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Haskell recruitment?
by Jochen L. Leidner 06 Sep '04

06 Sep '04

Dear Haskell list subscribers, I'd be interested to learn what experiences you have had with recruiting Haskell developers (I shall post a summary of infos worth mentioning to the list if you e-mail me). Also, does anyone here have noteworthy experiences in the area of integration of code from Haskell programmers and non-Haskell programmers in a team (N.B. I'm talking about the software process in terms of teamwork best practices rather than the software-technical interoperability). Finally, would it be considered spam to post Haskell-realted job postings in this group? Thanks in advance. Regards, Jochen -- Jochen L Leidner, MA MPhil (CSTIT) <leidner(a)acm.org> PhD student <Jochen.Leidner(a)ed.ac.uk> University of Edinburgh <http://www.iccs.informatics.ed.ac.uk/~s0239229/> Try Nuggets, the new mobile phone search engine! <http://www.myNuggets.net/>

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Call for Papers: Special Issue M4M
by Carlos Areces 06 Sep '04

06 Sep '04

Call for Papers for "Methods for Modalities" A Special Issue of the Journal of Applied Logic (http://www.sciencedirect.com/science/journal/15708683) The workshop `Methods for Modalities' (M4M) organized every two years aims to bring together researchers interested in developing proof tools and decision methods for modal logic broadly conceived, including description logic, hybrid logic, temporal logic, etc. During 1993 M4M-3, the third instance of the workshop was organized in Nancy, France. We have been invited by the Journal of Applied Logic to prepare a Special Issue containing selected publications from the workshop, in addition to other articles that might fit within the topics of interest of M4M. For that reason we are now distributing this Call for Papers. TOPICS OF INTEREST OF M4M The following list is provided as an example of suitable topics for the Special Issue. All topics should concern modal-like logics, broadly conceived. The list is by no means exhaustive and is given in an arbitrary order: * Automated theorem proving * Decision methods * Proof methods * Standard and non-standard inference problems * Model checking * Testing * Expressive power * Modelling * Applications * Successful uses of modal-like languages in other fields * Knowledge representation SUBMISSION DETAILS The final version of accepted papers has to follow the standard layout guidelines of the Journal of Applied Logic. Instructions for authors and the latex style files are available from http://staff.science.uva.nl/~m4m/SI/ Although not mandatory, we suggest to use the corresponding style files from that web-page also for your initial submission. The issue aims at high quality papers with a length around 20 to max. 30 pages. Please send your submission in postscript or pdf no later than October 31th, 2004 to areces(a)loria.fr. Notice that all papers will be refereed to ensure that their suitability for journal publication. IMPORTANT DATES Deadline for Submissions: October 31th, 2004 Reviews Due : November 21th, 2004 Final Versions Due : December 19th, 2004 GUEST EDITORS of the Special Issue Dr. Carlos Areces INRIA Lorraine 615, rue du Jardin Botanique 54602 Villers les Nancy Cedex, France phone : +33 (0)3 83 58 17 90 fax : +33 (0)3 83 41 30 79 e-mail : carlos.areces(a)loria.fr www : http://www.loria.fr/~areces

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Select using MArray
by Andreas Farre 06 Sep '04

06 Sep '04

Hi, I found myself needing to quickly and effectively compute the median of an array of ordered elements (read as: I want to build a perfectly balanced kD-tree). Of course there was a nice imperative one, implemented for language "so-and-so" and "this-and-that" but I couldn't find a Haskell implementation. So I'd thought I'd give it a go. I used (Select by Floyd and Rivest): http://portal.acm.org/citation.cfm?id=360694 wich is mainly targeted for Algol. It turns out that it works rather nice so I thought I'd post it here so that it could evolve even further (or be re-implemented), see attachment. /Andreas

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Call for Participation: FMCO 2004
by M.M. Bonsangue 06 Sep '04

06 Sep '04

Apologize if you receive multiple copies of this e-mail. ********************* CALL FOR PARTICIPATION ******************** Third International Symposium on Formal Methods for Components and Objects (FMCO 2004) The objective of this symposium is to bring together top researchers in the area of software engineering to discuss the state-of-the-art and future applications of formal methods in the development of large component-based and object-oriented software systems. DATES 2 - 5 November 2004 PLACE Lorentz Center, Leiden University, Leiden, The Netherlands URL http://fmco.liacs.nl/fmco04.html Early registration fee applies for registration before 20/09/2004 !!! Participation is limited to about 80 people, based on a first-in first-served policy. For more information about participation and registration see the FMCO site at http://fmco.liacs.nl/fmco04.html or consult either F.S. de Boer (frb(a)cwi.nl) or M.M. Bonsangue (marcello(a)liacs.nl) PRELIMINARY PROGRAM TUESDAY 2nd, November 2004 8:45 - 9:00 Welcome 9:00 - 10:00 Keynote: Robin Milner (Cambridge University, UK) 10:00 - 10:30 Break 10:30 - 11:15 Rocco de Nicola (University of Firenze, IT) 11:15 - 12:00 Eugenio Moggi (Genova University, IT) 12:00 - 13:30 Lunch break 13:30 - 14:30 Keynote: Kim Bruce (Williams College, USA) 14:30 - 15:00 Break 15:00 - 15:45 Julian Rathke (Sussex University, UK) 15:45 - 16:00 Break 16:00 - 16:45 Martin Steffen (Kiel University, DE) 16:45 - 17:30 Marcello Bonsangue (LIACS, NL) WEDNESDAY 3rd, November 2004 9:00 - 10:00 Keynote: Tom Henzinger (University of California, Berkeley, USA) 10:00 - 10:30 Break 10:30 - 11:15 Susanne Graf (Verimag, FR) 11:15 - 12:00 Wang Yi (Uppsala University, SE) 12:00 - 13:15 Lunch break 13:15 - 14:15 Keynote: Thomas Ball (Microsoft Research at Redmond, USA) 14:15 - 14:30 Break 14:30 - 15:15 Frits Vaandrager (Nijmegen University, NL) 15:15 - 16:00 Wolfgang Weck (Oberon Microsystems, CH) 17:00 - 19:15 Social Event 19:30 - Dinner THURSDAY 4th, November 2004 9:00 - 10:00 Keynote: Kim Larsen (Aalborg University, DK) 10:00 - 10:30 Break 10:30 - 11:15 Ed Brinksma (University of Twente, NL) 11:15 - 12:00 Andreas Podelski (Max Plank Inst. for Informatics, DE) 12:00 - 13:30 Lunch break 13:30 - 14:30 Keynote: Chris Hankin (Imperial College, UK) 14:30 - 15:00 Break 15:00 - 15:45 David Naumann (Stevens Institute of Technology, USA) 15:45 - 16:30 Tobias Nipkow (Munchen University, DE) 16:30 - 16:45 Break 16:45 - 17:30 Liu Zhiming (UNU-IIST, Macao) FRIDAY 5th, November 2004 9:00 - 10:00 Keynote: Samson Abramsky (Oxford University, UK) 10:00 - 10:30 Break 10:30 - 11:15 Luca de Alfaro (UC Santa Cruz, USA) 11:15 - 12:00 Luis Barbosa (Minho University, PT) 12:00 - 13:30 Lunch break 13:30 - 14:30 Keynote: Reinhard Wilhelm (Saarland University, DE) 14:30 - 15:00 Break 15:00 - 15:45 Olaf Owe (University of Oslo, NO) 15:45 - 16:30 Pierre Cointe (Ecole des Mines de Nantes, FR) ORGANIZING COMMITTEE F.S. de Boer (CWI and Utrecht University) M.M. Bonsangue (LIACS-Leiden University) S. Graf (Verimag) W.P. de Roever (CAU)

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ANNOUNCE: Haskell XML Toolbox Version 4.02
by Uwe Schmidt 06 Sep '04

06 Sep '04

Haskell XML Toolbox 4.02 I would like to announce a new version of the Haskell XML Toolbox for processing XML including a validating parser and a new XPath module. new features: * hierachical module structure * ghc package support the library is compiled into a package "hxt" for easy use with ghc and ghci * new configurable filters to ease parsing and writing More information and download: http://www.fh-wedel.de/~si/HXmlToolbox/index.html Please email comments, bugs, etc. to hxmltoolbox(a)fh-wedel.de Uwe Schmidt <uwe(a)fh-wedel.de> -- University of Applied Sciences, Wedel, Germany http://www.fh-wedel.de/~si/index.html

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Newbie Question about Types
by David Greenberg 06 Sep '04

06 Sep '04

Hi, I very recently just came to Haskell from the Java and Perl worlds, so my understanding of Haskell's type system is still a little vague. The tutorial and Google didn't seem to have an answer to my question, so I am hoping someone here might be able to help me. I am writing some code comparable to the following: class Fooable a where foo1 :: a -> a -> a foo2 :: a -> a -> a type MyType a = String -> a data (Fooable (MyType a)) => AnotherType a = AnotherType {str :: String, myval :: (MyType a)} instance (Fooable (MyType a)) => Fooable (AnotherType a) where (AnotherType s1 m1) `foo1` (AnotherType s2 m2) = AnotherType "dummy string" (m1 `foo1` m2) The trick here is I want to be able to pass a value of type MyType to the AnotherType constructor without making MyType directly an instance of Fooable. In other words, I want some sort of sub-type of MyType to be an instance of Fooable. That way I can use it in the constructor of AnotherType. I understand that type inference might make a lot of this easier, but I am trying to make a very strict API out of my module(s), and feel that relying on inference at this stage could become buggy. Thanks in advance for any help that you all can give me. -David

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Data.COrdering & Data.Tree.AVL updated
by Adrian Hey 06 Sep '04

06 Sep '04

Hello, I've posted undated versions of both these packages here.. http://homepages.nildram.co.uk/~ahey/HLibs/Data.COrdering/ http://homepages.nildram.co.uk/~ahey/HLibs/Data.Tree.AVL/ COrdering is needed by AVL. The AVL package has had quite a few new goodies added, including support for using AVL trees for sequences and sets. It's think it's pretty much complete now, but I can still think of a few extras that might be useful (like a "Zipper" maybe). If anybody else can think of things that would be useful but which can't be implemented easily or efficiently with the functions provided then please let me know. Regards -- Adrian Hey

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RE: [Haskell] Non-terminating compilation of non-positive construction.
by Simon Peyton-Jones 06 Sep '04

06 Sep '04

It's a documented bug in GHC. http://www.haskell.org/ghc/docs/latest/html/users_guide/bugs.html#BUGS-G HC Simon | -----Original Message----- | From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of Stefan | Karrmann | Sent: 05 September 2004 13:57 | To: haskell(a)haskell.org | Subject: [Haskell] Non-terminating compilation of non-positive construction. | | Hi, | | in Coq (cf. <http://pauillac.inria.fr/coq/coq1-eng.html>) inductive and | coinductive (aka lazy) types are restricted by the positivity condition | (cf. <http://pauillac.inria.fr/coq/doc8/Reference-Manual006.html#htoc91>). | | My first try to violate this condition in Haskell is: | --------------------------------------------------- | module Limits (module Limits) where | | import qualified Prelude$ | $ | data False = False !False | deriving (Prelude.Show) | -- Approximation of: data False = {- no Value -} | -- The lazy variant has the same result. | -- Of course there is: f = False f | | data Non_positive = Non_pos (Non_positive -> False) | | app :: Non_positive -> Non_positive -> False | app f x = case f of | Non_pos h -> h x | | delta :: Non_positive | delta = Non_pos (\ x -> app x x) | | -- Up to this definition ghc terminates. | | -- (\x -> x x) (\x -> x x) | loop :: False | loop = app delta delta | ---------------------------------------------------- | | The compilation by the Glorious Glasgow Haskell Compilation System, | version 6.2, loops on this small module. IMHO only the execution should | loop or non positive constructions should be excluded. | | Is it a bug or is non positivity too dangerous? | | Sincerly, | -- | Stefan Karrmann | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell

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Non-terminating compilation of non-positive construction.
by Stefan Karrmann 05 Sep '04

05 Sep '04

Hi, in Coq (cf. <http://pauillac.inria.fr/coq/coq1-eng.html>) inductive and coinductive (aka lazy) types are restricted by the positivity condition (cf. <http://pauillac.inria.fr/coq/doc8/Reference-Manual006.html#htoc91>). My first try to violate this condition in Haskell is: --------------------------------------------------- module Limits (module Limits) where import qualified Prelude$ $ data False = False !False deriving (Prelude.Show) -- Approximation of: data False = {- no Value -} -- The lazy variant has the same result. -- Of course there is: f = False f data Non_positive = Non_pos (Non_positive -> False) app :: Non_positive -> Non_positive -> False app f x = case f of Non_pos h -> h x delta :: Non_positive delta = Non_pos (\ x -> app x x) -- Up to this definition ghc terminates. -- (\x -> x x) (\x -> x x) loop :: False loop = app delta delta ---------------------------------------------------- The compilation by the Glorious Glasgow Haskell Compilation System, version 6.2, loops on this small module. IMHO only the execution should loop or non positive constructions should be excluded. Is it a bug or is non positivity too dangerous? Sincerly, -- Stefan Karrmann

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CFP - PADL'2005 - Deadline Sept. 10
by Manuel Hermenegildo 04 Sep '04

04 Sep '04

************************************************************************* * - PAPER SUBMISSION DEADLINE APPROACHING: *** September 10th! *** * * - BEST PAPER AWARD: A best paper award ($500) will be given to the * * paper judged most innovative and practical. * * - PADL 05 proceedings will be published as Springer Verlag LNCS. * * Past proceedings: LNCS 1551, 1753, 1990, 2257, 2562, and 3057. * ************************************************************************* FINAL CALL FOR PAPERS Seventh International Symposium on Practical Aspects of Declarative Languages 2005 (PADL 05) http://www.unm.edu/~herme/padl05/ Long Beach, California, USA January 10-11, 2005 Co-located with ACM POPL, January 12-14, 2005 Paper submission deadline: September 10th Declarative languages build on sound theoretical foundations to provide attractive frameworks for application development. These languages have been successfully applied to a wide array of different real-world situations, including database management, active networks, software engineering, decision support systems, or music composition. New developments in theory and implementation have opened up new application areas. At the same time, the application of declarative languages to novel problems raises numerous interesting research issues. Well-known questions include designing for scalability, language extensions for application deployment, and programming environments. Thus, applications often drive the progress in the theory and implementation of declarative systems, and benefit from this progress as well. PADL is a forum for researchers and practioners to present original work emphasizing novel applications and implementation techniques for all forms of declarative concepts, including, functional, logic, constraints, etc. Topics of interest include: * Innovative applications of declarative languages. * Declarative domain-specific languages and applications. * Practical applications of theoretical results. * New language developments and their impact on applications. * Evaluation of implementation techniques on practical applications. * Novel implementation techniques relevant to applications. * Novel uses of declarative languages in the classroom. * Practical experiences. PADL 05 welcomes new ideas and approaches pertaining to applications and implementation of declarative languages, and is not limited to the scope of the first six PADL symposia (past proceedings can be found in Springer Verlag LNCS, numbers 1551, 1753, 1990, 2257, 2562, and 3057). In this occasion PADL is co-located, as traditionally, with ACM POPL, which will be held immediately following PADL, January 12-14. IMPORTANT DATES Paper Submission: September 10, 2004 Notification: October 10, 2004 Camera-ready: November 10, 2004 Symposium: January 10-11, 2005 SUBMISSION GUIDELINES Authors should submit an electronic copy of the full paper (written in English) in Postscript (Level 2) or PDF. Submission should be completed using the electronic procedure available at the conference website. Papers must be no longer than 15 pages, written in 11-point font and with single spacing. Since the final proceedings will be published as Lecture Notes in Computer Science by Springer Verlag, authors are strongly encouraged to use the LNCS paper formatting guidelines for their submission. Each submission must include on its first page the paper title; authors and their affiliations; contact author's email and postal addresses, telephone and fax numbers, abstract, and three to four keywords. The keywords will be used to assist us in selecting appropriate reviewers for the paper. If electronic submission is impossible, please contact the program chairs for information on how to submit hard copies. MOST PRACTICAL PAPER AWARD A cash prize of US$500 will be awarded to the submission that is judged by the program committee to be the best in terms of practicality, originality, and clarity of presentation. The program committee may choose not to make an award; or may make multiple awards, in which case the award money will be evenly divided. CONTACTS Please visit the conference web site: http://www.unm.edu/~herme/padl05/ for further information. For additional information about papers and submissions, please contact the Program Chairs: Manuel Hermenegildo (1,2) herme(a)unm.edu, or Daniel Cabeza (2) dcabeza(a)fi.upm.es 1 Departments of Computer Science and Electrical and Computer Engineering The University of New Mexico, Albuquerque, NM 87131, U.S.A. 2 Facultad de Informatica, Universidad Politecnica de Madrid 28660-Boadilla del Monte, Madrid, Spain For additional information about the conference please contact the General Chair: Gopal Gupta Department of Computer Science University at Texas at Dallas, Dallas, TX, U.S.A. gupta(a)utdallas.edu SPONSORED BY: ACM SIGPLAN (applied for), COMPULOG Americas (http://www.cs.nmsu.edu/~complog) The Association for Logic Programming (http://www.cs.kuleuven.ac.be/~dtai/projects/ALP/) -- ----------------------------------------------------------------------------- Manuel Hermenegildo | University of New Mexico, NM, USA Professor, P. of Asturias Chair | Office: ECE 219A Depts. of Computer Science and | Tel: +1 (505) 277 -9328/-3112 Electrical and Computer Engineering | http://www.unm.edu/~herme -----------------------------------------------------------------------------

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