June 2009 - Haskell - Haskell.org

ANNOUNCE: Program to set the GNOME desktop background picture randomly
by Colin Paul Adams 22 Jun '09

22 Jun '09

I've just uploaded gnome-desktop to Hackage. This periodically picks a random picture from $HOME/Pictures, and sets it as the GNOME desktop background. It does this periodically. As a result, I now see a different beautiful picture of a dragonfly every 30 seconds, without needing to wait for the screensaver to kick in. Timings and directory can be set on the command line. -- Colin Adams Preston Lancashire

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ANNOUNCE: OpenGLRaw 1.0.0.0
by Sven Panne 22 Jun '09

22 Jun '09

As a first step to make the OpenGL package easier to install, more modular and a bit more flexible, a low-level binding for OpenGL has been uploaded to Hackage. From OpenGLRaw's package description: ------------------------------------------------------------ OpenGLRaw is a raw Haskell binding for the OpenGL 3.1 graphics system and lots of OpenGL extensions. It is basically a 1:1 mapping of OpenGL's C API, intended as a basis for a nicer interface. OpenGLRaw offers access to all necessary functions, tokens and types plus a general facility for loading extension entries. The module hierarchy closely mirrors the naming structure of the OpenGL extensions, making it easy to find the right module to import. All API entries are loaded dynamically, so no special C header files are needed for building this package. If an API entry is not found at runtime, a userError is thrown. OpenGL is the industry's most widely used and supported 2D and 3D graphics application programming interface (API), incorporating a broad set of rendering, texture mapping, special effects, and other powerful visualization functions. For more information about OpenGL and its various extensions, please see http://www.opengl.org/ and http://www.opengl.org/registry/. ------------------------------------------------------------ Version 1.0.0.0 covers the OpenGL 3.1 core, all ARB extensions and all EXT extensions. Great care has been taken to introduce as few build dependencies as possible, so neither autoconf is required, nor any OpenGL headers. Future versions of the OpenGL package will basically be a convenience layer above this package, but you can always fall back to the raw binding if required. To get a taste for it, have a look at http://aedion.de/haskell/SmoothRaw.hs, which should look extremely familiar to anyone who has used OpenGL's C API. Any feedback is highly appreciated. Cheers, S.

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ANN: haskell-src-exts 1.0.0 rc1 (aka 0.5.2)
by Niklas Broberg 22 Jun '09

22 Jun '09

Fellow Haskelleers, I'm pleased to report that I feel I have now completed the first milestone in my GSoC project for haskell-src-exts: Full Code Support. This means I feel ready to take that scary leap that means to drop the safe 0.x version numbering (experimental) and finally make the first stable release, version 1.0.0. But before I take that leap I want the library to be thoroughly tested, so I can with confidence say that it truly *is* stable. Therefore, I hereby announce the release on hackage of haskell-src-exts-0.5.2, which I consider (almost) a release candidate for 1.0.0. * Via cabal: cabal install haskell-src-exts * On Hackage: http://hackage.haskell.org/package/haskell-src-exts-0.5.2 * Via darcs: darcs get http://code.haskell.org/haskell-src-exts I would be delighted if as many as possible would consider testing it on their code, even those of you who feel that you may not have any immediate use of the library, just to cover as much code base as possible in the hunt for potential bugs and misfeatures. Testing it is really easy, four simple steps: > cabal install haskell-src-exts [...] > ghci [...] Prelude> :m Language.Haskell.Exts Prelude Language.Haskell.Exts> parseFile "YourFileHere.(l)hs" If you get a parse error on a file that you feel should have been accepted, let me know! If the parser gives you an AST result for a file that you feel it shouldn't have accepted, let me know! Here's the bug tracker: http://trac.haskell.org/haskell-src-exts/report/1 The reason I say it is "almost" a release candidate is that while I consider the functionality to be in place, I will tidy up the exports, add a few more convenient functions to export, and add a lot of documentation, before I make the actual release. If you have a request for a particularly conventient function to add to the list of exports from the package, it's thus not too late to get it into 1.0.0. :-) What's cool in haskell-src-exts-0.5.2: ============================ * Support for all syntactic extensions supported by GHC, with two exceptions: UnicodeSyntax and NewQualifiedOperators. These will likely be added in the next feature release. Exclusive support for the newly registered XmlSyntax and RegularPatterns extensions. No support (yet) for Hugs-specific extensions (RestrictedTypeSynonyms, ExtensibleRecords, HereDocuments). No support for CPP. Also does not support the GHC-specific relaxation of layout in do-blocks, which is an unregistered extension (that should be registered!). * Support for parametrising the parsing on what extensions it should recognise. With no extensions given, it assumes Haskell98. Note that 'parseFile' will look for language pragmas in your source file to decide what extensions to use when parsing. If you want to be explicit, you can use 'parseFileWithExts', or 'parseFileWithMode' that lets you set a few other things as well. I intend to add some convenient names of extension groups, such as 'ghcExtensions' and 'glasgowExts', this is one area where I would particularly welcome suggestions. * Support for correct fixities of infix operators. By default it uses the fixities defined in the Prelude, as well as in the current document (including local let-bound fixities). Use 'parseFileWithMode' to set a different set of fixities. Language.Haskell.Exts.Fixity defines preludeFixities and baseFixities (all fixities defined in the base package), as well as combinators for defining your own sets. Much thanks to Neil Mitchell for the meat of this code. * No (known) bugs! :-) Special note for users of HaRP/HSP: I've uploaded a new version of hsx, hsx-0.5.0, that works with haskell-src-exts-0.5.2. There is one known bug in this version though, it cannot handle 'proc' entities from the Arrows extensions, I'm still considering how to fix that. In the mean time you can use it just fine, as long as your files don't contain any 'proc' blocks (which the old version couldn't handle anyway). Cheers and happy Haskelling, /Niklas

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Haskell Weekly News: Issue 122 - June 21, 2009
by Brent Yorgey 21 Jun '09

21 Jun '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090621 Issue 122 - June 21, 2009 --------------------------------------------------------------------------- Welcome to issue 122 of HWN, a newsletter covering developments in the [1]Haskell community. Are you ready for the [2]12th Annual ICFP programming contest? It begins this Friday, don't miss it! Let's reclaim Haskell's rightful place as the programming language of choice for discriminating hackers. Announcements Haskell protocol-buffers version 1.5.0. Chris Kuklewicz [3]announced version 1.5.0 of the [4]protocol-buffers, [5]protocol-buffers-descriptor, and [6]hprotoc packages to Hackage. This catches up to Google's version 2.1.0: support for "repeated" fields for primitive types; fields can now be marked deprecated; the type name resolver will no longer resolve type names to fields; and more. 12th Annual ICFP Contest. Mark Huntington Snyder [7]announced the 12th Annual [8]ICFP Programming Contest, hosted by the University of Kansas Computer Systems Design Laboratory at the Information and Telecommunication Technology Center. The contest will be held on the weekend of June 26-29. The contest task will be released sixteen seconds after 13:00 Central Daylight Time (US) on Friday, and entries will be accepted until 13:00:16 CDT on Monday. There is no preregistration required, and participation is free and open to all. Teams may participate from any location, and may use any programming language(s). Read the [9]contest blog or subscribe to the [10]RSS feed to receive timely updates before and during the contest. clock 0.1 released. Cetin Sert [11]announced the release of [12]clock, a package for convenient access to high-resolution clock and timer functions of different operating systems. It is planned to consist of two layers; the lower layer will provide direct access to OS-specific clock and timer functions like clock_gettime of Posix or GetTickCount of Windows, and its upper layer shall then provide a common API for all supported systems. Currently only the lower level is being developed. Turbinado V0.7. Alson Kemp [13]announced version 0.7 of [14]Turbinado, a Ruby-On-Rails-like web server and web framework for Haskell. It is designed to make creating web application using Haskell both easy and joyful. The primary additions in version 0.7 are FastCGI support and a new templating system (which includes HAML and HTML support). Additional details can be found [15]here. haskeline-class. Antoine Latter [16]announced [17]haskeline-class, a small library providing a newtyped MonadState instance for haskeline which lifts the class operations to an inner monad (as opposed to its existing instance). hyena. Johan Tibell [18]announced the first release of [19]hyena, a library for building web servers, based on the work on [20]iteratee style I/O by Oleg Kiselyov. The library allows you to create web servers that consume their input incrementally, without resorting to lazy I/O. This should lead to more predictable resource usage. Haskell-based iPhone development. Conal Elliott [21]announced a [22]collaboration wiki page for anyone working with Haskell to make iPhone apps. Fwd: Boston Haskell June 23rd meeting: openings for Lightning Talks. Ravi Nanavati [23]announced that there are several available slots for "lightning" (5 minute) talks at the June 23 meeting of the [24]Boston Area Haskell Users' Group. haskell-src-exts 1.0.0 rc1. Niklas Broberg [25]announced a series of release candidates for haskell-src-exts-1.0.0 (as of this writing, the most recent release candidate is version 0.5.6). This version is intended to fully support parsing of almost all Haskell extensions. Please help with testing! BostonHaskell: Next meeting - June 23rd at MIT CSAIL Reading Room (32-G882). Ravi Nanavati [26]announced the second meeting of the [27]Boston Area Haskell Users' Group, scheduled for Tuesday, June 23rd from 6:30pm - 8:30pm. It will be held in the MIT CSAIL Reading Room (32-G882, i.e. a room on the 8th floor of the Gates Tower of the MIT's Stata Center at 32 Vassar St in Cambridge, MA). Talks include "Automagic Font Conversion with Haskell Typeclasses" by Frank Berthold, and "Intermediate Language Representations via GADTs" by Nirav Dave. traversal transformations. Sjoerd Visscher [28]exhibited some code for Church-encoded container structures using their Foldable instance, and later [29]announced the [30]fmlist package based on the same code, along with a surprising example of a lazy 'middle-infinite' list (where elements can be taken from the beginning or the end!). hledger 0.6 released. Simon Michael [31]announced the release of [32]hledger 0.6. See the announcement for a list of the new features and other information. Discussion Adding swap to Data.Tuple. roconnor [33]proposed adding swap and swap' functions to Data.Tuple. Revamping the module hierarchy. Johan Tibell began an interesting [34]discussion about package names, module names, and the module hierarchy. Confusion on the third monad law when using lambda abstractions. Jon Strait [35]asked about the third monad law, leading to some clarification on what precisely the law says, and some interesting discussion on idiomatic use of the (<=<) (Kleisli composition) operator. Need some help with an infinite list. Gunther Schmidt [36]asked for some help generating a particular infinite list, and got a number of interesting suggestions. Blog noise [37]Haskell news from the [38]blogosphere. Blog posts from people new to the Haskell community are marked with >>>, be sure to welcome them! * Thomas ten Cate: [39]Cosmetics. Nice-looking icons for EclipseFP! * Niklas Broberg: [40]GSoC status report, week 4. More release candidates for haskell-src-exts 1.0.0. * >>> Uwe Hoffmann: [41]publishing nike runs, part 4: string templates. Real-world example of using HStringTemplate. * Andy Gill: [42]Call for Participation in the 12th Annual ICFP Programming Contest!. June 26-29! * Sebastian Fischer: [43]Reinventing Haskell Backtracking. * Remco Niemeijer: [44]Programming Praxis - Monte Carlo factorization. Remco implements Pollard's factorization algorithm in 9 lines of Haskell. * >>> Lee Duhem: [45]Understanding Functions Which Use 'instance Monad []' by Equational Reasoning. * Alex McLean: [46]Patterns in Haskell. A Haskell music generation EDSL. * David Amos: [47]Group generators for graph symmetries. * >>> adam: [48]Experience writing a ray tracer in Haskell. Adam's final project in a Haskell class taught by Mark Jones and Tim Sheard. * Petr Rockai: [49]soc progress 4. * Yaakov Nemoy: [50]Haskell Bindings to C from Start to Finish. Yaakov outlines his experience getting c2hs and the FFI to work. * Alex McLean: [51]Patterns in Haskell. Representing rhythmic patterns in Haskell. * >>> Abhishek Tiwari: [52]Haskell for Bioinformatics. * Roman Cheplyaka: [53]Shootout. A hilarious comic featuring sound advice on Haskell optimization. * Ketil Malde: [54]Dephd updates. * Neil Mitchell: [55]Draft paper on Derive, comments wanted. * Remco Niemeijer: [56]Programming Praxis - Who Owns The Zebra?. * Erik de Castro Lopo: [57]Two More for the Debian New Queue.. * David Amos: [58]Graph symmetries. * Alson Kemp: [59]Announce: Turbinado V0.7. * Gergely Patai: [60]You can draw your own graphs now!. * >>> Jens Petersen: [61]Haskell cabal-install rocks . Quotes of the Week * Botje: <Cheery> oh man. de bruijn again kicked me to groin <Botje> the easy fix is to label your groin as (-1) :) * Pseudonym: Telling dons that something has been added to the shootout is the new telling Oleg that it can't be done in the type system. About the Haskell Weekly News New editions are posted to [62]the Haskell mailing list as well as to [63]the Haskell Sequence and [64]Planet Haskell. [65]RSS is also available, and headlines appear on [66]haskell.org. To help create new editions of this newsletter, please see the information on [67]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [68]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://icfpcontest.org/ 3. http://article.gmane.org/gmane.comp.lang.haskell.libraries/11331 4. http://hackage.haskell.org/package/protocol-buffers 5. http://hackage.haskell.org/package/protocol-buffers-descriptor 6. http://hackage.haskell.org/package/hprotoc 7. http://article.gmane.org/gmane.comp.lang.haskell.general/17298 8. http://icfpcontest.org/ 9. http://www.icfpcontest.org/wordpress 10. http://www.icfpcontest.org/wordpress/?feed=rss2 11. http://article.gmane.org/gmane.comp.lang.haskell.general/17279 12. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/clock 13. http://article.gmane.org/gmane.comp.lang.haskell.general/17277 14. http://wiki.github.com/turbinado/turbinado 15. http://www.alsonkemp.com/turbinado/announce-turbinado-v07/ 16. http://article.gmane.org/gmane.comp.lang.haskell.cafe/60246 17. http://hackage.haskell.org/package/haskeline-class 18. http://article.gmane.org/gmane.comp.lang.haskell.cafe/60117 19. http://hackage.haskell.org/package/hyena 20. http://hackage.haskell.org/package/iteratee 21. http://article.gmane.org/gmane.comp.lang.haskell.cafe/60104 22. http://haskell.org/haskellwiki/IPhone 23. http://article.gmane.org/gmane.comp.lang.haskell.cafe/60091 24. http://www.haskell.org/haskellwiki/Boston_Area_Haskell_Users%27_Group 25. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59993 26. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59991 27. http://www.haskell.org/haskellwiki/Boston_Area_Haskell_Users%27_Group 28. http://article.gmane.org/gmane.comp.lang.haskell.cafe/59894 29. http://article.gmane.org/gmane.comp.lang.haskell.cafe/60120 30. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/fmlist 31. http://www.haskell.org/pipermail/haskell-cafe/2009-June/062787.html 32. http://hledger.org/ 33. http://article.gmane.org/gmane.comp.lang.haskell.libraries/11326 34. http://thread.gmane.org/gmane.comp.lang.haskell.libraries/11325 35. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/60105 36. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/59999 37. http://planet.haskell.org/ 38. http://haskell.org/haskellwiki/Blog_articles 39. http://eclipsefp.wordpress.com/2009/06/20/cosmetics/ 40. http://nibrofun.blogspot.com/2009/06/gsoc-status-report-week-4.html 41. http://www.codemanic.com/uwe/2009/06/publishing-nike-runs-part-4-string-tem… 42. http://blog.unsafeperformio.com/?p=53 43. http://www-ps.informatik.uni-kiel.de/~sebf/pub/atps09.html 44. http://bonsaicode.wordpress.com/2009/06/19/programming-praxis-monte-carlo-f… 45. http://leeduhem.wordpress.com/2009/06/19/understanding-functions-which-use-… 46. http://yaxu.org/patterns-in-haskell/ 47. http://haskellformaths.blogspot.com/2009/06/group-generators-for-graph-symm… 48. http://blog.finiteimprobability.com/2009/06/18/experience-writing-a-ray-tra… 49. http://web.mornfall.net/blog/soc_progress_4.html 50. http://loupgaroublond.blogspot.com/2009/06/haskell-bindings-to-c-from-start… 51. http://yaxu.org/patterns-in-haskell/ 52. http://www.abhishek-tiwari.com/2009/06/haskell-for-bioinformatics.html 53. http://ro-che.blogspot.com/2009/06/shootout.html 54. http://blog.malde.org/index.php/2009/06/16/dephd-updates/ 55. http://neilmitchell.blogspot.com/2009/06/draft-paper-on-derive-comments-wan… 56. http://bonsaicode.wordpress.com/2009/06/16/programming-praxis-who-owns-the-… 57. http://www.mega-nerd.com/erikd/Blog/CodeHacking/Debian/safe_uniplate.html 58. http://haskellformaths.blogspot.com/2009/06/graph-symmetries.html 59. http://www.alsonkemp.com/turbinado/announce-turbinado-v07/ 60. http://just-bottom.blogspot.com/2009/06/you-can-draw-your-own-graphs-now.ht… 61. http://juhp.blogspot.com/2009/06/haskell-cabal-install-rocks.html 62. http://www.haskell.org/mailman/listinfo/haskell 63. http://sequence.complete.org/ 64. http://planet.haskell.org/ 65. http://sequence.complete.org/node/feed 66. http://haskell.org/ 67. http://haskell.org/haskellwiki/HWN 68. http://code.haskell.org/~byorgey/code/hwn/

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12th Annual ICFP Contest
by Mark Huntington Snyder 19 Jun '09

19 Jun '09

The University of Kansas is pleased to call for participation in the 12th Annual ICFP Programming Contest, hosted by the Computer Systems Design Laboratory at the Information and Telecommunication Technology Center. http://icfpcontest.org/ The contest, associated with the International Conference on Functional Programming, will be held on the weekend of June 26-29. The contest task will be released sixteen seconds after 13:00 Central Daylight Time (US) on Friday, and entries will be accepted until 13:00:16 CDT on Monday. There is no preregistration required, and participation is free and open to all. Teams may participate from any location, and may use any programming language(s). Last year, over 330 teams participated from around the globe. Solutions can be submitted to a lightning round (within the first 24 hours) and the regular 72-hour competition. First place, lightning round, and judges' choice prizes will be awarded, which will include prize money to help defray the costs of travel to the conference for the winners as well as small cash prizes. In addition, the winners of the contest will receive bragging rights for the programming language of their choice. This makes the contest a popular avenue for demonstrating the superiority of a favorite language, or for exercising an experimental tool. Stay tuned for more information as the contest approaches! Read the contest blog (http://www.icfpcontest.org/wordpress) or subscribe to the RSS feed (http://www.icfpcontest.org/wordpress/?feed=rss2) to receive timely updates before and during the contest. ~ 2009 Contest Organizers ~ The University of Kansas CSDL

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Re: [Haskell] ANN: haskell-src-exts 1.0.0 rc1 (aka 0.5.2)
by Niklas Broberg 17 Jun '09

17 Jun '09

Hi Sebastian, > This script may even simplify testing of large code bases: Thanks a lot, very useful! I'll add that to the darcs repository if you don't mind. :-) Cheers, /Niklas

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ANNOUNCE: clock 0.1 released
by Cetin Sert 16 Jun '09

16 Jun '09

clock <http://hackage.haskell.org/package/clock> is a library published under a BSD3 license that provides bindings to clock_gettime and clock_getres for monotonic, realtime, processtime and threadtime clocks from time.h <http://www.opengroup.org/onlinepubs/007908799/xsh/time.h.html>. It was implemented in response to a haskell-cafe discussion: http://www.mail-archive.com/haskell-cafe@haskell.org/msg51244.html Any suggestions for improvement, bug-fixes, joint-development offers are most welcome *^o^*!! Cetin Sert

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Re: [Haskell] ANNOUNCE: OpenGLRaw 1.0.0.0
by Tillmann Vogt 14 Jun '09

14 Jun '09

Sven Panne schrieb: > Am Donnerstag, 11. Juni 2009 19:23:17 schrieb Bryan O'Sullivan: >> [...] I think that "Graphics.Rendering." is clutter, and "OpenGL.GL." seems >> redundant to me. [...] > > I forgot to mention one thing here: "OpenGL.GL" is currently *not* redundant, > there is "OpenGL.GLU" in the OpenGL package, too. GL and GLU are separate > libraries, even living in separate DLLs/*.sos, having separate headers, etc., > so they should be kept separate in Haskell at some level, too. > > Nevertheless, with OpenGL 3.1 GLU is dead, Are you sure? glu is mainly for converting an arbitrary polygon into triangles. This is an art and so obviously wasn't put into hardware or driver. From a previous post I remember that tesselation was mentioned. But looking at some presentation slides from AMD/ATI I understand that tesselation in directx11 is using the following primitive patches: Triangles and Tri-patches, Quads and Quad Patches, Lines and Line Patches, see http://ati.amd.com/developer/gdc/2008/Tatarchuk-Tessellation_GDC08.pdf slide 31. I haven't found a lot of information in the OpenGL 3.1 Spec, so I assume they will do it similar to directx11. So, if glu is still needed, until I use a better algorithm in my library. > anyway, so in future versions there > will be no ".GL" part in the package names. > > Cheers, > S. > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell

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ANNOUNCE: Turbinado V0.7
by Alson Kemp 14 Jun '09

14 Jun '09

Turbinado is a Ruby-On-Rails-like web server and web framework for Haskell. It is designed to make creating web application using Haskell both easy and joyful. Turbinado continues to progress and I'd like to announce Turbinado V0.7. The primary additions are FastCGI support and a new templating system (which includes HAML and HTML support). Additional details are here: http://www.alsonkemp.com/turbinado/announce-turbinado-v07/. In order to accommodate collaboration, I've moved the project's homepage to GitHub: Homepage: http://wiki.github.com/turbinado/turbinado Source code: http://github.com/turbinado/turbinado

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ANN: hledger 0.6 released
by Simon Michael 13 Jun '09

13 Jun '09

I'm pleased to announce the release of hledger 0.6. For docs, online demo etc., see http://hledger.org . Some pre-built binaries are now available at http://hledger.org/ binaries . Or, install with: cabal install hledger [-fhapps] [-fvty]. (Using the latest Haskell Platform, "cabal install hledger -fhapps" works on gnu/ linux, mac and windows. Hurrah!) I'd like to hear feedback, especially if you hit trouble getting started. Happy tracking! - Simon (sm) 2009/06/13 hledger 0.6 ...................... * now cabal-installable on unix, mac, and windows, with Haskell Platform * provide experimental platform binaries * parsing: fix a silly failure to open ledger file paths containing ~ * parsing: show better errors for unbalanced transaction and missing default year * parsing: allow parentheses and brackets inside account names, as ledger does * parsing: fail on empty account name components, don't just ignore * add: description passed as arguments now affects first transaction only * add: better handling of virtual postings and default amounts * print, register: show virtual accounts bracketed/parenthesised * web: improved web ui supporting full patterns & period expressions * new "stats" command reports some ledger statistics * many dev/doc/deployment infrastructure improvements * move website into darcs repo, update home page * move issue tracker to google code Release stats: * Contributors: Simon Michael * Days since last release: 21 * Commits: 94 * Lines of non-test code: 2865 * Tests: 82 * Test coverage: 53% expressions * Known errors: 3 (inconsistent eliding, vty-related failures) * Performance: similar (http://hledger.org/profs/200906131120.bench)

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