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Fwd: Re: Anyone working on Scientific Squeak?
by Galchin Vasili 06 Sep '01

06 Sep '01

More FYI from Squeak land. Regards, Bill Halchin Note: forwarded message attached. __________________________________________________ Do You Yahoo!? Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger http://im.yahoo.com

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Fwd: Anyone working on Scientific Squeak?
by Galchin Vasili 06 Sep '01

06 Sep '01

Hello, More postings from the Squeak community (Smalltalk). This time it is about Scientific Python! I am posting this as a challenge to all of us in the Haskell world! Regards. Bill Halchin Note: forwarded message attached. __________________________________________________ Do You Yahoo!? Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger http://im.yahoo.com

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FME'2002 CFP
by Lars-Henrik Eriksson 06 Sep '01

06 Sep '01

apologies if you receive multiple copies... Please forward to interested collegues. FORMAL METHODS EUROPE FME 2002 "Formal Methods: Getting IT Right" International Symposium and Tutorials http://floc02.diku.dk/FME/ 20-24 July 2002 Call for Papers *************** FME 2002 is the eleventh in a series of symposia organised by Formal Methods Europe, an independent association whose aim is to stimulate the use of, and research on, formal methods for software development. These symposia have been notably successful in bringing together a community of users, researchers, and developers of precise mathematical methods for software development. In 2002 the symposium will be held in conjunction with the third Federated Logic Conference (FLoC'02) in Copenhagen, Denmark. The theme of FME 2002 is Formal Methods: Getting IT Right. The double meaning is intentional. On the one hand, the theme acknowledges the significant contribution formal methods can make to Information Technology, by enabling computer systems to be described precisely and reasoned about with rigour. On the other hand, it recognises that current formal methods are not perfect, and further research and practice are required to improve their foundations, applicability and effectiveness. FME seeks papers in all aspects of formal methods for computer systems, including the following: * theoretical foundations * practical use and case studies * specification and modelling techniques * software development and refinement * tool support and software engineering environments for formal methods * verification and validation * hidden formal methods, and making benefits available to non-experts * reusable domain theories * method integration * hardware verification In addition to presentations of submitted papers, the symposium will offer tutorials, workshops, invited speakers, and tool demonstrations. PAPERS Full papers should be submitted in Postscript or PDF format by e-mail to reach the Program Co-chairs by 15 January 2002. Papers will be refereed by the Program Committee and must be original research papers that have not been submitted elsewhere for publication. Accepted papers will be published in the symposium proceedings. Papers should not exceed twenty pages, although longer papers will be considered if their content justifies it. LNCS format should be used: see http://www.springer.de/comp/lncs/authors.html for details. Please include a short list of keywords on a separate line at the end of the abstract, beginning with the word "Keyword:" in boldface. OTHER SYMPOSIUM ACTIVITIES Tutorials and workshops will be held on 20-21 July 2002. Each tutorial will last one-half or one day. Proposals are welcome, and should be directed to the Program Co-chairs by 15 January 2002; more details will appear on the web-site above. Tool demonstrations will also take place during the symposium, with the opportunity for presentations to be made about each tool. Proposals for tool demonstrations should be made to the Tool Demonstration Coordinator, with whom provison of necessary computing facilities should be discussed. PEOPLE Organising Chair Dines Bjørner Informatics and Mathematical Modelling Building 322, Richard Petersens Plads Technical University of Denmark DK-2800 Lyngby, Denmark Tel: +45 4525 3720 Email: db(a)imm.dtu.dk Programme Co-chairs Lars-Henrik Eriksson, Industrilogik L4i AB Box 21024, SE-100 31 Stockholm, Sweden Tel: +46 1859 1690 Fax: +46 1847 17058 Email: lhe(a)L4i.se Peter Lindsay, Software Verification Research Centre The University of Queensland, Queensland 4072, Australia Tel: +61 7 3365 2005 Fax: +61 7 3365 1533 Email: Peter.Lindsay(a)svrc.uq.edu.au Programme Committee Bernhard Aichernig Graz University of Technology, Austria Juan Bicarregui SERC Rutherford Labs, UK Ernie Cohen Telcordia Technologies, USA Ben Di Vito NASA Langley Research Center, USA Cindy Eisner IBM Haifa Research Laboratory, Israel Lars-Henrik Eriksson (co-chair) Industrilogik, Sweden John Fitzgerald Transitive Technologies Ltd, UK Jim Grundy Intel Corporation, USA Yves Ledru LSR/IMAG, Domaine Universitaire, France Peter Lindsay (co-chair) University of Queensland, Australia Markus Montigel University of New Orleans, USA Richard Moore IFAD, Denmark Tobias Nipkow Technische Universität München, Germany Colin O'Halloran Qinetiq (ex-DERA), UK Jose Oliveira Universidade do Minho, Portugal Nico Plat West Consulting, The Netherlands Jeannette Wing Carnegie Mellon University, USA Jim Woodcock Oxford University, UK Joakim von Wright Åbo Akademi University, Finland Pamela Zave AT&T Laboratories, USA Tool Demonstration Coordinator Paul Mukherjee The Institute of Applied Computer Sciense (IFAD) Forskerparken 10, DK-5230 Odense M, Denmark Tel: +45 6315 7131 Fax: +45 6593 2999 Email: paul.mukherjee(a)ifad.dk IMPORTANT DATES Submission of papers, tutorial proposals and workshop proposals: 15 January 2002 Notification of acceptance/rejection: 27 March 2002 Camera ready final version of papers due: 10 May 2002

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Call for paper RTA-2002
by Pierre Lescanne 06 Sep '01

06 Sep '01

[Apologies for multiple copies] +----------------------------------------------------+ | REWRITING TECHNIQUES AND APPLICATIONS (RTA 2002) | | | | July 22, 2002 to July 24, 2002 | | in Copenhagen, Denmark | | as part of the Federated Logic Conference FLoC'02 | +----------------------------------------------------+ * RTA 2002 solicits original papers on all aspects of rewriting, including applications, foundations, frameworks, implementations, semantics. There are four submission categories: 1. regular research papers describing new results, 2. papers describing the experience of applying rewriting techniques in other areas, 3. problem sets that provide realistic and interesting challenges in the field of rewriting, 4. system descriptions. * BEST PAPER AWARD: A prize of 500 EUR will be given to the best paper as judged by the program committee. * IMPORTANT DATES: Submissions to reach the program chairperson: January 15, 2002 Notification to authors: March 22, 2002 Final (camera-ready) copy due: April 25, 2002. * PROGRAM COMMITTEE: Andrea Corradini (University of Pisa) Daniel J. Dougherty (Wesleyan University) Jürgen Giesl (RWTH Aachen) Bernhard Gramlich (TU Wien) Thérèse Hardin (University of Paris VI) Christopher Lynch (Clarkson University, Postdam) Jerzy Marcinkowski (University of Wroclaw) Aart Middeldorp (University of Tsukuba ) Joachim Niehren (University of Saarland) Femke van Raamsdonk (Free University Amsterdam) Albert Rubio (University of Barcelona ) Sophie Tison (University of Lille, chair) Ralf Treinen (University Paris-Sud) Click http://www.lifl.fr/~tison/RTA02.html for further information. A Postscript version of the call for paper is available at http://www.ens-lyon.fr/~plescann/CONTRIBUTIONS/CFP_RTA-2002.ps

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HOpenGL Tutorial updated
by Andre W B Furtado 05 Sep '01

05 Sep '01

After a couple of months of inactivity, I am pleased to say that my HOpenGL Tutorial was heavily updated in the last days. I've concluded all basic lessons, and hope to do the same with the intermediate ones soon. You can visit the tutorial at: http://www.cin.ufpe.br/~haskell/hopengl/ Any suggestions, comments or corrections are welcome. Thanks, Andre W B Furtado Recife, Brazil

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Haskell and bioinformatics
by Galchin Vasili 03 Sep '01

03 Sep '01

Hello, Here is a fowarded email from the Squeak (Smalltalk) group where there is a big discussion raging on bioinformatics and Squeak (as well as Java, Python). Please take a look at the Web page set up for BioSqueak. I thought I would start a similar discussion vis-a-vis Haskell. Regards, Bill Halchin Note: forwarded message attached. __________________________________________________ Do You Yahoo!? Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger http://im.yahoo.com

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Fwd: Re: [Biosqueak] The germ of an idea (Bio Haskell library??)
by Galchin Vasili 01 Sep '01

01 Sep '01

Note: forwarded message attached. __________________________________________________ Do You Yahoo!? Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger http://im.yahoo.com

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Re: H98: unicode
by Marcin 'Qrczak' Kowalczyk 31 Aug '01

31 Aug '01

Fri, 31 Aug 2001 11:54:29 +0100, Ross Paterson <ross(a)soi.city.ac.uk> pisze: > uniDigit -> any Unicode decimal digit > > One could mix digits from different languages, but the meaning would > be clear (the Unicode tables include the digit value). An alternative > would be to drop uniDigit; octal or hexadecimal numerals are already > limited to ASCII. Some people on linux-utf8 list were *strongly* in favor of not limiting digits to ASCII (in the context of Char.isDigit and Char.digitToInt). Especially as it seems that all characters marked as decimal digits are used in the same way and order as European digits for forming numbers. Unfortunately a predicate for ASCII digits is needed when the syntax we are going to recognize is specified as using only ASCII digits. One can always write c >= '0' && c <= '9', but named predicates like isDigit are handy as arguments to span, dropWhile etc. Perhaps Haskell 2002 should have both; it's not clear how they should be named. The above paragraph this is irrelevant for Haskell 98 clarification of course. -- __("< Marcin Kowalczyk * qrczak(a)knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK

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type signatures with existentially quantified data constructors
by Avi Pfeffer 31 Aug '01

31 Aug '01

Hi all, I'm trying to write an interpreter for a language embedded in Haskell, that "inherits" Haskell types and values. So I create a type Expr a, to represent expressions of type a, and an evaluator that takes an Expr a and produces an a. (To keep things simple, let's assume there are no variables.) I start with data Expr a = Haskell a | If (Expr Bool) (Expr a) (Expr a) eval :: Expr a -> a eval (Haskell x) = x eval (If x y z) = if eval x then eval y else eval z Next, applications. To correctly type an application expression, I need to introduce an existentially quantified type variable: data Expr a = ... | forall b . Appl (Expr (b->a)) (Expr a) eval (Appl x y) = (eval x) (eval y) Works fine. Things get tricky when I try to add pairs. In order to type a pair expression, I find I need to create a Pair class and introduce a class constraint: class Pair a b c | a -> b c, b c -> a instance Pair (b,c) b c data Expr a = ... | forall b c . Pair a b c => MkPair (Expr b) (Expr c) This seems to express the right type relationships. But now I find I can't write eval for MkPair: eval (MkPair x y) = (eval x, eval y) GHC produces the error message Cannot unify the type-signature variable `a' with the type `(t, t1)' Expected type: a Inferred type: (t, t1) in the definition of function `eval': (eval x, eval y) I have tried various ways of adding type annotations, but I can't seem to make it work. The problem seems to be the combination of class constraint with existential variables. How can I tell the compiler that it should in fact unify a with (t,t1) here? Or am I misunderstanding something, and there is a reason it can't? Perhaps there's a way of typing MkPair without introducing the Pair class? Or is there a completely different approach to my problem? All suggestions welcome. --Avi

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H98: unicode
by Simon Peyton-Jones 31 Aug '01

31 Aug '01

Folks, Thanks to Mark and Marcin for reminding me of one other H98 point. The proposal is: In the lexical syntax for 'symbol', replace symbol -> ascSymbol | uniSymbol by symbol -> ascSymbol | uniSymbol_<special | _ | : | " | '> The reasoning is in the message below. Marcin agreed that the change is correct. I'll adopt it unless anyone yells. Simon -----Original Message----- From: haskell-admin(a)haskell.org [mailto:haskell-admin@haskell.org] On Behalf Of Mark P Jones Sent: 23 July 2001 19:24 To: haskell(a)haskell.org Cc: Marcin 'Qrczak' Kowalczyk; Mark P. Jones Subject: Picky details about Unicode (was RE: Haskell 98 Report possible errors, part one) | 2.2. Identifiers can use small and large Unicode letters ... If we're picking on the report's handling of Unicode, here's another minor quibble to add to the list. In describing the lexical syntax of operator symbols, the report uses: varsym -> (symbol {symbol | :})_<reservedop> symbol -> ascSymbol | uniSymbol uniSymbol -> any Unicode symbol or punctuation The last line seems to include more characters than I'd expect. Specifically: ()[]{} are punctuation (Unicode type Pe, Ps) ` is a symbol, modifier (Unicode type Sk) "':;, are punctuation, other (Unicode type Po) _ is punctuation, connector (Unicode type Pc) And, so, if I read the report correctly, I should be able to define :-) as a consym and `div`, [], and "hello" as varsyms! (Not to mention some altogether more bizarre choices!) I guess the intention here is that: symbol -> ascSymbol | uniSymbol_<special | _ | : | " | '> In fact, since all the characters in ascSymbol are either punctuation or symbols in Unicode, the inclusion of ascSymbol is redundant, and a better specification might be: symbol -> uniSymbol_<special | _ | : | " | '> All the best, Mark P.S. A caveat: I'm not a Unicode expert! Perhaps Marcin can advise ... _______________________________________________ Haskell mailing list Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell

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