- Haskell - Haskell.org

Handling whitespace with parser combinator parsers
by Herman Graal 22 Nov '01

22 Nov '01

Hi, I'm new to this list so may have missed previous discussions relating to this. Anyway: Is there any good alternatives to having to "sprinkle" whitespace parsers all over a parser implemented with parser combinators? It kind of decreases the readability... ;-) I'm interested in any ideas. Would like a full picture of the different solutions out there? Are people actually doing both lexing and parsing in the same framework? If so, how do you handle whitespace? Best Regards, Herman Graal -- _______________________________________________ Sign-up for your own FREE Personalized E-mail at Mail.com http://www.mail.com/?sr=signup 1 cent a minute calls anywhere in the U.S.! http://www.getpennytalk.com/cgi-bin/adforward.cgi?p_key=RG9853KJ&url=http:/…

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Re: Haskell in the teaching of Maths
by S.J.Thompson 21 Nov '01

21 Nov '01

I am looking for some work in applying functional programming (Specially Haskell) in the teaching of Mathematics. The best place to start is Discrete Mathematics Using a Computer Cordelia Hall & John O'Donnell Springer-Verlag, 2000 ISBN 1-85233-089-9 Simon Thompson

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Haskell in the teaching of Maths
by Miguel Francisco Rocha 21 Nov '01

21 Nov '01

Hello, I am looking for some work in applying functional programming (Specially Haskell) in the teaching of Mathematics. If you are aware of some work in the are please email me at mrocha(a)di.uminho.pt Thanks in advance Miguel Rocha

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annotated haskell
by Hal Daume 20 Nov '01

20 Nov '01

Hi, Is there any development effort to create a Haskell interpreter/compiler/sublanguage that is annotated? For instance, I might be able to say something like: > sortByF f = sortBy (\a b -> compare (f a) (f b)) > > longest [] = error "longest on empty list" > longest (x:xs) = longest' xs (length x) > where longest' [] len = len > longest' (x:xs) len | length x > len = longest' xs (length x) > | otherwise = longest' xs len > > x = sortByF length (a long list of lists) > y = sortByF (longest y - . length) (another long list of lists) obviously x will evaluate properly and will sort it's list by length. y, whose intention is basically to sort by reverse length (yes, I know there are other ways to doing this), will error with "Loop" for obvious reasons. however, intuitively, we all know that the sorting of y doesn't affect the length of the longest element therein. is there any language extension that allows you to make these annotates in the definitions of longest and sortByF that would enable this definition of y to not produce an error? thanks! - hal -- Hal Daume III "Computer science is no more about computers | hdaume(a)isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume

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Joinig the mailing list
by Nuno Silva 20 Nov '01

20 Nov '01

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FLOPS 2002: Second Call For Papers
by Zhenjiang Hu 20 Nov '01

20 Nov '01

We apologize, if you receive this message more than once. ********************************************************************* * * * CALL FOR PAPERS * * * * Sixth International Symposium on Functional and Logic Programming * * (FLOPS 2002) * * (Co-located with ACM SIGPLAN ASIA-PEPM 2002) * * * * University of Aizu, Aizu, Japan * * September 15--17, 2002 * * * * http://www.ipl.t.u-tokyo.ac.jp/FLOPS2002/ * * * ********************************************************************* Background ========== The symposium is a forum for research on all issues concerning functional programming and logic programming. In particular, it wants to stimulate the cross-fertilization as well as integration of the two paradigms. The symposium takes place about every 1.5 years in Japan. Previous FLOPS meetings were held in Fuji Susuno (1995), Shonan Village (1996), Kyoto(1998), Tsukuba (1999), and Tokyo (2001). Topics ====== The Sixth International Symposium on Functional and Logic Programming (FLOPS 2002) solicits original papers in all areas of functional and logic programming, including (but not limited to): * Language issues: language design and constructs, programming methodology, integration of paradigms, interfacing with other languages, type systems, constraints, concurrency and distributed computing * Foundations: semantics, rewrite systems and narrowing, type theory, proof systems * Implementation: compilation techniques, memory management, program analysis and transformation, partial evaluation, parallelism * Applications: case studies, real-world applications, graphical user interfaces, internet applications, database connection, formal methods and model checking Invited Speakers ================ Kokichi Futatsugi (JAIST, Japan) Peter Stuckey (University of Melbourne, Australia) Philip Wadler (Avaya Labs, USA) Submissions =========== Submissions must be unpublished and not submitted for publication elsewhere. Submissions should fall into one of the following two categories: 1. Regular research papers: they should describe new results and will be judged on originality, correctness and significance. 2. System descriptions: they should contain a link to a working system and will be judged on originality, usefulness and design. All submissions must be written in English. Regular research papers can be up to 15 proceedings pages long, system descriptions will be up to 4 pages long. Authors are strongly encouraged to use LaTeX2e and the Springer llncs class file, available at http://www.springer.de/comp/lncs/authors.html The title page should indicate the submission category. Regular research papers should be supported by proofs and/or experimental results. In case of lack of space, this supporting information should be made accessible otherwise (e.g. a link to a web page, or an appendix). Submission is Web-based. In order to submit a paper, authors should fill in the submission form available at http://www.ucm.es/info/flops2002/www/submit.html where more detailed instructions are given. If submission through the Web is not possible, five hard copies may be sent to Mario Rodriguez-Artalejo Universidad Complutense de Madrid Departamento de Sistemas Informaticos y Programacion Edificio Fac. Matematicas Av. Complutense s/n 28040 Madrid, Spain Publication and presentation of accepted contributions ====================================================== The Proceedings of FLOPS 2002 will be published by Springer Verlag in the LNCS series. They will be available at the conference. One author of each accepted contribution is expected to attend the Symposium in order to present it. Presentations of regular research papers will be scheduled for 30 minutes, including questions from the audience. System presentations will be scheduled for 15 minutes. Important Dates =============== Submission Deadline: March 1, 2002 Notification: May 21, 2002 Final Version: June 25, 2002 Symposium: September 15-17, 2002 Program Co-Chairs ================= Zhenjiang Hu University of Tokyo, Japan Mario Rodriguez-Artalejo Universidad Complutense, Madrid, Spain E-Mail: flops2002(a)ucm.es Program Committee ================= Maria Alpuente Technical University of Valencia, Spain Wei-Ngan Chin National University of Singapore, Singapore Pierre Deransart INRIA-Rocquencourt, France Moreno Falaschi University of Udine, Italy Michael Hanus University of Kiel, Germany Zhenjiang Hu (Co-Chair) University of Tokyo, Japan Jan Maluszynski Linkoeping University, Sweden Aart Middeldorp University of Tsukuba, Japan Gopalan Nadathur University of Minnesota, USA Susumu Nishimura Kyoto University, Japan Catuscia Palamidessi The Pennsylvania State University, USA Mario Rodriguez-Artalejo (Co-Chair) Universidad Complutense, Madrid, Spain Francesca Rossi University of Padova, Italy Harald Sondergaard The University of Melbourne, Australia Kazunori Ueda Waseda University, Japan Kwangkeun Yi KAIST, Korea Local Arrangements Chair ======================== Taro Suzuki University of Aizu, Japan Sponsors ======== Sponsored by: Japan Society of Software Science and Technology (JSSST), Special Interest Group on Principles of Programming. In cooperation with: Association for Logic Programming (ALP).

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Haskell interpreter in Haskell?
by senganb＠ia.nsc.com 19 Nov '01

19 Nov '01

I was wondering wheter anyone has written a SMALL haskell interpreter in haskell? (& if so to what level of sophistication?) I would like a compiled Haskell application to provide the user with the option of writing Haskell macros without including ghc into the executable, because ghc would be overkill. Sengan

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FORTE 2002, Call For Papers
by Doron Peled 19 Nov '01

19 Nov '01

Formal Techniques for Networked and Distributed Systems FORMAL METHODS FOR PROTOCOL ENGINEERING AND DISTRIBUTED SYSTEM FORTE 2002 November 11 -- 14 , 2002, Houston, Texas http://www.ece.utexas.edu/FORTE Program Chairs: Doron A. Peled Dept. of Electrical and Comp. Eng. The University of Texas at Austin Austin, TX 78712 Phone: +1-512-232-9371 doron(a)ece.utexas.edu Moshe Y. Vardi Department of Comp.Science Rice University 6100 S. Main St. Houston, TX 77005 Phone: +1-713-348-5977 vardi(a)cs.rice.edu Program Committee: R. Alur, UPenn D. Bjorner, IT University G. v. Bochmann, Univ.of Ottawa T. Bolognesi, IEI, Italy E. Brinksma, Univ of Twente A. Cavalli, INT, France S. T. Chanson, Hong Kong Univ P. Dembinski, IPI-PAN H. Garavel, Inria S. Gnesi, CNR - IEI, Italy G. J. Holzmann, Bell Labs, USA A. Hu, UBC, Canada C. Jard, IRISA - CNRS G. Leduc, Univ. of Liege D. Lee, Bell Labs, China I. Lee, UPenn S. Leue, Univ. of Freiburg L. Logrippo, Univ.of Ottawa S. Mauw, Eindhoven K. McMillan, Cadence M. Morley, Verisity A. Muscholl, Paris 7 E. Najm, ENST, France A. Petrenko, CRIM, Canada S. Smolka, Stony Brook R. Tenney, Univ.of Massachusetts K. Turner, Univ.of Stirling B. Roscoe, Univ.of Oxford S. T. Vuong, Univ.of BC M. Yannakakis, Avaya Labs Steering Committee: G. v. Bochmann, Univ.of Ottawa E. Brinksma, Univ.of Twente S. Budkowski, INT, France G. Leduc, Univ.of Liege E. Najm, ENST, France R. Tenney, Univ.of Massachusetts K. Turner, Univ.of Stirling The IFIP TC6 WG 6.1 Joint International Conference on Formal Techniques for Networked and Distributed Systems (FORTE) is focused on formal methods for communication protocols. FORTE is the new name of the joint FORTE/PSTV meeting, which has combined FORTE and PSTV into a single joint meeting since 1997. The conference will include invited talks and tutorials by Edmund M.Clarke, David Harel, Dave Johnson, Dan Wallach and Elaine J. Weyuker. The conference is a forum for presentation and discussion of the state of the art in theory, application, tools and industrialization of Formal Description Techniques (FDT's). Research papers and industrial usage reports are solicited, particularly in the following areas: >FDT-based system and protocol engineering. >Semantical foundations. >Extensions of FDT's. >Formal approaches to concurrent/distributed Object-Oriented systems. >Real-time and probability aspects. >Performance modeling and analysis. >Quality of service modeling and analysis. >Verification and validation. >Relations between informal and formal specification. >FDT based protocol implementation. >Software tools and support environments. >FDT application to distributed systems, high speed internet protocols, multimedia and multicast protocols and services. >FDT application to wireless and mobile communication, intelligent networks, network management, network security and voice services. >Protocol testing, including conformance testing, interoperability testing, and performance testing. >Test generation, selection and coverage. >Practical experience and case studies. >Corporate strategic and financial consequences of using formal methods. Paper submission: Submission instruction will be available at the conference web site. Submissions should be received by April 20, 2002. The deadline is firm; late submissions and papers departing from the submission guidelines will not be considered. Authors will be notified of acceptance or rejection by June 30, 2002. Accepted papers will be published by Springer Verlag in the Lecture Notes in Computer Science series, and are due by August 12, 2002. The first page of the extended abstract and the cover letter should include the title of the paper, names and affiliations of authors, a brief synopsis (at most 10 lines), keywords, and contact author's name, address, phone number, fax number, and email address. Full original research papers and industrial usage reports should be up to 16 pages, including abstract, names and affiliations of all authors, and a list of keywords facilitating the assignment of papers to referees. For industrial usage reports, short papers up to 8 pages are also welcome. The submission must be in English and provide sufficient detail to allow the program committee to assess the merits of the paper. It should begin with a succinct statement of the issues, a summary of the main results, and a brief explanation of their significance and relevance to the conference, all phrased for the non-specialist. References and comparisons with related work should be included. Technical development directed to the specialist should follow. Submissions departing significantly from these guidelines risk rejection. The results must be unpublished and not submitted for publication elsewhere, including the proceedings of other symposia or workshops.

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seq / strictness and laziness
by Amanda Clare 19 Nov '01

19 Nov '01

I have some code which is being unnecessarily lazy (and occupying too much heap space). The code should read and process several files one by one. What's happening is that all files get read in but the processing is delayed by laziness, and the files are being retained. It looks something like this (after simplification): main = do result <- foldM countAFile initialcounts fileNameList prettyprint result countAFile oldcounts filename = do compiledFile <- readAndCompile filename let newcounts = countAssociations compiledFile oldcounts return newcounts I would love to have used CPS, but this seems to force me to lift a huge amount of code into both the IO monad and the CPS, as countAssociations just calls another function, which calls another, and so on. If I change countAFile to use a redundant test to force evaluation of newcounts: countAFile oldcounts filename = do compiledFile <- readAndCompile filename let newcounts = countAssociations compiledFile oldcounts if newcounts == newcounts then return newcounts else error "suitable error message" then the program runs beautifully (if a little slowly), occupying a constant amount of heap. If instead I use a strict data type to store my counts, or use seq, then I get no improvement, and it's just as if I hadn't used them. I understand why a strict data type won't help me, as it's the function calls that are lazy. But what about $! and seq? countAFile oldcounts filename = do compiledFile <- readAndCompile filename let newcounts = countAssociations compiledFile oldcounts return $! newcounts Does anyone understand why $! (or equivalently "seq") have no effect here? Is there a better way to do this? Amanda -- Amanda Clare http://users.aber.ac.uk/ajc99/ Tel: +44 (0)1970 621922 Fax: +44 (0)1970 622455 Dept. of Computer Science, University of Wales, Aberystwyth, SY23 3DB

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30th Spring School Theorical Computer Science - Early Registration
by ecole＠pps.jussieu.fr 19 Nov '01

19 Nov '01

======================================================================= 30th SPRING SCHOOL THEORETICAL COMPUTER SCIENCE 24 - 29 March, 2002 in AGAY (VAR, FRANCE) EARLY REGISTRATION [Apologies for multiple copies] ======================================================================= This spring school aims at bringing together students and researchers eager to learn about the fundamental questions which language designers and implementors are facing those days, and on the most up-to-date tools that theoreticians have developed or are in the process of developing (such as games and ludics, or realisability for classical logic and set theory). Denotational semantics was born some thirty years ago from the encounter of computer scientists who aimed at implementation independent definitions of programming constructs on one hand, and logicians who provided mathematical tools to this aim (domain theory) on the other hand. Algebraic tools such as initial algebra semantics were also instrumental to the birth of this subject. Thirty years later, the subject has enriched considerably, both in tools (including connections with proof theory and category theory) and in coverage and applications (functional programming, state, control, objects, parallelism, mobility,...). Concepts and constructs that have arisen in the design of programming languages have found counterparts in logic, logical systems have found their way to applications in the form of proof assistants, etc... The rapid development of new programming paradigms, in which distributed computation takes a more and more important part, infers a strong demand on theory, more than ever. With the rise of quite specialized subcommunities (like type theory, linear logic, pi-calculus, functional programming, etc...), it is important to keep an eye on more comprehensive training events, that can address the interrelations between research areas in rapid growth, and between theory-oriented research work and more goal-oriented one, with the prospect of solving problems or of improving our understanding in one domain using tools of another domain. The diversity of the proposed lectures, combined with their conceptual overall unity (as witnessed by the very limited number of core formal systems: lambda-calculus, linear logic, pi-calculus) addresses this issue. ======================================================================= LECTURES ======================================================================= Denotational semantics and games semantics (5 hours) : Thomas Ehrhard , Guy McCusker Ludics (4 hours) : Pierre-Louis Curien, Jean-Yves Girard Realisability (4 hours) : Vincent Danos, Jean-Louis Krivine Continuations (4 hours) : Olivier Danvy Compilation, objects, modules (4 hours) : Xavier Leroy Mobility (5 hours) : Luca Cardelli, Cedric Fournet Security (5 hours) : Martin Abadi, Francois Pottier ======================================================================= CONTACT, FURTHER IMFORMATION & EARLY REGISTRATION ======================================================================= An early registration form can be filled at the following web address : http://www.pps.jussieu.fr/~ecole/ email: ecole(a)pps.jussieu.fr Equipe Preuves Programmes et Systèmes Université Denis Diderot Case 7014 2 Place Jussieu 75251 PARIS Cedex 05 FRANCE

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