Ivan Lazar Miljenovic | 1 May 08:47 2009

ANNOUNCE: graphviz-2009.5.1

I'd like to announce version 2009.5.1[1] of the graphviz[2] library,
less than a week since Matthew Sackman passed maintainership onto me[3].
The graphviz library provides a Haskell interface to the GraphViz[4]

[1] http://hackage.haskell.org/packages/archive/graphviz/2009.5.1/graphviz-2009.5.1.tar.gz
[2] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/graphviz
[3] http://www.mail-archive.com/haskell <at> haskell.org/msg21994.html
[4] http://graphviz.org

Major changes with this release are:

* Supports polyparse >= 1.1 (the previous version didn't work with 1.3).

* Requires base == 4.* (i.e. GHC 6.10.*) due to the new exception

* Includes functions from my Graphalyze [5] library for actually running
  the various GraphViz commands, etc.

* Slight API breakages:

  - dirCommand, undirCommand and commandFor no longer return String, but

  - Data.GraphViz.ParserCombinators is no longer exported by the Cabal
    file, since I see no need for anyone to require acccess to this.  If
    this is a problem for you, please let me know and I'll re-export it.

(Continue reading)

Chris Eidhof | 1 May 10:44 2009

ANN: Dutch Haskell Users' Group (first meeting: May 6th)

Dear Haskellers,

During the last Haskell Hackathon a new user group was formed: the  
Dutch Haskell Users' Group (DHUG) [1]. We're happy to announce our  
first meeting on May 6th at 19:30 in Utrecht. We'll be talking about  
Haskell over drinks in The Stairway To Heaven [2], which is at walking  
distance from the Utrecht Central Station.

Everybody's invited, from complete novices to advanced Haskell users.  
We hope to see you this Wednesday!


[1]: http://haskell.org/haskellwiki/Dutch_HUG
[2]: http://www.stairway.nl/contact
Colin Paul Adams | 1 May 10:52 2009

Re: ANN: Dutch Haskell Users' Group (first meeting: May 6th)

>>>>> "Chris" == Chris Eidhof <chris <at> eidhof.nl> writes:

    Chris> We'll be talking about Haskell
    Chris> over drinks in The Stairway To Heaven [2]

Is the choice of venue programmatically significant? :-)

You don't want the whole thing to come crashing down like a led balloon.

Colin Adams
Preston Lancashire
Sean Leather | 1 May 16:12 2009

Re: ANN: Dutch Haskell Users' Group (first meeting: May 6th)

Colin Paul Adams wrote:
>>>>> "Chris" == Chris Eidhof <chris <at> eidhof.nl> writes:

   Chris> We'll be talking about Haskell
   Chris> over drinks in The Stairway To Heaven [2]

Is the choice of venue programmatically significant? :-)

Of course! It is one of the Houses of the Holy Haskell (H3+, or protonated molecular hydrogen, is one of the most abundant ions in the universe [1]).

You don't want the whole thing to come crashing down like a led balloon.

When the levee (or dike as they call it here) breaks, we're going to California. At that point, we might need to consider renaming the group, since we're no longer going Dutch.


[1] http://en.wikipedia.org/wiki/Protonated_molecular_hydrogen
Haskell mailing list
Haskell <at> haskell.org
Alistair Bayley | 1 May 17:16 2009

ANN: Takusen 0.8.4

ANN: Takusen 0.8.4

This is mainly a "get it working with ghc-6.10" release.

Changes since 0.8.3:

 - ODBC support: some bug fixes, and basic support for Out-parameters.
   There is at least one major outstanding bug with Out-parameters,
   where marshalling a String output bind-variable doesn't work correctly
   (if it was modified, you still get the String you passed in back,
   rather than the new String).

 - Sqlite: bug fix for resource leak: if a command (like rollback or commit)
   raised an error, the prepared-statement handle was not closed.

 - cabal: requires cabal 1.6 (or later). With ghc-6.6 on Windows you will
   need a later cabal than, as there is a bug which prevents building
   (setup configure fails with
   "setup: fdGetMode: invalid argument (Invalid argument)").
   Eric Mertens patch for ODBC on OS x. Greg Leclerq patch for cabal 1.6.
   Thanks also to Austin Siepp and Brian Callendar for their patches.

 - ghc-6.10: will build with ghc's 6.10, 6.8, 6.6.
   Note that Takusen won't work with ghc-6.10.2 out-of-the-box,
   because the time package is missing. If you install time manually
   then it should be OK (but this is untested).

   We use the new extensible exceptions, but we have done so by including it
   within our own source tree. This will make it easier to use Takusen with
   older ghc's, and reduces the number of external package dependencies.

   We have dropped support for 6.4. That's not to say Takusen isn't usable
   with 6.4, just that we no longer test that configuration.

The release bundle:
The latest code:
  darcs get http://darcs.haskell.org/takusen

If you have cabal-install, then this command should work:
  cabal install Takusen --flags="sqlite odbc oracle postgres"
... but it doesn't (at least for the version of cabal-install
that I have) because the .tar.gz file I uploaded has a bogus checksum.

A comprehensive description of API usage can be found in the documentation
for module Database.Enumerator (look for the Usage section):

Note that the haddock docs won't build with cabal- or earlier.
This is because our literate-haskell source files need to be properly
preprocessed before being passed to haddock.
At the time of writing, you'll need the cabal HEAD to build the docs.

Future plans:

 - Output bind-parameters and multiple-result sets for ODBC

 - support for Blobs and Clobs

 - FreeTDS backend (Sybase and MS Sql Server)... maybe

For those of you unfamiliar with Takusen, here is our HCAR blurb:

Takusen is a DBMS access library. Like HSQL and HDBC, we support
arbitrary SQL statements (currently strings, extensible to anything
that can be converted to a string).

Takusen's 'unique-selling-point' is safety and efficiency.
We statically ensure all acquired database resources - such
as cursors, connection and statement handles - are released, exactly
once, at predictable times. Takusen can avoid loading the whole result
set in memory, and so can handle queries returning millions of rows in
constant space. Takusen also supports automatic marshalling and
unmarshalling of results and query parameters. These benefits come
from the design of query result processing around a left-fold

Currently we fully support ODBC, Oracle, Sqlite, and PostgreSQL.
Duncan Coutts | 2 May 01:14 2009

Re: [Haskell] ANN: Takusen 0.8.4

On Fri, 2009-05-01 at 16:16 +0100, Alistair Bayley wrote:
> ANN: Takusen 0.8.4

> The release bundle:
>   http://hackage.haskell.org/packages/archive/Takusen/0.8.4/Takusen-0.8.4.tar.gz

> If you have cabal-install, then this command should work:
>   cabal install Takusen --flags="sqlite odbc oracle postgres"
> ... but it doesn't (at least for the version of cabal-install
> that I have) because the .tar.gz file I uploaded has a bogus checksum.

Note that it is easy (and recommended) to upgrade to the latest released
version of cabal-install:

$ cabal update
$ cabal install Cabal cabal-install

You can check using:

$ cabal --version
cabal-install version 0.6.2
using version of the Cabal library 

Sven Panne | 2 May 14:00 2009


A new version of the ALUT package has been uploaded to Hackage. Again, this is 
a bug fix only release, containing only tiny changes:

  * Include missing aclocal.m4 and examples in source distribution

  * Removed unused Makefiles and prologue.txt

  * Fixed OpenAL URLs

Sven Panne | 2 May 14:28 2009


A new version of the OpenAL package has been uploaded to Hackage. Again, this 
is a bug fix only release:

  * Include OpenAL header when checking values of constants

  * Include missing aclocal.m4 and examples in source distribution

  * Removed unused Makefiles and prologue.txt

  * Removed empty "demos" subdirectory

  * Fixed OpenAL URLs

Hopefully this release will fix build issues on MacOS X and Windows. Thanks to 
Balazs Komuves for making me aware of these bugs, and providing a patch.

Sven Panne | 2 May 18:22 2009


A new version of the GLUT package has been uploaded to Hackage. This is a bug 
fix only release, containing only tiny changes:

  * Include missing aclocal.m4 and examples in source distribution

  * Removed unused Makefiles and prologue.txt

Brent Yorgey | 2 May 20:33 2009

Haskell Weekly News: Issue 116 - May 2, 2009

Haskell Weekly News
Issue 116 - May 02, 2009

   Welcome to issue 116 of HWN, a newsletter covering developments in the
   [1]Haskell community.


   GHC 6.10.3 prerelease. Ian Lynagh [2]announced a [3]prerelease
   [4]version of GHC 6.10.3. There have been [5]very few changes relative
   to 6.10.2. Unless any major problems are uncovered, the final release
   is expected to be built in a couple of days.

   graphviz-2009.5.1. Ivan Lazar Miljenovic [6]announced version 2009.5.1
   of the [7]graphviz library, which provides a Haskell interface to the
   [8]GraphViz program. Major changes include support for polyparse >=
   1.1, dependency on GHC 6.10.*, functions from the [9]Graphalyze
   library, and more.

   priority-sync- Cooperative task prioritization.. Christopher
   Lane Hinson [10]announced the release of the [11]priority-sync package
   for cooperative task prioritization.

   HaL4: Local Haskell meeting, Halle/Saale, Germany, June 12. Henning
   Thielemann [12]requested proposals for talks for [13]HaL4, a local
   Haskell meeting in Halle, Germany on June 12.

   TraverseAccum: an effectful accumulating map.. Florent Balestrieri
   [14]posted some code implementing an effectful accumulating map.

   LondonHUG talk: Engineering Large Projects in Haskell. Don Stewart
   [15]posted [16]slides from last week's [17]London HUG talk, which
   attempts to document some of the tips and tricks Galois has accumulated
   using Haskell commercially for the past 10 years.

   atom-0.0.2. Tom Hawkins [18]announced the release of [19]atom, a
   Haskell DSL for designed hard realtime embedded programs. Eaton is
   using it to control hydraulic hybrid refuse trucks and shuttle buses.

   Bamse-0.9.4, a Windows Installer generator. Sigbjorn Finne
   [20]announced a new version of [21]Bamse, a package and application for
   letting you quickly put together Windows Installers for your software
   projects/products from within the comforts of Haskell. New in this
   release is the support for generating MSIs from your Cabal projects,
   having them either be built from source or just have them be installed
   and registered at install-time.

   Dutch Haskell Users' Group (first meeting: May 6th). Chris Eidhof
   [22]announced the first meeting of the newly formed [23]Dutch Haskell
   Users' Group (DHUG), on May 6th at 19:30 in Utrecht.

   Haskell Symposium Submission site now open. Stephanie Weirich
   [24]announced that [25]submission to the Haskell Symposium is now open.
   The submission deadline is May 8.

   OpenGL, GLUT, OpenAL, and ALUT updates. Sven Panne [26]announced
   [27]new [28]bugfix [29]releases for the [30]OpenGL, [31]GLUT,
   [32]OpenAL, and [33]ALUT packages.

   control-monad-exception-0.1: Explicitly typed exceptions. Pepe Iborra
   [34]announced the [35]control-monad-exception package, which provides
   explicitly typed exceptions for Haskell. The type of a computation in
   the EM monad carries a list of the exceptions that the computation may
   throw. A exception is raised with 'throw', which in addition adds it to
   the type, and captured with 'catch', which correspondingly removes it
   from the type. Only safe computations (all exceptions handled) can
   escape from the monad.

   Haskell File Manager. Michael Dever [36]announced the first release of
   [37]Haskell File Manager, a program for viewing/managing the files on
   your computer. It has all the common functionality you would expect
   from your current file manager, copying, moving, deleting, renaming,
   opening and searching.

   uu-parsinglib-2.0.0. S. Doaitse Swierstra [38]announced the release of
   [39]uu-parsinglib, the first version of the new parsing combinator
   library package from Utrecht University. Features include online result
   construction, much simpler internals than the combinators in the uulib
   package, error correction, parsing ambiguous grammars, a monadic
   interface, and more.

   Takusen 0.8.4. Alistair Bayley [40]announced version 0.8.4 of
   [41]Takusen, a database package; this is mostly a "get it working with
   ghc-6.10" release.


Google SoC: Space profiling reloaded. Patai Gergely [42]asked for ideas
   on his Google Summer of Code project to [43]improve the Haskell space
   profiling experience.

Blog noise

   [44]Haskell news from the [45]blogosphere.
     * Bryan O'Sullivan: [46]Slides from my Erlang Factory talk this
     * Thomas Hartman: [47]What to do when cabal install works in one
       environment, but not another..
     * Christopher Lane Hinson: [48]ANN: priority-sync.
     * Well-Typed.Com: [49]"Hello world" now only 11k using GHC with
       shared libs.
     * The GHC Team: [50]The new GHC build system is here!.
     * Well-Typed.Com: [51]First round of Industrial Haskell Group
       development work.
     * London Haskell Users Group: [52]Don's slides.
     * Galois, Inc: [53]Engineering Large Projects in Haskell: A Decade of
       FP at Galois.
     * JP Moresmau: [54]Haskell RPG Game uploaded on Hackage!.
     * Holumbus: [55]Distributed data structures.
     * Niklas Broberg: [56]GSoC09 => haskell-src-exts -> haskell-src.
     * >>> Remco Niemeijer: [57]Forcing evaluation in Haskell.
     * Chris Eidhof: [58]Building commercial Haskell applications.
     * >>> Lab49: [59]Differentiating Types in Haskell.

Quotes of the Week

     * MonadState: Do not try to change the state; that's impossible.
       Instead only try to realize the truth: There is no state.
     * Baughn: Those who would give up essential laziness for a little
       ephemeral performance, deserve neither laziness nor performance.
     * Axman6: what's  <at> flush do? saves stuff to dick?
     * bos: Crummy languages give static types a bad name.

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/ .


   1. http://haskell.org/
   2. http://article.gmane.org/gmane.comp.lang.haskell.glasgow.user/16852
   3. http://www.haskell.org/ghc/dist/stable/dist/ghc-
   4. http://www.haskell.org/ghc/dist/stable/dist/ghc-
   5. http://www.haskell.org/ghc/dist/stable/docs/users_guide/release-6-10-3.html
   6. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57826
   7. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/graphviz
   8. http://graphviz.org/
   9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Graphalyze
  10. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57776
  11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/priority-sync
  12. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57764
  13. http://www.iba-cg.de/hal4.html
  14. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57730
  15. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57719
  16. http://www.galois.com/blog/2009/04/27/engineering-large-projects-in-haskell-a-decade-of-fp-at-galois/
  17. http://www.londonhug.net/
  18. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57676
  19. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/atom
  20. http://article.gmane.org/gmane.comp.lang.haskell.cafe/57640
  21. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/bamse
  22. http://article.gmane.org/gmane.comp.lang.haskell.general/17142
  23. http://haskell.org/haskellwiki/Dutch_HUG
  24. http://article.gmane.org/gmane.comp.lang.haskell.general/17140
  25. http://www.easychair.org/conferences/?conf=haskell09
  26. http://article.gmane.org/gmane.comp.lang.haskell.general/17132
  27. http://article.gmane.org/gmane.comp.lang.haskell.general/17133
  28. http://article.gmane.org/gmane.comp.lang.haskell.general/17134
  29. http://article.gmane.org/gmane.comp.lang.haskell.general/17135
  30. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/OpenGL
  31. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/GLUT
  32. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/OpenAL
  33. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ALUT
  34. http://article.gmane.org/gmane.comp.lang.haskell.general/17120
  35. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/control%2Dmonad%2Dexception
  36. http://www.haskell.org//pipermail/haskell/2009-April/021271.html
  37. http://code.haskell.org/haskellfm
  38. http://www.haskell.org//pipermail/haskell/2009-April/021284.html
  39. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/uu%2Dparsinglib
  40. http://www.haskell.org//pipermail/haskell/2009-May/021293.html
  41. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Takusen
  42. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/57810
  43. http://socghop.appspot.com/student_project/show/google/gsoc2009/haskell/t124022468245
  44. http://planet.haskell.org/
  45. http://haskell.org/haskellwiki/Blog_articles
  46. http://www.serpentine.com/blog/2009/05/01/slides-from-my-erlang-factory-talk-this-morning/
  47. http://blog.patch-tag.com/2009/05/01/what-to-do-when-cabal-install-works-in-one-environment-but-not-another/
  48. http://blog.downstairspeople.org/2009/04/29/ann-priority-sync/
  49. http://blog.well-typed.com/2009/04/hello-world-now-only-11k-using-ghc-with-shared-libs/
  50. http://ghcmutterings.wordpress.com/2009/04/28/the-new-ghc-build-system-is-here/
  51. http://blog.well-typed.com/2009/04/first-round-of-ihg-development-work/
  52. http://www.londonhug.net/2009/04/27/dons-slides/
  53. http://www.galois.com/blog/2009/04/27/engineering-large-projects-in-haskell-a-decade-of-fp-at-galois/
  54. http://jpmoresmau.blogspot.com/2009/04/haskell-rpg-game-uploaded-on-hackage.html
  55. http://holumbus.fh-wedel.de/blog/?p=22
  56. http://nibrofun.blogspot.com/2009/04/gsoc09-haskell-src-exts-haskell-src.html
  57. http://bonsaicode.wordpress.com/2009/04/27/forcing-evaluation-in-haskell/
  58. http://blog.tupil.com/building-commercial-haskell-applications/
  59. http://blog.lab49.com/archives/3027
  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/