January 2007 - Haskell

OCaml Summer Project
by Yaron M. Minsky 30 Jan '07

30 Jan '07

(I know this is a bit off-topic, but there are a lot of crossover between the OCaml and Haskell communities, so I thought it worth sending this out. People on the list might be particularly interested in why this project is OCaml-only and doesn't include other languages. You can take a look at the FAQ for more information on that: http://osp2007.janestcapital.com/faqs/) I am pleased to announce the OCaml Summer Project. The project is aimed at encouraging growth in the OCaml community by funding students over the summer to work on open-source projects in OCaml. At the end of the summer, we will fly all of the students who have completed their projects succesfully out for a meeting in New York, where people will present their projects and get a chance to shmooze with other members of the OCaml community. The project is being funded and run by Jane Street Capital. We make extensive use of OCaml here at Jane Street, and are excited about the idea of encouraging and growing the OCaml community. If you'd like to learn more about the project, you can look at our website here: http://osp2007.janestcapital.com We'd love to have professors tell their students about the project, since we hope it will do some real good in terms of increasing interest in functional programming. It would also be great if people would publicize the project on their blogs or other programming-related websites. Please direct any questions or suggestions you have to osp(a)janestcapital.com. y

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Views in Haskell
by Simon Peyton-Jones 30 Jan '07

30 Jan '07

Dear Haskellers Provoked by a discussion with Don Syme, and after some helpful conversations at POPL, I have finally written up a proposal for adding "view patterns" to Haskell. We've wanted views for a long time, but they have never made it, into GHC at any rate. This proposal is a very lightweight (and hence, I hope, cost-effective) proposal for a view-like mechanism. http://hackage.haskell.org/trac/haskell-prime/wiki/ViewPatterns I'm thinking of implementing it in GHC, so I'd be interested in feedback of the form - how desirable is it to have a feature of this general form? - can this particular proposal be improved? I've made it into a Wiki page on the Haskell Prime site. It's probably premature to treat it as a serious contender for Haskell Prime (unless there is wild enthusiasm), because it hasn't been tried in practice yet, but that seems like the right forum to discuss it. Discussion would best be directed via the open Haskell-Prime mailing list haskell-prime(a)haskell.org. http://haskell.org/mailman/listinfo/haskell-prime Thanks Simon

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ETAPS 2007: Call for Participation
by João Saraiva 29 Jan '07

29 Jan '07

***************************************************************** *** *** *** ETAPS 2007 *** *** March 24 - April 1, 2007 *** *** Braga, Portugal *** *** *** *** http://www.di.uminho.pt/etaps07/ *** *** *** *** CALL FOR PARTICIPATION *** *** *** *** Early Registration Deadline: 12th February, 2007 *** *** *** ***************************************************************** The European Joint Conferences on Theory and Practice of Software (ETAPS) is the primary European forum for academic and industrial researchers working on topics related to Software Science. It is a confederation of five main conferences, several satellite workshops and other events. ETAPS 2007 is taking place in Braga, Portugal. Braga, capital of the Minho province, is an ancient city in the heart of the green and fertile region known as the Costa Verde. The region is known for its attractiveness in terms of climate, gastronomy, prices, and culture. Braga is known for its barroque churches and splendid 18th century houses. The old city is solemn and antique, but animated with commercial activity and academic life. ============================================================================ 5 Conferences - 18 Satellite Workshops - 3 Tutorials - Tool Demonstrations ============================================================================ ------------------------------------------------------------------------- Main Conferences ------------------------------------------------------------------------- CC 2007: International Conference on Compiler Construction http://cc2007.cs.brown.edu/ ESOP 2007: European Symposium on Programming http://rap.dsi.unifi.it/esop07/ FASE 2007: Fundamental Approaches to Software Engineering http://fase07.di.fc.ul.pt FOSSACS 2007: Foundations of Software Science and Computation Structures http://www2.in.tum.de/~seidl/fossacs07/ TACAS 2007: Tools and Algorithms for the Construction and Analysis of Systems http://www.doc.ic.ac.uk/tacas07/ ----------------------------------------------------------------------- Invited Speakers ----------------------------------------------------------------------- ETAPS 2007: Rance Cleaveland - University of Maryland, USA ETAPS 2007: Bertrand Meyer - ETH Zürich, Switzerland CC 2007: Don Batory - University of Texas at Austin, USA ESOP 2007: Andrew Pitts - Cambridge University, UK FASE 2007: Jan Bosch - Nokia, Finland FOSSACS 2007: Radha Jagadeesan - DePaul University, USA TACAS 2007: K. Rustan M. Leino - Microsoft Research, USA Further invited speakers are giving talks in the satellite workshops. ----------------------------------------------------------------------- Satellite Workshops ----------------------------------------------------------------------- ACCAT: Applied and Computational Category Theory http://tfs.cs.tu-berlin.de/workshops/accat2007/ AVIS: Int. Workshop on Automated Verification of Infinite-State Systems http://chacs.nrl.navy.mil/AVIS07 Bytecode: Bytecode Semantics, Verification, Analysis and Transformation http://www.sci.univr.it/~spoto/Bytecode07/ COCV: Sixth Workshop on Compiler Optimization Meets Compiler Verification http://pes.cs.tu-berlin.de/cocv2007/ FESCA: Formal Foundations of Embedded Software and Component-Based Software Architectures http://palab.dcs.kcl.ac.uk/fesca/ FinCo: Foundations of Interactive Computation http://www.cs.brown.edu/sites/finco07/ GT-VMT: Int. Workshop on Graph Transformation and Visual Modeling Techniques http://www.cs.le.ac.uk/events/GTVMT07/ HAV: Heap Analysis and Verification http://www.cs.tau.ac.il/~msagiv/hav.html HFL: Hardware design using Functional Languages http://hfl07.hflworkshop.org/ LDTA: Seventh Workshop on Language Descriptions, Tools and Applications http://www.di.uminho.pt/ldta07 MBT: Third Workshop on Model Based Testing http://react.cs.uni-sb.de/mbt2007/ MOMPES: Model-based Methodologies for Pervasive and Embedded Software http://www.di.uminho.pt/mompes OpenCert: Foundations and Techniques for Open Source Software Certification http://opencert.iist.unu.edu/ QAPL: Fifth Workshop on Quantitative Aspects of Programming Languages http://www.cse.yorku.ca/qapl07 SC: Software Composition http://ssel.vub.ac.be/sc2007 SLA++P: Model-driven High-level Programming of Embedded Systems http://web.uni-bamberg.de/wiai/gdi/SLAP07/ TERMGRAPH: Fourth International Workshop on Computing with Terms and Graphs http://www.termgraph.org.uk WITS: Seventh Workshop on Issues in the Theory of Security http://www.dsi.unive.it/IFIPWG1_7/wits2007.html ----------------------------------------------------------------------- Tutorials ----------------------------------------------------------------------- Program Transformation with Stratego/XT Martin Bravenboer (Utrecht University) and Eelco Visser (Delft University of Technology) Beyond the Generators: Practical Techniques for Real-World Software Generation Anthony M. Sloane (Macquarie University) Mobility, Ubiquity, and Security Gilles Barthe (INRIA), David Pichardie (IRISA), David Aspinall (Univ. of Edinburgh), Peter Müller (ETH Zurich), Lennart Beringer (LMU Munich) and Joe Kiniry (UC Dublin) ----------------------------------------------------------------------- Tool Demonstrations ----------------------------------------------------------------------- Demonstrations of tools presenting advances on the state of the art have been selected and are integrated in the programmes of the main conferences. ----------------------------------------------------------------------- Registration and Contact Details ----------------------------------------------------------------------- For online registration, please visit http://www.di.uminho.pt/etaps07/ and go to menu item "Registration". Contact details are available at the menu item "Contact us". In case of any questions not addressed on the web pages, please email etaps07(a)di.uminho.pt.

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ANNOUNCE: Happy version 1.16
by Simon Marlow 29 Jan '07

29 Jan '07

ANNOUNCING Happy 1.16 - The LALR(1) Parser Generator for Haskell I'm pleased to announce version 1.16 of Happy, the parser generator system for Haskell. Changes from version 1.15 to 1.16 * Switch to a Cabal build system: you need a recent version of Cabal (1.1.6 or later). If you have GHC 6.4.2, then you need to upgrade Cabal before building Happy. GHC 6.6 is fine. * New %error directive * New production forms: {%% .. } and {%^ .. } * Added Attribute Grammar support, by Robert Dockins NOTE: Happy version 1.16 is required for building GHC version 6.6 and later. Happy is available in source form, which can be compiled with GHC version 5.04+, and we also provide binaries for some architectures. The Happy homepage with links to the various distributions lives at: http://www.haskell.org/happy/ Please send any bug reports and comments to simonmar(a)microsoft.com.

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[Fwd: Re: Computer Language Shootout]
by Andrzej Jaworski 27 Jan '07

27 Jan '07

It would be enough to exhaustively analyse examples of the kind I gave: single algorithm with fast non-Haskell implementation but very slow in Haskell. The article describes laborious but unsuccessful attempt to pinpoint what makes Haskell over 500 times slower than SML on a genetic algorithm. 7 years have passed and nobody cares. So, for those avoiding fundamental issues I would suggest stretching imagination into successors of Wiki and consider something that starts as automated online benchmarking. It could: (1) initiate research that would answer the questions you asked me:-) (2) introduce performance awareness through immediate feedback (3) automatically collect test results (4) feed databases with classified results and reusable code (5) pinpoint bad solutions if combined with inductive database (6) evolve into a mighty development platform if combined with prove system. (7) in 20 years be referred as Haskell method...

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Re: [Haskell] [Fwd: Re: Computer Language Shootout]
by Brent Fulgham 27 Jan '07

27 Jan '07

Hi, I recently re-ran most of the benchmarks after we changed the following: A couple of things I changed recently on the shootout are: 1. I reran the various tests using higher 'N' values to force more work to be done. 2. I upgraded to the most recent GHC avaliable through Debian. 3. I don't recall which test was changed to its less-efficient counterpart, but as I recall this was due to some sniping that the lazy analysis was avoiding doing some of the work. After comparing the tests, we ended up agreeing and the Haskell implementation was modified. Let me know if you have any updates or revisions you would like us to apply. Thanks, -Brent ----- Original Message ---- From: Simon Peyton-Jones <simonpj(a)microsoft.com> To: Joel Reymont <joelr1(a)gmail.com> Cc: "haskell(a)haskell.org" <haskell(a)haskell.org> Sent: Thursday, January 25, 2007 1:04:41 AM Subject: RE: [Haskell] [Fwd: Re: Computer Language Shootout] http://www.mail-archive.com/haskell@haskell.org/msg18863.html (It was Simon Marlow actually, but we are joined at the hip so it hardly matters) | -----Original Message----- | From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of Joel Reymont | Sent: 25 January 2007 09:01 | To: Simon Marlow | Cc: haskell(a)haskell.org | Subject: Re: [Haskell] [Fwd: Re: Computer Language Shootout] | | Where are SPJs disclosed comments from Brent Fulgham? | | On Jan 25, 2007, at 8:55 AM, Simon Marlow wrote: | | > Forwarding on behalf of Andrzej Jaworski <himself(a)poczta.nom.pl>: | > | > -------- Original Message -------- | > From: Andrzej Jaworski <himself(a)poczta.nom.pl> | > | > Dear fellows, | > | > It is ironic that just after SPJ disclosed Comments from Brent | > Fulgham on | > Haskell and the shootout the situation has radically changed for | > the worse. _______________________________________________ Haskell mailing list Haskell(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell

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[Fwd: Re: Computer Language Shootout]
by Andrzej Jaworski 26 Jan '07

26 Jan '07

Hi John, Laziness is a double sword. In case of Clean it worked for it, I don't know however if the same was behind shooting Haskell in the foot in the recent Language Shootout. The example of a genetic algorithm that I gave and those that I wanted to spare you (from inductive functional programming or inferring molecular structures) point into the opposite direction. It is often about last moment heap blow-up on large data sets but not always. In cases where it is manageable it surely could be learned but first it should be understood, classified and taught. Perhaps optimizer like MLton could even be designed. They have already coined name Haskellton for this... Cheers, --Andrzej

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jhc - call for volunteers
by John Meacham 25 Jan '07

25 Jan '07

On Thu, Jan 25, 2007 at 06:18:01PM +0000, Neil Mitchell wrote: > Maybe if we had a greater number and variety of optimising compilers > we'd be able to more freely experiment with optimisation techniques in > different settings. At the moment GHC is all there is (with Jhc not > ready for mainstream use yet) Jhc has recently gotten a ghc back end, making it much closer to mainstream use as an optimizing 'front end' to ghc. In addition to some of jhc's crazy optimizations, it implements several extensions to the language which will likely prove interesting to play with to some. I would really welcome any volunteers who would like to help develop the ghc back end while I work on improving the grin back end and optimizations in general. There is now a mailing list for jhc at: http://www.haskell.org/mailman/listinfo/jhc I think one of the reasons jhc has been so slow to reach mainstream usability is that there aren't many eyes looking at it. When I work on it, my eyes tend to be very focused on the task at hand, which is likely some obscure optimization and I might not even notice for weeks if something basic like package support breaks or if a basic class instance is missing from the libraries. Besides me, Einar Karttunen has been the only other major developer but I would love it if more people wanted to help out, or just poke around. Simple things like filling out the libraries, or noticing where the front end isn't reporting an error it should or typing things incorrectly or working on the ghc back end could be done without knowing a lot about the internals of the compiler. Another good but bigger project (though it would take a lot more knowledge of the jhc source than the above) would be separate compilation support, there is no reason it couldn't work with the ghc back end, but one would need to add some infrastructure for actually spitting out partially compiled modules and calling ghc etc... And of course, new backends would be great. I have infrastructure built up for .NET, it parses and passes through hugs .NET compatible foreign declarations through the compiler so all that is needed is the final code generator and modifying some of the libraries to make the appropriate .NET calls instead of C ones. Basically, all that is needed is a module to convert jhc core (effectively equivalent to ghc core and system F) to .NET as all the front/middle end stuff is in place. John -- John Meacham - ⑆repetae.net⑆john⑈

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FW: A history of Haskell
by Simon Peyton-Jones 25 Jan '07

25 Jan '07

[Sorry to spam you, but I got the URL wrong. Darn!] Many of you will know that Paul Hudak, John Hughes, Phil Wadler and I have been working on a paper called A History of Haskell: being lazy with class which will appear at this year's ACM SIGPLAN History of Programming Languages Conference (HOPL-III) San Diego, California, June 9-10, 2007. It's finally done! You can get a copy here: http://research.microsoft.com/~simonpj/papers/history-of-haskell/index.htm We warmly thank all those of you who helped us get it done; I hope we remembered you all in the acknowledgements! (If not, let us know.) It's in copy-editing now, so if you spot typos, please drop us a line. Simon

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A history of Haskell
by Simon Peyton-Jones 25 Jan '07

25 Jan '07

Many of you will know that Paul Hudak, John Hughes, Phil Wadler and I have been working on a paper called A History of Haskell: being lazy with class which will appear at this year's ACM SIGPLAN History of Programming Languages Conference (HOPL-III) San Diego, California, June 9-10, 2007. It's finally done! You can get a copy here: http://camwwwdev/~simonpj/papers/history-of-haskell/index.htm We warmly thank all those of you who helped us get it done; I hope we remembered you all in the acknowledgements! (If not, let us know.) It's in copy-editing now, so if you spot typos, please drop us a line. Simon

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