or S7. Direct S7 flights will bring you from Frankfurt, Hannover, Tel-Aviv or Beijing to Novosibirsk and back. All participants will be met at the Novosibirsk airport and brought to Akademgorodok by a special transport. [WEATHER] The weather in Novosibirsk at the end of June is normally quite warm and sunny with the temperatures in the range of 25-30 C. Night swimming in the Ob lake is guaranteed. [SATELLITE WORKSHOPS] Additionally the following workshops will be satellite events of PSI06: - Educational Informatics (the workshop page is http://www.iis.nsk.su/psi06/education/index_e.shtml) - Program Understanding which will be held in Altai mountains (the workshop page is http://www.iis.nsk.su/psi06/p_understanding/index_e.shtml) [IMPORTANT DATES] January 23, 2006: submission deadline of extended abstracts April 7, 2006: notification of acceptance June 27-30, 2006: the conference dates September 1, 2006: final papers due

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formal verification for functional programming languages
by Wolfgang Jeltsch 14 Nov '05

14 Nov '05

Hello, where can I find information about formal verification techniques and tools for functional programming languages? Both introductionary texts and current research papers etc. are welcome. Best wishes, Wolfgang

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[ANNOUNCE] yhc - York Haskell Compiler
by Thomas Davie 14 Nov '05

14 Nov '05

Announcing the York Haskell Compiler - a Haskell 98 compiler with roots in nhc98. It's not totally finished, but is getting there quickly, and could well be of interest to Haskell developers. Webpage: http://www-users.cs.york.ac.uk/~ndm/yhc/ Project Blog: http://yhc06.blogspot.com/ Project Wiki: http://haskell.org/hawiki/Yhc Darcs: darcs get http://www.cs.york.ac.uk/fp/darcs/yhc As many of you now know, the York Haskell Compiler project is now getting well and truely off the ground. For those of you that don't know, I'll give you a quick summary. Over the last few months Tom Shackell has rewritten the back end of nhc98, to create the yhc compiler. The new compiler is extremely lightweight, runs fast, and generates code that runs at a speed roughly midway between hugs and ghc. Better than that though, the compiler generates bytecode to be run on a virtual machine, and thus can create portable binaries! The virtual machine is written in C and thus can bootstrap the whole compiler system on just about any platform (it's already known to work on linux, windows and OS X). Several problems that nhc had have been addressed in the rewrite including the hi-mem bug, and making it work on Windows (without cygwin). There is still a lot of work to do though - contributions welcome! Thanks Tom Davie (and the rest of the yhc team)

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Call For Papers - ICLP 2006
by A Serebrenik 14 Nov '05

14 Nov '05

FIRST CALL FOR PAPERS ICLP'06 22nd International Conference on Logic Programming Seattle, Washington, USA, 17-20 August, 2006 http://www.cs.uky.edu/iclp06/ Part of Fourth Federated Logic Conference, FLoC 2006 http://research.microsoft.com/floc06/ CONFERENCE SCOPE Since the first conference held in Marseilles in 1982, ICLP has been the premier international conference for presenting research in logic programming. Contributions (papers and posters) are sought in all areas of logic programming including but not restricted to: * Theory: Semantic Foundations, Formalisms, Nonmonotonic Reasoning, Knowledge Representation. * Implementation: Compilation, Memory Management, Virtual Machines, Parallelism. * Environments: Program Analysis, Program Transformation, Validation and Verification, Debugging, Profiling. * Language Issues: Concurrency, Objects, Coordination, Mobility, Higher Order, Types, Modes, Programming Techniques. * Alternative Paradigms: Constraint Logic Programming, Abductive Logic Programming, Inductive Logic Programming, Answer-Set Programming. * Applications: Deductive Databases, Data Integration, Software Engineering, Natural Language, Web Tools, Internet Agents, Artificial Intelligence. The three broad categories for submissions are: (1) technical papers, where specific attention will be given to work providing novel integrations of the areas listed above, (2) application papers, where the emphasis will be on their impact on the application domain as opposed to the advancement of the the state-of-the-art of logic programming, and (3) posters, ideal for presenting and discussing current work not yet ready for publication, for PhD thesis summaries and research project overviews. In addition to papers and posters, the technical program will include invited talks, advanced tutorials, several workshops and Doctoral Student Consortium. Details, as they become available will be posted at http://www.cs.uky.edu/iclp06/ PAPERS AND POSTERS Papers and posters must describe original, previously unpublished research, and must not be simultaneously submitted for publication elsewhere. They must be written in English. Technical papers and application papers must not exceed 15 pages in the Springer LNCS format (cf. http://www.springer.de/comp/lncs/index.html) The limit for posters is 2 pages in that format. The primary means of submission will be electronic. More information on the submission procedure will be available at http://www.cs.uky.edu/iclp06/ PUBLICATION The proceedings of the conference will be published by Springer-Verlag in the LNCS series. The proceedings will include the accepted papers and the abstracts of accepted posters. SUPPORT SPONSORING AND AWARDS The conference is sponsored by the Association for Logic Programming. The ALP has funds to assist financially disadvantaged participants. The ALP is planning to sponsor two awards for ICLP'06: for the best technical paper and for the best student paper. IMPORTANT DATES Papers Posters Abstract submission deadline 14 February N/A Submission deadline 21 February 14 March Notification of authors 7 April 14 April Camera-ready copy due 2 May 2 May ICLP'2006 ORGANIZATION General Chair: Manuel Hermenegildo (herme(a)fi.upm.es) Program Co-Chairs: Sandro Etalle (s.etalle(a)utwente.nl) Mirek Truszczynski (mirek(a)cs.uky.edu) Workshop Chair: Christian Schulte (schulte(a)imit.kth.se) Doctoral Student Consortium: Enrico Pontelli (epontell(a)cs.nmsu.edu) Publicity Chair: Alexander Serebrenik (a.serebrenik(a)tue.nl) PROGRAM COMMITTEE Maria Alpuente Krzysztof Apt Annalisa Bossi Veronica Dahl Giorgio Delzanno Pierre Deransart Agostino Dovier Thomas Eiter Sandro Etalle, co-chair John Gallagher Michael Gelfond Hai-Feng Guo Manuel Hermenegildo Tomi Janhunen Fangzhen Lin Michael Maher Victor Marek Eric Monfroy Stephen Muggleton Brigitte Pientka Maurizio Proietti I.V. Ramakrishnan Peter van Roy Harald Sondergaard Mirek Truszczynski, co-chair German Vidal Andrei Voronkov Roland Yap CONFERENCE VENUE The conference will be a part of the fourth Federated Logic Conference (FLoC'06) to be held August 10-21, 2006, in Seattle, Washington (http://research.microsoft.com/floc06/) Other participating conferences are: Computer-Aided Verification (CAV), Rewriting Techniques and Applications (RTA), Logic in Computer Science (LICS), Theory and Applications of Satisfiability Testing (SAT), and Int'l Joint Conference on Automated Reasoning (IJCAR). Plenary events involving multiple conferences are planned.

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Evaluation in hugs X ghc(i)
by Dusan Kolar 14 Nov '05

14 Nov '05

Hello all, My question may appear to be absolutely FAQ, in the end. Sorry for that if it's true. I've run some algorithms using ghc, ghci and hugs during the weekend. Some of them required wast amount of memory. From the results obtained, it seems like hugs is more eager on memory consumption or it evaluates with a different strategy than the ghc(i) does. Is there any difference? If yes, where can I read it? If not, is memory consumption of hugs given "just" by the fact it uses spineless tagless G-machine and not a code compiled to the binary of the target? If it is the point, how can I change compilation to allocate as much memory as I have effectively usable on my machine - I will supply the number on cmnd line, but from certain limit above no effect seems to be made ? Dusan -- Dusan Kolar tel: +420 54 114 1238 UIFS FIT VUT Brno fax: +420 54 114 1270 Bozetechova 2 e-mail: kolar(a)fit.vutbr.cz Brno 612 66 Czech Republic --

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Re: [Haskell] Making Haskell more open
by Andrea Sassanelli 14 Nov '05

14 Nov '05

Sorry to intrude myslf like this in the conversation. First of all, let me present myself: My name is Andrea Sassanelli, and I'm Italian. I have just started studying Haskell at the UoEdinburgh this year, and immediatelly fell in love with it. On a sidenote, the wikipedia does rely on moderators who review the changes, but common users are able to undo changes as well, and can therefore bring a maliciously messed up page back to it's origiinal state. Basically MediaWiki/WikiPedia rely on the assumption that there are more good folk than bad folk, and this (IMHO) should be even more true in the case of a relatvelly "medium/small-scale" thing like the Haskell Documentation (small compared to a whole encyclopedia, i mean). Open documentation like this is definitelly a good idea to make the language docs not only more accessible, but also more user-friendly, and would surely give a positive image to the community as a whole. I unfortunatelly am not suted (?yet?) to work on any usefull documentation, as I am a novice, but I think the system would work. Andrea Sassanelli

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Haskell based web server?
by Gregory Woodhouse 13 Nov '05

13 Nov '05

I've been reading the article "Tackling the Awkward Squad" by Simon Peyton Jones (and find it very readable and useful, BTW). I wonder if the HTTP/1.1 server referred to in this article is available on the web. If not, where else can I look for examples of TCP/IP based server applications written in Haskell? I ask because I'm very much a Haskell newbie, but have spent several years developing interfaces for medical information systems based on HL7, and am interested (among other things) in the possibilities of using Haskell to develop safety critical systems. === Gregory Woodhouse gregory.woodhouse(a)sbcglobal.net "Einstein was a giant. He had his head in the clouds and his feet on the ground." --Richard P. Feynman

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