July 2002 - Haskell - Haskell.org

ANNOUNCE: GHC version 5.04 released
by Simon Marlow 12 Jul '02

12 Jul '02

============================================================ The (Interactive) Glasgow Haskell Compiler -- version 5.04 ============================================================ We are pleased to announce a new major release of the Glasgow Haskell Compiler (GHC), version 5.04. Highlights include: * Hierarchical libraries, with documentation produced by Haddock. * New type system extensions: full rank-N types and kind annotations. * New heap profiling facilities (retainer profiling, biographical profiling). * MacOS X support See the release notes for a full list of the changes: http://www.haskell.org/ghc/docs/latest/html/users_guide/release-5-04.htm l 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.bz2 which can be installed wherever you want. The source distribution is also available from the same place. Packages will appear as they are built - if the package for your system isn't available yet, come back later. 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/html/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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CFP: PADL'03
by Dr. Gopal Gupta 11 Jul '02

11 Jul '02

[ - Paper submission deadline is July 31 - BEST PAPER AWARD: A best paper award ($500) will be given to the paper judged most innovative and practical. - PADL'03 proceedings will be published as Springer Verlag LNCS, past proceedings can be found in LNCS 1551, 1753 and 1990, and 2257 ] CALL FOR PAPERS!!! Fifth International Symposium on Practical Aspects of Declarative Languages 2003 (PADL '03) http://www.research.avayalabs.com/user/wadler/padl03/ New Orleans, Louisiana, USA Jan 13-14, 2003 Co-located with POPL 2003 Nothing is so practical as a good theory. Declarative languages build on sound theoretical bases to provide attractive frameworks for application development. Declarative approaches to programming include those based on logic, constraints, functions, and concurrency. Declarative languages have been successfully applied to a wide variety of real-world situations, ranging from database management to active networks to software engineering to decision support systems. New developments in theory and implementation have opened up new application areas. At the same time, applications of declarative languages to novel problems raise research issues. Questions include designing for scalability, language extensions for application deployment, and programming environments. Thus, applications drive the progress in the theory and implementation of declarative systems, and benefit from this progress as well. PADL provides a forum for researchers, practitioners, and implementors of declarative languages to exchange ideas on application areas and on the requirements for effective deployment of declarative systems. We invite papers dealing with practical applications of logic, constraint, functional, and concurrent programming. The scope of PADL includes, but is not limited to: o Innovative applications of declarative languages o Declarative domain-specific languages and applications o New developments in declarative languages and their impact on applications o Practical experiences o Novel uses of declarative languages in the classroom o Evaluation of implementation techniques on practical applications o Application letters (Applets) - see below o Declarative pearls - see below Papers should highlight the practical contribution of the work and the relevance of declarative languages to achieve that end. PADL 2003 will co-locate with ACM POPL 2003, in New Orleans. Application Letters (Applets) Real-world users of declarative languages may be so fully occupied writing declarative programs that they lack the time to write a full paper describing their work. Conference attendees often hear only from those developing declarative languages --- the users are too busy using them. In order to attract greater participation from users, the conference solicits application letters describing experience using declarative languages to solve real-world problems. Such papers might be half the length of a full paper (though any length up to a full paper is fine), and may be judged by interest of the application and novel use of declarative languages as opposed to a crisp new research result. Declarative Pearls Program committees traditionally expect a paper to make a contribution of a certain size. Ideas that are small, rounded, and glow with their own light may have a number of venues, but conferences are not typically among them. (Among the outlets have been columns such as Bentley's Programming Pearls in Communications of the ACM, Rem's Small Programming Exercises in Science of Computer Programming, and Barendregt's Theoretical Pearls and Bird's Functional Pearls in the Journal of Functional Programming.) The conference invites papers that develop a short declarative program. Such papers might be half the length of a full paper (though any length up to a full paper is fine), and may be judged by elegance of development and clarity of expression as opposed to a crisp new research result. Most Practical Paper Award The paper deemed "most practical" by the programm committee will be awarded a cash prize of US$500. Criteria for judging include practicality, innovation, quality of the work, and clarity of presentation. All submitted papers will automatically be candidates for this award. The program committee may choose not to make an award; or may make multiple awards, in which case the award money will be equally divided. Important Dates: o Paper Submission: Jul. 31, 2002 o Notification: Oct. 2, 2002 o Camera Ready: Nov. 6, 2002 o Symposium: Jan. 13-14, 2003 Paper Submission: Authors should submit a 100-200 word abstract and a full paper, written in English. Submissions should be no more than 15 pages in standard Springer-Verlag LNCS format: 122mm x 193mm in 10 point font, Computer Modern Roman or similar. Submissions that do not meet these guidelines may not be considered. Style files for Latex and Word are provided by Springer-Verlag. Papers should be submitted in PDF format, and be printable on both USLetter and A4 paper; details of web submission will be posted later. If this requirement is a hardship, please contact the program chairs. Each submission should include, on its first page, the paper title; authors and their affiliations; contact author's email and postal addresses, telephone and fax numbers; and a 100-200 word abstract. The abstract will be used to assist us in selecting appropriate reviewers for the paper. Submitted papers should have content that has not previously been published in other conferences or refereed venues, and simultaneous submission to other conferences or refereed venues is unacceptable. Each paper should explain its contributions in both general and technical terms, clearly identifying what has been accomplished, saying why it is significant, and comparing it with previous work. Authors should strive to make the technical content of their papers understandable to a broad audience. Program Committee: o Lennart Augustsson, Sandburst, USA o Phillipe Blache, CNRS & Universite de Provence, France o Veronica Dahl, Simon Fraser University, Canada (program co-chair) o Ines Dutra, Universidade Federal do Rio de Janeiro, Brazil o Kathleen Fisher, AT&T Labs, USA o Matthew Flatt, University of Utah, USA o Daniela Florescu, XQRL, USA o Juliana Freire, Bell Laboratories, USA o Matteo Frigo, Massachusetts Institute of Technology, USA o Terry Gaasterland, Argonne National Laboratory and University of Chicago, USA o Alejandro Garcia, Universidad Nacional del Sur, Argentina o Manuel Hermenegildo, Universidad Politecnica de Madrid, Spain o John Hughes, Goteborg University, Sweden o Neil Jones, University of Copenhagen, Denmark o Shriram Krishnamurthi, Brown University, USA o Naoki Kobayashi, Tokyo Institute of Technology, Japan o George Necula, University of California at Berkeley, USA o Luis Moniz Pereira, Universidade Nova de Lisboa, Portugal o Paul Tarau, BinNet Corporation and University of North Texas, USA o Philip Wadler, Avaya Labs, USA (program co-chair) o David S. Warren, State University of New York at Stony Brook, USA For more Information, please contact Philip Wadler Avaya Labs wadler(a)avaya.com 233 Mount Airy Road, room 2C05 http://www.research.avayalabs.com/user/wadler/ Basking Ridge, NJ 07920 USA office: +1 908 696 5137 fax: +1 908 696 5402

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HGL under MacOS X and XDarwin
by Sabine Timpf 11 Jul '02

11 Jul '02

I want to install HGL on the Unix System underpinning MacOSX. I get the following error with the make command: [localhost:/usr/local/soe] root# make -C graphics-2.0.4/lib/x11/ system=FreeBSD gcc3 -c -I/usr/X11R6/include -I/usr/share/hugs/include X.c -o X.o ld -dylib -L/usr/X11R6/lib -lX11 X.o -o X.so gcc3 -c -I/usr/X11R6/include -I/usr/share/hugs/include Xlib.c -o Xlib.o gcc3 -c -I/usr/X11R6/include -I/usr/share/hugs/include cbits/auxiliaries.c -o cbits/auxiliaries.o ld -dylib -L/usr/X11R6/lib -lX11 Xlib.o cbits/auxiliaries.o -o Xlib.so ld: Xlib.o illegal reference to symbol: _bzero defined in indirectly referenced dynamic library /usr/lib/libSystem.B.dylib make: *** [Xlib.so] Error 1 rm cbits/auxiliaries.o Can somebody help? Thanks, Sabine Dr. Sabine Timpf GIScience Lab Department of Geography, University of Zurich Winterthurerstr. 190, CH-8057 Zurich Tel.: +41-1-6355152, Fax: +41-1-6356848 home: www.geo.unizh.ch/~timpf/

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Spam filtering at haskell.org
by John C. Peterson 10 Jul '02

10 Jul '02

I hope everyone has enjoyed spam-free lists for the last couple of weeks. I've been moderating the spam away but I'm changing over to an automated spam tool, spam assassin. This is what the local support folks are starting to use throughout the campus and I'm going to defer to them in the spam hunt. As configured, we will be simply dropping messages identified as spam without replying. If you find your postings do not go through please contact me and I'll see what I can do. If the spam level becomes significant again we will turn up the filtering a bit. This affects all mailing lists hosted on haskell.org. John Peterson

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COLOGNET Joint Workshop: Call For Papers and Participation
by Manuel Carro 10 Jul '02

10 Jul '02

We apologize for multiple reception of this message. Please note the quite near deadline. ========================================================================== Call for Papers and Participation --------------------------------- COLOGNET Joint Workshop on -------------------------- Component-based Software Development ------------------------------------ and Implementation Technology for Computational Logic Systems --------------------------------------------------------- (http://clip.dia.fi.upm.es/COLOGNET-WS/) Affiliated with LOPSTR 2002 19 - 20 September 2002, Madrid, Spain COLOGNET (http://www.colognet.org) the European Network of Excellence in Computational Logic is organizing a workshop on two of its workpackages: Component-based Software Development (CBD) and Implementation Technology for Computational Logic Systems (ITCLS). This joint workshop will be collocated with SAS/LOPSTR/AGP (http://clip.dia.fi.upm.es/SAS-LOPSTR-AGP) The aim of the workshop is to present and discuss current research issues, both in academia and industry. The joint workshop will be organized in two sessions: Component Based Software Development ------------------------------------ The goal of this session is to examine the process of component-based software development in all phases of the development life-cycle (i.e., specification, design, composition, testing, deployment). Special emphasis will be placed on the use of Computational Logic throughout the process. A non-exhaustive list of topics includes: - Methodological foundation of component-based software development. - Modeling of component-based systems. - Tools supporting component-based development. - Integration of the component paradigm into existing environments. - Component testing, verification, distribution, maintenance. - Combination of heterogeneous component technologies. - The role of Computational Logic in all the above. - Industrial experience reports. Implementation Technology for Computational Logic Programming ------------------------------------------------------------- This session is intended to be a continuation of the series of workshops on Implementations of Logic Programming Systems held in the context of COMPULOG NET, the former Network of Excellence in Computational Logic. But, in contrast to the COMPULOG area meetings on implementation, which were rather centered toward logic and constraint logic programming systems, the target of this workshop is broader: it includes implementation technology for other areas which are part of the COLOGNET network. The aim is to bring together researchers from fields such as automated reasoning, natural language processing, constraint logic programming, model checking, etc., in order to share common problems and solutions regarding implementation issues which arise in the logic-based systems arena. Suggested topics of interest for the implementation workshop include, but are not limited to: - Implementation of resolution and model elimination theorem provers. - Implementation for non-monotonic reasoning systems and semantics. - Implementation of higher-order, linear, etc. logics. - Implementation techniques for natural language processing. - Standard and non-standard sequential implementation schemes for constraint logic programing languages (e.g., generalization / modification of WAM, translation to C, etc.) - Memory management and garbage collection issues. - Implementation of concurrency and parallelism in logic-based languages. - Extensions to the Warren Abstract Machine. Term indexing. Invited Talks ------------- The workshop programme will consist of invited talks and accepted papers. So far, invited talks include the following: Keynote Speaker (shared among CBD, ITCLS and LOPSTR): ---------------------------------------------------- Robert Hall, AT & T (still pending of final confirmation). Robert Hall does research on Automated Software Engineering, particularly in making networked services and components secure, reliable, and scalable. CBD: ---- Antonio Brogi, University of Pisa, Modeling Component Behaviors. Kung-Kiu Lau, University of Manchester, A Priori Reasoning for CBD. Manuel Carro, UPM, Madrid, The AMOS Project. ITCLS: ------ Michael Fisher, University of Liverpool, Implementing Temporal Logics: Tools for Execution and Proof. Submissions and Deadlines ------------------------- Authors are invited to contribute to the programme by submitting extended abstracts (6 pages maximum) or full papers (12 pages maximum) on the workshop themes. Limits are strict, and the llncs format (http://www.springer.de/comp/lncs/authors.html) must be used. Submissions are to be sent to the organizing committee by emailing them to: - kung-kiu(a)cs.man.ac.uk (for CBD papers) or to - colognet-imp(a)clip.dia.fi.upm.es (for ITCLS papers) Submission deadline: July 26 Notification to authors: August 5 Camera-ready copies: September 5 Workshop: September 19-20 Informal proceedings will be available at the workshop. Organizing Committee -------------------- Antonio Brogi, University of Pisa, Italy. Manuel Carro, UPM, Madrid, Spain. Shui Ming Ho, University of Manchester, UK. Kung-Kiu Lau, University of Manchester, UK. Mario Ornaghi, University of Milan, Italy. German Puebla, UPM, Madrid, Spain. Claudio Vaucheret, UPM, Madrid, Spain. =========================================================================== -- +--------------------------------------------------------------------------+ |Manuel Carro -- Facultad de Informática -- U. Politécnica de Madrid (UPM) | | Email: mcarro(a)fi.upm.es --- Ph: +34-91336-7455 --- FAX: +34-91336-7412 | |http://lml.ls.fi.upm.es/~boris --- http://clip.dia.fi.upm.es/Software/Ciao|

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IFL 2002 CALL FOR PARTICIPATION
by Ricardo Pe~na 09 Jul '02

09 Jul '02

IFL 2002 Call for Participation =============================== (Apologies for multiple postings) NEW: Registration to workshop is now open !! NEW: Paper submission is now open !! ============================================================ IFL 2002 14th International Workshop on the IMPLEMENTATION OF FUNCTIONAL LANGUAGES Madrid Spain September 16 - 18, 2002 ============================================================= Important dates --------------- Registration deadline: July 30th, 2002 Submission deadline : August 26th, 2002 further details : http://dalila.sip.ucm.es/ifl02 ============================================================= Scope of IFL 2002 ----------------- The aim of the workshop is to bring together researchers and users actively engaged in the implementation and application of functional programming languages to discuss results and new directions of research. The workshop is intended to provide an open forum for researchers who wish to present and discuss new ideas and concepts, work in progress, preliminary results etc. related primarily but not exclusively to the implementation of functional or function-based languages. A not necessarily exhaustive list of topics includes language concepts type checking compilation techniques (abstract) interpretation automatic program generation (abstract) machine architectures array processing concurrent/parallel programming and program execution heap management runtime profiling and performance measurements debugging and tracing verification of functional programs tools and programming techniques Contributions on applications of functional programming, e.g., in teaching, or on theoretical work in any of the above areas are also welcome. Contributions ------------- All attendees are encouraged to submit papers to be published in the draft proceedings and to give presentations at the workshop. Submitted papers must be written in English, conform to the LNCS format (available at: http://www.springer.de/comp/lncs/authors.html) and not exceed 16 pages. Papers should be submitted by August 26th as postscript or pdf files using the submission page of the workshop accessible through http://dalila.sip.ucm.es/ifl02. After the workshop, we will publish a high-quality subset of contributions in the Springer LNCS series. All speakers attending the workshop are invited to submit a paper. Papers for the LNCS proceedings will be refereed according to normal conference standards (see Program Committee at the web page) Ricardo Pe~na (IFL 2002 Organizing Committee Chairman) Departamento de Sistemas Informaticos y Programacion Facultad de Informatica Universidad Complutense de Madrid, 28040 MADRID e-mail: ricardo(a)sip.ucm.es Ph: (+ 34) 91 394 4313 FAX: (+ 34) 91 394 4602 http://dalila.sip.ucm.es/~ricardo

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creating a new array vs updating an old one
by Hal Daume III 09 Jul '02

09 Jul '02

I have large, two dimensional arrays. Usually something like: > Array (Int,Int) Double where they represent probability distributions, for instance: P(x|y) := arr ! (x,y) where x and y are int representations of events. many times, i calculate these distributions by collecting counts and then normalizing over sums, something like: > normalize arr = > arr // [((i,j), arr ! (i,j) / sum of elements in j column...] of course, this could also be written: > normalize arr = > array bounds [((i,j), arr ! (i,j) / sum of elements in j column...] my question is this: which is the better operation? in the first case, we are updating every element in the array, so there's no performance gain in the sense that there's less information to be written; furthermore, presumably the elements will be touched in the same order. once i normalize, i never use the old array, so in *theory* the compile could do it in place, which would make the first much better; in practice, this doesn't seem to always happen (though I haven't looked at it vigorously -- how could i find out?). -- 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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unsafePerformIO around FFI calls
by Hal Daume III 08 Jul '02

08 Jul '02

I'm curious exactly what is "safe" and what is "unsafe" to wrap unsafePerformIO around when it comes to FFI calls. If there's a general discussion of this somewhere and someone could send me a pointer that would be another acceptable solution. I googled for "unsafePerformIO FFI" but nothing relevant turned up. Anyway, here's the issue at hand. I have a function which takes a value and an IO action, allocates some memory, put the value in there, executes the IO action (which is an FFI function), gets the result, deallocates the memory and then returns the rest. For instance, we have an FFI function from LAPack which computes, say, eigenvalues. Because this is from fortran and in fortran everything is by reference, the function is an IO action of (simplified) type: > maxEigenvalue :: HMatrix -> IO Double implemented using FFI. We also have the CPS function to make the HMatrix: > withMatrix :: [[Double]] -> (HMatrix -> IO Double) -> IO Double which looks basically like (I'm on vacation so I don't have the real code right now): > withHMatrix m action = > do memory <- allocate memory > hm <- write m into memory > result <- action hm > deallocate memory > return result (it's slightly more complex because i need to make it safe in the case that action throws an exception and the memory is still deallocated before the exception is re-raised.) i can then wrap these together and say: > compEig :: [[Double]] -> IO Double > compEig m = withHMatrix m maxEigenvalue so the question is: Under what circumstances is it safe to make instead: > compEig' :: [[Double]] -> Double > compEig' m = unsafePerformIO $ withHMatrix m maxEigenvalue ??? Thanks! - Hal p.s., Please continue to CC Carl as this issue came up in conversations with him -- 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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Re: encapsulation
by Ashley Yakeley 08 Jul '02

08 Jul '02

At 2002-07-07 16:30, Andrew J Bromage wrote: >It _is_ a matter of opinion, and people can agree to disagree on these >points. What it boils down to is: What do you _want_ from >encapsulation? I think it's a homework question... -- Ashley Yakeley, Seattle WA

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encapsulation
by Mark Fielder 07 Jul '02

07 Jul '02

How does Haskell provide encapsulation? What mechanisms does it use? What are Haskell's encapsulation strengths and weaknesses? Thanks for the help! Mark __________________________________________________ Do You Yahoo!? Sign up for SBC Yahoo! Dial - First Month Free http://sbc.yahoo.com

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