June 2005 - Haskell - Haskell.org

haddock
by Christian Maeder 22 Jun '05

22 Jun '05

Hi, haddock generates html-Files named after the module. Since hierarchical modules contain dots, such files are seen to have multiple extensions (regardless of case) by our apache web server. http://httpd.apache.org/docs-2.0/mod/mod_mime.html#multipleext Unfortunately "map" is the extension for our imap handler. Therefore accessing the file Data.Map.html fails: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… As far as I can see only Data.Map causes the problem, but a clean solution would be to avoid multiple extensions for html-files generated by haddock! Is there a chance that haddock can be changed that way? (Replacing the dot by some other character, maybe "-", in html file names only?) Has only our web server a problem with Data.Map.html? Cheers Christian

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FACS'05: Second Call for Papers
by Luis Barbosa 22 Jun '05

22 Jun '05

[apologies for cross-posting] --------------------------------------------- SECOND CALL FOR PAPERS FACS'05 II International Workshop on Formal Aspects of Component Software Macao October 24-25, 2005 www.iist.unu.edu/facs05/ --------------------------------------------- IMPORTANT DATES: Submission: Jul 15, 2005 Notification: Sep 15, 2005 Final Version: Sep 30, 2005 Workshop: Oct 24-25, 2005 INVITED SPEAKERS: * Farhad Arbab (CWI, LIACS, Leiden University and University of Waterloo) * Paolo Ciancarini (Università di Bologna) * Edmund Clarke (Carnegie Mellon University) AIMS AND SCOPE The objective of FACS'2005 is to bring together researchers in the areas of component software and formal methods to promote a deep understanding of this paradigm and its applications. The Workshop will also be interested in defining the common aspects of components and component-based development. It is expected that formal paper presentations be followed by lively debate in a stimulating atmosphere. Possible topics include, but are not limited to: * formal models for software components and component interaction * design and verification methods for component software * component composition and deployment: models, calculi, languages * component testing * specification of extra-functional properties in component software * certification of components and software architectures * component software vs object orientation * components for real-time, safety-critical, secure and/or embedded systems * experience reports and case studies in component software BACKGROUND: Component-based software emerged as a promising paradigm to deal with the ever increasing need for mastering systems' complexity, their evolution and reuse, and driving software engineering into sound production and engineering standards. Soon, however, it became a popular technology long before consensual definitions and principles, let alone formal foundations, have been put forward. Issues like mathematical models for components, their interaction and composition, or rigourous approaches to verification, deployment, testing and certification remain open research questions and challenging opportunities for formal methods. Moreover, new challenges are raised by applications to non conventional areas, such as safety-critical, mobile, and/or embedded systems. FACS'05 is the second in a series of workshops, founded by the International Institute for Software Technology of the United Nations University. The first FACS workshop was held in Pisa, Italy, in September 2003, collocated with FM'03. ORGANIZATION: UNU-IIST (Macao) PROGRAM COMMITTEE: Farhad Arbab (CWI, The Netherlands) Luis Barbosa (PC Chair, Universidade do Minho, Portugal) Marcello Bonsangue (LIACS-Leiden University, The Netherlands) Christiano Braga (Universidade Federal Fluminense, Brazil) Manfred Broy (Technical University of Munich, Germany) Calos Canal (Universidad de Malaga, Spain) João Faria (Universidade do Porto, Portugal) Jose Fiadeiro (University of Leicester, United Kingdom) Susanne Graf (VERIMAG, France) Mathai Joseph (Tata Consultancy Services Limited, India) Atsushi Igarashi (Kyoto University, Japan) Kung-Kiu Lau (The University of Manchester, United Kingdom) Zhiming Liu (PC Chair, UNU-IIST, Macao) Antónia Lopes (University of Lisbon, Portugal) Markus Lumpe (Iowa State University, USA) Tom Maibaum (McMaster University, Canada) Sun Meng (National University of Singapore, Singapore) Ugo Montanari (University of Pisa, Italy) David Naumann (Stevens Institute of Technology, USA) Anders Ravn (Aalborg University, Denmark) Bernhard Schätz (Technical University of Munich, Germany) Carolyn Talcott (SRI International, USA) ORGANISING COMMITTEE: He Jifeng, UNU-IIST, Macao (OC chair) Antonio Cerone, UNU-IIST, Macao Bernhard Aichernig, UNU-IIST, Macao Chan Iok Sam , UNU-IIST, Macao Xiaoshan Li, Univ. Macao RELATED EVENTS: ICTAC'05 will be held in Hanoi, Vietnam, the week before. SUBMISSION AND PUBLICATION: Submissions to the workshop will be judged on the basis of originality, relevance, technical soundness and presentation quality. Papers should be written in English and not exceed 15 pages in ENTCS format. Publication of the workshop proceedings in Electronic Notes in Theoretical Computer Science, Elsevier, is anticipated.

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A MonadPlusT with fair operations and pruning
by oleg＠pobox.com 22 Jun '05

22 Jun '05

On Wed Jan 5 20:17:37 EST 2005, Andrew Bromage wrote on the Haskell-Cafe mailing list: > BTW, if someone would like an "interesting" monad to play with, here is > one that I've been playing with for a while. It's a nondeterminism > monad transformer with negation-as-failure and if-then-else with soft > cut. The appropriate contexts/continuations for an efficient > implementation (using the Hughes/Hinze technique) turn out to be quite > difficult to find. > > The operations that we need to implement are: > > - the Monad operations (return and bind), > - the MonadTrans operation (lift), > - the MonadPlus ones (mzero and mplus), and > - one other operation, which plays the role of logical if-then-else. We have implemented all the above operations, plus "don't care non-determinism" (aka `once') plus fair conjunctions and disjunctions, plus bagOfN. We have two implementations of the enhanced MonadPlus Transformer: one is based on genuine continuations. The other, direct-style realization, relies on the first-class delimited continuation transformer library by Sabry, Dybvig, and Peyton-Jones. The continuation-passing implementation uses two (rather than three) continuations: success, failure -- but no cut continuation. Still, control logical operations are supported. The continuation-passing implementation was indeed difficult to find, although the result is deceptively simple. The code is freely available under the MIT license: http://pobox.com/~oleg/ftp/packages/LogicT.tar.gz Our joint work (with Amr Sabry, Chung-chieh Shan and Daniel P. Friedman) is described in the paper to be presented at ICFP'05: http://pobox.com/~oleg/ftp/papers/LogicT.pdf Since Andrew Bromage wished for that interesting monad, perhaps he has in mind a good example of its use. We are particularly interested in a short example illustrating soft-cut (and, perhaps, `once'). To be sure, the paper has several examples. Since we have a couple of pages left, we would like to describe something more extensive. Alas, all examples we have in mind are either too simple or take too much space to describe. Comments and suggestions are very appreciated.

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OS requirements for "Haskell version of Crystal Space 3D?"
by Benjamin L. Russell 22 Jun '05

22 Jun '05

My apologies, but I forgot to mention my OS requirements for the potential Haskell version of Crystal Space 3D that I'm looking for in my previous post: * Mac OS X 10.2.8 Jaguar (or higher if necessary--I can upgrade) Also, I forgot to mention the URL for the example of PlaneShift (the fantasy MMORPG written using Crystal Space 3D) in my previous inquiry. It is as follows: * http://www.planeshift.it/main_01.html It even runs on Mac OS X 10.2.8, too. If anybody knows of any Haskell tools/libraries useful for writing something similar to PlaneShift using a Haskell version of something similar to Crystal Space 3D on Mac OS X 10.2.8 or higher, I'd greatly appreciate any information. Thanks again, Benjamin L. Russell

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Re: [Haskell] Bignums in Haskell
by robert dockins 21 Jun '05

21 Jun '05

> Thank you for the prompt response. Do you have any insight as to why > the GMP library is used instead of another library for arbitrary > precision? Also, I understand that Haskell does not specify an > implementation for bignums, but why would the developers of GHC not > implement bignums directly instead of using an outside library? Unfortunately, I don't have the answers to those questions; I'm not really a GHC hacker. I would speculate however that the reasons are largely practical in nature: GMP already exists, is pretty dang fast, and is fairly portable. Robert Dockins

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Haskell XML RPC
by Johannes Waldmann 21 Jun '05

21 Jun '05

Dear all, I am looking at the Haskell XML RPC library http://www.haskell.org/haxr/ First of all, this is a very nice thing to have, and installation is really easy, using Cabal and the packaged source archives. Some questions though: *) Of course I want to dervie XmlRpcType instances automatically. The examples suggest $(asXmlRpcStruct (reifyDecl Person)) but I cannot get this to compile (with ghc-6.4). It seems reifyDecl is gone, and reify has different type. I worked out this: helper name = asXmlRpcStruct ( ( reify name ) >>= ( \ (TyConI dec) -> return dec )) $(helper ''Person) Does xmlrpc.cabal should contain a build-dependency on template-haskell? (Otherwise I get linker errors.) *) what is the recommended representation that should be created for data T = A { .. } | B { .. } | ... i. e. discriminated unions? Certainly some solution can be coded, but ... *) what about the "Java side of things" - perhaps I want (need) to interface to a Java Client. If it's Haskell-to-Haskell, then both server and client of course can derive their XmlRpcType instances from identical data declaraions and everything is fine. For intergration with a different language, what do you recommend: Start from a Haskell data declaration, and derive a Java representation, directly or indirectly? Or start from some language independent data declaration, as it happens (I assume) for JAXB? Best regards, -- -- Johannes Waldmann -- Tel/Fax (0341) 3076 6479/80 -- ---- http://www.imn.htwk-leipzig.de/~waldmann/ -------

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Re: [Haskell] translation of "kind"
by Wolfgang Jeltsch 21 Jun '05

21 Jun '05

Am Montag, 20. Juni 2005 11:46 schrieben Sie: > Wolfgang Jeltsch wrote: > > can anybody tell me what the German translation of the word "kind" as > > used in type theory and especially in Haskell is? > > Even Peter Thiemann in "Grundlagen der funktionalen Programmierung" > (1994) did not translate "Kind", This is very bad IMO because of the existence of the German word "Kind" which you also mention below which means child. > although he used "geschönfinkelt" for "curry" (honoring logicians > Schönfinkel and Curry) This is crazy! Someone who doesn't know Schönfinkel (as I did so far) may think that "schönfinkeln" (which would be the infinitive) is a combination of "schön" (nice) and a previously unknown word "finkeln" which is extremely similar to... Hmm, Germans will know which word I think of. :-) :-) > I'ld prefer "der Kind" (and avoid situtations that allowed confusion > with "das Kind") > > Cheers Christian Best wishes, Wolfgang

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Bignums in Haskell
by Marco Morazan 20 Jun '05

20 Jun '05

Dear All, I am searching for documents/web pages that describe how bignums (integers of arbitrary size) are implemented in Haskell. In particular, I am interested in how bignums are represented, the algorithms used for bignum arithmetic, base conversion algorithms, and performance studies. Any pointers you can provide will be greatly appreciated. Best wishes, Marco

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FLoC 2006: Call For Workshop Proposals
by Kreutzer + Schweikardt 20 Jun '05

20 Jun '05

FLoC'06: The 2006 Federated Logic Conference Call For Workshop Proposals The fourth Federated Logic Conference (FLoC'06), will be held in Seattle, Wash., in August 2006, at the Seattle Sheraton. The following six conferences will participate in FLoC: - Conference on Computer-Aided Verification (CAV). - International Conference on Logic Programming (ICLP). - International Joint Conference on Automated Deduction (IJCAR). - IEEE Symposium on Logic in Computer Science (LICS). - Conference on Rewriting Techniques and Applications (RTA). - International Conference on Theory and Applications of Satisfiability Testing (SAT). For more information see http://research.microsoft.com/floc06/. The organizers have made arrangements to facilitate the running of pre-, post-, and mid-FLoC workshops. Each workshop will have its own registration. It is not necessary to register for FLoC in order to attend workshops. Meeting rooms and accommodations have been reserved at the Seattle Sheraton. - Pre-FLoC workshops: Thurs. August 10 - Fri. August 11, 2006. - Mid-FLoC workshops: Tues. August 15 - Wed. August 16, 2006. - Post-FLoC workshops: Mon. August 21 - Tues. August 22, 2006. Researchers and practitioners are invited to submit proposals for workshops on topics relating logic, broadly understood, applied to computer science. Each workshop proposal must indicate one sponsoring conference among the participating conferences. (It is suggested that prospective workshop organizers contact the conference program chair before submitting a proposal.) Workshops will have to be financially self-supporting, unless the sponsoring conference accepts financial responsibility. The FLoC Organizing Committee will determine the final list of accepted workshops based on the recommendations from the sponsoring conferences and subject to the availability of space and facilities. Proposals should consist of two parts. First, a short scientific justification of the proposed topic, its significance, and the particular benefits of a workshop. A second, organizational, part should include: - contact information about organizers - proposed format and agenda - procedures for selecting papers and participants - duration (which may vary from one day to three days) and preferred period. - proposed sponsoring conference Additional organizational plans may include names of potential invited speakers, proposed demo sessions and tutorials, plans for proceedings or other publications, etc. Proposals are due by July 31, 2005. Organizers will be notified by August 31, 2005. Proposals should be submitted either electronically, and should be addressed to the Program Chair of the sponsoring conference as well as to Gopal Gupta (Workshop Chair) Department of Computer Science University of Texas at Dallas Richardson, TX 75080 Email: gupta(a)utdallas.edu Phone: +1 972 883 4107 Fax: +1 972 883 2399

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translation of "kind"
by Wolfgang Jeltsch 20 Jun '05

20 Jun '05

Hello, can anybody tell me what the German translation of the word "kind" as used in type theory and especially in Haskell is? Best wishes, Wolfgang

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