September 2011 - Haskell

ANNOUNCE: ioctl 0.0.1
by Maciej Piechotka 13 Sep '15

13 Sep '15

A package for type-safe I/O control. Currently only ioctl is supported. Currently simply a extract from my tuntap fork TODO: - Return the integer as well as structure (will break the API) - Port for Windows Network.Socket.IOCtl (as soon as I manage to setup some sane environment on this platform) - Wrapping around DeviceIoControl Example (in hsc): data NotRead = NotRead instance NotRead Int where ioctlReq _ = #const FIONREAD notRead s = ioctlsocket' s NotRead Regards

2 1

CFP: Term and Graph rewriting, special issue of MSCS
by Rachid Echahed 13 Feb '14

13 Feb '14

-------------------------------------------------------------------------- First Call for Papers Special Issue of Mathematical Structures in Computer Science (MSCS) on "TERM and GRAPH Rewriting" -------------------------------------------------------------------------- Scope -------------------------------------------------------------------------- Rewriting techniques constitute a foundational theory of computing science. They are being investigated for several structures such as lambda-terms, first-order terms or graphs and have been successfully used in many areas such as programming languages, automated reasoning, program verification, security, etc. This is witnessed by the leading international events ICGT, RTA or TLCA among others. During the last decade, a particular interest has been devoted to the study of the impact of shared structures in term and graph rewriting through the international editions of TERMGRAPH series of workshops. Sharing is indeed ubiquitous in several research areas, for instance: the modelling of first- and higher-order term rewriting by (acyclic or cyclic) graph rewriting, the modelling of biological or chemical abstract machines, the implementation techniques of programming languages. Term and graph rewriting are also used in automated theorem proving and symbolic computation systems working on shared structures... This special issue is devoted to recent developments in all aspects of TERM and GRAPH rewriting. This includes (but is not limited to): term rewriting, graph transformation, proof methods, programming languages, infinitary rewriting, rewrite strategies, semantics, properties of rewriting ... -------------------------------------------------------------------------- Submissions -------------------------------------------------------------------------- Submitted papers must be original and not submitted for publication elsewhere, and will be subject to the standard journal refereeing process of the Mathematical Structures in Computer Science (MSCS) journal. Submissions should be in pdf format following the MSCS instruction for contributors (http://assets.cambridge.org/MSC/MSC_ifc.pdf) and should be submitted electronically via the following easy-chair web site: https://www.easychair.org/conferences/?conf=mscsrewriting2012 -------------------------------------------------------------------------- Important Dates -------------------------------------------------------------------------- January 20, 2012 : Abstract submission February 20, 2012: Paper submission June 15, 2012 : Notification of acceptance -------------------------------------------------------------------------- Guest Editor: -------------------------------------------------------------------------- Rachid Echahed, CNRS LIG Lab., Grenoble, France echahed(a)imag.fr --------------------------------------------------------------------------

1 8

ANNOUNCE: GHC version 7.2.1
by Ian Lynagh 26 Mar '12

26 Mar '12

============================================================= The (Interactive) Glasgow Haskell Compiler -- version 7.2.1 ============================================================= The GHC Team is pleased to announce a new major release of GHC, 7.2.1. The 7.2 branch is intended to be more of a "technology preview" than normal GHC stable branches; in particular, it supports a significantly improved version of DPH, as well as new features such as compiler plugins and "safe Haskell". The design of these new features may evolve as we get more experience with them. See the release notes for more details of what's new and what's changed. We are also using this branch as an opportunity to work out the best workflows to use with git. We expect the 7.2 branch to be short-lived, with 7.4.1 coming out shortly after ICFP as normal. Full release notes are here: http://www.haskell.org/ghc/docs/7.2.1/html/users_guide/release-7-2-1.html How to get it ~~~~~~~~~~~~~ The easy way is to go to the web page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in the native package format for many platforms, and the source distribution is available from the same place. Packages will appear as they are built - if the package for your system isn't available yet, please try again later. Background ~~~~~~~~~~ Haskell is a standard lazy functional programming language. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces (C, whatever). GHC is distributed under a BSD-style open source license. A wide variety of Haskell related resources (tutorials, libraries, specifications, documentation, compilers, interpreters, references, contact information, links to research groups) are available from the Haskell home page (see below). On-line GHC-related resources ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Relevant URLs on the World-Wide Web: GHC home page http://www.haskell.org/ghc/ GHC developers' home page http://hackage.haskell.org/trac/ghc/ Haskell home page http://www.haskell.org/ Supported Platforms ~~~~~~~~~~~~~~~~~~~ The list of platforms we support, and the people responsible for them, is here: http://hackage.haskell.org/trac/ghc/wiki/Contributors Ports to other platforms are possible with varying degrees of difficulty. The Building Guide describes how to go about porting to a new platform: http://hackage.haskell.org/trac/ghc/wiki/Building Developers ~~~~~~~~~~ We welcome new contributors. Instructions on accessing our source code repository, and getting started with hacking on GHC, are available from the GHC's developer's site run by Trac: http://hackage.haskell.org/trac/ghc/ Mailing lists ~~~~~~~~~~~~~ We run mailing lists for GHC users and bug reports; to subscribe, use the web interfaces at http://www.haskell.org/mailman/listinfo/glasgow-haskell-users http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs There are several other haskell and ghc-related mailing lists on www.haskell.org; for the full list, see http://www.haskell.org/mailman/listinfo/ Some GHC developers hang out on #haskell on IRC, too: http://www.haskell.org/haskellwiki/IRC_channel Please report bugs using our bug tracking system. Instructions on reporting bugs can be found here: http://www.haskell.org/ghc/reportabug

4 3

Open PhD and PostDoc positions at Marburg University
by Klaus Ostermann 04 Jan '12

04 Jan '12

ear all, we are happy to announce that we have new openings at the PhD and PostDoc level. The Programming Language and Software Technology Group, headed by Klaus Ostermann, conducts research dedicated to developing new technologies that help to construct high-quality software in a productive way. We use and develop an exciting set of technologies involving functional, object-oriented, domain-specific and aspect-oriented programming languages, software product lines, parser technology, language-integrated queries, static and dynamic software analysis, type systems, and many other topics. For more information consult http://www.uni-marburg.de/fb12/ps/ We offer positions with a lot of freedom to choose and develop research topics, few obligations, collaboration with a very strong group of researchers, competitive salary, and opportunities to develop a strong academic career path (e.g. by founding their own junior research group). For the PostDoc positions, we expect applicants to have demonstrated scientific excellence in areas related to our own research. For PhD positions, we expect evidence of the potential for scientific excellence. Knowledge of German is not required; the communication language in our group is English. Marburg is an attractive small "student town" right in the center of Germany. We are only an hour ride away from Frankfurt Airport, which will bring you to many destinations worldwide in a single hop. To apply for a position, please send informal inquiries to Klaus Ostermann (contact data can be found on our website). We are flexible with regard to the starting date, but generally the sooner the better. We are looking forward to hearing from you. Best wishes, Klaus Ostermann on behalf of the PS group at Marburg University http://www.uni-marburg.de/fb12/ps

2 1

Proposal to incorporate Haskell.org
by Don Stewart 16 Dec '11

16 Dec '11

Hello everyone. The haskell.org committee[1], in the interest of the long-term stability of the open source Haskell community infrastructure, has decided to incorporate haskell.org as a legal entity. This email outlines our recommendation, and seeks input from the community on this decision. The committee's proposal is that haskell.org incorporate as an entity under the Software Freedom Conservancy umbrella organization (the same group that Darcs joined recently): http://sfconservancy.org/ If we proceed with this move, haskell.org will be a legal entity, and registered as a non-profit, allowing us to more directly accept (US tax-deductible) donations, and to invest in assets that benefit the Haskell open source community. We welcome your feedback on the proposal attached below. -- Don Stewart (on behalf of the Haskell.org committee) ------------------------------------------------------------------------ = A proposal for the incorporation of Haskell.org = In recent years, haskell.org has started to receive assets, e.g. money from Google Summer Of Code, donations for Hackathons, and a Sparc machine for use in GHC development. We have also started spending this money: in particular, on hosting haskell.org itself. There is also interest in running fundraising drives for specific things such as Hackathon sponsorship and hosting fees. However, haskell.org doesn't currently exist as a legal entity, meaning that these assets have had to be held on our behalf by other entities, such as Galois and various universities. This leads to tricky situations, with no-one being sure who should decide how the haskell.org assets can be used. To solve these problems, we propose that haskell.org applies to become a member project of the Software Freedom Conservancy (SFC) <http://conservancy.softwarefreedom.org/>. The SFC is a non-profit organization that provides free financial and administrative services to open source projects. Additionally, it has 501(c)(3) status, meaning donations from the US are tax-deductible. The SFC would hold haskell.org's money and other assets, and would be able to accept donations on behalf of haskell.org. The haskell.org committee, as described here [2], will make decisions on spending assets and other decisions related to governing the non-profit. Before proceeding, we are inviting input from the community in the form of specific objections or queries regarding the plan. We've tried to answer some of the most likely questions: Q: Does this mean that my Haskell project must now be covered by a copyleft licence such as GPL? A: No, but Haskell projects using haskell.org resource should use an Open Source licence <http://www.opensource.org/licenses/alphabetical>. Q: Will it still be possible to use community.h.o to host non-open-source material, such as academic papers? A: An overall minority of such content, as is the current situation, is not a problem. Q: Will it still be possible to have job ads on the haskell.org mailing lists and website? A: Yes. Q: Will this affect our ability to host the Haskell Symposium <http://www.haskell.org/haskell-symposium/> and Industrial Haskell Group<http://industry.haskell.org/> webpages within haskell.org? A: No. Q: What will be the relationship between haskell.org and other organizations such as the Haskell Symposium and Industrial Haskell Group? A: Those organisations will continue to exist as separate entities. Q: If an umbrella non-profit organisation "The Haskell Foundation" was created, would haskell.org be able to join it? A: Yes. It's likely that in such a scenario, the Haskell Foundation would become the owner of the haskell.org domain name, with the cost divided between the members. The entity that is part of the SFC would be renamed "community.haskell.org" in order to avoid confusion. [1]: http://www.haskell.org/haskellwiki/Haskell.org_committee [2]: http://www.haskell.org/haskellwiki/Haskell.org_committee#Operation

5 6

getting started
by haskell 06 Oct '11

06 Oct '11

i am new to haskell can you tell me the softwares to install in haskell i have install hugs emacs but when i write any code it gives same error can you help me start i have lekash too i have installed some more packages -- View this message in context: http://haskell.1045720.n5.nabble.com/getting-started-tp4848583p4848583.html Sent from the Haskell - Haskell mailing list archive at Nabble.com.

6 10

VSTTE 2012 verification competition: call for participation
by Gudmund Grov 30 Sep '11

30 Sep '11

VSTTE 2012 Verification Competition ----------------------------------- A software verification competition is organized on behalf of the VSTTE 2012 conference (https://sites.google.com/site/vstte2012) The purposes of this competition are: to help promote approaches and tools, to provide new verification benchmarks, to stimulate further development of verification techniques, and to have fun. The contest takes place during two days, 17-19 November 2011, two months prior to the conference. Problems will be put on the website of the conference. Solutions must be sent by email to the competition organizers. Any programming language, specification language, and verification tool is allowed. Problems -------- There will be several, independent problems. Each problem is presented as an algorithm, using English or pseudocode, and a list of properties to formally prove about it, also expressed in plain English and standard mathematical notation. Evaluation ---------- Submissions are ranked according to the total sum of points they score. Each problem includes several sub-tasks, e.g. safety, termination, behavioral correctness, etc., and each sub-task is given a number of points. While evaluating the submissions, judges take into account the accuracy and thoroughness of solutions as well as their terseness and elegance. A certain degree of subjectivity is inevitable and should be considered as part of the game. Participants ------------ Anybody interested can take part in the contest. Team work is allowed. However, only teams up to 4 members are eligible for the first prize. The technical requirements are as follows: - access to the web to download the problems (PDF file); - access to the email to submit the solutions; - any software used in the solutions should be freely available to the public (this does not exclude closed source programs such as Microsoft's Z3) and usable on an x86 Linux or Windows machine. Submission ---------- A submission is a (possibly compressed) tarball that contains exactly one directory (named by the team, for instance). This directory should contain at least a text file named README, and one directory for each problem solved. Thus it must look like: team/ -+ +- README +- problem1/ +- problem2/ + ... +- problemN/ +- other stuff... The README file should contain the following information: - contact information (email); - detailed description of the submitted solutions: properties that have been specified and/or proved, restrictions and/or generalizations, anything that may facilitate the review; - detailed instructions to replay the solutions, including the software to use, URLs to get it from, compilation commands, etc. Organizers ---------- - Jean-Christophe Filliâtre (CNRS, France) - Andrei Paskevich (Univ Paris Sud, France) - Aaron Stump (University of Iowa, USA) Schedule -------- Thursday 17 Nov 2011, 15:00 UTC - competition starts Saturday 19 Nov 2011, 15:00 UTC - competition stops Monday 12 Dec 2011 - the winner is notified 28-29 Jan 2012 - results are announced at VSTTE 2012 Prize ----- The winner is awarded a talk slot at VSTTE 2012, to present any research of his/her choice of interest for the VSTTE community. In particular, a presentation of solutions to the competition problems and/or of the techniques and system used would be appreciated. -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

1 0

PhD studentship in Nottingham
by Graham Hutton 29 Sep '11

29 Sep '11

Dear all, I am currently advertising a PhD Studentship in Functional Programming at the University of Nottingham in the UK: http://tinyurl.com/phd-nottingham Due to the nature of the funding, the position is only to UK/EU students who have resided in the UK for the last three years. If you are interested in applying yourself, please drop me a note by email. If you know of any good candidates who may be interested in applying, or there is a local mailing list for advertising such things, I'd be much obliged if you could pass on the above link. Many thanks, Graham Hutton -- Prof Graham Hutton Functional Programming Lab School of Computer Science University of Nottingham, UK http://www.cs.nott.ac.uk/~gmh This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please send it back to me, and immediately delete it. Please do not use, copy or disclose the information contained in this message or in any attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. 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.

1 0

Haskell Weekly News: Issue 201
by Daniel Santa Cruz 29 Sep '11

29 Sep '11

Welcome to issue 201 of the HWN, a newsletter covering developments in the Haskell community. This release covers the week of September 18 to 24, 2011. You can find the HTML version of this issue at: http://contemplatecode.blogspot.com/2011/09/haskell-weekly-news-issue-201.h… Announcements Jasper Van der Jeugt sent more details about the 9th GhentFPG meeting, which will take place on October the 4th, at 19:30 in the Technicum building of Ghent University. "You don't have to be a Functional Programming guru to attend, everyone eager to learn is welcome." [1] http://goo.gl/hAa5Zn New and Updated Projects * usb, bindings-libusb, usb-iteratee (Bas van Dijk; 1.0, 1.4.4, 0.4) Wrapers around the portable C library libusb-1.0 [2] http://goo.gl/lTMNJn * ivy-web (James Deng; 0.1) A lightweight web framework, with type-safe routes, based on invertible syntax, and i18n support, influenced by Django, Snap and Yesod. [3] http://goo.gl/dTcPEn * lushtags (Bit Connor) ctags compatible tags files for Haskell programs. [4] http://goo.gl/30TYen * lightweight monadic regions family (Bas van Dijk; multiple versions) Updates to regios, regions-mtl, regions-monadstf, regional-pointers, safer-file-handles, safer-file-handles-bytestring, safer-file-handles-text, and usb-safe. [5] http://goo.gl/g8P6Kn * skein (Felipe Almeida Lessa; 0.1) A family of fast secure cryptographic hash functions. [6] http://goo.gl/xwafmn Quotes of the Week * dafis: I thought a C++ friend class was one you allowed to touch your private parts * edwardk: any time i can help, just ask. i may not actually help, but i'll be sure to note your suffering. * edwardk: i have a lot fewer [haddock problems] now since i stopped bothering trying to document ;) * edwardk: Had i thought of it earlier i could have named trifecta kessel run. at this point it looks like it'll contain at least 12 parsecs. * ddarius: The history of iteratees is making a simple idea complex. * shachaf: You can never escape having learned monads. If you learn two monads, though, you can go back to only knowing one. Top Reddit Stories * GHCi now supports all top-level declarations Domain: github.com, Score: 104, Comments: 35 On Reddit: [7] http://goo.gl/GfTc9n Original: [8] http://goo.gl/Md5B3n * The best ghc bug ever Domain: twitter.com, Score: 93, Comments: 27 On Reddit: [9] http://goo.gl/3sCHUn Original: [10] http://goo.gl/N7IGdn * Running a startup on Haskell Domain: bos.github.com, Score: 73, Comments: 33 On Reddit: [11] http://goo.gl/HevD3n Original: [12] http://goo.gl/IsXedn * No chrome, Haskell is not Danish. Domain: i.imgur.com, Score: 73, Comments: 26 On Reddit: [13] http://goo.gl/AYyq4n Original: [14] http://goo.gl/whKijn * Did Haskell Platform miss the July release? It's already September. Domain: trac.haskell.org, Score: 46, Comments: 12 On Reddit: [15] http://goo.gl/6m8Yln Original: [16] http://goo.gl/r9k6tn * Iteratees at Tsuru Capital: various contributions to the hackage iteratee library used in a production trading system Domain: blog.kfish.org, Score: 36, Comments: 12 On Reddit: [17] http://goo.gl/rCTO6n Original: [18] http://goo.gl/PikaAn * Apprendre Haskell vous fera le plus grand bien ! -- LYAH in French Domain: lyah.haskell.fr, Score: 33, Comments: 15 On Reddit: [19] http://goo.gl/pV3jvn Original: [20] http://goo.gl/ixiXWn * Would You Bet $100,000,000 on Haskell? Domain: digitalmars.com, Score: 28, Comments: 44 On Reddit: [21] http://goo.gl/oPI5Kn Original: [22] http://goo.gl/YYeOln * Galois offers Haskell course: The Tao of Functional Programming Domain: corp.galois.com, Score: 26, Comments: 9 On Reddit: [23] http://goo.gl/6HX8Kn Original: [24] http://goo.gl/n7urdn Top StackOverflow Questions * What are Haskell's strictness points? votes: 59, answers: 7 Read on SO: [25] http://goo.gl/5PiDHn * Can someone explain the traverse function in Haskell votes: 14, answers: 3 Read on SO: [26] http://goo.gl/P5WtFn * Why do we have map, fmap and liftM? votes: 13, answers: 1 Read on SO: [27] http://goo.gl/TCRKwn * Does a function like this already exist? (Or, what's a better name for this function?) votes: 12, answers: 4 Read on SO: [28] http://goo.gl/QY6i8n * Question about the ~ and @ operators in Haskell votes: 11, answers: 2 Read on SO: [29] http://goo.gl/pXnV6n * Folding across Maybes in Haskell votes: 8, answers: 5 Read on SO: [30] http://goo.gl/y1ALtn * How is foldl lazy? votes: 7, answers: 4 Read on SO: [31] http://goo.gl/LQAxNn * avoid explicit passing of lookup table votes: 7, answers: 4 Read on SO: [32] http://goo.gl/tKh2wn * Why is [Char]-based input so much slower than the [Char]-based output in Haskell? votes: 7, answers: 1 Read on SO: [33] http://goo.gl/2nuqNn Until next time, Daniel Santa Cruz References 1. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/92680 2. http://permalink.gmane.org/gmane.comp.lang.haskell.general/18935 3. http://permalink.gmane.org/gmane.comp.lang.haskell.general/18936 4. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/92480 5. http://permalink.gmane.org/gmane.comp.lang.haskell.general/18940 6. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/92528 7. https://github.com/ghc/ghc/commit/3db757241ce7fb99c096c30481aefa86bb9855a1 8. http://www.reddit.com/r/haskell/comments/kmxf2/ghci_now_supports_all_toplev… 9. http://twitter.com/#!/bos31337/status/116372971509121025 10. http://www.reddit.com/r/haskell/comments/kmk6q/the_best_ghc_bug_ever/ 11. http://bos.github.com/strange-loop-2011/talk/talk.html#(1) 12. http://www.reddit.com/r/haskell/comments/km2b8/running_a_startup_on_haskell/ 13. http://i.imgur.com/D4QEO.png 14. http://www.reddit.com/r/haskell/comments/koom1/no_chrome_haskell_is_not_dan… 15. http://trac.haskell.org/haskell-platform/wiki/ReleaseTimetable 16. http://www.reddit.com/r/haskell/comments/kk9hl/did_haskell_platform_miss_th… 17. http://blog.kfish.org/2011/09/iteratees-at-tsuru.html 18. http://www.reddit.com/r/haskell/comments/kjem1/iteratees_at_tsuru_capital_v… 19. http://lyah.haskell.fr/ 20. http://www.reddit.com/r/haskell/comments/km1l6/apprendre_haskell_vous_fera_… 21. http://www.digitalmars.com/d/archives/digitalmars/D/Would_You_Bet_100_000_0… 22. http://www.reddit.com/r/haskell/comments/klhln/would_you_bet_100000000_on_h… 23. http://corp.galois.com/haskell-course 24. http://www.reddit.com/r/haskell/comments/kp6as/galois_offers_haskell_course… 25. http://stackoverflow.com/questions/7490768/what-are-haskells-strictness-poi… 26. http://stackoverflow.com/questions/7460809/can-someone-explain-the-traverse… 27. http://stackoverflow.com/questions/7463500/why-do-we-have-map-fmap-and-liftm 28. http://stackoverflow.com/questions/7518589/does-a-function-like-this-alread… 29. http://stackoverflow.com/questions/7506684/question-about-the-and-operators… 30. http://stackoverflow.com/questions/7464208/folding-across-maybes-in-haskell 31. http://stackoverflow.com/questions/7487455/how-is-foldl-lazy 32. http://stackoverflow.com/questions/7504012/avoid-explicit-passing-of-lookup… 33. http://stackoverflow.com/questions/7510078/why-is-char-based-input-so-much-…

1 1

mapM with Traversables
by thomas burt 28 Sep '11

28 Sep '11

Hi - I have a function, "f :: Monad m => a -> m b", as well as a list of a's. I'd like to produce a sequence (Data.Sequence) of b's, given the a's: g :: [a] -> m (Seq b) g a = do Data.Traversable.mapM f a -- type error! I see that "Data.Traversable.mapM f a" doesn't work... is this like asking the compiler to infer the cons/append operation from the type signature of g? Do I need to write my own function that explicitly calls the "append" functions from Data.Sequence or can I do something else that would work for any "g :: Traversable t, Traversable u => t a -> m (u b)" given "f :: a -> m b"? Thanks for any comments! Thomas

1 0