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Haskell Weekly News: Issue 214
by Daniel Santa Cruz 09 Feb '12

09 Feb '12

Welcome to issue 214 the HWN, a newsletter covering stories, questions, and remarks seen around the web during the week of January 29 to February 4, 2012. You can find the HTML version at: http://contemplatecode.blogspot.com/2012/02/haskell-weekly-news-issue-214.h… Quotes of the Week * Jafet: [on memoising an O(n) algorithm:] This is like trying to save work in a police investigation by having each detective determine whether another detective has already removed all evidence from his area by walking through it to search for evidence in the area. * CodeWeaver: keep in mind encryption's only as good as how much you trust that the implementors got it right. * cmccann: length [1..10^20] lambdabot: mueval-core: Time limit exceeded cmccann: looks like 10^20 is infinity * elliott: race condition waiting to happen * elliott: o'reilly publishes attoparsec tutorial: exactly the same as their parsec tutorial, but 10^-18th the size * rwbarton: Num works for Float/Double, it's Float/Double that doesn't work for Num * ddarius: Space isn't that big. * Brent Yorgey: > Sometimes, I suspect that Haskell not only makes easier of the hard > things for imperative programming languages but also makes harder of > some easy things. This is true. But usually these are things that you don't *want* to be easy, like shooting yourself in the kidney. (But these features are often described in ways that make them sound great, like "flexible usage of bullet-placement tools".) Inserting arbitrary print statements into the middle of some code is difficult for a reason. Top Reddit Stories * GHC 7.4.1 is out. Here's the release notes Domain: haskell.org, Score: 107, Comments: 59 On Reddit: [1] http://goo.gl/su4jl Original: [2] http://goo.gl/Nstve * Coming soon, to a bookstore near you Domain: yesodweb.com, Score: 82, Comments: 16 On Reddit: [3] http://goo.gl/6gZXg Original: [4] http://goo.gl/zSW1l * ImplicitCAD is a Programmatic CAD Tool/3D Modelling Engine in Haskell. Also my first big Haskell project. Feedback, advice? Domain: github.com, Score: 63, Comments: 23 On Reddit: [5] http://goo.gl/YHMRa Original: [6] http://goo.gl/39rc3 * Using monadic effects to reverse a merge sort Domain: github.com, Score: 42, Comments: 4 On Reddit: [7] http://goo.gl/dVuyp Original: [8] http://goo.gl/jL9qj * Exciting changes coming to conduit 0.2 Domain: yesodweb.com, Score: 38, Comments: 7 On Reddit: [9] http://goo.gl/neyW2 Original: [10] http://goo.gl/1ikN5 * Vectorisation without Replication in Data Parallel Haskell Domain: disciple-devel.blogspot.com, Score: 35, Comments: 4 On Reddit: [11] http://goo.gl/iJ4OD Original: [12] http://goo.gl/uMp4S * If software purity in functional languages is such an awesome idea, why are we still writing Python, Ruby or Java? Domain: self.haskell, Score: 33, Comments: 136 On Reddit: [13] http://goo.gl/F0QCY Original: [14] http://goo.gl/F0QCY * Released Data.Array.Accelerate 0.9.0.0 — the Haskell array library for GPUs Domain: justtesting.org, Score: 32, Comments: 3 On Reddit: [15] http://goo.gl/NqUwp Original: [16] http://goo.gl/JYTQ4 * Fun With -XPolyKinds : Polykinded Folds Domain: typesandotherdistractions.com, Score: 24, Comments: 1 On Reddit: [17] http://goo.gl/daxL8 Original: [18] http://goo.gl/u9gHi * Introduction to using acid-state, IxSet and data-lens as a native Haskell, noSQL, RAM-cloud database Domain: happstack.com, Score: 23, Comments: 21 On Reddit: [19] http://goo.gl/9bliO Original: [20] http://goo.gl/ZGXyW * Can't wait for the Haskell Platform? -- Compiling GHC 7.4.1 from source has never been easier. Domain: blog.jasonknight.us, Score: 21, Comments: 8 On Reddit: [21] http://goo.gl/IKjm6 Original: [22] http://goo.gl/dgMF2 * Generating random functions Domain: mainisusuallyafunction.blogspot.com, Score: 20, Comments: 6 On Reddit: [23] http://goo.gl/DB4f6 Original: [24] http://goo.gl/aOAPo * How to deal with undesired values when designing types Domain: self.haskell, Score: 19, Comments: 28 On Reddit: [25] http://goo.gl/aPCbQ Original: [26] http://goo.gl/aPCbQ * Guarded Pipes or How to write Conduit.List Combinators in Pipes. Domain: pcapriotti.wordpress.com, Score: 17, Comments: 16 On Reddit: [27] http://goo.gl/vo8ip Original: [28] http://goo.gl/mhnfH * UHC JavaScript Backend Project Page (Work in Progress) Domain: uu-computerscience.github.com, Score: 16, Comments: 0 On Reddit: [29] http://goo.gl/42xXs Original: [30] http://goo.gl/Cz8R6 Top StackOverflow Questions * What are the rules about concurrently accessing a persistent database votes: 17, answers: 1 Read on SO: [31] http://goo.gl/m3QhB * Functions don't just have types: They ARE Types. And Kinds. And Sorts. Help put a blown mind back together votes: 15, answers: 2 Read on SO: [32] http://goo.gl/fKjQR * Defining polymorphic constants in Haskell votes: 12, answers: 2 Read on SO: [33] http://goo.gl/3H3ke * Do guarded pipes behave the same as pipes using await? votes: 12, answers: 2 Read on SO: [34] http://goo.gl/Mf3HQ * What is the purpose of the IdentityT transformer? votes: 11, answers: 2 Read on SO: [35] http://goo.gl/L7Syk * call/cc implementation? votes: 10, answers: 5 Read on SO: [36] http://goo.gl/tfLLz * Understanding bind function in Haskell votes: 9, answers: 4 Read on SO: [37] http://goo.gl/amtSd * How to show that a monad is a functor and an applicative functor? votes: 8, answers: 2 Read on SO: [38] http://goo.gl/Cg0EQ * Avoiding lift with Monad Transformers votes: 7, answers: 2 Read on SO: [39] http://goo.gl/fBhCz * Container element types votes: 7, answers: 1 Read on SO: [40] http://goo.gl/UfZnG Until next time, Daniel Santa Cruz References 1. http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/release-7-4-1.html 2. http://www.reddit.com/r/haskell/comments/p886g/ghc_741_is_out_heres_the_rel… 3. http://www.yesodweb.com/blog/2012/01/coming-soon 4. http://www.reddit.com/r/haskell/comments/p4hpt/coming_soon_to_a_bookstore_n… 5. https://github.com/colah/ImplicitCAD 6. http://www.reddit.com/r/haskell/comments/p9jzh/implicitcad_is_a_programmati… 7. https://github.com/DanBurton/Blog/blob/master/Literate%20Haskell/recovery.l… 8. http://www.reddit.com/r/haskell/comments/p2kar/using_monadic_effects_to_rev… 9. http://www.yesodweb.com/blog/2012/01/conduit-changes-0-2 10. http://www.reddit.com/r/haskell/comments/p1iu0/exciting_changes_coming_to_c… 11. http://disciple-devel.blogspot.com/2012/02/vectorisation-without-replicatio… 12. http://www.reddit.com/r/haskell/comments/p7f6u/vectorisation_without_replic… 13. http://www.reddit.com/r/haskell/comments/pavb1/if_software_purity_in_functi… 14. http://www.reddit.com/r/haskell/comments/pavb1/if_software_purity_in_functi… 15. http://justtesting.org/released-dataarrayaccelerate-0900-the-haskell 16. http://www.reddit.com/r/haskell/comments/p5sij/released_dataarrayaccelerate… 17. http://www.typesandotherdistractions.com/2012/02/fun-with-xpolykinds-polyki… 18. http://www.reddit.com/r/haskell/comments/p8djh/fun_with_xpolykinds_polykind… 19. http://www.happstack.com/docs/crashcourse/AcidState.html 20. http://www.reddit.com/r/haskell/comments/p75ko/introduction_to_using_acidst… 21. http://blog.jasonknight.us/2012/02/how-to-install-ghc-741-in-ubuntu-from.ht… 22. http://www.reddit.com/r/haskell/comments/pabfi/cant_wait_for_the_haskell_pl… 23. http://mainisusuallyafunction.blogspot.com/2012/02/generating-random-functi… 24. http://www.reddit.com/r/haskell/comments/p89fq/generating_random_functions/ 25. http://www.reddit.com/r/haskell/comments/p5lv0/how_to_deal_with_undesired_v… 26. http://www.reddit.com/r/haskell/comments/p5lv0/how_to_deal_with_undesired_v… 27. http://pcapriotti.wordpress.com/2012/02/02/an-introduction-to-guarded-pipes/ 28. http://www.reddit.com/r/haskell/comments/p8g55/guarded_pipes_or_how_to_writ… 29. http://uu-computerscience.github.com/uhc-js/ 30. http://www.reddit.com/r/haskell/comments/p1nqh/uhc_javascript_backend_proje… 31. http://stackoverflow.com/questions/9055214/what-are-the-rules-about-concurr… 32. http://stackoverflow.com/questions/9074261/functions-dont-just-have-types-t… 33. http://stackoverflow.com/questions/9088821/defining-polymorphic-constants-i… 34. http://stackoverflow.com/questions/9145656/do-guarded-pipes-behave-the-same… 35. http://stackoverflow.com/questions/9122825/what-is-the-purpose-of-the-ident… 36. http://stackoverflow.com/questions/9050725/call-cc-implementation 37. http://stackoverflow.com/questions/9074284/understanding-bind-function-in-h… 38. http://stackoverflow.com/questions/9098247/how-to-show-that-a-monad-is-a-fu… 39. http://stackoverflow.com/questions/9054731/avoiding-lift-with-monad-transfo… 40. http://stackoverflow.com/questions/9078168/container-element-types

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A fun afternoon in Oxford
by Tom Harper 08 Feb '12

08 Feb '12

Calling all functional programmers, The Department of Computer Science at the University of Oxford will be holding a Fun in the Afternoon on the 28th of February, 2012. Fun in the Afternoon is a seminar series that has been held at various universities in the UK to bring together anyone interested for an afternoon of talks about functional programming. There will be a few talks and plenty of chances to socialise. The atmosphere is friendly and informal, and anyone is welcome to attend. The talks are a great chance for people to present something they have been working on or think others might find interesting. If you think you would like to give a 15-30 minute presentation, please contact me at tom.harper(a)cs.ox.ac.uk. The sooner the better; the 28th of Feb is not that far away! You do not have to be an academic or professional functional programmer to attend (or even give a talk), just have an interest in functional programming. There’ll be more details soon, but mark your calendar, and please get in contact if you’ve got roughly 15–30 minutes of fun to share. We would also like to get an idea of the number of attendees, so if you intend to come, please register using the link below. Register here: http://goo.gl/ycPmp A handy map: http://g.co/maps/f5zsb More info: http://sneezy.cs.nott.ac.uk/fun/ Hope to see you there! -- Tom Harper DPhil Student Teaching Assistant Department of Computer Science University of Oxford

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CFP TFPIE 2012
by Marco Morazan 03 Feb '12

03 Feb '12

CALL FOR PAPERS/PRESENTATIONS TFPIE 2012 International Workshop on Trends in Functional Programming in Education 2012 June 11 2012 University of St Andrews, Scotland http://www.cs.ru.nl/P.Achten/TFPIE_2012/TFPIE_2012_home.html The first International Workshop on Trends in Functional Programming in Education, TFPIE 2012, will be co-located with TFP 2012 at the University of St Andrews in Scotland. The goal of TFPIE is to gather researchers, professors, teachers, and all professionals that use or are interested in the use of functional programming in education. TFPIE aims to be a venue where novel ideas, classroom-tested ideas, and work in progress on the use of functional programming in education are discussed. The one-day workshop will foster a spirit of open discussion by having a review process for publication after the workshop. The program chairs of TFPIE 2012 will screen submissions to ensure that all presentations are within scope and are of interest to participants. Potential presenters are invited to submit an extended abstract (4-6 pages) or an article (up to 16 pages). The authors of all accepted presentations will have their preprints and their slides made available on the workshop's website/wiki. Any visitors to the TFPIE 2012 website/wiki will be able to add comments. This includes presenters who may respond to comments and questions as well as provide pointers to improvements and follow-up work. After the workshop, the program committee will review, using prevailing academic standards, the articles accepted for presentation to select the best for publication in Electronic Proceedings in Theoretical Computer Science (EPTCS). Articles rejected for presentation and all extended abstracts will not be formally reviewed by the PC. TOPICS OF INTEREST TFPIE 2012 welcomes submissions describing practical techniques used in the classroom, tools used and/or developed, and any creative use of functional programming (FP) to aid education in or outside Computer Science. Topics of interest include, but are not limited to: FP and beginning CS students FP in Artificial Intelligence FP in Robotics FP and Music Advanced FP for undergraduates FP in graduate education Engaging students in research using FP FP in Programming Languages FP in the high school curriculum FP as a stepping stone to other CS topics FP and Philosophy If you are not sure if your work is appropriate for TFPIE 2012, please contact the PC chairs by e-mail at: tfpie2012(a)cs.ru.nl . Program Committee Peter Achten, Radboud University Nijmegen Jost Berthold, University of Copenhagen Marc Feeley, University of Montreal Ralf Hinze, University of Oxford Shriram Krishnamurthi, Brown University Michel Mauny, ENSTA Paris Tech James McKinna, UK Marco T. Morazan, Seton Hall University Rinus Plasmeijer, Radboud University Nijmegen Simon Thompson, University of Kent Important Dates May 20 submission of abstract or article May 25 notification of acceptance June 11 TFPIE July 6 submission of formal paper September 10 notification of acceptance October 1 camera-ready paper Venue The University of St Andrews is Scotland's first university and the third oldest in the English-speaking world, founded in 1413. Over six centuries it has established a reputation as one of Europe's leading and most distinctive centers for teaching and research. St Andrews is situated on the east coast of Fife, Scotland, UK. The town is approximately 50 miles north-east of Edinburgh, 14 miles south-east of Dundee, 78 miles south of Aberdeen, and 82 miles east of Glasgow making it easily accessible by any means of transportation. Help on traveling to St Andrews can be found at: http://www.st-andrews.ac.uk/visiting/GettingtoStAndrews/ . Questions? If you have any questions, do not hesitate to contact us at: tfpie2012(a)cs.ru.nl . -- Cheers, Marco

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ANNOUNCE: GHC version 7.4.1
by Ian Lynagh 02 Feb '12

02 Feb '12

============================================================= The (Interactive) Glasgow Haskell Compiler -- version 7.4.1 ============================================================= The GHC Team is pleased to announce a new major release of GHC, 7.4.1. Here are some of the highlights of the 7.4 branch since 7.2 and 7.0: * The Num class no longer has Eq or Show superclasses. * There is a new feature Safe Haskell (-XSafe, -XTrustworthy, -XUnsafe). The design has changed since 7.2. * There is a new feature kind polymorphism (-XPolyKinds). A side-effect of this is that, when the extension is not enabled, in certain circumstances kinds are now defaulted to * rather than being inferred. * There is a new feature constraint kinds (-XConstraintKinds). * It is now possible to give any sort of declaration at the ghci prompt. For example, you can now declare datatypes within ghci. * The profiling and hpc implementations have been merged and overhauled. Visible changes include renaming of profiling flags, and a new semantics for the cost-centre stacks (which should in most cases result in more useful and intuitive profiles). The +RTS -xc flag now also gives a stack trace. * It is now possible to write compiler plugins. * DPH support has been significantly improved. * There is now preliminary support for registerised compilation using LLVM on the ARM platform. Full release notes are here: http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/release-7-4-1.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

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PhD studentship in Nottingham (closing date 10th February)
by Graham Hutton 02 Feb '12

02 Feb '12

Dear all, I am currently advertising a PhD Studentship in Functional Programming at the University of Nottingham in the UK: http://www.nottingham.ac.uk/jobs/currentvacancies/ref/SCI1088 The closing date is *** Friday 10th February 2012 ***. If you would like to apply, please follow the instructions in the advert, rather than clicking on "apply online". 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.

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ANN: hledger 0.17
by Simon Michael 02 Feb '12

02 Feb '12

Happy new year all. hledger and hledger-web 0.17 are released. Not quite as planned, this release mainly fixes bugs and updates dependencies. Also the hledger-vty and hledger-chart packages have been demoted to "unmaintained extras" for now to save time. hledger is a library, command-line tool, and web app for reporting on financial transactions stored in a text file. It is a haskell port and friendly fork of John Wiegley's Ledger. Home: http://hledger.org To install: cabal update, then cabal install hledger (or cabal-install hledger-web). If you have any trouble, please let me know, or watch the mail list/bug tracker for updates. (Ready to run binaries are provided on request to project donors, a great way to support the project - see http://hledger.org/DOWNLOAD.html.) Release notes for 0.17: * support HP 2011.4.0.0 * support and require cmdargs 0.9 * allow non-threaded builds, supporting more debian architectures * parsing: give a clearer error when journal file path contains ~ * parsing: -B/--cost now ignores P historical prices, like ledger * parsing: inferred amounts now use the cost commodity if known, like ledger (#69) * balance: report differently-priced lots in an account as a single amount, like ledger * web: support and require yesod >= 0.9.4 * web: use the main aeson package again * web: fix a regression with dollar signs in hamlet templates * web: add form allowed blank account names (#81) * chart, vty: hledger-chart and hledger-vty demoted to non-maintained extras for now Best, -Simon

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Haskell Weekly News: Issue 213
by Daniel Santa Cruz 02 Feb '12

02 Feb '12

Welcome to issue 213 of the HWN, a newsletter covering quotes, stories, and questions seen around the net concerning Haskell during the week of January 22 to 28, 2012. You can read the HTML version at: http://contemplatecode.blogspot.com/2012/02/haskell-weekly-news-issue-213.h… Quotes of the Week * monochrom: great way to answer a semantics question by commenting on the font ... "what is the semantics of IO?" "the I may be narrower than O in some fonts, and same width in some other fonts" ... "on very old typewriters, it also denotes the number 10 (ten), for those of you looking for a denotation" * elliott: |\/|/-\|-|-|=|\||} is my preferred mappend operator * merijn: rostayob: I used to be a functional programmer like you, but then I took an UML diagram to the knee >.> * mauke: monoids are simple elliott: And as we all know, monads are basically just monoids! monochrom: haskell is basically just ascii * O'Keefe: "Elegance is not optional." * O'Keefe: "If I don't write it, I won't wrong it." * kmc: "monads are like containers, as long as you forget everything you know about containers, and treat it as a synonym for 'monad'" * Enigmagic: this calls for mfix and some tequila Top Reddit Stories * SPJ : Escape From the Ivory Tower: The Haskell Journey, From 1990 to 2011 Domain: yow.eventer.com, Score: 67, Comments: 12 On Reddit: [1] http://goo.gl/JqRUW Original: [2] http://goo.gl/9ILW1 * Make Things Now! - Pragmatic FP With Haskell (slides) Domain: code.haskell.org, Score: 44, Comments: 22 On Reddit: [3] http://goo.gl/WJQnH Original: [4] http://goo.gl/UMd9y * ANNOUNCE: GHC 7.4.1 Release Candidate 2 Domain: haskell.org, Score: 37, Comments: On Reddit: [5] http://goo.gl/D9F37 Original: [6] http://goo.gl/sdD1L * Web application that uses UHC to compile Haskell to JavaScript Domain: alessandrovermeulen.me, Score: 36, Comments: 13 On Reddit: [7] http://goo.gl/A3S0k Original: [8] http://goo.gl/lyX2K * Web app that shows you the changes between releases of packages on hackage Domain: hdiff.luite.com, Score: 33, Comments: 4 On Reddit: [9] http://goo.gl/6ioFh Original: [10] http://goo.gl/aZAyc * Combining Regions and Iteratees Domain: haskell.org, Score: 30, Comments: 10 On Reddit: [11] http://goo.gl/LEPiQ Original: [12] http://goo.gl/k3wpd * MonadBaseControl is unsound : Inside 233 Domain: blog.ezyang.com, Score: 29, Comments: 19 On Reddit: [13] http://goo.gl/ptCF6 Original: [14] http://goo.gl/Y5bbh * Yesod example: wiki, markdown, chat subsite, event source Domain: yesodweb.com, Score: 29, Comments: 1 On Reddit: [15] http://goo.gl/GyfzS Original: [16] http://goo.gl/on96C * inner beauty of tree traversals: pre- and post-order Domain: blog.moertel.com, Score: 29, Comments: On Reddit: [17] http://goo.gl/6fKzq Original: [18] http://goo.gl/NpjrO * Seem like there's a boycott of Elsevier going on. Domain: thecostofknowledge.com, Score: 29, Comments: 1 On Reddit: [19] http://goo.gl/2B106 Original: [20] http://goo.gl/dvxML * Unifying Monoids and Monads with Polymorphic Kinds Domain: jonmsterling.com, Score: 26, Comments: 29 On Reddit: [21] http://goo.gl/kTafx Original: [22] http://goo.gl/A3IrU * Modelling IO: MonadIO and beyond Domain: blog.ezyang.com, Score: 26, Comments: 4 On Reddit: [23] http://goo.gl/gr2M1 Original: [24] http://goo.gl/0n1a9 Top StackOverflow Questions * Is it a good idea to compile a language to C? votes: 26, answers: 7 Read on SO: [25] http://goo.gl/V8sSx * Haskell GHC: what is the time complexity of a pattern match with N constructors? votes: 19, answers: 1 Read on SO: [26] http://goo.gl/SU0l8 * What to use instead of a main loop in Haskell? votes: 12, answers: 2 Read on SO: [27] http://goo.gl/iYasz * Associated types and container elements votes: 12, answers: 2 Read on SO: [28] http://goo.gl/zBNWU * Undefined at the type level votes: 12, answers: 1 Read on SO: [29] http://goo.gl/m9Acn * Is there a good reason why `deleteBy` does not have its most general type? votes: 10, answers: 3 Read on SO: [30] http://goo.gl/dQDrf * Using low bitsize integral types like `Int8` and what they are for votes: 9, answers: 2 Read on SO: [31] http://goo.gl/YaE68 * How is the ghc runtime support for profiling implemented? votes: 9, answers: 2 Read on SO: [32] http://goo.gl/yz7eC * how to achieve “product of two monads” effect? votes: 9, answers: 1 Read on SO: [33] http://goo.gl/pLhVK * Combine two monads when neither has a transformer? votes: 9, answers: 1 Read on SO: [34] http://goo.gl/yw8tr * Why don't type synonyms permit recursion in Haskell? votes: 8, answers: 2 Read on SO: [35] http://goo.gl/hPzVq Until next time, Daniel Santa Cruz References 1. http://yow.eventer.com/events/1004/talks/1054 2. http://www.reddit.com/r/haskell/comments/ovc9s/spj_escape_from_the_ivory_to… 3. http://code.haskell.org/~dons/talks/padl-keynote-2012-01-24.pdf 4. http://www.reddit.com/r/haskell/comments/oxg3c/make_things_now_pragmatic_fp… 5. http://www.haskell.org/pipermail/glasgow-haskell-users/2012-January/021714.… 6. http://www.reddit.com/r/haskell/comments/p0x96/announce_ghc_741_release_can… 7. http://alessandrovermeulen.me/2012/01/26/getting-rid-of-javascript-with-has… 8. http://www.reddit.com/r/haskell/comments/oz27a/web_application_that_uses_uh… 9. http://hdiff.luite.com/ 10. http://www.reddit.com/r/haskell/comments/ozjys/web_app_that_shows_you_the_c… 11. http://www.haskell.org/pipermail/haskell-cafe/2012-January/098704.html 12. http://www.reddit.com/r/haskell/comments/orh4f/combining_regions_and_iterat… 13. http://blog.ezyang.com/2012/01/monadbasecontrol-is-unsound/ 14. http://www.reddit.com/r/haskell/comments/ot5f2/monadbasecontrol_is_unsound_… 15. http://www.yesodweb.com/blog/2012/01/wiki-chat-subsite 16. http://www.reddit.com/r/haskell/comments/oub3p/yesod_example_wiki_markdown_… 17. http://blog.moertel.com/articles/2012/01/26/the-inner-beauty-of-tree-traver… 18. http://www.reddit.com/r/haskell/comments/oyu7d/inner_beauty_of_tree_travers… 19. http://thecostofknowledge.com/ 20. http://www.reddit.com/r/haskell/comments/ozi7i/seem_like_theres_a_boycott_o… 21. http://www.jonmsterling.com/posts/2012-01-12-unifying-monoids-and-monads-wi… 22. http://www.reddit.com/r/haskell/comments/osn5d/unifying_monoids_and_monads_… 23. http://blog.ezyang.com/2012/01/modelling-io/ 24. http://www.reddit.com/r/haskell/comments/ourfu/modelling_io_monadio_and_bey… 25. http://stackoverflow.com/questions/8976423/is-it-a-good-idea-to-compile-a-l… 26. http://stackoverflow.com/questions/9027384/haskell-ghc-what-is-the-time-com… 27. http://stackoverflow.com/questions/9015318/what-to-use-instead-of-a-main-lo… 28. http://stackoverflow.com/questions/9016521/associated-types-and-container-e… 29. http://stackoverflow.com/questions/9036554/undefined-at-the-type-level 30. http://stackoverflow.com/questions/9004937/is-there-a-good-reason-why-delet… 31. http://stackoverflow.com/questions/8963942/using-low-bitsize-integral-types… 32. http://stackoverflow.com/questions/9010808/how-is-the-ghc-runtime-support-f… 33. http://stackoverflow.com/questions/9013329/how-to-achieve-product-of-two-mo… 34. http://stackoverflow.com/questions/9034060/combine-two-monads-when-neither-… 35. http://stackoverflow.com/questions/8963376/why-dont-type-synonyms-permit-re…

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Call for Papers - Workshop on Reversible Computation 2012
by Janis Voigtländer 01 Feb '12

01 Feb '12

============================================================== Call for Papers 4th Workshop on Reversible Computation (RC 2012) July 2nd-3rd, 2012, Copenhagen, Denmark Abstract Submission: March 2nd, 2012 Submission Deadline: March 9th, 2012 http://www.reversible-computation.org ============================================================== Reversible computation has a growing number of promising application areas such as low power design, coding/decoding, program debugging, testing, database recovery, discrete event simulation, reversible algorithms, reversible specification formalisms, reversible programming languages, process algebras, and the modeling of biochemical systems. Furthermore, reversible logic provides a basis for quantum computation with its applications, for example, in cryptography and in the development of highly efficient algorithms. First reversible circuits and quantum circuits have been implemented recently and are seen as promising alternatives to conventional CMOS technology. The workshop will bring together researchers from computer science, mathematics, and physics to discuss new developments and directions for future research in Reversible Computation. This particularly includes applications of reversibility in quantum computation. Research papers, tutorials, tool demonstrations, and work-in-progress reports are within the scope of the workshop. Contributions on the following topics in Reversible Computation are welcome: * Applications * Architectures * Algorithms * Circuit Design * Debugging * Fault Tolerance and Error Correction * Hardware * Information Theory * Physical Realizations * Programming Languages * Quantum Computation * Software * Synthesis * Theoretical Results * Testing * Verification ===== Important Dates ===== - Abstract Submission: March 2nd, 2012 - Submission Deadline: March 9th, 2012 (strict) - Notification to Authors: May 7th, 2012 - Final Version: June 1st, 2012 - Workshop: July 2nd-3rd, 2012 ===== Paper submission ===== Interested researchers are invited to submit full research papers (12 pages maximum), tutorials (12 pages maximum), as well as work-in-progress reports or demonstration papers (6 pages maximum). All submissions will be accepted as PDF file using the LNCS style (more details can be found at the workshop website). A preliminary version of the proceedings will include all accepted papers and will be available at the workshop. Furthermore, authors of selected papers will be invited after the workshop to prepare a final version of their paper to be published in an official publication venue. Paper can be submitted through the following webpage: http://www.reversible-computation.org/2012/cms/index.php?paper_submission ===== Program Chairs ===== Robert Glück University of Copenhagen glueck(a)acm.org Tetsuo Yokoyama Nanzan University tyokoyama(a)acm.org ===== Program Committee ===== * Stéphane Burignat (Gent University, Belgium) * Vincent Danos (Université Paris Diderot, France) * Gerhard W. Dueck (University of New Brunswick, Canada) * Nate Foster (Cornell University, USA) * Luca Gammaitoni (University of Perugia, Italy) * Simon Gay (University of Glasgow, United Kingdom) * Markus Grassl (Centre for Quantum Technologies, Singapore) * Jarkko J. Kari (University of Turku, Finland) * Martin Kutrib (University of Giessen, Germany) * Per Larsson-Edefors (Chalmers University of Technology, Sweden) * Kazutaka Matsuda (Tohoku University, Japan) * D. Michael Miller (University of Victoria, Canada) * Shin-ichi Minato (Hokkaido University, Japan) * Kenichi Morita (Hiroshima University, Japan) * Ilia Polian (University of Passau, Germany) * Michel Schellekens (University College Cork, Ireland) * Irek Ulidowski (University of Leicester, United Kingdom) * Janis Voigtländer (University of Bonn, Germany) * Robert Wille (University of Bremen, Germany) * Paolo Zuliani (Carnegie Mellon University, USA) ===== Workshop Organizer ===== Holger Bock Axelsen University of Copenhagen Department of Computer Science Universitetsparken 1 2100 Copenhagen, Denmark info(a)reversible-computation.org http://www.reversible-computation.org

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WING 2012: First Call for Papers
by Gudmund Grov 30 Jan '12

30 Jan '12

[Please post - apologies for multiple copies.] ---------------------------------------------------- WING 2012 - 4th International Workshop on INvariant Generation http://cs.nyu.edu/acsys/wing2012/ June 30, 2012 Manchester, UK (a satellite Workshop of IJCAR 2012) ---------------------------------------------------- --- First Call for Papers --- General ------- The ability to automatically extract and synthesize auxiliary properties of programs has had a profound effect on program analysis, testing, and verification over the last several decades. A key impediment for program verification is the overhead associated with providing, debugging, and verifying auxiliary invariant annotations. Releasing the software developer from this burden is crucial for ensuring the practical relevance of program verification. In the context of testing, suitable invariants have the potential of enabling high-coverage test-case generation. Thus, invariant generation is a key ingredient in a broad spectrum of tools that help to improve program reliability and understanding. As the design and implementation of reliable software remains an important issue, any progress in this area will have a significant impact. The increasing power of automated theorem proving and computer algebra has opened new perspectives for computer-aided program verification; in particular for the automatic generation of inductive assertions in order to reason about loops and recursion. Especially promising breakthroughs are invariant generation techniques by Groebner bases, quantifier elimination, and algorithmic combinatorics, which can be used in conjunction with model checking, theorem proving, static analysis, and abstract interpretation. The aim of this workshop is to bring together researchers from these diverse fields. Scope ----- We encourage submissions presenting work in progress, tools under development, as well as work by PhD students, such that the workshop can become a forum for active dialogue between the groups involved in this new research area. Relevant topics include (but are not limited to) the following: * Program analysis and verification * Inductive Assertion Generation * Inductive Proofs for Reasoning about Loops * Applications to Assertion Generation using the following tools: - Abstract Interpretation, - Static Analysis, - Model Checking, - Theorem Proving, - Theory Formation, - Algebraic Techniques * Tools for inductive assertion generation and verification * Alternative techniques for reasoning about loops Committee ----------------- Program Chairs: * Gudmund Grov (University of Edinburgh, UK) * Thomas Wies (New York University, USA) Program Committee: * Clark Barrett (New York University, USA) * Nikolaj Bjorner (Microsoft Research, USA) * Gudmund Grov (University of Edinburgh, UK) * Ashutosh Gupta (IST Austria) * Bart Jacobs (Katholieke Universiteit Leuven, Belgium) * Moa Johansson (Chalmers University of Technology, Sweden) * Laura Kovacs (Vienna University of Technology, Austria) * David Monniaux (VERIMAG, France) * Enric Rodriguez Carbonell (Technical University of Catalonia, Spain) * Helmut Veith (Vienna University of Technology, Austria) * Thomas Wies (New York University, USA) Important Dates --------------- Submission deadline: April 06, 2012 Notification of acceptance: May 04, 2012 Final version due: June 08, 2012 Workshop: June 30, 2012 Submission ---------- WING 2012 encourages submissions in the following two categories: * Original papers: contain original research (simultaneous submissions are not allowed) and sufficient detail to assess the merits and relevance of the submission. Given the informal style of the workshop, papers describing work in progress, with sufficient detail to assess the contribution, are also welcome. Original papers should not exceed 15 pages. * Extended abstracts: contain preliminary reports of work in progress, case studies, or tool descriptions. These will be judged based on the expected level of interest for the WING community. They will be included in the CEUR-WS proceedings. Extended abstracts should not exceed 5 pages. All submissions should conform to Springer's LNCS format. Formatting style files can be found at http://www.springer.de/comp/lncs/authors.html Technical details may be included in an appendix to be read at the reviewers' discretion and to be omitted in the final version. Please prepare your submission in accordance with the rules described above and submit a pdf file via https://www.easychair.org/?conf=wing2012 Publication ----------- All submissions will be peer-reviewed by the program committee. Accepted contributions will be published in archived electronic notes, as a volume of CEUR Workshop Proceedings. A special issue of the Journal of Science of Computer Programming with extended versions of selected papers will be published after the workshop. -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

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ANNOUNCE multiarg - parser combinators for command line parsing
by Omari Norman 29 Jan '12

29 Jan '12

multiarg is a parser combinator library to build command line parsers. With it you can easily create parsers with options that take more than one option argument--for example, I created multiarg due to the apparent lack of such ability amongst other parsers. Its basic design is loosely inspired by Parsec. Provides ParserT, a monad you use to build parsers. ParserT is a monad transformer, so you can layer it on top of other monads. For instance you could layer it on the IO monad so that your parser can perform IO. It also has a simple, pre-built parser built with the underlying combinators, which works for many situtations and shields you from the underlying complexity if you don't need it. Any feedback you might have is much appreciated. You can email or fork it on github. The Haddock comments are extensive so those should be able to get you started. multiarg on Hackage: http://hackage.haskell.org/package/multiarg multiarg's git repository: https://github.com/massysett/multiarg

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