December 2007 - Haskell

Nested guards?
by Iavor Diatchki 06 Dec '07

06 Dec '07

Hi, Lately I have been using pattern guards more than usual and I find that occasionally I need to nest them (i.e., I have alternatives with a common prefix). This seems to happen when I need to do some preliminary checking, followed by some decision making. Here is an example: server text | Just xs <- parse text , | "field1" `elem` xs = ... do one thing ... | "field2" `elem` xs = ... do something else ... server _ = ... invalid request ... As far as I can see this should be a fairly simple change to the pattern bindings extension. Would anyone else find this a useful feature, and if so what syntax should we use? -Iavor

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CfPart: 3rd Int'l Workshop on Automated Specification and Verification of Web Systems (WWV'07)
by demis＠dimi.uniud.it 05 Dec '07

05 Dec '07

-- We apologize for multiple copies -- ******************************************************************* ****************** Call for participation ******************* ******************************************************************* 3rd International Workshop on Automated Specification and Verification of Web Sites (WWV'07) December 14, 2007, San Servolo, Venice (Italy) http://wwv07.dimi.uniud.it EARLY REGISTRATION DEADLINE: DECEMBER 11th ******************************************************************* WWV'07 will be held in Venice (Italy) in the convention centre of the island of San Servolo. SCOPE The increased complexity of Web sites and the explosive growth of Web-based applications has turned their design and construction into a challenging problem. Nowadays, many companies have diverted their Web sites into interactive, completely-automated, Web-based applications (such as Amazon, on-line banking, or travel agencies) with a high complexity that requires appropriate specification and verification techniques and tools. Systematic, formal approaches to the analysis and verification can address the problems of this particular domain with automated and reliable tools that also incorporate semantic aspects. The program contains papers on formal methods and techniques applied to Web sites, Web services or Web-based applications, such as: * rule-based approaches to Web site analysis, certification, specification, verification, and optimization * formal models for describing and reasoning about Web sites * model-checking, synthesis and debugging of Web sites WWV'07 provides a forum for researchers from the communities of Rule- based programming, Automated Software Engineering, and Web-oriented research to facilitate the cross-fertilization and the advancement of hybrid methods that combine the three areas. REGISTRATION Registration is web-based via the following link: http://wwv07.dimi.uniud.it/registration.html The deadline for early registration is DECEMBER 11th. ACCOMODATION The organization of the workshop has blocked single rooms in the research centre of the island of San Servolo at a very special rate for the nights of Dec. 13th and 14th (so, you can arrive on the 13th and depart on the 15th). Some rooms are still available. For further information, follow the link: http://wwv07.dimi.uniud.it/#accomodation INVITED SPEAKERS Paolo Traverso ITC-IRST, Italy Joost Visser Software Improvement Group, The Netherlands PROGRAM CO-CHAIRS Santiago Escobar Technical University of Valencia, Spain Massimo Marchiori University of Padova, Italy WORKSHOP CHAIR Demis Ballis University of Udine, Italy PROGRAM COMMITTEE Jesus Almendros University of Almeria, Spain Maria Alpuente Technical University of Valencia, Spain Uwe Assmann Technische Universtität Dresden, Germany Demis Ballis University of Udine, Italy Gilles Barthe INRIA Sophia-Antipolis, France Tevfik Bultan University of California, Santa Barbara, USA Santiago Escobar Technical University of Valencia, Spain Moreno Falaschi University of Siena, Italy Nora Koch Ludwig Maximilians Universität München, Germany Temur Kutsia RISC, Linz, Austria Massimo Marchiori University of Padova, Italy Tiziana Margaria University of Potsdam, Germany Catherine Meadows Naval Research Laboratory, USA Sebastian Schaffert Salzburg Research, Austria ACCEPTED PAPERS - Musab AlTurki and Jose Meseguer. Reduction Semantics and Formal Analysis of Orc Programs - Peter Hofner and Florian Lautenbacher. Algebraic Structure of Web Services - Jesus M. Almendros-Jimenez. A RDF Query Language Based on Logic Programming - Maria-Jose Hidalgo, Jose-Antonio Alonso, Francisco-Jesus Martin-Mateos and Jose-Luis Ruiz-Reina. From a generic framework for the ALC description logic to formally verified reasoners - Faisal Abouzaid and John Mullins. A Calculus for Generation, Verification and Refinement of BPEL Specifications - Alessandro Lapadula, Rosario Pugliese and Francesco Tiezzi. Service discovery and negotiation with COWS - Robin Message and Alan Mycroft. Controlling control flow in web applications - Nawal Guermouche, Olivier Perrin and Christophe Ringeissen. Timed Specification For Web Services Compatibility Analysis - Sonia Flores, Salvador Lucas and Alicia Villanueva. Formal Verification of Websites

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Postdoctoral position in Functional Programming and Many-Cores
by Sven-Bodo Scholz 05 Dec '07

05 Dec '07

+----------------------------------------------------------------------------+ POSTDOCTORAL RESEARCH FELLOW IN PROGRAMMING LANGUAGES School of Computer Science University of Hertfordshire, UK Applications are invited for a 3-year postdoctoral research fellowship in functional programming, to work with Dr Sven-Bodo Scholz on the EU-funded project "Architecture Paradigms and Programming Languages for Efficient programming of multiple CORES" (Apple-CORE). The advent of multicore processors has raised new demand for techniques that allow mainstream programmers to effectively utilise machines with a rapidly growing amount of concurrency available at the hardware level. Decades of research into parallel programming have identified several challenges that need to be overcome to achieve this goal. Although the functional paradigm substantially facilitates the identification of concurrently executable tasks, its resource scheduling has proven to be a major challenge. Only in restricted settings, such as the data parallel setting of the functional language SaC (<http://www.sac-home.org/>), has it been shown that satisfactory auto-parallelisation can be achieved by means of sophisticated program analysis. This project is based on a novel micro-threaded hardware architecture developed at the University of Amsterdam (<http://www.science.uva.nl/research/csa/microgrids.html>). Its unique features are support for resource scheduling and fine-grain synchronisation facilities in hardware. These features make it an ideal target architecture for functional programs. The aim of the project is to explore how this may be achieved. If successful, we expect not only an improvement in the data-prallel setting, but we also believe that scalable auto-parallelisation could be possible with other forms of concurrency. Applicants for this position will hold a PhD in Computer Science, and have research experience in programming languages. Experience in any of the following areas is desireable: functional programming, compiler construction, type systems, concurrency theory, high-performance computing, or scientific applications. The successful applicant will work in collaboration with the Compiler Technology and Computer Architecture group at the University of Hertfordshire, a rapidly expanding centre for research on functionally inspired approaches to the efficient utilisation of highly parallel architectures. The group currently comprises 4 academic staff, 1 research staff, and 4 PhD students plus a regular influx of shorter-term research visitors from other labs in the EU, Japan, and the US. Salary will be within the range 25,134 - 32,796 pounds per year, depending on qualifications and experience. The post is available immediately, and will be offered on a term contract for 3 years. Further details regarding the position and how to apply are available from Dr Sven-Bodo Scholz, S.Scholz(a)herts.ac.uk. Applications will be screened as they arrive. For full consideration apply before 9. January 2008. +----------------------------------------------------------------------------+ | Dr Sven-Bodo Scholz Email : S.Scholz(a)herts.ac.uk | | School of Computer Science | | University of Herfordshire Web : hompages.feis.herts.ac.uk/~comqss/ | | College Lane Campus | | Hatfield, Herts, AL10 9AB, UK Phone : +44 (0)1707 28 6403 | +----------------------------------------------------------------------------+

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3 PhD Stipends in Functional Programming and Many-Cores
by Sven-Bodo Scholz 05 Dec '07

05 Dec '07

+----------------------------------------------------------------------------+ PHD STUDENTSHIPS IN PROGRAMMING LANGUAGES School of Computer Science University of Hertfordshire, UK Applications are invited for a 3-year PhD studentship in the Compiler Technology and Computer Architecture group within the School of Computer Science. We can offer three EU-funded PhD studentships as part of the EU projects "Self-Adaptive Embedded Technologies for Pervasive Computing Architectures" (Aether) and "Architecture Paradigms and Programming Languages for Efficient Programming of Multiple Cores" (Apple-CORE). The advent of multicore processors has raised new demand for techniques that allow mainstream programmers to effectively utilise machines with a rapidly growing amount of concurrency available at the hardware level. In both of the aforementioned EU-projects we address that challenge using functional techniques. While the Aether project is concerned with a stream-processing approach based on the language S-Net (<http://snet.feis.herts.ac.uk/>), the Apple-CORE project investigates the suitability of a novel micro-threaded hardware architecture as a compilation target for functional programming languages such as the high-performance language SaC (<http://www.sac-home.org/>). The architecture under consideration is developed by our partners at the University of Amsterdam (<http://www.science.uva.nl/research/csa/microgrids.html>). To strengthen our research team we are looking for up to three new PhD students, who want to be involved in the theoretical and practical aspects of programming language and compiler research for the upcoming generation of highly parallel hardware architectures. Applicants should have a good honours degree or equivalent in a relevant discipline. Experience in any of the following areas is desireable: functional programming, compiler construction, type systems, concurrency theory, high-performance computing, or scientific applications. Successful applicants will become a member of the Compiler Technology and Computer Architecture group at the University of Hertfordshire, a rapidly expanding centre for research on functionally inspired approaches to the efficient utilisation of highly parallel architectures. The group currently comprises 4 academic staff, 1 research staff, and 4 PhD students plus a regular influx of shorter-term research visitors from other labs in the EU, Japan, and the US. The studentships come with a usually tax-free stipend of approximately GBP 12,600 per annum with all tuition fees and research costs being covered separately. Although the studentships do not include any teaching obligations, teaching experience can be gained by taking up extra duties which are paid for on an hourly basis. Further details regarding the studentships and how to apply are available from Mrs Lorraine Nicholls, Research Student Administrator, STRI, Faculty of Engineering and Information Sciences, University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AB, UK. Tel: +44 (0) 1707 286083 Fax: +44 (0) 1707 284185 or email: L.Nicholls(a)herts.ac.uk. Note, all applications must be made via Lorraine Nicholls. Informal discussions with one of the potential PhD supervisors, Dr Sven-Bodo Scholz (S.Scholz(a)herts.ac.uk) are encouraged before handing in an application. The short-listing process will beginn on 9. January 2008. +----------------------------------------------------------------------------+ | Dr Sven-Bodo Scholz Email : S.Scholz(a)herts.ac.uk | | School of Computer Science | | University of Herfordshire Web : hompages.feis.herts.ac.uk/~comqss/ | | College Lane Campus | | Hatfield, Herts, AL10 9AB, UK Phone : +44 (0)1707 28 6403 | +----------------------------------------------------------------------------+

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New releases for Edison, Shellac, and the Lambda Shell
by Robert Dockins 05 Dec '07

05 Dec '07

Fellow Haskellers, The following packages have now all been updated to compile correctly with GHC 6.8.x and Cabal 1.2.x. Cabal 1.2 is now supported and required. GHC 6.6.x and 6.8.x are supported. I would also like to announce that these projects are now hosted from a new web home. If you have bookmarks or automated build systems that point to older versions of these packages, please update them to point to the new locations listed below. The old website will not dissapear, but it will no longer be updated. Thank you! Edison 1.2.1.1 Edison is a library of purely function data structures for Haskell. Project homepage: http://www.cs.princeton.edu/~rdockins/edison/home/ Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/EdisonAPI-1.2.1 http://hackage.haskell.org/cgi-bin/hackage-scripts/package/EdisonCore-1.2.1… Shellac 0.9.1 Shellac is a framework for building read-eval-print style shells. Shells are created by declaratively defining a set of shell commands and an evaluation function. Project homepage: http://www.cs.princeton.edu/~rdockins/shellac/home/ Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Shellac-0.9.1 http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Shellac-readline… Lambda Shell 0.9.1 The Lambda Shell is a feature-rich shell environment and command-line tool for evaluating terms of the pure, untyped lambda calculus. The Lambda Shell builds on the shell creation framework Shellac, and showcases most of Shellac's features. Project homepage: http://www.cs.princeton.edu/~rdockins/lambda/home/ Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/LambdaShell-0.9.1

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Re: Haskell Digest, Vol 52, Issue 1
by Rishiyur Nikhil 04 Dec '07

04 Dec '07

Simon Peyton-Jones said: > But since the read may block, it matters *when* you perform it. > For example if you print "Hello" and then read the IVar, you'll > block after printing; but if you read the IVar and then print, the > print won't come out. If the operation was pure (no IO) then you'd > have a lot less control over when it happened. But this is true of any expression in a non-strict language. Why the special treatment of IVars? Nikhil

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Small Workshop: DEPENDENTLY TYPED PROGRAMMING
by Peter Morris 04 Dec '07

04 Dec '07

Hi everybody, You may be interested to know that we (Thorsten Altenkirch, Tarmo Uustalu & myself) are organizing a small TYPES workshop on *Dependently Typed Programming*. This is a workshop in the tradition of previous workshops on "Dependent Types in Programming" and "Dependently Typed Programming" which cover the use of dependent types in programming in languages like Agda, Cayenne, Coq's CIC, DML, Epigram, Omega, ... The workshop is taking place 18-20 February in Nottingham at the NCSL conference centre. This is on campus but much nicer than the usual student accommodation! The invited speakers at the workshop will be Lennart Augustsson and Xavier Leroy. For more details see the web page: http://sneezy.cs.nott.ac.uk/darcs/DTP08 <http://sneezy.cs.nott.ac.uk/darcs/> The deadline for talks and registration will be in January. However, if you know you would like to come we would appreciate it if you could email us (_@_ dtpnott08 cs.nott.ac.uk) as soon as possible to register your intentions. We have to promise a certain number of rooms and you will also ensure you get accommodation at the NCSL. Cheers, The Organizers

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REMINDER: HC&A Report (December 2007 edition)
by Andres Loeh 04 Dec '07

04 Dec '07

Dear Haskellers, the deadline for the December 2007 edition of the Haskell Communities and Activities Report is only a few days away. If you haven't already, please write an entry for your new project, or update your old entry. Until now, I have about 30 reactions. This is okay compared to the development of previous editions, but not enough given the number of announcements on this list during the past months. Also, many regular contributors haven't yet submitted their entries. Please do! The deadline is Friday, 7 December 2007. If you absolutely cannot make it by Friday, I may be able to give a few days extension on an individual basis. Please contact me if you have any questions. Please mail your entries to <hcar at haskell dot org>, in plain text or pseudo-(La)TeX format. More information can be found in the original Call for Contributions at http://www.haskell.org/pipermail/haskell/2007-November/019988.html I look forward to receiving your contributions. Thanks a lot, Andres (current editor)

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Jobs in Functional Programming event at Chalmers
by John Hughes 03 Dec '07

03 Dec '07

I'm proud to announce that the first "Jobs in Functional Programming" recruitment evening will be held at Chalmers University on the 14th of December. As far as I am aware, this is the first time such an event has been held anywhere in the world. While we're holding the event at Chalmers because we have many skilled functional programmers among our students, it is of course open to anyone who would like to take part. All the details can be found at www.jobs-in-fp.org. Welcome to what promises to be a very exciting event! John Hughes

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