March 2009 - Haskell - Haskell.org

ANN: The Monad.Reader (13)
by Wouter Swierstra 16 Mar '09

16 Mar '09

I am pleased to announce that a new issue of The Monad.Reader is now available: http://www.haskell.org/haskellwiki/The_Monad.Reader The Monad.Reader is a quarterly magazine about functional programming. Issue 13 consists of the following four articles: * Stephen Hicks Rapid Prototyping in TEX * Brent Yorgey The Typeclassopedia * Chris Eidhof, Eelco Lempsink Book Review: "Real World Haskell" * Derek Elkins Calculating Monads with Category Theory Special thanks to Ashley Yakeley for his help with publishing The Monad.Reader on the Haskell wiki. If you'd like to write something for the next issue of The Monad.Reader, please get in touch. I haven't fixed the deadline for the next issue, but it should be mid-May or thereabouts. Wouter

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ANNOUNCE: dzen-utils 0.1
by Felipe Lessa 15 Mar '09

15 Mar '09

Hello! I'm please to announce dzen-utils 0.1. I don't feel like it is ready to be released, but let's see how everything goes. :) == WHAT == dzen-utils contains various utilities for creating dzen input strings in a type-safe way using some combinators, including the ability to apply colors locally (instead of applying for everything beyond some point). It can also emulate dbar and gdbar, do automatic padding, and more. == WHY == I don't like to write bash scripts for dzen, and I don't like the way xmobar treats its configuration and its inability to show anything other than text. This package is a short-term solution for my problems. Maybe I'll write xmozen in the future. ;) == WHERE, HOW, etc. == It is in Hackage already, go get it[1]. Please see the documentation of System.Dzen for some small examples. [1] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/dzen-utils Thanks for your time, -- Felipe.

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Haskell Weekly News: Issue 109 - March 14, 2009
by Brent Yorgey 14 Mar '09

14 Mar '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090314 Issue 109 - March 14, 2009 --------------------------------------------------------------------------- Welcome to issue 109 of HWN, a newsletter covering developments in the [1]Haskell community. Congratulations to the authors of RWH on their [2]Jolt award! Some cool libraries released this week (as usual), and some really cool PhD [3]opportunities at Strathclyde. Also, it seems that I was censured last week for not including any quotes in the HWN, which is because tunes.org (which hosts the #haskell logs) was down while I was putting it together. So, this time I've included quotes going back two weeks, I HOPE YOU'RE HAPPY Community News Tom DuBuisson (TomMD) has [4]moved to Portland and will be starting a PhD at Portland State soon. Announcements darcs fundraising drive - only $720 left to go!. Eric Kow [5]announced that [6]donations are still being accepted to help pay for travel to the upcoming Haskell hackathon. So far we have raised $280, so we're almost a third of the way there. Think you can help? Vintage BASIC 1.0. Lyle Kopnicky [7]announced the initial release of [8]Vintage BASIC, an interpreter for microcomputer-era BASIC. Fully unit-tested, it faithfully implements the common elements of the language. On the web site, you can find 102 games from the classic book BASIC Computer Games, all of which run flawlessly. Have fun! ThreadScope: Request for features for the performance tuning of parallel and concurrent Haskell programs. Satnam Singh [9]requested feedback on infrastructure for logging run-time events and a graphical viewer program called [10]ThreadScope. The goal is for these features to make it into the next release of GHC. torch-0.1. Yusaku Hashimoto [11]announced a new unit test framework, [12]torch-0.1. sparsebit 0.5 - Sparse Bitmaps for Pattern Match Coverage. Ki Yung Ahn [13]announced the release of the [14]sparsebit library. This library packages the functional peal paper [15]Sparse Bitmaps for Pattern Match Coverage submitted to ICFP 2009 by Ki Yung Ahn and Tim Sheard. happs-tutorial 0.8. Crieghton Hogg [16]announced the release of [17]happs-tutorial 0.8, which is compatible with [18]happstack-0.2. A number of changes have occurred in this release, including general code cleanup, migration to the new Happstack.Server.SimpleHTTP API, and more. Future 1.1.0 concurrency library. ChrisK [19]announced the [20]future package, which ought to do what C++ standard futures/promises do, plus a bit more. The main operation is forkPromise :: IO a -> IO (Promise a), which sets the "IO a" operation running in a fresh thread; the eventual result can be accessed in many ways (non-blocking, blocking, blocking with timeout). Holumbus-MapReduce 0.0.1. Stefan Schmidt [21]announced three new libraries: [22]Holumbus-MapReduce, [23]Holumbus-Distribution, and [24]Holumbus-Storage, which provide tools for building distributed systems. These libraries are used as the backbone of the [25]Holumbus search engine. Turbinado V0.6. Alson Kemp [26]announced the release of [27]Turbinado 0.6, a Rails-ish Model-View-Controller web serving framework for Haskell. New features include support for CGI serving, statically compiled Layouts, Views, and Controllers, lower case paths, support for cookies and encrypted cookie sessions, easier installation, and support for GHC 6.10. iteratee-0.1.0. John Lato [28]announced the hackage release of [29]iteratee-0.1.0. This library implements enumerators and iteratees [30]as proposed by Oleg Kiselyov. Harpy 0.4.4 - Runtime code generation for x86 machine code. Dirk Kleeblatt [31]announced the release of [32]Harpy 0.4.1, a library for runtime code generation for x86 machine code. The new release features additional Eq instances, support for new prefetching instructions, and some bug fixes. Discussion Suggestion for a Haskell mascot. Maur�cio [33]suggested using a sloth as the Haskell mascot. If you would like to know how to say 'sloth' in just about every language ever, read this thread. Jobs Microsoft PhD Scholarship at Strathclyde. Conor McBride [34]announced another PhD opportunity at Strathclyde, sponsored by Microsoft Research, to investigate the practical and theoretical impact of extending Haskell's type system with numeric expressions (representing sizes, or ranges, or costs, for example) and constraints capturing richer safety properties than are currently managed by static typing. Blog noise [35]Haskell news from the [36]blogosphere. * Braden Shepherdson: [37]Pimp Your XMonad #4: Urgency Hooks. * Thomas M. DuBuisson: [38]Explicit Parallelism via Thread Pools. * Ketil Malde: [39]Current developments. Ongoing development of the biohaskell libraries for bioinformatics. * Philip Wadler: [40]Cafe Scientifique. Philip will be giving a talk, "Proofs are Programs: 19th Century Logic and 21st Century Computing", on Monday in Edinburgh. * Yi: [41]Yi 0.6.0 Release Notes. * Alson Kemp: [42]ANNOUNCE: Turbinado V0.6. * GHC / OpenSPARC Project: [43]Thread activity plotting. * Real-World Haskell: [44]We won a Jolt Award!. * Real-World Haskell: [45]Real World Haskell on the Kindle 2. * Christophe Poucet (vincenz): [46]Bootstrapping cabal. * Gtk2HS: [47]Mickinator File Manager. * Osfameron: [48](rough) Grids in Haskell. Some notes on representing 2D grids in Haskell. * Manuel M T Chakravarty: [49]These graphs summarise the performance of Data Parallel Haskell.... * GHC / OpenSPARC Project: [50]Project midpoint. * GHC / OpenSPARC Project: [51]The GNU Debugger and me. * Don Stewart (dons): [52]Evolving faster Haskell programs. Using genetic algorithms to find optimal flag combinations. * Xmonad: [53]Xmonad and the Gimp. * Xmonad: [54]xmonad on eee. * Mark Wassell: [55]Conversations with a type checker. * Holumbus: [56]Holumbus-MapReduce on Hackage. Some neat libraries for building distributed systems! * Darcs: [57]darcs weekly news #20. * Nick Mudge: [58]First Bay Area Haskell Meeting. * Dan Piponi (sigfpe): [59]Dinatural Transformations and Coends. Quotes of the Week * mmorrow: when i first saw haskell i was like "holy shitfork! that's what i've been trying to do in C for forever!" * pastah: the maybe monad is like cheating. everything is so awesomelly easy. * wli: Monads are like constipation. Comonads are like Ex-Lax. * TomMD: Never trust IO. * Axman6: let blah f x = f (blah f x) in blah ("blah "++) "" * MyCatVerbs: Lazy IO is implemented in terms of unsafePerformIO, you, you, you silly bipedal carbon-based organism. * MyCatVerbs: Amdahl's law is mostly to be used for making people feel depressed. * Axman6: -ddump-occur-anal <- another terrible name... * AchimSchneider: Finite automata don't go bottom in any case, at least not if you don't happen to shoot them and their health drops below zero. * ski: the truth (semantics), the whole truth (completeness), and nothing but the truth (soundness) * f4hy: wait you can do a show on an infinite list?! (I am starting to think haskell is not a programming language, it is evil wizardry) * Baughn: concat $ forM [(1,2), (4,5)] $ \(a,b) -> show (b,a+b) About the Haskell Weekly News New editions are posted to [60]the Haskell mailing list as well as to [61]the Haskell Sequence and [62]Planet Haskell. [63]RSS is also available, and headlines appear on [64]haskell.org. To help create new editions of this newsletter, please see the information on [65]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [66]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://www.realworldhaskell.org/blog/2009/03/12/we-won-a-jolt-award/ 3. http://article.gmane.org/gmane.comp.lang.haskell.general/16944 4. http://tommd.wordpress.com/2009/03/13/explicit-parallelism-via-thread-pools/ 5. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54758 6. http://www.darcs.net/donations.html 7. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54652 8. http://www.vintage-basic.net/ 9. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54521 10. http://raintown.org/threadscope 11. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54445 12. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/torch 13. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54436 14. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/sparsebit 15. http://kyagrd.dyndns.org/wiki/SparseBitmapsForPatternMatchCoverage 16. http://www.haskell.org//pipermail/haskell-cafe/2009-March/057305.html 17. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/happs%2Dtutorial 18. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/happstack 19. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54409 20. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/future 21. http://article.gmane.org/gmane.comp.lang.haskell.cafe/54325 22. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Holumbus%2DMapRe… 23. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Holumbus-Distrib… 24. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Holumbus-Storage 25. http://www.holumbus.org/redmine/wiki/holumbus 26. http://article.gmane.org/gmane.comp.lang.haskell.general/16953 27. http://www.turbinado.org/ 28. http://article.gmane.org/gmane.comp.lang.haskell.general/16945 29. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/iteratee 30. http://okmij.org/ftp/Haskell/Iteratee/ 31. http://article.gmane.org/gmane.comp.lang.haskell.general/16942 32. http://uebb.cs.tu-berlin.de/harpy/ 33. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/54418 34. http://article.gmane.org/gmane.comp.lang.haskell.general/16944 35. http://planet.haskell.org/ 36. http://haskell.org/haskellwiki/Blog_articles 37. http://braincrater.wordpress.com/2009/03/14/pimp-your-xmonad-4-urgency-hook… 38. http://tommd.wordpress.com/2009/03/13/explicit-parallelism-via-thread-pools/ 39. http://blog.malde.org/index.php/2009/03/13/current-developments/ 40. http://wadler.blogspot.com/2009/03/cafe-scientifique.html 41. http://yi-editor.blogspot.com/2009/03/yi-060-release-notes.html 42. http://www.alsonkemp.com/haskell/announce-turbinado-v06/ 43. http://ghcsparc.blogspot.com/2009/03/thread-activity-plotting.html 44. http://www.realworldhaskell.org/blog/2009/03/12/we-won-a-jolt-award/ 45. http://www.realworldhaskell.org/blog/2009/03/13/real-world-haskell-on-the-k… 46. http://cpoucet.wordpress.com/2009/03/12/bootstrapping-cabal/ 47. http://haskell.org/gtk2hs/archives/2009/03/10/mickinator-file-manager/ 48. http://greenokapi.net/blog/2009/03/10/rough-grids-in-haskell/ 49. http://justtesting.org/post/85103645 50. http://ghcsparc.blogspot.com/2009/03/project-midpoint.html 51. http://ghcsparc.blogspot.com/2009/03/gnu-debugger-and-me.html 52. http://donsbot.wordpress.com/2009/03/09/evolving-faster-haskell-programs/ 53. http://xmonad.wordpress.com/2009/03/08/xmonad-and-the-gimp/ 54. http://xmonad.wordpress.com/2009/03/08/xmonad-on-eee/ 55. http://www.poundstone.org/blog/?p=23 56. http://holumbus.fh-wedel.de/blog/?p=18 57. http://blog.darcs.net/2009/03/darcs-weekly-news-20.html 58. http://nickmudge.info/?post=115 59. http://blog.sigfpe.com/2009/03/dinatural-transformations-and-coends.html 60. http://www.haskell.org/mailman/listinfo/haskell 61. http://sequence.complete.org/ 62. http://planet.haskell.org/ 63. http://sequence.complete.org/node/feed 64. http://haskell.org/ 65. http://haskell.org/haskellwiki/HWN 66. http://code.haskell.org/~byorgey/code/hwn/

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Lazy IO breaks purity
by oleg＠okmij.org 14 Mar '09

14 Mar '09

We demonstrate how lazy IO breaks referential transparency. A pure function of the type Int->Int->Int gives different integers depending on the order of evaluation of its arguments. Our Haskell98 code uses nothing but the standard input. We conclude that extolling the purity of Haskell and advertising lazy IO is inconsistent. Henning Thielemann wrote on Haskell-Cafe: > Say I have a chain of functions: read a file, ... write that to a file, > all of these functions are written in a lazy way, which is currently > considered good style Lazy IO should not be considered good style. One of the common definitions of purity is that pure expressions should evaluate to the same results regardless of evaluation order, or that equals can be substituted for equals. If an expression of the type Int evaluates to 1, we should be able to replace every occurrence of the expression with 1 without changing the results and other observables. The expression (read s) where s is the result of the (hGetContents h1) action has the pure type, e.g., Int. Yet its evaluation does more than just producing an integer: it may also close a file associated with the handle h1. Closing the file has an observable effect: the file descriptor, which is a scarce resource, is freed. Some OS lock the open file, or prevent operations such as renaming and deletion on the open file. A file system whose file is open cannot be unmounted. Suppose I use an Haskell application such as an editor to process data from a removable drive. I mount the drive, tell the application the file name. The (still running) application finished with the file and displayed the result. And yet I can't unplug the removable drive, because it turns out that the final result was produced without needing to read all the data from the file, and the file remains unclosed. Some people say: the programmer should have used seq. That is the admission of guilt! An expression (read s)::Int that evaluates to 1 is equal to 1. So, one should be able substitute (read s) with 1. If the result of evaluating 1 turns out not needed for the final outcome, then not evaluating (read s) should not affect the outcome. And yet it does. One uses seq to force evaluation of an expression even if the result may be unused. Thus the expression of a pure type has *side-effect*. The advice about using seq reminds me of advice given to C programmers that they should not free a malloc'ed pointer twice, dereference a zero pointer and write past the boundary of an array. If lazy IO is considered good style given the proper use of seq, then C should be considered safe given the proper use of pointers and arrays. Side affects like closing a file are observable in the external world. A program may observe these effects, in an IO monad. One can argue there are no guarantees at all about what happens in the IO monad. Can side-effects of lazy IO be observable in _pure_ Haskell code, in functions with pure type? Yes, they can. The examples are depressingly easy to write, once one realizes that reading does have side effects, POSIX provides for file descriptor aliasing, and sharing becomes observable with side effects. Here is a simple Haskell98 code. > {- Haskell98! -} > > module Main where > > import System.IO > import System.Posix.IO (fdToHandle, stdInput) > > -- f1 and f2 are both pure functions, with the pure type. > -- Both compute the result of the subtraction e1 - e2. > -- The only difference between them is the sequence of > -- evaluating their arguments, e1 `seq` e2 vs. e2 `seq` e1 > -- For really pure functions, that difference should not be observable > > f1, f2:: Int -> Int -> Int > > f1 e1 e2 = e1 `seq` e2 `seq` e1 - e2 > f2 e1 e2 = e2 `seq` e1 `seq` e1 - e2 > > read_int s = read . head . words $ s > > main = do > let h1 = stdin > h2 <- fdToHandle stdInput > s1 <- hGetContents h1 > s2 <- hGetContents h2 > print $ f1 (read_int s1) (read_int s2) > -- print $ f2 (read_int s1) (read_int s2) One can compile it with GHC (I used 6.8.2, with and without -O2) and run like this ~> /tmp/a.out 1 2 -1 That is, we run the program and type 1 and 2 as the inputs. The program prints out the result, -1. If we comment out the line "print $ f1 (read_int s1) (read_int s2)" and uncomment out the last line the transcript looks like this ~> /tmp/a.out 1 2 1 Running the code with Hugs exhibits the same behavior. Thus a pure function (-) of the pure type gives different results depending on the order of evaluating its arguments. Is 1 = -1?

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ANNOUNCE: Turbinado V0.6
by Alson Kemp 13 Mar '09

13 Mar '09

Turbinado (http://www.turbinado.org) is a Rails-ish Model-View-Controller web serving framework for Haskell. It's in heavy development, is making excellent progress and is designed to make building websites in Haskell a joy. It’s been long enough since Turbinado V0.4 that I figured I’d skip V0.5 and go straight to announcing Turbinado V0.6. Lots of new excellent features: * By popular demand, support for CGI serving. Apparently some web hosts don’t support HTTP proxying, so some folks requested CGI support. * Statically compiled Layouts, Views, Controllers (to complement dynamic loading). * Support for “.format” in routes. If a request path is “/User/List.xml”, then the following View will be called: /App/Views/User/ListXml.hs. * Lower case paths. * Support for cookies (see here for examples). * Encrypted cookie sessions (see here to see how to use them). * Much easier installs using cabal-install. * Support for GHC 6.10. GHC 6.8 is no longer supported. Turbinado V0.7 will be all about: * Documentation. (seriously.) * User authentication. * Tutorials.

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Call for papers: Workshop on Termination (WST 2009)
by Johannes Waldmann 12 Mar '09

12 Mar '09

Dear all, the 10th Intl. Workshop on Termination welcomes contributions from the functional programming community. See the general call for papers below, and let me add a few words here. The typical functional (compiler) programmer needs - termination of programs - termination of program transformations (rules) - termination of program analysis (type checking/inference) So I'm sure the workshop topic is highly relevant, and we are looking for *your* contributions. Also, we have an annual competition for automated termination provers, http://termination-portal.org/wiki/Termination_Competition and since 2007 it contains a Haskell category. The problems there are taken directly from the Standard Prelude. So if you have some kind of Haskell source code analyzer that knows something about termination (perhaps only internally), then you're welcome turn it into a Haskell termination prover and submit it to this competition. (Details will be discussed at the workshop.) Best regards, Johannes Waldmann. ..................................................................... Tenth International Workshop on Termination (WST 2009) Leipzig, Germany, June 3-5, 2009 http://www.imn.htwk-leipzig.de/wst09/ Termination is a fundamental topic in computer science. Classical undecidability results show that termination is difficult. On the other hand, programs are usually required to terminate. So methods are needed that prove termination and non-termination automatically for a wide range of programs. Termination proofs are essential not only for program verification, but also as components of program transformation systems. The topic is challenging both in theory (mathematical logic, proof theory) and practice (software development, formal methods), and many interesting ramifications are yet to be explored. The 10th International Workshop on Termination will delve into all aspects of termination of processes. It will continue the sequence of successful workshops held in St. Andrews (1993), La Bresse (1995), Ede (1997), Dagstuhl (1999), Utrecht (2001), Valencia (2003), Aachen (2004), Seattle (2006), and Paris (2007). It will attain the same friendly atmosphere as those past workshops. The intent is to bring together, in an informal setting, researchers interested in all aspects of termination, whether this interest be practical or theoretical, primary or derived. The workshop shall help exchange ideas from term rewriting and from the various programming language communities. Contributions from the imperative, constraint, functional, and logic programming communities, and papers investigating new applications of termination are particularly welcome. Program Committee: Frederic Blanqui, INRIA, FR and Tsinghua University, CN Byron Cook, Microsoft Corporation, US Alfons Geser, HTWK Leipzig, DE (chair) Michael Hanus, Universität Kiel, DE Janis Voigtlander, Technische Universität Dresden, DE Local organization: Johannes Waldmann, HTWK Leipzig, DE Important Dates: Paper submission 19 April 2009 Notification 26 April 2009 Final Paper Version 3 May 2009 Conference Venue: The workshop will be held in the city of Leipzig, at the conference center Mediencampus Villa Ida. Hosting institution: Hochschule fur Technik, Wirtschaft und Kultur Leipzig, in cooperation with Leipzig School of Media and Medienstiftung der Sparkasse Leipzig.

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Announce: iteratee-0.1.0
by John Lato 12 Mar '09

12 Mar '09

I am pleased to announce the hackage release of iteratee-0.1.0. This library implements enumerators and iteratees as proposed by Oleg Kiselyov (http://okmij.org/ftp/Haskell/Iteratee/) Significant differences from his original code include: - Seeking is allowed within any monad; the specific RBIO monad is neither required nor provided. - Data buffers may be of arbitrary types as specified by the StreamChunk type class. This allows for user-provided buffer types (e.g. arrays, vectors, etc.). Instances are provided for lists and ByteStrings. This, in conjunction with seeking, allows for efficient processing of binary data in addition to text. - Cross-platform support. Currently this is slightly less efficient than the Posix operations, but should run on any system targeted by a Haskell compiler. Although basic I/O specific enumerators are provided, this library should allow seamless interoperation with user-provided iteratees and enumerators. I hope that this flexibility will encourage a much wider adoption of enumerator-based IO in the Haskell community. This library is experimental, and the API is subject to change if it will seem advantageous. Patches are welcome: the darcs repo is at http://inmachina.net/~jwlato/haskell/iteratee . Discussion and comments are also always welcome. I would like to acknowledge several individuals for their contributions and suggestions: Oleg Kiselyov Paulo Tanimoto Johan Tibell Cheers, John Lato

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Microsoft PhD Scholarship at Strathclyde
by Conor McBride 10 Mar '09

10 Mar '09

Apologies for crossposting. Please forward this message to individuals or lists who may be interested. In addition to the recently advertised PhD position at Strathclyde on "Reusability and Dependent Types", I am delighted to advertise the following PhD opportunity. {--------------------------------------------------------- -- Haskell Types with Numeric Constraints ---------------- ---------------------------------------------------------} We are grateful to Microsoft Research for their sponsorship of this project, which includes an internship, and with it the chance to make a real difference to world of principled but practical programming. The project investigates the practical and theoretical impact of extending Haskell's type system with numeric expressions (representing sizes, or ranges, or costs, for example) and constraints capturing richer safety properties than are currently managed by static typing. It has three strands: (1) to investigate type inference with numeric constraints, (2) to investigate new programming structures, patterns, and techniques which exploit numeric indexing, and (3) to study the performance benefits derivable from richer guarantees. A bright student could bring significant benefits to developers using Haskell, a language with increasing industrial traction — not least at Microsoft. Work on the Glasgow Haskell Compiler, at Strathclyde! {---------------------------------------------------------} The position is fully funded, covering stipend, fees (at the home/EU rate), equipment, and travel, starting in October 2009. The closing date for applications is 15th April 2009. For further details, see: http://personal.cis.strath.ac.uk/~conor/phds/ or email me (conor(a)cis.strath.ac.uk) I look forward to hearing from you. Yours &c Conor McBride

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ANNOUNCE: Harpy 0.4.4 - Runtime code generation for x86 machine code
by Dirk Kleeblatt 10 Mar '09

10 Mar '09

Dear Haskell community, we are pleased to announce the release of Harpy 0.4.1, a library for runtime code generation for x86 machine code. Harpy is available from Hackage or from Harpy's homepage: http://uebb.cs.tu-berlin.de/harpy/ *** New in version 0.4.1 *** New Instances: - Many of Harpy's types are now instances of Eq. New instructions: - Added support for the prefetching instructions PREFETCH0, PREFETCH1, PREFETCH2 and PREFETCHNTA. Bug fixes: - Harpy.X86Disassembler.disassembleBloc was too strict and caused stack overflows for large inputs. This was fixed. - Disassembler: The instruction prefix list was not cleared when beginning to parse a new instruction. This caused incorrect disassembly of SSE instructions. - Disassembler: A bug has been fixed in the parsing routine for the addressing mode "scaled index + 32 bit offset" without base register. Enjoy, Dirk

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Google Summer of Code 2009
by Malcolm Wallace 10 Mar '09

10 Mar '09

Gentle Haskellers, The Google Summer of Code will be running again this year. Once again, haskell.org has the opportunity to bid to become a mentoring organisation. (Although, as always, there is no guarantee of acceptance.) If you have ideas for student projects that you think would benefit the Haskell community, now is the time to start discussing them on mailing lists of your choice. We especially encourage students to communicate with the wider community: if you keep your ideas private, you have a much worse chance of acceptance than if you develop ideas in collaboration with those who will be your "customers", end-users, or fellow-developers. This is the open-source world! The timeline is that Haskell.org will apply for GSoC membership between 9-13 March, and if we are successful, students can submit applications between 23 March - 3 April. If you wish to help publicise GSoC amongst students, there are official posters/fliers available (not specific to haskell.org) http://code.google.com/p/google-summer-of-code/wiki/GsocFlyers Regards, Malcolm

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