- Haskell - Haskell.org

rigid variables
by Rodney D Price 20 Jul '06

20 Jul '06

I've gotten this sort of error several times, which mysteriously disappears when I add more functions to the code: storeError.hs:13:38: Couldn't match expected type `a' (a rigid variable) against inferred type `String' `a' is bound by the type signature for `throwError' at <no location info> Expected type: a Inferred type: String In the first argument of `return', namely `msg' In the call (return msg) (This is GHCi.) The code is below. The type variable a can't be bound to String, obviously, but a relative novice like myself has no idea why. Can someone tell me? Thanks, -Rod -- module Store where import Control.Monad.Error import Control.Concurrent.STM data StoreError = Default String instance Error StoreError where noMsg = Default "Store error" strMsg = Default instance MonadError StoreError STM where throwError (Default msg) = return msg

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Re: [Haskell] semantice of seq
by voigt.16734551＠bloglines.com 20 Jul '06

20 Jul '06

--- roconnor(a)theorem.ca wrote: > Do you have an example of use of seq on a function type? (Of course I > don't want to ban it, just change its behaviour.) I don't have any wisdom to offer on how we would want to ban or change the behavior of seq on a function type without using type classes. Nor do I have an example at hand where one absolutely needs to use seq on a function type. But in any case, your request seems to be beside the point, as it comes from the assumption that only seq on function types is dangerous. But that is not true. Polymorphic use of seq can also have dire consequences when the type in question is later instantiated with, say, Int (or whatever). See numerous examples in: http://wwwtcs.inf.tu-dresden.de/~voigt/seqFinal.pdf Ciao, Janis Voigtlaender.

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semantice of seq
by roconnor＠theorem.ca 19 Jul '06

19 Jul '06

Would the problematic semantics of seq be resolved if seq did nothing on function types? That is to say seq (\x -> undefined `asTypeOf` x) y reduced to y and seq (undefined `asTypeOf` id) y also reduced to y -- Russell O'Connor <http://r6.ca/> ``All talk about `theft,''' the general counsel of the American Graphophone Company wrote, ``is the merest claptrap, for there exists no property in ideas musical, literary or artistic, except as defined by statute.''

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CFP: IEEE ICDM'06 Workshops
by Jia Hu 19 Jul '06

19 Jul '06

[Apologies if you receive this more than once] ================================================================== Call for Workshop Papers ICDM'06: The 6th IEEE International Conference on Data Mining Hong Kong Convention and Exhibition Centre, Hong Kong, China, 18-22 December 2006 Sponsored by the IEEE Computer Society http://www.comp.hkbu.edu.hk/iwi06/icdm/?index=workshop (Full Workshop Papers Due: 30 July 2006) Accepted papers will be published in the conference proceedings by the IEEE Computer Society Press that are indexed by EI. Note: we will not have a separate workshop registration fee this year (i.e., conference registration covers everything). =================================================================== As an important part of the conference, the workshop program will focus on new research challenges and initiatives. All papers accepted for workshops will be included in the Workshop Proceedings published by the IEEE Computer Society Press that are indexed by EI, which will be available at the workshops. ------------------- Accepted Workshops: ------------------- 1. ICDM 2006 Workshop on Ontology Mining and Knowledge Discovery from Semistructured Documents (http://sky.fit.qut.edu.au/~nayak/MSD06/overview.html) 2. ICDM 2006 Workshop on Data Mining in Bioinformatics (http://icdm06.biomap.org/) 3. ICDM 2006 Workshop on Mining Complex Data (http://eric.univ-lyon2.fr/~mcd06/) 4. ICDM 2006 Workshop on Mining Spatial and Spatio-temporal Data (http://www.cs.hku.hk/~nikos/sstdm06/) 5. ICDM 2006 Workshop on Foundation of Data Mining and Novel Techniques in High Dimensional Structural and Unstructured Data (http://www.cs.sjsu.edu/~tylin/ICDM06/index.html) 6. ICDM 2006 Workshop on Privacy Aspects of Data Mining (http://www-kdd.isti.cnr.it/padm06/) 7. ICDM 2006 Workshop on Data Mining for Design and Marketing (http://www2.ipcku.kansai-u.ac.jp/~yada/conf/dmdm06/) 8. ICDM 2006 Workshop on Mining Stream/Evolving Data (http://www.csse.monash.edu.au/~mgaber/iwmesd/) 9. ICDM 2006 Workshop on Risk Mining (http://www.med.shimane-u.ac.jp/med_info/risk_mining/cfp.html) 10. ICDM 2006 Workshop on Reliability Issues in Knowledge Discovery (http://www3.it.deakin.edu.au/~hdai/RIKD06/) 11. ICDM 2006 Workshop on Data Mining and Wireless Sensor Networks (http://cs.acadiau.ca/~shussain/dm-wsn/cfp.html) 12. ICDM 2006 Workshop on Optimization-based Data Mining Techniques with Applications (http://www.dtke.ac.cn/meeting/meeting_5.htm) Note: we will not have a separate workshop registration fee this year (i.e., conference registration covers everything). For more information, please visit the conference website at http://www.comp.hkbu.edu.hk/iwi06/icdm/?index=workshop. ++++++++++++++++++++++++++ Workshop Paper Submission ++++++++++++++++++++++++++ http://wi-lab.com/cyberchair/icdm06/scripts/ws_submit.php (Until Jul 30, 2006, 11.59pm *Pacific Daylight Time*.) *** Contact Information *** Yiuming Cheung Hong Kong Baptist University, HK E-mail: ymc(a)Comp.HKBU.Edu.HK

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CFP: IEEE/WIC/ACM WI-IAT'06 Workshops
by Jia Hu 19 Jul '06

19 Jul '06

[Apologies if you receive this more than once] ============================================================== Call for Workshop Papers 2006 IEEE/WIC/ACM International Joint Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT'06) Hong Kong Convention and Exhibition Centre, Hong Kong, China, 18-22 December 2006 http://www.comp.hkbu.edu.hk/iwi06/wi/?index=workshop or http://www.comp.hkbu.edu.hk/iwi06/iat/?index=workshop (Full Workshop Papers Due: 30 July 2006) Accepted papers will be published in the conference proceedings by the IEEE Computer Society Press that are indexed by EI. Note: we will not have a separate workshop registration fee this year (i.e., conference registration covers everything). =================================================================== As an important part of the conference, the workshop program will focus on new research challenges and initiatives. All papers accepted for workshops will be included in the Workshop Proceedings published by the IEEE Computer Society Press that are indexed by EI, and will be available at the workshops. Detailed information is available at the conference homepage. We will not have a separate workshop registration fee this year (i.e., conference registration covers everything). --------------------------------- I. Accepted as Fullday Workshops: --------------------------------- 1. International Workshop on Agent and Data Mining Interaction (ADMI) (http://datamining.it.uts.edu.au/iadm/about.php) 2. International Workshop on Web Privacy Intelligence (http://cusp.smu.ca/Workshop/) 3. International Workshop on Service Composition (http://events.deri.at/sercomp2006/) 4. The 3rd International Workshop on Web-based Support Systems (WSS'06) (http://www2.cs.uregina.ca/~wss/wss06/index.html) ---------------------------------- II. Accepted as Halfday Workshops: ---------------------------------- 5. International Workshop on Intelligent Agents in Wireless Sensor Networks (IA-WSN) (http://cs.acadiau.ca/~eshakshu/IA-WSN-2006.htm) 6. International Workshop on Adaptation and Personalisation for e-Business Intelligence (http://www.ru5.cti.gr/WI06/) 7. International Workshop on Semantics in VO and WS (http://www.dur.ac.uk/w.w.song/SVO&WS2006-main.html) 8. International Workshop on Communication between Human and Artificial Agents (http://www.cs.umanitoba.ca/~ckemke/IAT06Workshop/workshop.html) 9. International Workshop on Intelligent Web Interaction (IWI-2006) (http://ymd.ex.nii.ac.jp/ws/iwi/06/) 10. International Workshop on P2P Computing and Autonomous Agents (http://www.yl.is.s.u-tokyo.ac.jp/~ragab/P2PAA2006_WI.html) 11. International Workshop on GrC and Brain Informatics (BI) for WI (http://cs.tongji.edu.cn/prog/InforWeb/publish/newsdetail.jsp?newsno=716) 12. International Workshop on Multi-Agent Systems in E-Business: Concepts, Technologies and Applications (MASeB'06) (http://software.ucv.ro/%7Ebadica_costin/maseb2006/) 13. International Workshop on Research of Agent-based Government Horizon Business Integration Management Systems (http://management.dlut.edu.cn/wi-iat/index.htm) 14. International Workshop on Technologies and Applications of Knowledge Computing on the Web (http://charade.kuis.kyoto-u.ac.jp/%7Esyed/KCW.html) Note: we will not have a separate workshop registration fee this year (i.e., conference registration covers everything). For more information, please visit the conference website at http://www.comp.hkbu.edu.hk/iwi06/wi/?index=workshop or http://www.comp.hkbu.edu.hk/iwi06/iat/?index=workshop ++++++++++++++++++++++++++ Workshop Paper Submission ++++++++++++++++++++++++++ http://wi-consortium.org/wiiat06/scripts/ws_submit.php (Until Jul 30, 2006, 11.59pm *Pacific Standard Time*.) *** Contact Information *** Yiuming Cheung Hong Kong Baptist University, HK E-mail: ymc(a)Comp.HKBU.Edu.HK

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ANN: hdbc-odbc 1.0.0.1
by John Goerzen 18 Jul '06

18 Jul '06

Hi, I have released HDBC-odbc, the ODBC backend driver for HDBC, version 1.0.0.1. This update contains compatibility fixes for those that use Windows -- it will now build correctly out of the box on that platform. Download from http://quux.org/devel/hdbc -- John

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ICFP 2006 --- Call for Participation
by John Reppy 18 Jul '06

18 Jul '06

------------------------------------------------------------------------ CALL FOR PARTICIPATION The 11th ACM SIGPLAN International Conference on Functional Programming (ICFP 2006) Portland, Oregon September 18-20, 2005 http://icfp06.cs.uchicago.edu ------------------------------------------------------------------------ ICFP 2006 provides a forum for researchers and developers to hear about the latest work on the design, implementations, principles, and uses of functional programming. The conference covers the entire spectrum of work, from practice to theory, including its peripheries. Conference Organizers: General Chair: John Reppy, University of Chicago Program Chair: Julia Lawall, DIKU Local Arrangements Chair: James Hook, Portland State University Workshop Chairs: Matthias Blume, Toyota Technological Institute at Chicago Patricia Johann, Rutgers University Programming Contest Chairs: Carl Krary, CMU Robert Harper, CMU ------------------------------------------------------------------------ For more details, see http://icfp06.cs.uchicago.edu Preliminary Program: http://icfp06.cs.uchicago.edu/schedule.html Registration information: http://regmaster2.com/conf/icfp2006.html Hotel information: http://icfp06.cs.uchicago.edu/hotel.html ------------------------------------------------------------------------

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FOOL/WOOD 2007 --- Call for papers
by John Reppy 18 Jul '06

18 Jul '06

Call For Papers 2007 International Workshop on Foundations and Developments of Object-Oriented Languages (FOOL/WOOD '07) Sponsored by ACM SIGPLAN Saturday, 20 January 2007 Nice, France Following POPL '07 http://foolwood07.cs.uchicago.edu Deadlines Submissions: Friday, 6 October 2006, 12:00 noon CDT (19:00 UTC) Notifications: Friday, 24 November 2006 Final versions: Friday, 22 December 2006 Workshop Description The search for sound principles for object-oriented languages has given rise to much work during the past two decades, leading to a better understanding of the key concepts of object-oriented languages and to important developments in type theory, semantics, program verification, and program development. The merger of the FOOL and WOOD workshops is intended to bring together researchers to share new ideas and results in these areas. The second joint workshop, FOOL/WOOD '07, will be held in Nice, France on Saturday, 20 January 2007, the day after POPL. Submissions for this event are invited in the general area of foundations of object-oriented languages and program analysis. Topics of interest include language semantics, type systems, program analysis and verification, formal calculi, concurrent and distributed languages, database languages, and language-based security issues. Papers are welcome to include formal descriptions and proofs, but these are not required; the key consideration is that papers should present novel and valuable ideas or experiences. The main focus in selecting workshop contributions will be the intrinsic interest and timeliness of the work, so authors are encouraged to submit polished descriptions of work in progress as well as papers describing completed projects. A web page will be created and made available as an informal electronic proceedings. Historically, presentation at FOOL/WOOD does not count as prior publication, and many of the results presented at FOOL/WOOD have later been published ECOOP, OOPSLA, POPL, and other conferences. Submission Instructions We solicit submissions on original research not previously published or currently submitted for publication elsewhere. The program chair should be informed of any related submissions; see the ACM SIGPLAN Republication Policy. Submissions should be PDF or PostScript in standard SIGPLAN 9pt conference format for a US-letter size page; templates are available at http://www.acm.org/sigs/sigplan/authorInformation.htm While submissions can be up to 12 pages, shorter papers describing promising preliminary work are also encouraged. Program Chair John Reppy (University of Chicago) e-mail: foolwood07 at mailman.cs.uchicago.edu Program Committee Derek Dreyer (Toyota Technological Institute at Chicago) Erik Ernst (University of Aarhus) Atsushi Igarashi (Kyoto University) Rustan Leino (Microsoft) Luigi Liquori (INRIA Sophia Antipolis) Todd Millstein (University of California - Los Angeles) David Walker (Princeton University) Elena Zucca (University of Genova) Steering Committee Viviana Bono (Universita di Torino) Michele Bugliesi (Universita Ca' Foscari) Sophia Drossopoulou (Imperial College) Kathleen Fisher (AT&T Labs) [Chair] Martin Odersky (Ecole Polytechnique Federale de Lausanne) Benjamin Pierce (University of Pennsylvania) Philip Wadler (University of Edinburgh)

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Re: [Haskell] What would Haskell middleware look like?
by Clemens Grelck 18 Jul '06

18 Jul '06

Hi Paul, Paul Johnson wrote: > I've noticed that many other languages have a middleware to handle > distribution and concurrency issues. Haskell has STM for shared-memory > concurrency, but there is no mechanism (AFAIK) for distribution. You may interested into the Eden project jointly developed at Marburg and Madrid: http://www.mathematik.uni-marburg.de/~eden/ Eden is a kind of Haskell extension for describing process networks and the communication within them. Clemens -- Dr. Clemens Grelck University of Hertfordshire Dept of Computer Science College Lane, Hatfield, AL10 9AB United Kingdom

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Visual Haskell for Visual Studio 2005
by Krasimir Angelov 18 Jul '06

18 Jul '06

Hello Guys, In the past year I had a lot of requests for Visual Haskell for Visual Studio 2005. Unfortunately the Visual Haskell code was broken after the latest GHC changes. These days I had enough time to fix it and now it is working well with VStudio 2003. There are very few changes that are required to run it under VStudio 2005 and they are already implemented. The problem is that I can't test it because I had only VStudio 2005 beta and its evaluation period is expired. If there are volunteers to do the port I would be happy to cooperate. Cheers, Krasimir

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