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Erlang workshop call for papers
by John Hughes 20 Apr '12

20 Apr '12

Why not adapt some cool Haskell ideas to Erlang too? Six weeks to go... John Hughes [http://www.erlang.org/workshop/2011/erlang090.gif] CALL FOR PAPERS Eleventh ACM SIGPLAN Erlang Workshop Copenhagen, Denmark Friday, September 14, 2012 [http://www.erlang.org/workshop/2011/acm_logo_wordmark.gif] A satellite event of the 17th ACM SIGPLAN International Conference on Functional Programming (ICFP 2012<http://icfpconference.org/icfp2012/>). Erlang is a concurrent, distributed functional programming language aimed at systems with requirements on massive concurrency, soft real time response, fault tolerance, and high availability. It has been available as open source for over a decade, creating a community that actively contributes to its already existing rich set of libraries and applications. Originally created for telecom applications, its usage has spread to other domains including e-commerce, banking, databases, and computer telephony and messaging. Erlang programs are today among the largest applications written in any functional programming language. These applications offer new opportunities to evaluate functional programming and functional programming methods on a very large scale and suggest new problems for the research community to solve. This workshop will bring together the open source, academic, and industrial programming communities of Erlang. It will enable participants to familiarize themselves with recent developments on new techniques and tools tailored to Erlang, novel applications, draw lessons from users' experiences and identify research problems and common areas relevant to the practice of Erlang and functional programming. We invite three sorts of submissions. * Technical papers describing language extensions, critical discussions of the status quo, formal semantics of language constructs, program analysis and transformation, virtual machine extensions and compilation techniques, implementations and interfaces of Erlang in/with other languages, and new tools (profilers, tracers, debuggers, testing frameworks, etc.). The maximum length for technical papers is restricted to 12 pages. * Practice and application papers describing uses of Erlang in the "real-world", Erlang libraries for specific tasks, experiences from using Erlang in specific application domains, reusable programming idioms and elegant new ways of using Erlang to approach or solve a particular problem. The maximum length for the practice and application papers is restricted to 12 pages. Note that this is a maximum length: we welcome shorter papers also; the program committee will evaluate all papers on an equal basis independent of their lengths. * Poster presentations describing topics related to the workshop goals. Each of them includes max 2 pages of the abstract and summary. Presentations in this category will be given an hour of shared simultaneous demonstration time. Workshop Chair * Torben Hoffmann, Issuu, Denmark Program Chair * John Hughes, Chalmers University of Technology/Quviq AB, Gothenburg, Sweden Program Committee (Note: the Workshop and Program Chairs are also committee members) * Clara Benac Earle, Technical University of Madrid, Madrid, Spain * Scott Lystig Fritchie, Basho Technologies, USA * Simon Peyton Jones, Microsoft Research, Cambridge, England * Tamas Kozsik, Eötvös Loránd University, Budapest, Hungary * Kenneth Lundin, Ericsson AB, Stockholm, Sweden * Kostis Sagonas, Uppsala University, Uppsala, Sweden * Erik Stenman, Klarna AB, Stockholm, Sweden * Kresten Krab Thorup, Trifork A/S, Aarhus, Denmark * Steve Vinoski, Basho Technologies, USA Important Dates * Submission deadline: Sunday, June 3, 2012 * Author notification: Wednesday, June 27, 2012 * Final submission for the publisher: Tuesday, July 10, 2012 * Workshop date: Friday, September 14, 2012 Instructions to authors Papers must be submitted online via EasyChair (via the "Erlang2012" event). The submission page is https://www.easychair.org/conferences/?conf=erlang2012. Submitted papers should be in portable document format (PDF), formatted using the ACM SIGPLAN style guidelines. Each submission must adhere to SIGPLAN's republication policy. Violation risks summary rejection of the offending submission. Accepted papers will be published by the ACM and will appear in the ACM Digital Library. Paper submissions will be considered for poster submission in the case that they are not accepted as full papers. Venue & Registration Details For registration, please see the ICFP 2012 web site. Related Links * ICFP 2012 web site: http://www.icfpconference.org/icfp2012/ * Past ACM SIGPLAN Erlang workshops: http://www.erlang.org/workshop/ * Open Source Erlang: http://www.erlang.org/ * EasyChair submission site: https://www.easychair.org/account/signin.cgi?conf=erlang2012 * Author Information for SIGPLAN Conferences: http://www.sigplan.org/authorInformation.htm

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ANNOUNCE: curlhs-0.0.1, bindings to libcurl
by Krzysztof Kardzis 19 Apr '12

19 Apr '12

Hello! I'm pleased to announce the first release of curlhs package (curlhs-0.0.1), a new Haskell bindings to libcurl, the multiprotocol file transfer library which powers popular curl tool. hackage: http://hackage.haskell.org/package/curlhs github: https://github.com/kkardzis/curlhs Package is distributed under ISC License (MIT/BSD-style, see LICENSE file for details). Current version of curlhs follows libcurl in version 7.25.0. It is also possible to use curlhs with older versions of libcurl, but some features may not be available then (curlhs should easily compile with libcurl from version 7.20.0 upward). Bindings are not complete, there is still a lot of work to do, but I think that for many simple tasks it's enough. The aim is to provide a mid-level interface to libcurl, which will be fairly complete and close to the original API. With this initial release I hope to gain some feedback from potential users. Any comments and suggestions are welcome. Greetings, Krzysztof Kardzis

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ANNOUNCE: graphviz-2999.13.0.0
by Ivan Lazar Miljenovic 19 Apr '12

19 Apr '12

I'm hoping the second part of the version number isn't ominous, but I've just uploaded the latest release in my bindings for the Graphviz suite of graph visualisation tools. The changes in this release are: * Added support for the `osage` and `patchwork` visualisation tools, available as of Graphviz-2.28.0. * Updated attributes as of Graphviz-2.28.0: - `SVG` colors are now supported, and the support for different colors has been revamped. - `overlap=false` is now equivalent to `overlap=prism` and the `RemoveOverlaps` option has been removed. - `LabelScheme` and `Rotation` are new attributes for use with `sfdp`. - `Scale` is a new attribute for use with `twopi`. - Add new italics, bold, underline, superscript and subscript options for HTML-like labels. - `LHeight` and `LWidth` for getting the height and width of the root graph and clusters. * Updated attributes from the current development branch of Graphviz (i.e. 2.29.*). Please note that these will probably not work yet, but are implemented now for future-proofing. - A new style for edges: `Tapered`. - `XLabel` allows you to specify labels external to a node or edge. `ForceLabels` allow you to specify that these should be drawn even when they will cause overlaps. - `ImagePath` allows you to specify where to search for images. - HTML-like labels now support `ID` values as well as horizontal and vertical rules. - `BgColor` and `FillColor` now take a list of colors: this allows gradient fills for graphs, clusters and nodes. The `Radial` style and `GradientAngle` are also used for this purpose. - `FillColor` is now used by edges to set the color of any arrows. - [WebP](http://en.wikipedia.org/wiki/WebP) output support added. * Other attribute changes: - Use a specified data type for the `Ordering` attribute rather than an arbitrary `Text` value, and provide a documented wrapper in `Data.GraphViz.Attributes`. - `Bb` has been renamed `BoundingBox`. - `ID` now only takes `EscString` (a type alias for `Text`) values rather than arbitrary `Label`s. - The `Data.GraphViz.Attributes.HTML` module has had all values re-named and is now meant to be imported qualified. It is also no longer re-exported from `Data.GraphViz.Attributes.Complete`. * The `ToGraphID` class provides a common wrapper to help create cluster identifiers, etc. * Cabal's `Test-Suite` functionality is now used. As part of this, the `Data.GraphViz.Testing` module and sub-modules are no longer exported by the library. * The new `Benchmark` support in Cabal-1.14 is now used for the benchmark script. * Dropped support for base-3. * The `Data.GraphViz.State` module is no longer exposed, as there's no need for users to use it. * Bugfixes: - Some corner cases in canonicalisation prevented it from being idempotent. - The `TestParsing` script will no longer crash and refuse to continue if an IO-based error (e.g. unable to successfully call `dot`) occurs. - A typo was spotted by **Gabor Greif**. -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com http://IvanMiljenovic.wordpress.com

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Haskell Weekly News: Issue 223
by Daniel Santa Cruz 19 Apr '12

19 Apr '12

Welcome to issue 223 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of April 8 to 14, 2012. Quotes of the Week * merijn: I'm tempted to just do unsafePerformIO newEmptyMVar at the top level quicksilver: I can't really be expected to deal with your sinfulness. That's between you and your god. * acowley: Good haskell code is 20 LANGUAGE pragmas, 40 imports, then one line of perl. * deggis: oh. running GHC HEAD. must try that next week if coffee just someday isn't enough * dmwit: hGetContents does not close its handle. dmwit: hGetContents semicloses its handle. * monochrom: isTrue = (unsafeCoerce :: Either a b -> Bool) . (unsafeCoerce :: Maybe c -> Either a b) . (unsafeCoerce :: Bool -> Maybe c) * dmwit: For basically all good properties P, IEEE 754 is not P. * Cale: Little known fact: For any positive integer n, the infinite sequence of Project Euler problems has only finitely many elements whose solution is not divisible by n. Top Reddit Stories * Announcing Yesod 1.0 Domain: yesodweb.com, Score: 101, Comments: 42 On Reddit: [1] http://goo.gl/izD19 Original: [2] http://goo.gl/oTSto * Why reasoning about space usage in Haskell is hard Domain: ro-che.info, Score: 63, Comments: 14 On Reddit: [3] http://goo.gl/yIkI4 Original: [4] http://goo.gl/IAQtu * GHC HEAD now has type level natural number/ literals Domain: github.com, Score: 63, Comments: 18 On Reddit: [5] http://goo.gl/GfGbB Original: [6] http://goo.gl/Lkp6v * Working Together Domain: yesodweb.com, Score: 62, Comments: 31 On Reddit: [7] http://goo.gl/o3G85 Original: [8] http://goo.gl/jBdJA * How less is more : polymorphic types can improve safety even in monomorphic functions Domain: blog.malde.org, Score: 61, Comments: 13 On Reddit: [9] http://goo.gl/fzUlO Original: [10] http://goo.gl/WHE3A * A Hopefully Fair and Useful Comparison of Haskell Web Frameworks Domain: softwaresimply.blogspot.com, Score: 60, Comments: 30 On Reddit: [11] http://goo.gl/WuDuL Original: [12] http://goo.gl/DXBA8 * First impressions of Haskell: A review of my Haskell adventure Domain: binarysculpting.com, Score: 46, Comments: 36 On Reddit: [13] http://goo.gl/gG0fl Original: [14] http://goo.gl/ZqUT3 * A "radix tree" import syntax? Domain: self.haskell, Score: 41, Comments: 26 On Reddit: [15] http://goo.gl/kBOLZ Original: [16] http://goo.gl/kBOLZ * Using ContT to please the eye Domain: self.haskell, Score: 28, Comments: 15 On Reddit: [17] http://goo.gl/hbFrs Original: [18] http://goo.gl/hbFrs * Designing a DCPU-16 emulator in Haskell: on determinism and I/O Domain: jaspervdj.be, Score: 28, Comments: 6 On Reddit: [19] http://goo.gl/KHIgP Original: [20] http://goo.gl/NT89i Top StackOverflow Questions * What are type quantifiers? votes: 15, answers: 3 Read on SO: [21] http://goo.gl/d3hnH * Haskell: How does 'atomicModifyIORef' work? votes: 12, answers: 2 Read on SO: [22] http://goo.gl/3b5dK * Is there a runtime penalty associated with typeclasses? votes: 12, answers: 1 Read on SO: [23] http://goo.gl/Isw7k * Timing out pure functions votes: 11, answers: 1 Read on SO: [24] http://goo.gl/aTzVG * Haskell - simple constructor comparison (?) function votes: 11, answers: 3 Read on SO: [25] http://goo.gl/ZC6CC * Partial Application with Infix Functions votes: 10, answers: 3 Read on SO: [26] http://goo.gl/QvabF * Haskell: Why is there no type mismatch (and why does this compile)? votes: 9, answers: 2 Read on SO: [27] http://goo.gl/1gxFE * “Dependent optional” data in Haskell votes: 9, answers: 4 Read on SO: [28] http://goo.gl/9K5Wx * How can I help SpecConstr in GHC? votes: 8, answers: 2 Read on SO: [29] http://goo.gl/PGa4C * How to get good performance when writing a list of integers from 1 to 10 million to a file? votes: 7, answers: 2 Read on SO: [30] http://goo.gl/Kym6r * Efficiently turn a ByteString into a hex representation votes: 7, answers: 1 Read on SO: [31] http://goo.gl/aq2ct Until next time, Daniel Santa Cruz References 1. http://www.yesodweb.com/blog/2012/04/announcing-yesod-1-0 2. http://www.reddit.com/r/haskell/comments/s0tr2/announcing_yesod_10/ 3. http://ro-che.info/articles/2012-04-08-space-usage-reasoning.html 4. http://www.reddit.com/r/haskell/comments/rzu8a/why_reasoning_about_space_us… 5. https://github.com/ghc/packages-base/blob/b5b5ec18819fb85ebf1bdb6345ac03178… 6. http://www.reddit.com/r/haskell/comments/s0vln/ghc_head_now_has_type_level_… 7. http://www.yesodweb.com/blog/2012/04/working-together 8. http://www.reddit.com/r/haskell/comments/s2ei5/working_together/ 9. http://blog.malde.org/posts/polymorphic-types-are-safer.html 10. http://www.reddit.com/r/haskell/comments/s7q3b/how_less_is_more_polymorphic… 11. http://softwaresimply.blogspot.com/2012/04/hopefully-fair-and-useful-compar… 12. http://www.reddit.com/r/haskell/comments/s3pbm/a_hopefully_fair_and_useful_… 13. http://binarysculpting.com/2012/04/12/a-review-of-my-haskell-adventure/ 14. http://www.reddit.com/r/haskell/comments/s6okb/first_impressions_of_haskell… 15. http://www.reddit.com/r/haskell/comments/s2o8p/a_radix_tree_import_syntax/ 16. http://www.reddit.com/r/haskell/comments/s2o8p/a_radix_tree_import_syntax/ 17. http://www.reddit.com/r/haskell/comments/s49kk/using_contt_to_please_the_ey… 18. http://www.reddit.com/r/haskell/comments/s49kk/using_contt_to_please_the_ey… 19. http://jaspervdj.be/posts/2012-04-12-st-io-dcpu-16.html 20. http://www.reddit.com/r/haskell/comments/s5xqb/designing_a_dcpu16_emulator_… 21. http://stackoverflow.com/questions/10062253/what-are-type-quantifiers 22. http://stackoverflow.com/questions/10102881/haskell-how-does-atomicmodifyio… 23. http://stackoverflow.com/questions/10148897/is-there-a-runtime-penalty-asso… 24. http://stackoverflow.com/questions/10071560/timing-out-pure-functions 25. http://stackoverflow.com/questions/10112733/haskell-simple-constructor-comp… 26. http://stackoverflow.com/questions/10131300/partial-application-with-infix-… 27. http://stackoverflow.com/questions/10091874/haskell-why-is-there-no-type-mi… 28. http://stackoverflow.com/questions/10136222/dependent-optional-data-in-hask… 29. http://stackoverflow.com/questions/10145954/how-can-i-help-specconstr-in-ghc 30. http://stackoverflow.com/questions/10080273/how-to-get-good-performance-whe… 31. http://stackoverflow.com/questions/10099921/efficiently-turn-a-bytestring-i…

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ANN: cabal-install-0.14.0
by Andres Löh 18 Apr '12

18 Apr '12

I'm pleased to announce the long-awaited new release of cabal-install-0.14.0 If you are already using cabal-install then you can upgrade both using: $ cabal update $ cabal install Cabal cabal-install New users you can get it from: http://haskell.org/cabal/download.html For users on unix systems there is a source tarball with a bootstrap script. For users on Windows systems there is a pre-compiled cabal.exe (The Windows binary hasn't really been tested yet. Feedback welcome.) Release notes ============= cabal-install-0.14.0 -------------------- Changes since 0.10.2: * Works with ghc-7.4 * Completely new modular dependency solver (default in most cases) * Some tweaks to old topdown dependency solver * Install plans are now checked for reinstalls that break packages * Flags --constraint and --preference work for nonexisting packages * New constraint forms for source and installed packages * New constraint form for package-specific use flags * New constraint form for package-specific stanza flags * Test suite dependencies are pulled in on demand * No longer install packages on --enable-tests when tests fail * New "cabal bench" command * Various "cabal init" tweaks Future plans ------------ There will probably be another incremental 0.14.2 release in the not too distant future, followed by an 0.16.0 release that should work with ghc-7.6. Bugs and feature requests ========================= This is an excellent opportunity to make sure your favourite bug or feature request is properly described in our bug tracker: http://hackage.haskell.org/trac/hackage/ To help us guide development priorities please add yourself to the ticket's cc list and describe why that bug or feature is important to you. Credits ======= On behalf of the Cabal hackers and the community generally I'd like to thank the people who have contributed patches for this release: * Tuncer Ayaz * Max Bolingbroke * Duncan Coutts * Ben Millwood * Jens Petersen * David Terei * Johan Tibell * Thomas Tuegel * Brent Yorgey Get involved ============ If you'd like to contribute, then please: * subscribe to the cabal-devel mailing list: http://www.haskell.org/mailman/listinfo/cabal-devel * check out the information on our trac: http://hackage.haskell.org/trac/hackage/ Andres

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ANNOUNCE: haskell-src-exts-1.13.2
by Niklas Broberg 18 Apr '12

18 Apr '12

Fellow Haskelleers, I'm pleased to announce the release of haskell-src-exts-1.13.2! * On hackage: http://hackage.haskell.org/package/haskell-src-exts * Via cabal: cabal install haskell-src-exts * Darcs repo: http://code.haskell.org/haskell-src-exts This release contains only a few small tweaks and bug-fixes. Changelog: 1.13.1 --> 1.13.2 =============== * Fix the bug with the precedence of unary prefix minus. Previously it was resolved as binding more tightly than any infix operator, now it is correctly treated as having the same fixity as binary infix minus. 1.13.0 --> 1.13.1 =============== * Allow an optional semi before the closing tag of an element. This achieves a similar effect for XmlSyntax in do blocks as DoAndIfThenElse does for the if construct. No more need to indent the closing tag one step further than the opening tag. * Add a dummy 'noLoc :: SrcLoc' to L.H.E.SrcLoc, to use when generating code. It could definitely be done more elegantly, but not without inducing another major version bump, so later. * Fix a regression from 1.11.x where the parser would crash upon encountering non-simple class/data declaration heads, e.g. 'data A [a]'. Now fails with a parse error as intended. Cheers, /Niklas

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CFT -- Haskell Implementors' Workshop 2012
by Johan Tibell 17 Apr '12

17 Apr '12

Call for Talks ACM SIGPLAN Haskell Implementors' Workshop http://haskell.org/haskellwiki/HaskellImplementorsWorkshop/2012 Copenhagen, Denmark, September 14th, 2012 The workshop will be held in conjunction with ICFP 2012 http://www.icfpconference.org/icfp2012/ Important dates Proposal Deadline: 10th July 2012 Notification: 27th July 2012 Workshop: 14th September 2012 The Haskell Implementors' Workshop is to be held alongside ICFP 2012 this year in Copenhagen, Denmark. There will be no proceedings; it is an informal gathering of people involved in the design and development of Haskell implementations, tools, libraries, and supporting infrastructure. This relatively new workshop reflects the growth of the user community: there is a clear need for a well-supported tool chain for the development, distribution, deployment, and configuration of Haskell software. The aim is for this workshop to give the people involved with building the infrastructure behind this ecosystem an opportunity to bat around ideas, share experiences, and ask for feedback from fellow experts. We intend the workshop to have an informal and interactive feel, with a flexible timetable and plenty of room for ad-hoc discussion, demos, and impromptu short talks. Scope and target audience ------------------------- It is important to distinguish the Haskell Implementors' Workshop from the Haskell Symposium which is also co-located with ICFP 2012. The Haskell Symposium is for the publication of Haskell-related research. In contrast, the Haskell Implementors' Workshop will have no proceedings -- although we will aim to make talk videos, slides and presented data available with the consent of the speakers. In the Haskell Implementors' Workshop, we hope to study the underlying technology. We want to bring together anyone interested in the nitty-gritty details behind turning plain-text source code into a deployed product. Having said that, members of the wider Haskell community are more than welcome to attend the workshop -- we need your feedback to keep the Haskell ecosystem thriving. The scope covers any of the following topics. There may be some topics that people feel we've missed, so by all means submit a proposal even if it doesn't fit exactly into one of these buckets: * Compilation techniques * Language features and extensions * Type system implementation * Concurrency and parallelism: language design and implementation * Performance, optimisation and benchmarking * Virtual machines and run-time systems * Libraries and tools for development or deployment Talks ----- At this stage we would like to invite proposals from potential speakers for a relatively short talk. We are aiming for 20 minute talks with 10 minutes for questions and changeovers. We want to hear from people writing compilers, tools, or libraries, people with cool ideas for directions in which we should take the platform, proposals for new features to be implemented, and half-baked crazy ideas. Please submit a talk title and abstract of no more than 200 words to: johan.tibell(a)gmail.com We will also have a lightning talks session which will be organised on the day. These talks will be 2-10 minutes, depending on available time. Suggested topics for lightning talks are to present a single idea, a work-in-progress project, a problem to intrigue and perplex Haskell implementors, or simply to ask for feedback and collaborators. Organisers ---------- * Lennart Augustsson (Standard Chartered Bank) * Manuel M T Chakravarty (University of New South Wales) * Gregory Collins - co-chair (Google) * Simon Marlow (Microsoft Research) * David Terei (Stanford University) * Johan Tibell - co-chair (Google)

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Who should be contacted for changes to the front page of http://www.haskell.org ?
by Bernie Pope 17 Apr '12

17 Apr '12

Greetings, The front page of http://www.haskell.org/haskellwiki/Haskell is (rightly) protected. Who then should we contact if we have suggestions for changes? I apologise profusely if the answer is staring me in the face, but I couldn't seem to find it. Incidentally, and tediously, my suggestion is sadly pedantic: to change "Books & tutorials" to "Books and tutorials", to be more pleasant on the (or my) eye and to be consistent with the rest of the page. Cheers, Bernie.

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Cross-platform scripts on Linux and Windows
by Vinay Sajip 16 Apr '12

16 Apr '12

I've been given a set of .hs files which contain the shebang line #!/usr/bin/env runhaskell and I would like them to work on Windows, but none of the Windows binaries seem to be able to process them without a <script.hs>:1:1: parse error on input `#!' These files came from a Linux machine, where they run without trouble. Is there any way I can get the Windows executables to run these files? I asked on IRC and it was suggested that I change the files to literate Haskell, but I'd rather have some way of having cross-platform operation which does not involve making changes to the scripts themselves. Is there something that can be done e.g. by using particular command line options or configuration settings? Thanks & regards, Vinay Sajip

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ANNOUNCE : Juicy.Pixels 1.2.1
by Vincent Berthoux 16 Apr '12

16 Apr '12

Hello everyone, I'm pleased to announce you the new version of Juicy.Pixels, the 1.2.1, no new major features, here's the changelog : - Removed dependency on the array package. - Updated dependency list to handle latest mtl version. - Helper functions to save files without thinking about it. - Some code snippets in the API documentations GitHub : https://github.com/Twinside/Juicy.Pixels Hackage : http://hackage.haskell.org/package/JuicyPixels Regards Vincent Berthoux

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