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Survey of Haskell in Higher Education
by John Hughes 28 Nov '05

28 Nov '05

I'm carrying out another survey of the Haskell community, this time to find out how Haskell is being used in university teaching. If you're teaching a course and using Haskell in any way, then this survey is aimed at you! You can find the survey form at http://www.cs.chalmers.se/~rjmh/Wash/Survey/TeachingSurvey.cgi Once again, as a reward for completing the form, you will see the results so far! I'm only surveying courses being taught this academic year, but I would like to gather as complete information as possible. I know that not all teachers using Haskell read this list, so I would appreciate it if you could help me by informing colleagues who are using Haskell about the existence of the survey. The information gathered will be used in the "History of Haskell" paper that I, Simon PJ, Phil Wadler and Paul Hudak are working on. Thanks very much for you help! John Hughes PS I now have over 500 responses to my earlier survey on use of Haskell--thank you very much! The results are interesting, and can be obtained from http://www.cs.chalmers.se/~rjmh/Wash/Survey/Survey.cgi.

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Records (was Re: [Haskell] Improvements to GHC)
by Georg Martius 28 Nov '05

28 Nov '05

Hi folks, rather than discussing about which operator symbol to use for record access, which is really a question of personal taste we should try to seriously discuss the proposals and get to a solutions! We all seem to agree that records are broken in Haskell. In order to fix that we need a new and most probably incompatible solution. However, I think the new solution should go in a new version of the Haskell standard (among other things :-) ). I would strongly disadvice to try to stick with the old system and improve it. Just because there are lots of different opinions we should still try to find a reasonable solution soon. Desite the minor problem of '.' that dominated the discussion so far, what are the REAL offences against Simons proposal [1] (denoted as SR in the following)? To me it sounds like a very reasonable starting point. Which other proposals exist? I quote David Roundy's list of problems [2] with a short annotation whether SR solves them: 1. The field namespace issue. solved by not sharing the same namespace with functions 2. Multi-constructor getters, ideally as a function. not solved. only possible by hand - As stated by Wolfgang Jeltsch [3] another datatype design might be better - I can image a solution is within SR example: > data Decl = DeclType { name :: String, ... } > | DeclData { name :: String, ... } > | ... > d :: Decl in addition to > d.DeclType.name > d.DeclData.name we provide (only if save, see 3.) > d.name 3. "Safe" getters for multi-constructor data types. not supported as it is - with the above suggestion it could be possible (don't know if desireable) 4. Getters for multiple data types with a common field. - solved with contrains > getx :: (r <: { x :: a }) => r -> a 5. Setters as functions. doesn't seem to be supported, or I don't see it right now. 6. Anonymous records. Supported 7. Unordered records. I don' t understand it. points added from me: 8. Subtyping Supported, quite nicely 9. higher order versions for selecting, updateing ... [4] not supported seems important to me, any solutions? Regards Georg [1] http://research.microsoft.com/~simonpj/Haskell/records.html [2] http://www.haskell.org//pipermail/haskell-cafe/2005-November/012226.html [3] http://www.haskell.org//pipermail/haskell-cafe/2005-November/012227.html [4] http://www.haskell.org//pipermail/haskell-cafe/2005-November/012162.html Am Donnerstag, 17. November 2005 19:08 schrieb Dimitry Golubovsky: > Sebastian Sylvan wrote: > >Personally I think that the dot is way to good of a symbol to be > >"wasted" on function composition. I mean, how often do you really use > >function composition in a way which doesn't obfuscate your code? I use > >($) way more often than (.). Some people do use it more often than I > > I found it useful to use (mainly for debugging purposes) > > mapM (putStrLn . show) <some list> > > if I want to print its elements each on a new line. > > -- > Dimitry Golubovsky > > Anywhere on the Web -- ---- Georg Martius, Tel: (+49 34297) 89434 ---- ------- http://www.flexman.homeip.net ---------

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RE: [Haskell] Re: Records
by Ralf Lammel 28 Nov '05

28 Nov '05

Good questions. You can't have a polymorphic typecase like "`extQ` (show :: Show a => a -> String )" because that's not really a *type*case. It is too polymorphic. You can have a polymorphic typecase like "`extQ` ( lshow :: [ a ] -> String )" because that's covered by the SYB2 paper; you need ext1Q (extQ1, depending on version). With SYB3, the second case is easier; it's just an instance. The first case ... still doesn't work ... this time for reasons of the class system. The type system doesn't allow to write one "default" instance for the case that a certain constraint is satisfiable (here: Show a) and to have yet another "default" instance to kick in *otherwise* to the SYB version. It would be great to have typeclass case to deal with this issue. Questions asking for typeclass case pop every now and then. The idea of the example is that you would need to define your own generic show function from scratch. The limitation of SYB1/SYB2 is that you would hit a closed-world-assumption. That's why SYB3! It allows you to add instances to the new generic show, as you go. Because of the lack of typeclass case, you still wouldn't be able to use the normal Prelude show function as default. You can use it instance-per-instance, by adopting each (attractive) show instances to be become instance of the new generic show function. However, you need to clone code because you probably want to re-tie the recursive knot in the new generic function. SYB3 is shipped separately, please use the distribution you pointed to. Simon PJ and I are still undecided regarding the modalities for adding SYB3 to the GHC libraries. Basically, we don't like the idea of having two libraries; SYB3 is more powerful but the combinator types are somewhat more complicated. However, using the separate SYB3 distribution is safe because it comes with TH support and a standalone mini SYB library. Regards, Ralf > -----Original Message----- > From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] > On Behalf Of Johannes Waldmann > Sent: Monday, November 28, 2005 7:33 AM > To: haskell(a)haskell.org > Subject: [Haskell] Data.Generics question > > Dear all, in Data.Generics.Text > http://cvs.haskell.org/cgi- > bin/cvsweb.cgi/fptools/libraries/base/Data/Generics/Text.hs?rev=1.10 > I find this nice example > > gshow = ( \t -> > "(" > ++ showConstr (toConstr t) > ++ concat (gmapQ ((++) " " . gshow) t) > ++ ")" > ) `extQ` (show :: String -> String) > > but I couldn't figure out how to use this to declare a useful show > instance. I would need something like > > `extQ` (show :: Show a => a -> String ) > > i. e. use Show instance if available, or > > `extQ` ( lshow :: [ a ] -> String ) > > i. e. use another function if argument type is a list type > > > BTW: I guess the above is related to > http://homepages.cwi.nl/~ralf/syb3/ > Do the current (6.4) ghc compiler/libraries correspond to what's in > that paper? > -- > -- Johannes Waldmann -- Tel/Fax (0341) 3076 6479/80 -- > ---- http://www.imn.htwk-leipzig.de/~waldmann/ ------- > > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell

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Call for Proposals: FM08: The 15th International Symposium on Formal Method s
by events-admin＠fmeurope.org 28 Nov '05

28 Nov '05

Formal Methods Europe Call for Proposals FM08: The 15th International Symposium on Formal Methods Formal Methods Europe invites proposals from organisations interested in hosting the 15th International Symposium on Formal Methods (FM08), to be held in Europe in Spring 2008. Formal Methods Europe (FME, http://www.fmeurope.org/) is a worldwide association bringing together researchers and practitioners in all aspects of formal methods for the evelopment, analysis and maintenance of computing systems and software. Its activities include the dissemination of research findings and industrial experience through symposia and sponsored events, notably the long running and highly regarded series of FM symposia. The 14th symposium in the series (http://fm06.mcmaster.ca/) is being organised by McMaster University, Ontario, Canada for August 2006. We invite enquiries and proposals from potential hosts for the 15th Symposium (FM08), which will be held at a European location, in spring 2008. Symposia take place approximately every 18 months and have at their core an international technical conference based on high quality refereed papers with published proceedings. A programme of workshops, tutorials and exhibitions adds to the event. However, there are few fixed rules regarding the format and potential hosts are invited to discuss options with FME. Attendances typically range from 125 to 260 participants. Important Dates - January 15, 2006 Proposals due Following receipt of proposals, FMEs board will discuss proposals by email with the proposers. - April 15, 2006 Latest date for notification of proposal acceptance Proposal Submission Proposals should be regarded as expressions of interest and will serve as a basis for discussion. They are not binding agreements and acceptance of a proposal does not constitute a final commitment on either side. Proposals should be no more than 3 pages in length and should contain: A brief description of why hosting the symposium is of interest to the proposing institution. The names and contact information (web page, email address) of the proposed organising committee. Previous experience in events organisation. A description of the facilities that will be available for the symposium. We welcome informal enquiries. Please send your proposals and any enquiries by electronic mail to: info(a)fmeurope.org. Proposals should be submitted in PDF. _______________________________________________ events mailing list events(a)fmeurope.org http://www.fmeurope.org/mailman/listinfo/events

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Data.Generics question
by Johannes Waldmann 28 Nov '05

28 Nov '05

Dear all, in Data.Generics.Text http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/libraries/base/Data/Gener… I find this nice example gshow = ( \t -> "(" ++ showConstr (toConstr t) ++ concat (gmapQ ((++) " " . gshow) t) ++ ")" ) `extQ` (show :: String -> String) but I couldn't figure out how to use this to declare a useful show instance. I would need something like `extQ` (show :: Show a => a -> String ) i. e. use Show instance if available, or `extQ` ( lshow :: [ a ] -> String ) i. e. use another function if argument type is a list type BTW: I guess the above is related to http://homepages.cwi.nl/~ralf/syb3/ Do the current (6.4) ghc compiler/libraries correspond to what's in that paper? -- -- Johannes Waldmann -- Tel/Fax (0341) 3076 6479/80 -- ---- http://www.imn.htwk-leipzig.de/~waldmann/ -------

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Can anyone help me with partition numbers?
by whoals (sent by Nabble.com) 28 Nov '05

28 Nov '05

A partition of a positive integer n is a representation of n as the sum of any number of positive integral parts. For example, there are 7 partitions of the number 5: 1+1+1+1+1, 1+1+1+2, 1+1+3, 1+2+2, 1+4, 2+3 and 5. Define a function parts which returns the list of distinct partitions of an integer n. For example, parts 4 = [[1,1,1,1],[1,1,2],[1,3],[2,2],[4]]. -- Sent from the Haskell - Haskell forum at Nabble.com: http://www.nabble.com/Can-anyone-help-me-with-partition-numbers--t612331.ht…

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Re: ANNOUNCE: Frag: a First Person Shooting game
by Daniel �rstadius 27 Nov '05

27 Nov '05

I cannot get Frag to compile. Running "ghc --make -O2 -fglasgow-exts main.hs" gives ... Compiling Quaternion ( ./Quaternion.hs, ./Quaternion.o ) Compiling ReadImage ( ./ReadImage.hs, ./ReadImage.o ) ./ReadImage.hs:60: Type constructor or class not in scope: `PixelData' ./ReadImage.hs:68: Data constructor not in scope: `PixelData' I am using ghc 6.2.2. I have tried adding "-package GLUT" to the command line, but still the same output. Daniel __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com

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Coordination 2006: Second call for papers
by Jean-Marie JACQUET 27 Nov '05

27 Nov '05

[ Our apologies for multiple copies. ] ====================================================================== Second Call for Papers COORDINATION 2006 8th International Conference on Coordination Models and Languages http://www.cs.unibo.it/discotec06/Coordination06 as part of DisCoTec'06 - Distributed Computing Techniques co-located with DAIS'06 & FMOODS'06 http://www.cs.unibo.it/discotec06 Bologna, Italy 14-16 June 2006 ====================================================================== IMPORTANT DATES * Submission of abstract: 10 January 2006 * Submission of papers: 17 January 2006 * Notification of acceptance: 7 March 2006 * Final version: 28 March 2006 * Conference: 14-16 June 2006 ====================================================================== CONFERENCE GOALS Modern information systems rely increasingly on combining concurrent, distributed, mobile, reconfigurable and heterogenous components. New models, architectures, languages, verification techniques are necessary to cope with the complexity induced by the demands of today's software development. Coordination languages have emerged as a successful approach, in that they provide abstractions that cleanly separate behavior from communication, therefore increasing modularity, simplifying reasoning, and ultimately enhancing software development. Building on the success of the previous editions, this conference provides a well-established forum for the growing community of researchers interested in models, languages, architectures, and implementation techniques for coordination. PREVIOUS EDITIONS The previous editions of COORDINATION took place in Cesena (Italy), Berlin (Germany), Amsterdam (Netherlands), Limassol (Cyprus), York (UK), Pisa (Italy) and Namur (Belgium). More details are available at http://www.coordination2005.org. TOPICS OF INTEREST They include but are not limited to: * Theoretical models and foundations for coordination: component composition, concurrency, mobility, dynamic aspects of coordination, emergent behavior. * Specification, refinement, and analysis of software architectures: patterns and styles, verification of functional and non-functional properties. * Coordination, architectural, and interface definition languages: implementation, interoperability, heterogeneity. * Multiagent systems and coordination: models, languages, infrastructures. * Dynamic software architectures: mobile code and agents, configuration, reconfiguration, self-organization. * Coordination and modern distributed computing: Web services, peer-to-peer networks, grid computing, context-awareness, ubiquitous computing. * Programming languages, middleware, tools, and environments for the development of coordinated applications * Industrial relevance of coordination and software architectures: programming in the large, domain-specific software architectures and coordination models, case studies. * Interdisciplinary aspects of coordination PROCEEDINGS Proceedings of previous editions of this conference were published by Springer, in the Lecture Notes in Computer Science (LNCS) series and are available as LNCS volumes 1061, 1282, 1594, 1906, 2315, 2949 and 3454. The intention is to continue this series. SUBMISSION INSTRUCTIONS Authors are invited to submit full papers electronically in PostScript or PDF using a two-phase online submission process. Registration of the paper information and abstract (max. 250 words) must be completed before 10 January 2006. Submission of the full paper is due no later than 17 January 2006. Further instructions on the submission procedure will be published at http://www.cs.unibo.it/discotec06/Coordination06. Submissions must be formatted according to the LNCS guidelines (see http://www.springer.de/comp/lncs/authors.html) and must not exceed 15 pages in length. Papers that are not in the requested format or significantly exceed the mandated length may be rejected without going through the review phase. Submissions should explicitly state their contribution and their relevance to the theme of the conference. Other criteria for selection will be originality, significance, correctness, and clarity. Simultaneous or similar submissions to other conferences or journals are not allowed. CONFERENCE LOCATION The conference will be hosted by the Department of Computer Science of the University of Bologna. PROGRAM COMMITTEE Co-Chairs Paolo Ciancarini University of Bologna, Italy Herbert Wiklicky Imperial College London, UK Members Farhad Arbab CWI Amsterdam, The Netherlands Antonio Brogi University of Pisa, Italy Wolfgang Emmerich University College London, UK Frank de Boer CWI & Utrecht University, The Netherlands Jean-Marie Jacquet University of Namur, Belgium Josst Kok Leiden University, The Netherlands Toby Lehman IBM Almaden, US D.C. Marinescu University of Central Florida, US Ronaldo Menezes Florida Institute of Technology, US Andrea Omicini University of Bologna, Italy Paolo Petta OeFAI, Austria Gian Pietro Picco Politecnico di Milano, Italy Ernesto Pimentel University of Malaga, Spain Rosario Pugliese University of Florence, Italy Gruia Catalin Roman Washington University, USA Robert Tolksdorf FU Berlin, Germany Emilio Tuosto University of Leicester, UK Carlos Varela Rensselaer Polytechnic Institute, US Alan Wood University of York, UK

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Call For Papers: ISMM 2006 (International Symposium on Memory Management)
by Erez Petrank 27 Nov '05

27 Nov '05

***************************************************************************** Call For Papers The 2006 International Symposium on Memory Management (ISMM'06) Co-located with PLDI 2006 Ottawa, Canada June 10-11 2006 http://www.cs.technion.ac.il/~erez/ismm06 ***************************************************************************** IMPORTANT DATES: Submission: January 23, 2006, 11PM PST Notification: March 6, 2006 Camera-ready: Monday, April 3, 2006 ISMM is a forum for research in management of dynamically allocated memory. ISMM solicits full-length papers on all areas of memory management. Survey papers that present an aspect of memory management with a new clarity and insight are also welcome. Papers are solicited on, but not limited to, these topics, - Explicit storage allocation and de-allocation - Garbage collection algorithms and implementations - Compiler analyses to aid memory management - Interaction with languages, operating systems, and hardware, especially the memory system - Memory system interaction with programming languages, operating systems, and hardware. The ISMM 2006 paper reviewing process adds two features new to ISMM: double blind reviewing, and an opportunity for rebuttal; see the ISMM webpage for more details. Full submissions should be at most 12 pages excluding bibliography and well-marked appendices but including all figures and tables, using at least 11-point font and reasonable margins for US Letter paper. Papers that violate these guidelines will be rejected by the program chair. Program committee members are not required to read appendices, and so a paper should be intelligible without them. Submitted papers must be in English and formatted to print on US Letter (8.5 x 11 inches) paper. Submissions must contain an abstract and postal and electronic mailing addresses for at least one author. Instructions for on-line submission of papers will become available on the ISMM webpage at http://www.cs.technion.ac.il/~erez/ismm06. Submissions will be read by the program committee and designated reviewers and judged on scientific merit, innovation, readability, and relevance. Papers previously published or already being reviewed by another conference are not eligible; if a closely related paper has been submitted to a journal, the authors must notify the program chair. The proceedings will be published by ACM. Authors should read the ACM Author Guidelines and related information. Authors of accepted papers must guarantee that their paper will be presented at the conference. For additional information please feel free to contact the Program Chair, Eliot Moss (moss(a)cs.umass.edu) General Chair: Erez Petrank (Technion, Israel) Program Chair: J. Eliot B. Moss (Univ. of Mass. at Amherst) Program Committee: Vikram Adve (Univ. of Illinois at Urbana-Champaign) Richard Jones (Univ. of Kent) Hillel Kolodner (IBM Haifa Research Lab) Chandra Krintz (Univ. of California at Santa Barbara) Kathryn S McKinley (Univ. of Texas at Austin) Greg Morrisett (Harvard University) Ravi Rajwar (Intel) Yannis Smaragdakis (Georgia Tech) Guy Steele (Sun Microsystems)

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ANNOUNCE: Frag: a First Person Shooting game
by Mun Hon Cheong 26 Nov '05

26 Nov '05

Frag is a 3D First Person Shooting game. Features: *Yampa, a domain-specific embedded language for the programming of hybrid systems that using the concepts of Functional Reactive Programming (FRP) was used to program the game entities. *The Quake 3 BSP level format, Q3Map2, and the MD3 format for models and animations are used in this game. *Sven Panne's OpenGL binding, HOpenGL is used to render graphics. Requirements: HOpenGL which is provided with GHC OpenGL drivers that support the vertex array and multitexture OpenGL extensions Darcs: darcs get http://www.cse.unsw.edu.au/~pls/repos/frag Thanks goes to Don Stewart, this project would not have become public if not for him. Enjoy, Mun

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