- Haskell - Haskell.org

Idioms and Proposals
by Ashley Yakeley 01 Feb '06

01 Feb '06

I've added a few Haskell idioms and proposals (well, ideas for changes) to the wiki: http://haskell.org/haskellwiki/Category:Idioms http://haskell.org/haskellwiki/Category:Proposals I particularly wanted to include "perennial" ideas that often seem to get discovered independently (for instance, type arithmetic). Of the proposals, I think only MonadPlus reform might be worth moving to the Haskell Prime process. Please add, improve, etc.

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Internships at Microsoft Research, Cambridge
by Simon Peyton-Jones 01 Feb '06

01 Feb '06

Internships are available at Microsoft Research, Cambridge, for this summer. More information is available here: http://research.microsoft.com/aboutmsr/jobs/internships/ Internships are usually for graduate students (PhD or Masters) and last 12 weeks (although longer projects are also possible). Furthermore, although there is a deadline of *28 Feb* for the main batch of summer internships, MSR is now taking interns year-round, a non-summer internship may even be easier to arrange (because it misses the Big Rush). The reason for this mail is to highlight the fact that Simon & I would particularly like to encourage applicants interested in working on Haskell-related projects. We have a number of projects in mind, but feel free to suggest your own: - Parallel garbage collection: to complement GHC's new support for SMP parallelism, replacing single-threaded garbage collection with parallel GC is a high priority goal, with plenty of interesting research too. - Parallel Haskell applications: investigate using SMP/multicore parallelism for real, either implicit parallelism or using concurrency & STM, by tackling some applications. - Haskell debugging in GHCi: we have some ideas for building a debugger into GHCi, there are some research angles here too. - GHC as a library: we have made a start on providing a library interface to GHC, but there is much left to do. Re-targetting Haddock on top of GHC would make a good project, for example. - C-- code generation: we have a project student working on C-- code gen, but there's a lot to do here. The ultimate goal is to divide the code generator into two: first generate C-- and then CPS-convert it into C-- with only tail calls, suitable for generating code using the existing paths (native code and via-C) too. Let us know by email if you apply. Good luck! Simon Peyton Jones and Simon Marlow

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TYPES 2006 Workshop
by peter morris 01 Feb '06

01 Feb '06

Registration for TYPES 2006 is now open. Early registration until 15/3/2006. Cheers, The TYPES06 Team -------------------------------------------------------------------------- TYPES 2006 Main Conference of the Types Project Nottingham, UK, 18-21 April 2006 http://www.cs.nott.ac.uk/types06/ This is the latest meeting in a series that started 1992, the last conference was in December 2004 in Paris. The topic of the meeting is formal reasoning and computer programming based on Type Theory : languages and computerised tools for reasoning, and applications in several domains such as analysis of programming languages, certified software, formalisation of mathematics and mathematics education. TYPES 2006 is colocated with TFP 2006 (Trends in Functional Programming) and we plan to hold a joint session on Dependently Typed Programming. The conference takes place at Jubilee campus of the University of Nottingham, on-site accomodation will be available together with the registration. For more information see: http://www.cs.nott.ac.uk/types06/ Registration is open now. You will be able to submit your talk and abstract together with your registration. We will try to accomodate all talks which fit into the scope of the TYPES project. There will also be invited lectures from Bart Jacobs, Simon Peyton Jones (joint with TFP) and Hongwei Xi. Please direct all emails related to TYPES 2006 to types06(a)cs.nott.ac.uk Cheers, The Organisation Comittee Thorsten Altenkirch, James Chapman, Conor McBride, Peter Morris and Wouter Swierstra .

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Everything Your Professor Failed to Tell You About Functional Programming
by Shannon -jj Behrens 31 Jan '06

31 Jan '06

Shameless plug: I wrote an article for "Linux Journal" called "Everything Your Professor Failed to Tell You About Functional Programming". Hopefully you will enjoy the article. http://www.linuxjournal.com/article/8850 (By the way, I'm not on the cafe mailing list, so please cc me on any replies.)

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Re: [Haskell] page names on the new Haskell wiki
by Wolfgang Jeltsch 31 Jan '06

31 Jan '06

Am Freitag, 27. Januar 2006 19:54 schrieb John Peterson: > You're absolutely right! Please move pages as needed. Old habits die > hard! > > John Hello, I just started moving pages. But know I wonder which case I should use for inner-title words. Should the page title be "Books and tutorials" or "Books and Tutorials", for example? Since pages are only small documents, I chose the lower-case alternative but currently the Haskell website uses upper-case. Best wishes, Wolfgang

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Type-Level arithmetic library
by Robert Dockins 30 Jan '06

30 Jan '06

While cleaning up my home directory, I discovered some code I worked on a while ago which implements type level arithmetic. I have cleaned it up and decided to release. This library includes the following operations on type level naturals: addition subtraction multiplication division remainder GCD and also contains the following predicates test for zero test for equality < > <= >= This library uses a binary representation and can handle numbers at the order of 10^15 (at least). It also contains a test suite to help validate the somewhat unintuitive algorithms. You can retrieve this library with the following command darcs get --partial --tag '0.1' http://www.eecs.tufts.edu/~rdocki01/ typenats/ Enjoy, Rob Dockins PS Please let me know if you come up with useful ways to use this library! (I'm mostly just curious) Speak softly and drive a Sherman tank. Laugh hard; it's a long way to the bank. -- TMBG

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Haskell Weekly News: January 30, 2006
by dons＠cse.unsw.edu.au 30 Jan '06

30 Jan '06

Haskell Weekly News: January 30, 2006 Greetings, and thanks for reading the 22nd issue of HWN, a weekly newsletter for the Haskell community. Each Monday, new editions are posted to [1]the Haskell mailing list and to [2]The Haskell Sequence. [3]RSS is also available. 1. http://www.haskell.org/mailman/listinfo/haskell 2. http://sequence.complete.org/ 3. http://sequence.complete.org/node/feed New Releases * C-- Frontend. Robert Dockins [4]announced the initial alpha release of a [5]C-- frontend (parser, pretty printer, and semantic checker) written in Haskell. The goal when beginning this project was to create a modular frontend that could be used both by people writing and by those targeting C-- compilers. This implementation attempts to follow the C-- spec as exactly as possible. 4. http://article.gmane.org/gmane.comp.lang.haskell.general/13174 5. http://www.cminusminus.org/ * Type level arithmetic. Robert Dockins [6]also released a library for arithmetic on the type level. This library uses a binary representation and can handle numbers at the order of 10^15 (at least). It also contains a test suite to help validate the somewhat unintuitive algorithms. 6. http://article.gmane.org/gmane.comp.lang.haskell.general/13206 Haskell' This section covers activity on [7]Haskell' this week. The topics this week have been diverse. Next week we'll try to cover activity on the wiki as well. From the mailing list: * [8]Wildcard type annotations * [9]Reworking the Numeric class * [10]Partial application ideas * [11]A more flexible hierarchical module namespace * [12]Record updates * [13]On the importance of libraries * [14]Syntactic support for existentials * [15]Module system/namespace management * [16]Fixing the monomorphism restriction * [17]k patterns * [18]~ patterns * [19]Kind annotations * [20]Class method types * [21]A Match class * [22]Scoped type variables in class instances * [23]Inline comment syntax 7. http://hackage.haskell.org/trac/haskell-prime 8. http://www.haskell.org/pipermail/haskell-prime/2006-January/000001.html 9. http://www.haskell.org/pipermail/haskell-prime/2006-January/000002.html 10. http://www.haskell.org/pipermail/haskell-prime/2006-January/000004.html 11. http://www.haskell.org/pipermail/haskell-prime/2006-January/000009.html 12. http://www.haskell.org/pipermail/haskell-prime/2006-January/000014.html 13. http://www.haskell.org/pipermail/haskell-prime/2006-January/000023.html 14. http://www.haskell.org/pipermail/haskell-prime/2006-January/000031.html 15. http://www.haskell.org/pipermail/haskell-prime/2006-January/000032.html 16. http://thread.gmane.org/gmane.comp.lang.haskell.prime/15 17. http://thread.gmane.org/gmane.comp.lang.haskell.prime/31 18. http://thread.gmane.org/gmane.comp.lang.haskell.prime/54 19. http://thread.gmane.org/gmane.comp.lang.haskell.prime/65 20. http://article.gmane.org/gmane.comp.lang.haskell.prime/102 21. http://article.gmane.org/gmane.comp.lang.haskell.prime/123 22. http://article.gmane.org/gmane.comp.lang.haskell.prime/28 23. http://thread.gmane.org/gmane.comp.lang.haskell.prime/104 Discussion * Adding Impredicative Types to GHC. Simon Peyton-Jones [24]pushed a patch into GHC to handle impredicative polymorphism (see [25]Boxy types: type inference for higher-rank types and impredicativity). Secondly, GHC now supports GADTs in the more simplified way described in [26]Simple unification-based type inference for GADTs 24. http://article.gmane.org/gmane.comp.lang.haskell.cvs.ghc/13254 25. http://research.microsoft.com/~simonpj/papers/boxy/ 26. http://research.microsoft.com/~simonpj/papers/gadt/ * New IO library. Bulat Ziganshin [27]sought information on the low-level IO mechanisms used in GHC's IO libraries, in the context of his work on a high-performance IO lib. Some interesting points relating to IO primitives were raised. 27. http://thread.gmane.org/gmane.comp.lang.haskell.glasgow.user/9261 Darcs Corner Darcs is popular. Isaac Jones [28]brought to our attention the results of the Debian package popularity contest. For the first time a program written in Haskell is more popular than the Haskell toolchain itself. Congratulations to the darcs developers! 28. http://article.gmane.org/gmane.comp.lang.haskell.cafe/11089 Quote of the Week <araujo> Haskell is bad, it makes you hate other programming languages. Contributing to HWN You can help us create new editions of this newsletter. Please see the [29]contributing information, send stories to dons -at- cse.unsw.edu.au. The darcs repository is available at darcs get http://www.cse.unsw.edu.au/~dons/code/hwn 29. http://sequence.complete.org/hwn-contrib

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Re: Contents of Haskell Digest, Vol 29, Issue 33
by 조희연 30 Jan '06

30 Jan '06

-----Original Message----- From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of haskell-request(a)haskell.org Sent: Tuesday, January 31, 2006 1:41 AM To: haskell(a)haskell.org Subject: Haskell Digest, Vol 29, Issue 33 Send Haskell mailing list submissions to haskell(a)haskell.org To subscribe or unsubscribe via the World Wide Web, visit http://www.haskell.org/mailman/listinfo/haskell or, via email, send a message with subject or body 'help' to haskell-request(a)haskell.org You can reach the person managing the list at haskell-owner(a)haskell.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Haskell digest..." Today's Topics: 1. Re: IO == ST RealWorld (John Meacham) 2. ACM PPDP'06 call for papers (Simon Marlow) 3. Visual Haskell: Could not find module `Control.Monad.Writer' (Bernd Holzm?ller) 4. TFP2006: Third Call for Papers (Henrik Nilsson) 5. Re: page names on the new Haskell wiki (Wolfgang Jeltsch) 6. Re: page names on the new Haskell wiki (Sam Goldman) 7. Re: IO == ST RealWorld (Marcin 'Qrczak' Kowalczyk) ---------------------------------------------------------------------- Message: 1 Date: Sun, 29 Jan 2006 04:32:05 -0800 From: John Meacham <john(a)repetae.net> Subject: Re: [Haskell] IO == ST RealWorld To: haskell <haskell(a)haskell.org> Message-ID: <20060129123205.GE10970(a)momenergy.repetae.net> Content-Type: text/plain; charset=utf-8 On Mon, Jan 23, 2006 at 09:55:39PM +0100, Twan van Laarhoven wrote: > Is there any reason why IO should not be defined as: > > type IO a = ST RealWorld a > in implementations that support ST? > > This way IORef/STRef and IOArray/STArray can be merged. I know under the > hood they already share code, but this way they can also share an interface. ST doesn't have exceptions which IO does. It would be no good to make ST pay for the cost of exception handling. GHC handles them behind the scenes (I think?) but in jhc they are explicit and IO is defined as follows: > data World__ > > data IOResult a = FailIO World__ IOError | JustIO World__ a > newtype IO a = IO (World__ -> IOResult a) I belive other implementations have used continuations for IO as well. John -- John Meacham - brepetae.netbjohnb ------------------------------ Message: 2 Date: Mon, 30 Jan 2006 09:30:40 -0000 From: "Simon Marlow" <simonmar(a)microsoft.com> Subject: [Haskell] ACM PPDP'06 call for papers To: <haskell(a)haskell.org> Message-ID: <2E9B33CE230409489A7ED37E5E34090F03515208@EUR-MSG- 20.europe.corp.microsoft.com> Content-Type: text/plain; charset="us-ascii" [ posting on behalf of Agostino Cortesi <cortesi(a)unive.it> ] ................................................................ PPDP 2006 Preliminary Call For Papers 8th ACM-SIGPLAN International Symposium on Principles and Practice of Declarative Programming Venice, Italy, July 10-12, 2006 http://www.dsi.unive.it/ppdp2006/ ................................................................ IMPORTANT DATES Submission 15 March 2006 Notification 22 April 2006 SCOPE: PPDP 2006 is a forum for the declarative programming communities, gathering researchers working on logic, constraint and functional programming, but also on other programming language paradigms like visual programming, executable specification languages, database languages, AI and knowledge representation languages for the "semantic web". MAIN TOPICS: Logic, Constraint, and Functional Programming; Database, AI and Knowledge Representation Languages; Visual Programming; Executable Specification for Languages; Applications of Declarative Programming; Methodologies Program Design and Development; Declarative Aspects of Object-Oriented Programming; Concurrent Extensions to Declarative Languages; Declarative Mobile Computing; Paradigm Integration; Proof Theoretic and Semantic Foundations; Type and Module Systems; Program Analysis and Verification; Program Transformation; Abstract Machines and Compilation; Programming Environments. PROCEEDINGS: Proceedings will be published by ACM Press. RELATED EVENTS: PPDP 2006 will be co-located with the 33rd International Colloquium on Automata, Languages and Programming (ICALP 2006), which will take place on July 9-16, 2006 (http://icalp06.dsi.unive.it) CONFERENCE CHAIR: Annalisa Bossi, U. Ca' Foscari di Venezia PROGRAM CHAIR: Michael Maher, National ICT Australia PROGRAM COMMITTEE: Nick Benton (Microsoft Research, UK) Annalisa Bossi (U. Ca' Foscari di Venezia, Italy) Manuel Chakravarty (U. NSW, Australia) Bart Demoen (K. U. Leuven, Belgium) Moreno Falaschi (U. Udine, Italy) Radha Jagadeesan (DePaul U., USA) Bharat Jayaraman (SUNY Buffalo, USA) Yukiyoshi Kameyama (U. Tsukuba, Japan) Andy King (U. Kent, UK) Francois Laburthe (Bouyges, France) David Sands (Chalmers U., Sweden) Christian Schulte (KTH, Sweden) Pascal Van Hentenryck (Brown U., USA) Roland Yap (NUS, Singapore) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- prof. agostino cortesi tel. 0039 041 234.8450 dipartimento di informatica fax 0039 041 234.8419 universita' ca' foscari mail cortesi(a)dsi.unive.it via torino 155 url www.dsi.unive.it/~cortesi 30170 Venezia location: studio n.1

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RE: [Haskell] IO == ST RealWorld
by Simon Peyton-Jones 30 Jan '06

30 Jan '06

| Is there any reason why IO should not be defined as: | > type IO a = ST RealWorld a | in implementations that support ST? | | This way IORef/STRef and IOArray/STArray can be merged. I know under the | hood they already share code, but this way they can also share an interface. Indeed, this was the way we had it originally in GHC. It does seem like a good idea. We changed it for reasons that I know that we have forgotten, alas, because we tried to recall about a year ago. It's always possible that the original reasons for the change no longer apply. Perhaps someone can try it out? Simon

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TFP2006: Third Call for Papers
by Henrik Nilsson 30 Jan '06

30 Jan '06

Dear Colleague, Please find enclosed the third call for papers for Trends in Functional Programming (TFP) 2006. Please note that the abstract submission deadline is fast approaching: 17 Feb. Also note the co-location with Types 2006 and the Spring School on Datatype-Generic Programming. My apologies for duplicate copies. Best regards, /Henrik -- 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. TFP 2006 Seventh Symposium on Trends in Functional Programming Nottingham, UK, 19 - 21 April, 2006 http://www.cs.nott.ac.uk/~nhn/TFP2006 Co-located with Types 2006 and Spring School on Datatype-Generic Programming CALL FOR PAPERS The Symposium on Trends in Functional Programming (TFP) is an international forum for researchers with interests in all aspects of functional programming languages, focusing on providing a broad view of current and future trends in Functional Programming. It aspires to be a lively environment for presenting the latest research results through acceptance by extended abstracts. A formal post-symposium refereeing process then selects the best papers presented at the symposium for publication in a high-profile volume. TFP 2006 is going to be held in Nottingham, UK, 19 - 21 April. Note that this is significantly earlier in the year than past TFPs that generally were held in August - September. TFP 2006 is co-located with Types 2006 (18 - 21 April). The TFP symposium is the successor to the successful series of Scottish Functional Programming Workshops. Previous TFP symposia were held in Edinburgh, Scotland in 2003, in Munich, Germany in 2004, and in Tallinn, Estonia in 2005 (co-located with ICFP and GPCE). For further general information about TFP, see http://www.tifp.org/. SCOPE OF THE SYMPOSIUM The Symposium recognises that new trends may arise through various routes. As part of the Symposium's focus on trends we therefore identify the following five categories of paper. High-quality papers are solicited in any of these categories: Research Papers: leading-edge, previously unpublished research work Position Papers: on what new trends should or should not be Project Papers: descriptions of recently started new projects Evaluation Papers: what lessons can be drawn from a finished project Overview Papers: summarising work with respect to a trendy subject Papers must be original, and not submitted for simultaneous publication in any other forum. They may consider any aspect of functional programming: theoretical, implementation-oriented, or more experience-oriented. Also applications of functional programming techniques to other languages may be considered. Papers on the following subject areas are particularly welcome: o dependently typed functional programming o validation and verification of functional programs o debugging for functional languages o functional programming and security o functional programming and mobility o functional programming and formally motivated computing o functional languages for telecommunications applications o functional languages for embedded systems o functional programming applied to global computing o functional GRIDs o functional languages for reasoning about imperative/object- oriented programs o interoperability with imperative programming languages o any new emerging trend in the functional programming area If you are in doubt on whether your paper is within the scope of TFP, please contact the TFP 2006 programme chair, Henrik Nilsson, nhn(a)cs.nott.ac.uk. BEST STUDENT PAPER AWARD TFP traditionally pays special attention to research students, acknowledging that students are almost by definition part of new subject trends. To acknowledge this, a prize for the best student paper is awarded each year. CO-LOCATION WITH TYPES 2006 AND DATATYPE-GENERIC PROGRAMMING 2006 TFP 2006 is co-located with Types 2006 (to be held 18 - 21 April). To take advantage of the synergies offered by these two complementary events, we will invite a number of joint keynote speakers, hold joint sessions on topics of mutual interest, such as dependently typed functional programming, and run common social events. The schedule will be arranged so that participants may freely move between parallel sessions of the two events. See http://www.cs.nott.ac.uk/types06/ for further details. TFP 2006 and Types 2006 are immediately followed by the Spring School on Datatype-Generic Programming 2006 (24 - 27 April), which should be of direct interest to many of the TFP and Types Participants. See http://www.cs.nott.ac.uk/ssdgp2006/ for further details. SUBMISSION AND LOCAL PROCEEDINGS Acceptance to the symposium is by extended abstracts of between 6 and 10 pages. Accepted abstracts are to be completed to full papers before the symposium for publication in the local symposium proceedings and on-line. Important dates: Deadline for abstract submission: 17 February, 2006 Notification of acceptance: 27 February, 2006 Registration deadline: 17 March, 2006 Camera-ready copy of full paper: 24 March, 2006 The submission must clearly indicate to which category it belongs: research, position, project, evaluation or overview paper. It should also indicate whether the main author or authors are research students. Abstracts and full papers must be written in English. Papers for the symposium proceedings must adhere to the formatting instructions provided on the TFP 2006 site. Papers must not exceed 16 pages; papers in some categories may comprise considerably fewer pages. The papers of the local proceedings will also be made available on-line under the following conditions, with which all authors are asked to agree: The documents distributed by this server have been provided by the contributing authors as a means to ensure timely dissemination of scholarly and technical work on a noncommercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders, notwithstanding that they have offered their works here electronically. It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder. See the TFP 2006 website for further instructions to authors and details on how to submit. POST SYMPOSIUM REFEREEING AND PUBLICATION In addition to the local symposium proceedings, we intend to continue the TFP tradition of publishing a high-quality subset of contributions in the Intellect series on Trends in Functional Programming (see http://www.intellectbooks.co.uk/series.php?series=1) All TFP authors will be invited to submit revised papers after the symposium. These will will be refereed to normal conference standards, and a subset of the best papers over all categories will be selected for publication. Papers will be judged on their contribution to the research area, with appropriate criteria applied to each category of paper. Papers submitted for publication by Intellect must follow formatting and any other instructions provided by the Programme Chair. For TFP 2005, in order to enhance the quality of student submissions, a process where student papers were given extra feedback was tried out. A similar process might be put in place for this TFP, contingent on the outcome of that trial. ORGANISATION Symposium Chair: Marko van Eekelen, Radboud University Nijmegen, NL Programme Chair: Henrik Nilsson, University of Nottingham, UK Treasurer: Greg Michaelson, Heriot-Watt University, UK Local Arrangements: Joel Wright, University of Nottingham, UK PROGRAMME COMMITTEE: o Kenichi Asai, Ochanomizu University o Gilles Barthes, INRIA, Sophia Antipolis o Olaf Chitil, University of Kent at Canterbury o Catherine Dubois, IIE, Evry o Marko van Eekelen, Radboud Universiteit Nijmegen o Jeremy Gibbons, Oxford University o Kevin Hammond, University of St Andrews o Zoltán Horváth, Eötvös Loránd University o Frank Huch, Christian-Albrechts-University of Kiel o Johan Jeuring, Universiteit Utrecht o Greg Michaelson, Heriot-Watt University o Henrik Nilsson, University of Nottingham o Ricardo Peña, Universidad Complutense de Madrid o Morten Rhiger, Roskilde University o Colin Runciman, University of York o Carsten Schürmann, IT University of Copenhagen o Zhong Shao, Yale University o Phil Trinder, Heriot-Watt University SPONSORS We are actively looking for additional TFP sponsors, who may help to subsidise attendance by research students, for example. If you or your organisation might be willing to sponsor TFP, or if you know someone who might be willing to do so, please do not hesitate to contact the Symposium chair: Marko van Eekelen. Your students will be grateful!

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