- Haskell - Haskell.org

AI Strike Force
by Andrew Wagner 28 Mar '07

28 Mar '07

Apologies to those of you who will see this announcement twice. The time has come! Calling all Haskell programmers interested in AI! I've established a new home base at http://www.haskell.org/haskellwiki/AI . Functional programming has long been recognized as an excellent paradigm for Artificial Intelligence. It's time to make Haskell an important language in that area! The goal is to provide a toolkit of AI tools in Haskell that can easily be applied to a wide variety of applications: e.g., Neural Networks, genetic algorithms, natural language processing tools, etc.

2 2

Hardcopy of 'All about Monads'
by unknown＠example.com 28 Mar '07

28 Mar '07

I have been reading 'All about Monads' and I would like to get a hardcopy (preferably PDF) of that file to read and study away from the computer. Is there such a hardcopy available? Thanks, Dave Feustel

1 0

Re: [Haskell-cafe] Re: Why the Prelude must die
by Andrzej Jaworski 28 Mar '07

28 Mar '07

On blessed Wed Mar 28 05:52:03 EDT 2007 Simon Marlow wrote: > I support both reducing the prelude to just a few commonly used combinators, and > requiring an explicit import Prelude. (...) So YOU are the GOD's angle with the sword! And thus we leave the orchard for a battlefield. I really like this:-) Holy regards, -Andrzej

1 0

Lift Info
by unknown＠example.com 27 Mar '07

27 Mar '07

I've been looking for an explanation of the Haskell lift function which I don't yet get. There seem to be two kinds of lifting, one of which is making normal functions usable inside monads. I don't understand either type. I've googled for lift but what I've found has not helped me much. Is there a tutorial on what problem using lift solves? Thanks, Dave Feustel

2 1

Re: [Haskell] Lift Info [moving to -cafe]
by Andrew Wagner 27 Mar '07

27 Mar '07

I'm no expert, but I will point you to 2 links that I think will be helpful on this topic on the wiki: http://www.haskell.org/haskellwiki/Lifting (especially if you're familiar with functors) http://www.haskell.org/haskellwiki/Simple_StateT_use (for a simple example with a monad transformer) I'm also re-directing this question to haskell-cafe, where it's more likely to get a better response. Best of luck! On 3/27/07, Dave(a)haskell.org <Dave(a)haskell.org> wrote: > I've been looking for an explanation of the Haskell lift function which > I don't yet get. There seem to be two kinds of lifting, one of which is > making normal functions usable inside monads. I don't understand either > type. I've googled for lift but what I've found has not helped me much. > Is there a tutorial on what problem using lift solves? > > Thanks, > > Dave Feustel > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell >

1 0

Second Call for papers - Workshop on Termination (WST 2007) - Paris
by Simon Marlow 27 Mar '07

27 Mar '07

[ posting on behalf of Alexander Serebrenik <aserebre(a)win.tue.nl> ] Call for Papers Ninth International Workshop on Termination (WST 2007) Paris, France, June 29, 2007 Affiliated with RDP 2007 Termination is a fundamental topic in computer science. Though termination of processes is often a strict requirement, it may be hard to establish. Classical results state the undecidability of various termination problems, so research focuses on automated methods that prove termination or non-termination in practical cases. The topic is challenging both in theory (mathematical logic, proof theory) and practice (software development, formal methods), and many interesting ramifications are yet to be explored. The 9th International Workshop on Termination will delve into all aspects of termination. It will continue the sequence of successful workshops held in St. Andrews (1993), La Bresse (1995), Ede (1997), Dagstuhl (1999), Utrecht (2001), Valencia (2003), Aachen (2004), and Seattle (2006). We hope to attain the same friendly atmosphere as those past workshops. The intent is to bring together, in an informal setting, researchers interested in various aspects of termination, whether this interest be practical or theoretical, primary or derived. The workshop is hoped to provide a ground for cross-fertilisation of ideas from term rewriting and from programming. Contributions from the imperative, object-oriented, constraint, functional, and logic programming communities, and papers investigating new applications of termination are particularly welcome. Paper Submissions: Extended abstracts in the prescribed format, not exceeding 4 pages, should be submitted electronically through EasyChair's WST 2007 submission site http://www.easychair.org/WST2007/. A common workshop style file will be made available on the WST'2007 web site. Papers should be submitted in PostScript or PDF format. We expect proceedings to be made available through the Computing Research Repository, CoRR. The Termination Competition: The competition will run again in 2007, and entries are strongly encouraged. Detailed instructions for submission of problems and programs will be made available at the competition website http://www.lri.fr/~marche/termination-competition/2007/ Program Committee Nachum Dershowitz (Tel Aviv, Israel) Daniel De Schreye (Leuven, Belgium) Samir Genaim (Madrid, Spain) Juergen Giesl (Aachen, Germany) Isabelle Gnaedig (Nancy, France) Dieter Hofbauer (Kassel, Germany), co-chair Aart Middeldorp (Innsbruck, Austria) Etienne Payet (La Reunion, France) Alexander Serebrenik (Eindhoven, The Netherlands), co-chair Termination Competition Committee Claude Marche (Paris, France) Johannes Waldmann (Leipzig, Germany) Hans Zantema (Eindhoven, The Netherlands) Workshop Themes (non-exhaustive list) Termination of programs Termination of rewriting Normalization of lambda calculi Implementation of termination methods Challenging termination problems and proofs Application of termination methods, e.g. to program transformation and compilation Comparison and classification of termination methods Non-termination detection Termination methods for theorem provers Termination in distributed systems Termination proof methods for liveness and fairness Derivational complexity Well-quasi-orderings and ordinal notations Important Dates: Deadline for electronic submission of papers : April 8, 2007 Notification of acceptance : May 6, 2007 Deadline for final versions : May 27, 2007 Competition Deadlines: Submission of public problems : May 1, 2007 Registration of termination tools : May 21, 2007 Submission of secret problems : June 1, 2007 Submission of termination tools : June 1, 2007 Start of competition : June 4, 2007 Workshop Venue and Related Events: WST 2007 is part of the Federated Conference on Rewriting, Deduction, and Programming 2007. Co-located events include RTA'07, HOR'07, PATE'07, RULE'07, SecReT'07, UNIF'07, WFLP'07, and WRS'07. These colloquia will run from June 25 to June 29, 2007, in Paris (France). For details see the RDP website at http://www.rdp07.org/. Web Sites WST 2007: http://www.rdp07.org/wst.html Termination Competition: http://www.lri.fr/~marche/termination-competition/2007/ RDP 2007: http://www.rdp07.org/

1 0

Re: [Haskell-cafe] What ever happened to Haskell 98 as a "stablebranch"?
by Andrzej Jaworski 26 Mar '07

26 Mar '07

>Diversity is generated by mutations. This is hardly a revelation. My point was that you need two competing components in relative balance to grow something meaningful. Cancer growth is based solely on mutation! Also I was not theological. It is the advice to multiply Prelude and use time to verify them rather cosmic in scale. It implies the assumption that the world will freeze and wait for the verdict.

1 0

Announce: Text.HTML.Chunks
by Matthew Sackman 25 Mar '07

25 Mar '07

Text.HTML.Chunks is a clone with improvements of the Perl HTML::Chunks module. My apologies to those of you who already feel ill at this point... http://www.wellquite.org/chunks or http://www.wellquite.org/non-blog/chunks-browseable/doc/ The main achievement is the use of template-haskell to combine the template into the code at compile time. This then allows for static checking that the variables/fields that the templates are expecting are indeed being provided and that the templates the code is trying to use do indeed exist. The template is then incorporated within the code, removing the dependency on the template. The downside is that if you ever change the template you must recompile the code - this may be considered a good thing as it ensures that the template is rechecked before it can be used: no more tweaking parts of the template and forgetting to update all the use-points. Download at http://www.wellquite.org/non-blog/chunks-2007-3-25.tgz Any comments, patches, bug reports etc gratefully received. Many thanks, Matthew

1 0

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

4 3

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

1 0