December 2004 - Haskell

CFP: FOAL 2005, Foundations Of Aspect-Oriented Languages
by Ralf Laemmel 02 Dec '04

02 Dec '04

FOAL: Foundations of Aspect-Oriented Languages A one day workshop affiliated with AOSD 2005 in Chicago, USA, on Monday, 14 March 2005. Themes and Goals FOAL is a forum for research in foundations of aspect-oriented programming languages. Areas of interest include but are not limited to: * Semantics of aspect-oriented languages * Specification and verification for such languages * Type systems * Static analysis * Theory of testing * Theory of aspect composition * Theory of aspect translation (compilation) and rewriting The workshop aims to foster work in foundations, including formal studies, promote the exchange of ideas, and encourage workers in the semantics and formal methods communities to do research in the area of aspect-oriented programming languages. All theoretical and foundational studies of this topic are welcome. The goals of FOAL are to: * Make progress on the foundations of aspect-oriented programming languages. * Exchange ideas about semantics and formal methods for aspect-oriented programming languages. * Foster interest within the programming language theory and types communities in aspect-oriented programming languages. * Foster interest within the formal methods community in aspect-oriented programming and the problems of reasoning about aspect-oriented programs. Workshop Format The planned workshop format is primarily presentation of papers and group discussion. Talks will come in three categories: long (30 minutes plus 15 minutes of discussion), short (20 minutes plus 5 minutes of discussion) and very short (7 minutes plus 3 minutes of discussion). The very short talks will allow for short presentations of topics for which results are not yet available, perhaps for researchers who are seeking feedback on ideas or seek collaborations. We also plan to ensure sufficient time for discussion of each presentation by limiting the number of long talks and having only a few short talks. Submissions Invitation to the workshop will be based on papers selected by the program committee; those wishing to attend but not having a paper to submit should contact the organizers directly to see if there is sufficient space in the workshop. FOAL solicits full-length, short, and very short papers on all areas of formal foundations of AOP languages. Submissions will be read by the program committee and designated reviewers. Papers will be selected for long, short, and very short presentation at the workshop based on their length, scientific merit, innovation, readability, and relevance. Papers previously published or already being reviewed by another conference are not eligible. Some papers may not be selected for presentation, and some may be selected for presentation in shorter talks than their paper length would otherwise command. We will limit the length of paper presentations and the number of papers presented to make sure that there is enough time for discussion. Papers presented at the workshop will be included in a technical report (from Iowa State University). Authors will retain their own copyright to the papers. Publication of papers at other venues will thus remain possible. We will also investigate having a special issue of a journal for revisions of selected papers after the workshop. Authors should note the following details: * Submissions are due no later than 23:00 GMT, Sunday, 16 January 2005. This is a firm deadline. * Authors must indicate whether they wish to be considered for a long, short, or very short presentation. * Papers for long presentations must not exceed 10 pages in length; those for short presentations must not exceed 5 pages in length, and those for very short presentations must not exceed 3 pages in length. * Some papers may not be selected for presentation, and some may be selected for presentation in shorter talks than requested. * We encourage use of the ACM Conference format for submissions, as this will be required for accepted papers. You must add page numbers (which are not part of the standard format) to your submissions, to make adding comments easier. * Submissions are to be sent as PDF (preferred) or postscript attachments in an email to Curtis Clifton, cclifton -at- cs -dot- iastate -dot- edu. We will notify the corresponding author of papers that are selected for presentation at the workshop by 3 February 2005. The early registration deadline for AOSD will be 10 February 2005. FOAL attendees must be registered for AOSD. Final versions of papers for the proceedings will be due on 1 March 2005. For more information, visit the FOAL Workshop home page at http://www.cs.iastate.edu/FOAL. Important Dates Submission Deadline 23:00 GMT, 16 January 2005 Notification of Acceptance 3 February 2005 Final Versions of Papers Due 1 March 2005 Workshop 14 March 2005

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controlling the scope of instances
by Ralf Laemmel 02 Dec '04

02 Dec '04

Hi, I refer to Section 5.3 (title see subject line) in Type classes: exploring the design space by Simon Peyton Jones, Mark P. Jones and Erik Meijer HW 1997. There it is argued very briefly that a type system with controlled scope of instances risks coherence. Likewise, in Wadler's and Blotts original paper on ad-hoc polymorphism, Appendix A.7 sheds light on the related problem of principal typings. Global scope is suggested while wondering about less restrictive conditions that retain principal typing. The interaction with the module system is not really considered. I also know of /Functional Pearl: Implicit Configuration -- or, Type Classes Reflect the Value of Types/ Oleg Kiselyov, Chung-chieh Shan, Haskell Workshop 2004, which sheds some fancy light on the subject. The paper deals with local instances, but not so much with scoping via the module system. Does anyone know of a published, somewhat deeper analysis regarding the possibility to scope instances via the normal module system? For instance, why can't we have as many distinguished "incarnations" of a class in the type system as there are different sets of instances created in various scopes. That is, references to methods are to be *implicitly qualified* by the corresponding class incarnation (i.e., sets of instances). Methods of different incarnations are not to be confused by the type system. This would solve all coherence issues that I can think of. Or is this just getting too complicated? Any pointers greatly appreciated. Regards, Ralf **

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RE: [Haskell] discrepancy between nhc and ghc
by Simon Peyton-Jones 02 Dec '04

02 Dec '04

The Report explicitly specifies that you can export a class method "naked", for exactly the reason you give. So I think GHC is right here. Simon | -----Original Message----- | From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of John Meacham | Sent: 02 December 2004 01:28 | To: haskell(a)haskell.org | Subject: [Haskell] discrepancy between nhc and ghc | | | | ghc: | import Random(Random(randomR)) -- good | import Random(randomR) -- good | | nhc: (1.16) | import Random(Random(randomR)) -- good | import Random(randomR) -- ERROR! nhc says randomR is not found. | | | I was wondering whether this was intentional and which was correct? I | much much prefer the ghc behavior since it lets you export methods | without exporting the class and lets you hide the implementation detail | of whether a function is implemented as a method or normal declaration. | | | John | | -- | John Meacham - ⑆repetae.net⑆john⑈ | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell

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why no strictness annotations in labelled fields?
by S. Alexander Jacobson 02 Dec '04

02 Dec '04

Is there a good reason one can't do: data Foo = Foo {bar::!String} -Alex- ______________________________________________________________ S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com

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discrepancy between nhc and ghc
by John Meacham 02 Dec '04

02 Dec '04

ghc: import Random(Random(randomR)) -- good import Random(randomR) -- good nhc: (1.16) import Random(Random(randomR)) -- good import Random(randomR) -- ERROR! nhc says randomR is not found. I was wondering whether this was intentional and which was correct? I much much prefer the ghc behavior since it lets you export methods without exporting the class and lets you hide the implementation detail of whether a function is implemented as a method or normal declaration. John -- John Meacham - ⑆repetae.net⑆john⑈

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pattern matching accross instance declarations
by S. Alexander Jacobson 02 Dec '04

02 Dec '04

Doing read/show on existential types would be a lot easier if pattern matching worked *accross* instance declarations and not only within them For example, this code produces an "Ambiguous type variable" GHC error, but it would be really helpful if it didn't: data MyExistantialType=forall v.(Show v)=>EType v class MyExistentialTypeable a where toMyType::String->MyExistantialType instance MyExistentialTypeable String where toMyType "String" = EType "foo" instance MyExistentialTypeable Int where toMyType "Int" = EType "bar" tVal (EType v)=show v main = print $ tVal $ toMyType "String" I know Haskell has a general prohibition on defining functions in multiple locations, but instance declarations already violate it. Why not go all the way? My current approach is manually writing lookup functions in addition to per-instance functions and that is both annoying and error-prone. -Alex- ______________________________________________________________ S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com

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Coordination 2005: Last call for papers
by Jean-Marie JACQUET 01 Dec '04

01 Dec '04

[ Our apologies for multiple copies. ] ====================================================================== Last Call for Papers COORDINATION 2005 7th International Conference on Coordination Models and Languages Namur, Belgium, 20-23 April 2005 http://www.coordination2005.org ====================================================================== IMPORTANT NEWS * Publication of the proceedings in the Lecture Notes of Computer Science of Springer-Verlag * Publication of selected work in Science in Computer Programming ====================================================================== IMPORTANT DATES * Submission of abstract: December 15, 2004 * Submission of papers: December 21, 2004 * Notification of acceptance: February 1, 2005 * Final version: February 15, 2005 * Conference: April 20-23, 2005 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), and Pisa (Italy). More details are available at http://music.dsi.unifi.it/coordination. 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 The conference proceedings will be published by Springer, in the Lecture Notes in Computer Science (LNCS) series. Proceedings of the previous editions of this conference are also available in the LNCS series: volumes 1061, 1282, 1594, 1906, 2315, and 2949. A selection of the best papers will published in a special issue of the journal Science of Computer Programming. 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 December 15, 2004. Submission of the full paper is due no later than December 21, 2004. Submissions are handled through a conference management system, accessible from the conference web site: http://www.coordination2005.org. 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 Institute of Informatics at the University of Namur, Belgium. Capital of the Walloon Region, Namur is a beautiful city of 80.000 inhabitants. Its position at the confluent of two rivers gave it military and economic appeal, exploited by the Roman Empire and by many others since then. Much evidence of Namur's past can be visited nowadays, including the citadel, one of the greatest in Europe. Close to Brussels (60 km) and at the intersection of European railways and highways, Namur can be easily reached by road, train, and plane. PROGRAM COMMITTEE Co-Chairs Jean-Marie Jacquet University of Namur, Belgium jmj(a)info.fundp.ac.be www.info.fundp.ac.be/~jmj/ Gian Pietro Picco Politecnico di Milano, Italy picco(a)elet.polimi.it www.elet.polimi.it/upload/picco Members Farhad Arbab CWI, The Netherlands Luca Cardelli Microsoft Research, United Kingdom Gianluigi Ferrari University of Pisa, Italy Paola Inverardi University of l'Aquila, Italy Toby Lehman IBM Almaden Research Center, USA Ronaldo Menezes Florida Institute of Technology, USA Amy Murphy University of Lugano, Switzerland Andrea Omicini University of Bologna, Italy George Papadopoulos University of Cyprus, Cyprus Ernesto Pimentel University of Malaga, Spain Rosario Pugliese University of Firenze, Italy Antonio Porto New University of Lisbon, Portugal Carolyn Talcott SRI International, USA Sebastian Uchitel Imperial College, United Kingdom Jan Vitek Purdue University, USA Michel Wermelinger New University of Lisbon, Portugal The Open University, UK Herbert Wiklicky Imperial College, United Kingdom Alexander Wolf University of Colorado, USA Alan Wood University of York, United Kingdom Gianluigi Zavattaro University of Bologna, Italy

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CLIMA VI :: First Call for Papers
by clima VI <clima-vi＠deis.unibo.it> 01 Dec '04

01 Dec '04

Apologies for cross-postings. Please send to interested colleagues and students ============================ First Call for Papers ============================ CLIMA VI Sixth International Workshop on Computational Logic in Multi-Agent Systems City University, London, UK June 27-29, 2005 http://clima.deis.unibo.it/ =============================================================================== Aims and scope -------------- Multi-Agent Systems are communities of problem-solving entities that can perceive and act upon their environments to achieve their individual goals as well as joint goals. The work on such systems integrates many technologies and concepts in artificial intelligence and other areas of computing as well as other disciplines. Over recent years, the agent paradigm gained popularity, due to its applicability a full spectrum of domains, from search engines to educational aids to electronic commerce and trade, e-procurement, recommendation systems, simulation and routing, to cite only some. Although commonly implemented by means of imperative languages, mainly for reasons of efficiency, agent-related concepts have recently increased their influence in the research and development of Computational Logic based systems. Computational Logic provides a well-defined, general, and rigorous framework for studying syntax, semantics and procedures for various tasks by individual agents, as well as interaction amongst agents in multi-agent systems, for attending implementations, environments, tools, and standards, and for linking together specification and verification of properties of individual agents and multi-agent systems. The purpose of this workshop is to discuss techniques, based on Computational Logic, for representing, programming and reasoning about Agents and Multi-Agent Systems in a formal way. We solicit unpublished papers that present formal approaches to multi-agent systems based upon or relating to computational logic. The approaches must make a significant contribution to the practice of multi-agent systems. Topics ------ Relevant topics include, but are not limited to, the following: * logical foundations of multi-agent systems * knowledge and belief representation and updates in multi-agent systems * agent and multi-agent hypothetical reasoning and learning * extensions of logic programming for multi-agent systems * non-monotonic reasoning in multi-agent systems * theory and practice of argumentation for agent reasoning and interaction * operational semantics and execution agent models * model checking algorithms, tools, and applications for multi-agent logics * semantics of interaction and agent communication languages * distributed constraint satisfaction in multi-agent systems * temporal reasoning for multi-agent systems * modal logic approaches to multi-agent systems * logic based programming languages for multi-agent systems * distributed theorem proving for multi-agent systems * logic based implementations of multi-agent systems * decision theory for multi-agent systems * specification and verification of formal properties of agent systems Submissions ----------- We welcome and encourage the submission of high quality, original papers, which are not simultaneously submitted for publication elsewhere. Papers should be written in English, formatted according to the Springer LNCS style, which can be obtained from http://www.springeronline.com, and not exceed 16 pages including figures, references, etc. Important Dates --------------- * Submission: April 7, 2005 * Notification: May 6, 2005 * Camera-Ready: May 27, 2005 * CLIMA VI: June 27-29, 2005 Proceedings and post-workshop publications ------------------------------------------ A printed volume with the proceedings will be available at the workshop. Past editions of CLIMA have been published in journal special issues (Electronic Notes in Theoretical Computer Science vol. 70(5) of 2002, Annals of Mathematics and Artificial Intelligence vol. 37(1-2) of 2003 and vol. 42(1-3) of 2004), and book series such as the recent vol. 3259 of Springer-Verlag Lecture Notes in Artificial Intelligence (CLIMA IV) and the forthcoming issue of the same series, featuring the post-proceedings of CLIMA V. Organising committee -------------------- Workshop Chairs * Francesca Toni, Department of Computing, Imperial College London, UK * Paolo Torroni, DEIS, University of Bologna, Italy Local Organisation Chair * Kostas Stathis, Department of Computing, City University London, UK Web Support * Federico Chesani, DEIS, University of Bologna, Italy * Fabio Bucciarelli, DEIS, University of Bologna, Italy Programme committee ------------------- * José Júlio Alfers, New University of Lisbon, Portugal * Rafael H. Bordini, University of Durham, UK * Gerhard Brewka, University of Leipzig, Germany * Jürgen Dix, Technical University of Clausthal, Germany * Thomas Eiter, Vienna University of Technology, Austria * Klaus Fischer, DFKI, Germany * Michael Fisher, University of Manchester, UK * James Harland, RMIT, Australia * Katsumi Inoue, National Institute of Informatics, Japan * Antonis Kakas, University of Cyprus * Evelina Lamma, University of Ferrara, Italy * João Leite, New University of Lisbon, Portugal * Paolo Mancarella, University of Pisa, Italy * Paola Mello, University of Bologna, Italy * John Jules Ch. Meyer, Utrecht University, The Netherlands * Leora Morgenstern, IBM T.J. Watson Research Center, USA * Wojciech Penczek, Polish Academy of Sciences, Poland * Jeremy Pitt, Imperial College London, UK * Enrico Pontelli, New Mexico State University, USA * Fariba Sadri, Imperial College London, UK * Ken Satoh, National Institute of Informatics, Japan * Renate Schmidt, University of Manchester, UK * Trao Can Son, New Mexico State University, USA * Kostas Stathis, City University London, UK * Wiebe van der Hoek, University of Manchester, UK * Cees Witteveen, Delft University of Technology, The Netherlands

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ANNOUNCE: DrIFT 2.1.0
by John Meacham 01 Dec '04

01 Dec '04

DrIFT 2.1.0 is out! http://repetae.net/john/computer/haskell/DrIFT/ Here are the recent changes: * added 'get' utility which creates foo_g for each label which returns its value in a failing monad rather than raising an error. * added 'from' utility which creates fromFoo for each constructors * no longer an error for DERIVEPATH to not be set * added -i to ignore directives in file. useful with -g and -r for testing * added 'Query' which creates from, get, has, and is functions, but in a class with an instance for the data type. useful for extensible data types * added deriving rule for 'Monoid' * added deriving rule for 'FunctorM' * added deriving rule for 'RmapM' * added code subdirectory with support code and perhaps more importantly, DrIFT is now in a darcs repository! the repository is at: http://repetae.net/john/repos/DrIFT/ and it may be browsed here: http://repetae.net/cgi-bin/darcs.cgi/DrIFT/ Several people have sent me patches recently, and unfortunatly I lost some of my email, so if you sent me a patch and your code didn't make it into this release, please resend it, or better yet use darcs to send a patch. The half-minute tutorial for sending me a patch if you don't know darcs is ;darcs get http://repetae.net/john/repos/DrIFT/ ;cd DrIFT edit code ;darcs record ;darcs send more info on darcs can be gotten from http://abridgegame.org/darcs/ John -- John Meacham - ⑆repetae.net⑆john⑈

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