March 2007 - Haskell - Haskell.org

ANNOUNCE: Data.CompactString 0.3 - Unicode ByteString with different encodings
by Twan van Laarhoven 24 Mar '07

24 Mar '07

Hello all, I would like to announce version 0.3 of my Data.CompactString library. Data.CompactString is a wrapper around Data.ByteString that represents a Unicode string. This new version supports different encodings, as can be seen from the data type: > data Encoding a => CompactString a Currently the following encodings are supported: - UTF-8, UTF-16 and UTF-32 (both big and little endian) - ASCII - ISO-8859-1 (latin1) - A custom compact encoding Conversion between different encodings, and between CompactStrings and ByteStrings is possible. There are also functions to automatically detect the encoding of files based on a byte order mark. Just this part of CompactString could be used as an encoding library for ByteStrings. In addition to overloaded functions like > length :: Encoding a => CompactString a -> Int, there are also modules Data.CompactString.UTF8, Data.CompactString.UTF16, etc. which are restricted to a single encoding: > length :: CompactString UTF8 -> Int I expect that these will be more useful in most cases. The library is now feature complete, but it has not been optimized yet. There are also some problems with I/O functions, since it is difficult to determine what kind of encoding should be used given a Handle. Homepage: http://twan.home.fmf.nl/compact-string/ Haddock: http://twan.home.fmf.nl/compact-string/doc/html/ Source: darcs get http://twan.home.fmf.nl/repos/compact-string Twan van Laarhoven

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Last chance to join the Summer of Code!
by Malcolm Wallace 23 Mar '07

23 Mar '07

Haskell.org is currently looking rather short of student proposals for Summer of Code 2007 compared to last year. If you haven't yet thought about submitting an application, why not consider it now? You could be paid $4500 for three months work June-Aug! Apparently, the more proposals we get, the more places are likely to be funded. Also, Google have announced a relaxation of the deadline for student proposals. The new deadline is Mon 26th March at 1700 Pacific Standard Time (Tue 27th, 0000 UTC), so you have all weekend to get writing! Regards, Malcolm

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ANNOUNCE: strict-0.1, strict versions of (some) standard Haskell types
by Roman Leshchinskiy 21 Mar '07

21 Mar '07

I am pleased to announce the first release of package strict which provides strict versions of standard Haskell types. At the moment, pairs, Maybe and Either are defined. For instance, strict Maybe is defined as data Maybe a = Nothing | Just !a Package homepage: http://www.cse.unsw.edu.au/~rl/code/strict.html Hackage page: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/strict-0.1 Download: http://www.cse.unsw.edu.au/~rl/code/strict/strict-0.1.tar.gz or from Hackage http://hackage.haskell.org/packages/archive/strict/strict-0.1.tar.gz Online documentation: http://www.cse.unsw.edu.au/~rl/code/doc/strict Darcs repository: http://www.cse.unsw.edu.au/~rl/code/darcs/strict Please send bug reports, suggestions etc. to Roman Leshchinskiy <rl(a)cse.unsw.edu.au>

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NYTimes.com: John W. Backus, 82, Fortran Developer, Dies
by paul.hudak＠yale.edu 20 Mar '07

20 Mar '07

This page was sent to you by: paul.hudak(a)yale.edu. John Backus, inventor of Fortran, Turing Award winner, and also an early pioneer in functional programming, died Saturday at his home in Oregon. Many of us have fond memories of him in the earlier days of our careers, and we all owe a lot to him for giving credibility to functional programming through his Turing Award lecture, "Can Programming Be Libarated From the von Neumann style?" Here is an article from the New York Times. BUSINESS | March 20, 2007 John W. Backus, 82, Fortran Developer, Dies By STEVE LOHR Mr. Backus assembled and led the I.B.M. team that created Fortran, the first widely used programming language. http://www.nytimes.com/2007/03/20/business/20backus.html?ex=1175054400&en=d… ---------------------------------------------------------- ABOUT THIS E-MAIL This e-mail was sent to you by a friend through NYTimes.com's E-mail This Article service. For general information about NYTimes.com, write to help(a)nytimes.com. NYTimes.com 500 Seventh Avenue New York, NY 10018 Copyright 2007 The New York Times Company

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Summer of Code project proposal
by nikhil n 19 Mar '07

19 Mar '07

Hello All, > > I am Nikhil N, a third year Computer Science student from India. I am > looking at building a good IDE for people learning Haskell(as part of SoC).This IDE will be modeled on Dr Scheme or blueJ. > I love coding in C and Haskell.I believe that the Haskell IDE will > enhance the understandability and popularity of the language. I am looking for someone who could mentor me and guide me through the project. I am confident of completing the project successfully and am excited at contributing to the community. Regards Nikhil N

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ANNOUNCE: ndp-0.1, nested data parallelism in Haskell
by Roman Leshchinskiy 19 Mar '07

19 Mar '07

We are pleased to announce the first release of the NDP package, a library for writing nested data-parallel programs on shared-memory multiprocessors. The NDP library is part of the Data Parallel Haskell project. For a description of the project, see http://haskell.org/haskellwiki/GHC/Data_Parallel_Haskell. At the moment, the library is far from complete and contains numerous bugs and inefficiencies. However, it can be used for writing simple data-parallel programs. The paper "Data Parallel Haskell: a status report" (http://www.cse.unsw.edu.au/~chak/papers/CLPKM07.html) describes the underlying design and go through an example program. This release includes the following features: * Efficient, flat data-parallel arrays with a wide range of sequential and parallel operations. * Preliminary support for segmented arrays. * Automated fusion of sequential and parallel array operations. * Example programs. Project homepage: http://haskell.org/haskellwiki/GHC/Data_Parallel_Haskell Download: http://www.cse.unsw.edu.au/~pls/projects/ndp/src/ndp-0.1.tar.gz Darcs repository: http://darcs.haskell.org/packages/ndp Please send bug reports, suggestions etc. to Roman Leshchinskiy <rl at cse.unsw.edu.au> The Data Parallel Haskell team

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Haskell Chess
by Steffen Mazanek 19 Mar '07

19 Mar '07

Hello, I recently implemented Chess in Haskell. The implementation is not very efficient, but pretty straightforward from a purely functional point of view. Simple mate problems can be solved. Have a look at http://www.steffen-mazanek.de/blog/2007/02/haskell-chess.html I used this implementation for Haskell exercises and the students liked it - probably because of the fact, that it is possible to write a real Chess program in about 200 lines of code. I guess implementing such a game is a good thing in Haskell didactics, in particular the game can easily be divided in several completely independent modules (board data structure and stuff, move generator, gametree and minmax algorithm), there are quick results and the students can experiment a lot. A nice thing to tell them is the fact, that many of the implemented functions are not Chess-specific at all, in particular the generation of the gametree and the application of the minimax algorithm can be easily generalized. If somebody is interested I gladly provide the used project definition and the particular work orders (in German only). Best regards, Steffen Mazanek -- Dipl.-Inform. Steffen Mazanek Institut für Softwaretechnologie Fakultät Informatik Universität der Bundeswehr München 85577 Neubiberg Tel: +49 (0)89 6004-2505 Fax: +49 (0)89 6004-4447 E-Mail: steffen.mazanek (at) unibw.de

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same type multiply implementing a class
by Daniel Mahler 16 Mar '07

16 Mar '07

Is there any way for the same type to implement a typeclass multiple ways. The particular situation I have in mind is composing two monad trasformers of the same type, say reader monad. In pure theory one reader can lift through another, but in an implementation one gets a name clash. thanks Daniel

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small boys performance
by Andrzej Jaworski 14 Mar '07

14 Mar '07

Hi Knights, As I regretfully pointed out earlier in [Fwd: Re: Computer Language Shootout] large search and simulations are not for Haskell. This is equally true with GHC 6.5 http://eric_rollins.home.mindspring.com/haskellAnt.html. Also there is much illusion about Haskell potential ease at handling mathematics. Yes Haskell is excellent for demonstration but trying to implement algorithms that would do trickier things is pretty tough. A thing where Haskell could potentially offer something that a regular CAS cannot is calculating a tensors with symbolic indices (without components) so that one could have components calculated for specific cases on the end of general calculation. Perhaps somebody more technical than me could take the challenge? It could lure theoretical physicists into Haskell which might pay back. One of them has recently provided Curry with the fastest compiler:-) Cheers, -Andrzej

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APLAS'07 CFP
by Henrik Nilsson 14 Mar '07

14 Mar '07

Posted on behalf of Zhong Shao --------------------------------------------------------------------------------- The Fifth ASIAN Symposium on Programming Languages and Systems (APLAS 2007) CALL FOR PAPERS Singapore November 29 - December 1, 2007 http://flint.cs.yale.edu/aplas2007/ APLAS aims at stimulating programming language research by providing a forum for the presentation of recent results and the exchange of ideas and experience in topics concerned with programming languages and systems. APLAS is based in Asia, but is an international forum that serves the worldwide programming languages community. The APLAS series is sponsored by the Asian Association for Foundation of Software (AAFS), which has recently been founded by Asian researchers in cooperation with many researchers from Europe and the USA. The past formal APLAS symposiums were successfully held in Sydney (2006, Australia), Tsukuba (2005, Japan), Taipei (2004, Taiwan) and Beijing (2003, China) after three informal workshops held in Shanghai (2002, China), Daejeon (2001, Korea) and Singapore (2000). Proceedings of the past symposiums were published in Springer-Verlag's LNCS 2895, 3302, 3780, and 4279. TOPICS: The symposium is devoted to both foundational and practical issues in programming languages and systems. Papers are solicited on, but not limited, to the following topics: * semantics, logics, foundational theory * type systems, language design * program analysis, optimization, transformation * software security, safety, verification * compiler systems, interpreters, abstract machines * domain-specific languages and systems * programming tools and environments Original results that bear on these and related topics are solicited. Papers investigating novel uses and applications of language systems are especially encouraged. Authors concerned about the appropriateness of a topic are welcome to consult with the program chair (shao(a)cs.yale.edu) prior to submission. IMPORTANT DATES: Paper Submission Deadline: 11:00 AM (in Samoan Time), June 15, 2007 Author Notification: August 17, 2007 Camera Ready: September 7, 2007 Conference: November 29-December 1, 2007 SUBMISSIONS INFORMATION: Papers should be submitted electronically online via the conference submission webpage. Acceptable formats are PostScript or PDF, viewable by Ghostview or Acrobat Reader. Submissions should not exceed 16 pages in LNCS format, including bibliography and figures. Submitted papers will be judged on the basis of significance, relevance, correctness, originality, and clarity. They should clearly identify what has been accomplished and why it is significant. Submitted papers must be unpublished and not submitted for publication elsewhere. The proceedings of the symposium is planned to be published as a volume in Springer-Verlag's Lecture Notes in Computer Science series. GENERAL CHAIR Joxan Jaffar (National University of Singapore, Singapore) PROGRAM CHAIR Zhong Shao (Yale University, USA) PROGRAM COMMITTEE Lars Birkedal (IT University of Copenhagen, Denmark) Martin Hofmann (Univ of Munich, Germany) Kohei Honda (Queen Mary, University of London, UK) Atsushi Igarashi (Kyoto University, Japan) Suresh Jagannathan (Purdue University, USA) Annie Liu (State University of New York at Stony Brook, USA) Shin-Cheng Mu (Academia Sinica, Taiwan) Henrik Nilsson (University of Nottingham, UK) Michael Norrish (NICTA, Australia) Jens Palsberg (University of California, Los Angeles, USA) G. Ramalingam (Microsoft Research, India) Zhong Shao (Yale University, USA) Zhendong Su (University of California, Davis, USA) Martin Sulzmann (National University of Singapore, Singapore) Eijiro Sumii (Tohoku University, Japan) Jrme Vouillon (CNRS, France) Kwangkeun Yi (Seoul National University, Korea) Jian Zhang (Chinese Academy of Sciences, China) LOCAL ARRANGEMENT CHAIR Wei-Ngan Chin (National University of Singapore, Singapore) -- Henrik Nilsson School of Computer Science and Information Technology The University of Nottingham nhn(a)cs.nott.ac.uk This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation.

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