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Data.Tree.drawTree more spacefilling?
by Johannes Waldmann 03 Jan '08

03 Jan '08

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear all, I'm looking for a Data.Tree.drawTree that is a bit more "spacefilling" (put some subtrees side by side). Thanks - Johannes Waldmann, Leipzig. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHfTr53ZnXZuOVyMIRAhqkAKCkXFRyqtR+6KaTnFf2msAGd1hf1QCeOFpB /WMg+//boG/vAos+yO0iHZo= =P13d -----END PGP SIGNATURE-----

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garbage collection of Concurrent Haskell threads?
by Conal Elliott 03 Jan '08

03 Jan '08

The classic paper "The Incremental Garbage Collection of Processes" ( http://citeseer.ist.psu.edu/baker77incremental.html) describes "futures" and how particularly garbage collecting them when their pending result is no longer referenced. I've been playing with an implementation of futures in Concurrent Haskell (http://haskell.org/haskellwiki/Reactive) using MVars, and I'm stumped about how to GC non-winning threads in a race between futures ("parallel or"). I'm having winner kill loser, which seems to work fine, though is potentially dangerous w.r.t locked resources. Still, the elegance of a GC-based solution appeals to me. Has anyone explored process GC ideas for Concurrent Haskell (or STM)? Futures are implemented using Concurrent Haskell's MVars. I first tried using STM and TVars, simply using orElse to implement mappend for futures. However, I didn't see how to avoid nesting "atomically", which yielded a run-time error. If anyone has ideas about using STM & TVars for futures, I'd love to hear. Thanks, - Conal

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Empty instance declaration
by Hugo Macedo 03 Jan '08

03 Jan '08

Dear all A student from a beginners course on Functional Programming came to me with a problem, he declared a type like: data WeekDay = Mon | Tue | Fri -- ... He had forgot to complete a Show instance definition. instance Show WeekDay where (empty) Then he complained about getting *** Exception: stack overflow when he tried to invoke some function on that type. After checking the Haskell98 grammar I found out that this is allowed syntactically and probably semantically too. Is there any reason to do that? Now I'm wondering: Shouldn't a class be an warranty of a well defined interface? Thus forcing the user to define the show function or showPrec? Am I missing any point? My best regards, Hugo

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announcing qtHaskell-1.1.1, the first preview release of qtHaskell
by David Harley 03 Jan '08

03 Jan '08

For all interested in Haskell GUIs, there is now a first preview release of qtHaskell - a set of Haskell bindings for Trolltech's Qt available at http://qthaskell.sourceforge.net Any feedback, comments etc welcome Merry Christmas David Harley P.S. if anyone can get the system to build and work on a non-linux or Windows environment - in particular MacOs - could the let me know the precise install steps required.

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SAS 2008 Third Call for Papers
by German Vidal 02 Jan '08

02 Jan '08

PLEASE POST --> SAS 2008 at the Technical University of Valencia We are happy to announce that SAS 2008, the Static Analysis Symposium, will take place at the Technical University of Valencia: Submission of abstract: January 12, 2008 Submission of full paper: January 19, 2008 Notification: March 7, 2008 Camera-ready version: April 5, 2008 Conference: July 16-18, 2008 Please see: http://www.dsic.upv.es/~sas2008/ ** The submission site is now open ** Maria Alpuente, German Vidal (PC co-chairs) --------------------------------------------------------------------------- Call for papers Static Analysis Symposium - SAS 2008 16-18 July 2008, Valencia, Spain (co-located with LOPSTR 2008) url http://www.dsic.upv.es/~sas2008 email sas2008(a)dsic.upv.es Static Analysis is increasingly recognized as a fundamental tool for high performance implementations and verification of programming languages and systems. The series of Static Analysis Symposia has served as the primary venue for presentation of theoretical, practical, and application advances in the area. The technical programme for SAS 2008 will consist of invited lectures and presentations of refereed papers. Contributions are welcome on all aspects of static analysis, including, but not limited to: abstract domains abstract interpretation abstract testing compiler optimizations control flow analysis data flow analysis model checking program specialization security analysis theoretical analysis frameworks type based analysis verification systems Submissions can address any programming paradigm, including concurrent, constraint, functional, imperative, logic, and object-oriented programming. Survey papers, that present some aspect of the above topics from a new perspective, and application papers, that describe experience with industrial applications, are also welcome. Papers must describe original work, be written and presented in English, and must not substantially overlap with papers that have been published, or that are simultaneously submitted to a journal or a conference with refereed proceedings. Submitted papers should be at most 15 pages formatted in LNCS style (excluding bibliography and well-marked appendices not intended for publication). PC members are not required to read the appendices, and thus papers should be intelligible without them. The conference proceedings is planned to be published by Springer-Verlag in the Lecture Notes in Computer Science series. Invited Speakers Roberto Giacobazzi (Universita' degli Studi di Verona, Italy) Ben Liblit (University of Wisconsin-Madison, USA) PC co-chairs Maria Alpuente (Technical University of Valencia, Spain) German Vidal (Technical University of Valencia, Spain) PC members Elvira Albert (Complutense University of Madrid, Spain) Roberto Bagnara (University of Parma, Italy) Maurice Bruynooghe (Katholieke Universiteit Leuven, Belgium) Radhia Cousot (CNRS & Ecole Polytechnique, France) Javier Esparza (Technical University of Munchen, Germany) Sandro Etalle (University of Twente, The Netherlands) Moreno Falaschi (University of Siena, Italy) Stephen Fink (IBM T.J. Watson Research Center, USA) John Gallagher (Roskilde University, Denmark) Maria del Mar Gallardo (University of Malaga, Spain) Chris Hankin (Imperial College, UK) Manuel Hermenegildo (Technical University of Madrid, Spain) Julia Lawall (University of Copenhagen, Denmark) Alexey Loginov (IBM T.J. Watson Research Center, USA) Hanne Riis Nielson (Technical University of Denmark, Denmark) David Schmidt (Kansas State University, USA) Harald Sondergaard (University of Melbourne, Australia) Tachio Terauchi (Tohoku University, Japan) Ji Wang (National Laboratory for Parallel and Distributed Processing, China) Organizing committee chair Alicia Villanueva (Technical University of Valencia, Spain) Important dates Submission of abstract: January 12, 2008 Submission of full paper: January 19, 2008 Notification: March 7, 2008 Camera-ready version: April 5, 2008 Conference: July 16-18, 2008 ---------------------------------------------------------------------------

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Postdoctoral position at INRIA Nancy (France)
by Eric Kow 28 Dec '07

28 Dec '07

Linguistic Field(s): Computational Linguistics Topic: Surface realisation and large scale over-generation detection Deadline: February 15, 2008. Employer: INRIA (French National Institute for Research in Computer Science) Nancy Grand Est (France) Job Description: The Lorraine Laboratory of IT Research and its Applications (Nancy, France) has a position for a Postdoctoral fellow to work on the development of a surface realiser for French. Applicants must have a ** recent doctoral degree ** (Doctoral thesis less than one year old before the recruitment's date) or defend their PhD before the end of 2008. They must have expertise in an area relevant to the project (linguistics, computational linguistics, computer science), strong hands-on experience in Natural Language Processing and a particular interest in NL generation. A good knowledge of Haskell is a necessity. Further particulars and details of how to apply are available at: http://www.loria.fr/~gardent The official closing date is February 15, 2007, but applications will be processed until the position is filled. Contact: Claire Gardent <claire.gardent(a)loria.fr> -- Eric Kow PGP Key ID: 08AC04F9

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Summer School LERNET 2008 - Call for Participation
by Alberto Pardo - INCO 27 Dec '07

27 Dec '07

=================================================================== Call for Participation International Summer School on Language Engineering and Rigorous Software Development LERNET 2008, Piriapolis, Uruguay February 25 to March 1, 2008 http://www.fing.edu.uy/inco/eventos/lernet2008 email: lernet(a)fing.edu.uy *** REGISTRATION IS OPEN *** =================================================================== The aim of the school is the dissemination of advanced scientific knowledge and the promotion of international contacts among scientists. The school is directed to students and researchers working in computer science and interested in formal techniques for the design and construction of software systems and programming languages. The school is partially supported by the EU LerNet ALFA project (http://www.di.uminho.pt/lernet/) which implements a joint PhD programme on Software Design and Programming Language Engineering, based on a co-tutoring scheme and conformed by 6 european universities and 5 from Latin America. PROGRAM LERNET 2008 will consist of six courses: - Introduction to Type Theory Herman Geuvers (Radboud University Nijmegen, The Netherlands) - Theory and Applications of the PF-transform Jose Nuno Oliveira (University of Minho, Portugal) - Embedded Domain Specific Languages: Combinator Parsers Doaitse Swierstra (Utrecht University, The Netherlands) - Dependent Types at Work Peter Dybjer and Ana Bove (Chalmers University, Sweden) - Formal Programming Language Semantics with Inductive Types Yves Bertot (INRIA Sophia-Antipolis, France) - Verification Methods for Software Security and Correctness Gilles Barthe (INRIA Sophia-Antipolis, France) In addition, there will be some PhD sessions where students from the LerNet project will expose advances of their PhD thesis. VENUE LERNET 2008 will be held at Argentino Hotel (http://www.argentinohotel.com.uy) located in Piriápolis, a seaside city, 100 kms east from Montevideo. REGISTRATION To register, fill in the registration form at http://www.cs.chalmers.se/Cs/Research/Logic/LerNet08/registration.html The deadline for registration is January 31, 2008. Early registration is encouraged. FEES Details about the registration fees can be found in the school's webpage (http://www.fing.edu.uy/inco/eventos/lernet2008) GRANTS We may be able to offer a reduction in the value of the registration fee to a limited number of students. Priority will be given to students from Latin America. Details of the fee reduction application can be found in the school's webpage (http://www.fing.edu.uy/inco/eventos/lernet2008) Deadline for grant application is also January, 31 2008. Early application is encouraged. SCHOOL ORGANISERS Luis Barbosa (Univerity of Minho, Portugal) Ana Bove (Chalmers University, Sweden) Alberto Pardo (Universidad de la República, Uruguay) Jorge Sousa Pinto (Univerity of Minho, Portugal) LOCAL ORGANISATION Alberto Pardo Luis Sierra Carlos Luna Instituto de Computación Facultad de Ingeniería Universidad de la República Montevideo, Uruguay FURTHER INFORMATION For further details on the school, visit the webpage http://www.fing.edu.uy/inco/eventos/lernet2008

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Re: [Haskell] Re: ANNOUNCE: GHC version 6.8.2
by Benjamin L. Russell 26 Dec '07

26 Dec '07

--- Juanma Barranquero <lekktu(a)gmail.com> wrote: ... > > Though, if you're using Emacs on Windows and you do > want it to use a > different HOME you can set > HOME=C:\this\is\my\emacs\home as a new > string value in the HKLM\Software\Gnu\Emacs key of > the registry. The registry ... I hadn't thought of that one. Thanks for the tip. However, usually I steer clear of the registry unless absolutely necessary because making a mistake there can render Windows unbootable. In that case, though, would you happen to know which value in the registry would allow me to override HOMEPATH for GHCi? Benjamin L. Russell

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Re: [Haskell] Re: ANNOUNCE: GHC version 6.8.2
by Benjamin L. Russell 26 Dec '07

26 Dec '07

--- Juanma Barranquero <lekktu(a)gmail.com> wrote: ... > > Though, if you're using Emacs on Windows and you do > want it to use a > different HOME you can set > HOME=C:\this\is\my\emacs\home as a new > string value in the HKLM\Software\Gnu\Emacs key of > the registry. > On Dec 25, 2007 2:36 AM, Benjamin L. Russell > <dekudekuplex(a)yahoo.com> wrote: > > > However, usually I steer clear of the > > registry unless absolutely necessary because > making a > > mistake there can render Windows unbootable. > > Setting something in HLKM\Software\GNU\Emacs would > not render your > Windows unbootable, though it *could* preclude Emacs > from starting. > > > In that case, though, would you happen to know > which > > value in the registry would allow me to override > > HOMEPATH for GHCi? > > AFAIK, GHCi does not read anything from the > registry. You can use the > registry to set HOME (and perhaps modify HOMEPATH / > HOMEDRIVE), but > the effect wouldn't be GHCi-specific. > > What I said about Emacs works because Emacs for > Windows takes the > trouble to read HKLM\Software\GNU\Emacs and > interpret some keys as > environment variables. This information is all very useful for customizing Emacs. Thank you for sharing this information. In that case, may I suggest to the developers of GHCi that in the next release, they design GHCi to read the Windows registry for HKEY_LOCAL_MACHINE\SOFTWARE\Haskell\GHCi\<next-release-version-number> for a HOME key set as the GHCi HOME environmental variable, so that I can set HOME=<drive-letter>:\this\is\my\GHCi\home there (also well as adding suitable documentation for this new feature in the FAQ)? There is already a directory there for Hugs called HKEY_LOCAL_MACHINE\SOFTWARE\Haskell\Hugs\WinhugsSep 2006, and it would seem to make sense to add a directory for GHCi there as well. Benjamin L. Russell

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ANNOUNCE: Haskell Communities & Activities Report (13th ed., December 2007)
by Andres Loeh 22 Dec '07

22 Dec '07

On behalf of the many, many contributors, I am pleased to announce that the Haskell Communities and Activities Report (13th edition, December 2007) http://www.haskell.org/communities/ is now available from the Haskell Communities home page in PDF and HTML formats. Many thanks go to all the people that contributed to this report, both directly, by sending in descriptions, and indirectly, by doing all the interesting things that are reported. I hope you will find it as interesting a read as we did. If you haven't encountered the Haskell Communities and Activities Reports before, you may like to know that the first of these reports was published in November 2001. Their goal is to improve the communication between the increasingly diverse groups, projects and individuals working on, with, or inspired by Haskell. The idea behind these reports is simple: Every six months, a call goes out to all of you enjoying Haskell to contribute brief summaries of your own area of work. Many of you respond (eagerly, unprompted, and well in time for the actual deadline ;) ) to the call. The editor collects all the contributions into a single report and feeds that back to the community. When we try for the next update, six months from now, you might want to report on your own work, project, research area or group as well. So, please put the following into your diaries now: ---------------------------------------- End of April 2008: target deadline for contributions to the May 2008 edition of the HC&A Report ---------------------------------------- Unfortunately, many Haskellers working on interesting projects are so busy with their work that they seem to have lost the time to follow the Haskell related mailing lists and newsgroups, and have trouble even finding time to report on their work. If you are a member, user or friend of a project so burdened, please find someone willing to make time to report and ask them to `register' with the editor for a simple e-mail reminder in the middle of April (you could point me to them as well, and we can then politely ask if they want to contribute, but it might work better if you do the initial asking). Of course, they will still have to find the ten to fifteen minutes to draw up their report, but maybe we can increase our coverage of all that is going on in the community. Feel free to circulate this announcement further in order to reach people who might otherwise not see it. Enjoy! Andres Loeh <hcar at haskell.org> -- Haskell Communities and Activities Report (http://haskell.org/communities)

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