[Haskell-cafe] Haskell Weekly News: Issue 118 - May 16, 2009

Brent Yorgey byorgey at seas.upenn.edu
Sat May 16 21:32:23 EDT 2009

Haskell Weekly News
Issue 118 - May 16, 2009

   Welcome to issue 118 of HWN, a newsletter covering developments in the
   [1]Haskell community.

   Welcome to the Google Summer of Code special edition! I asked each
   of the five students with accepted GSoC projects to describe what they
   plan to work on. You'll find their descriptions below, with links to
   their blogs. And keep watching this space: as I did last summer, I plan
   to provide readers of the HWN with weekly updates on the progress of
   the GSoC projects.

Google Summer of Code

   Haddock improvements! Isaac Dupree is [2]working on improvements to
   [3]Haddock. "Besides the various inevitable small fixes/improvements,
   my specific projects are to make cross-package documentation work, and
   to refactor the comment-parsing out of GHC and into the Haddock

   EclipseFP. Thomas Ten Cate will be [4]working on EclipseFP: "Compared
   to more mainstream languages, Haskell has surprisingly poor IDE
   support, even though its static typing system allows for much more help
   from the IDE than in the case of dynamic languages. For the Java
   language, a very mature and powerful IDE exists in the form of Eclipse.
   A plugin for Haskell support in Eclipse, called EclipseFP, is in the
   works, but its development has been standing still for some time. I
   will bring EclipseFP to a more usable state. For this, I will use the
   Scion IDE library, which interfaces with the GHC API, so that more
   advanced features like type inference become possible. I will also add
   support for Cabal. Hopefully, this type of IDE support will lead to
   greater acceptance and use of Haskell, and be useful for development as
   well as education."

   Improving the Haskell space profiling experience. Gergely Patai's
   [5]project will be focused on space profiling: "At the present moment,
   heap profiling Haskell programs means analysing logs off-line, using
   conversion tools to visualise data. However, instead of generating
   graphs with hp2ps, it should be possible to present the data in a
   graphical application in real time, which is useful while developing
   interactive applications, and it should also be made easier to export
   profiler output in different formats. The aim of the project is to
   create a set of tools that make heap profiling of Haskell programs
   easier in various ways. In particular, the following components are
   planned: a library to process profiler output in an efficient way and
   make it easily accessible for other tools in the future; a real-time
   visualiser (most likely using OpenGL); some kind of history manager to
   keep track of profiling data and make it possible to perform a
   comparative analysis of performance between different versions of your
   program; a maintainable and extensible replacement for hp2ps; and
   converters to provide input for other profiling tools."

   haskell-src-exts -> haskell-src. Niklas Broberg: "My [6]project, dubbed
   'haskell-src-exts -> haskell-src' is really two projects in one
   wrapping. The first milestone is to bring my haskell-src-exts library
   to the point where it can supersede the old haskell-src library as the
   de facto package for haskell source manipulation. The main problem that
   I need to solve is to implement a scheme that lets the user decide what
   extensions to recognize when parsing a source document. Currently,
   haskell-src-exts assumes all extensions are always on, which means that
   some valid H98 programs will be incorrectly parsed due to stolen syntax
   by e.g. Template Haskell. The second milestone is to extend the focus
   from source code to full source documents, and implement a scheme for
   handling comments as well. The ultimate goal here is to have (pretty .
   parse) == id, to allow haskell-src-exts to be run on source documents
   without changing them. This would open up for some really interesting
   applications, in particular refactoring tools that could automatically
   apply transformations to a source document while still preserving

   darcs. Last but not least, Petr Rockai will be [7]working on
   improvements to [8]darcs: "My project revolves around the idea of fast
   darcs for medium and large repositories. Three are quite a few
   haskellers who use darcs in their day to day (haskell) work. A fair
   number of hackage packages is maintained in darcs. Even though many of
   these repositories are of a relatively modest size, there is a number
   of relatively large real-world darcs repositories out there. The
   primary target of the project is to improve scalability of darcs for
   large working trees. This should help those users with existing large
   darcs repositories, as well as encourage people to use darcs for larger
   projects, whenever the development model fits. I intend to make the
   darcs working tree handling comparably fast to git. And then, git is
   written in C, hand-tuned for a specific operating system. And unlike
   mercurial, I do not plan to introduce a C library for low level
   routines. So let's prove that Haskell is up to the challenge."


   2009.2.1: version freeze for Haskell Platform approaching on Monday.
   Don Stewart [9]announced that the last chance to propose bug fix
   version bumps to be included in the first minor release (2009.2.1) of
   the [10]Haskell Platform is Monday. Please ensure that, as maintainer
   for one of the 2009.2.x series of packages, any bug fixes are in place
   by Monday, or they'll be bumped to the next platform release.

   OpenGL Sven Panne [11]announced the release of a new version
   of the [12]OpenGL package. This is a feature release, containing a
   number of changes and additions.

   Programming in Haskell -- solutions to exercises. Graham Hutton
   [13]announced that solutions to the exercises from "Programming in
   Haskell" are now [14]available online.

   Bookshelf. Emil Axelsson [15]announced the first release of
   [16]Bookshelf, a simple document organizer with some wiki
   functionality. Documents in a directory tree are displayed as a set of
   HTML pages. Documents in Markdown format are converted to HTML
   automatically using Pandoc.

   Request for feedback: HaskellDB + HList. Brian Bloniarz [17]requested
   feedback on a branch of [18]HaskellDB which replaces the home-grown
   Record code with HList records.

   RESTng 0.1 + RedHandlers 0.1 (request handlers) + YuiGrids 0.1 (yahoo
   grids). Sergio Urinovsky [19]announced the release of three new
   packages developed for a RESTful web framework called RESTng:
   [20]RESTng, [21]redHandlers, and [22]yuiGrid.

   #haskell.pt IRC channel. Marco Túlio Gontijo e Silva [23]announced the
   formation of the #haskell.pt channel on irc.freenode.net for
   Portuguese-speaking Haskellers.

   Fun with type functions. Simon Peyton-Jones [24]requested feedback on a
   [25]draft tutorial paper about type families (aka associated data
   types, or type functions).


   conflicting variable definitions in pattern. Martin Hofmann [26]asked
   about the possibility of repeated variables in patterns, resulting in
   an interesting discussion.

   Removing mtl from the Haskell Platform. Russell O'Connor began a
   [27]discussion around the possibility of removing the mtl package from
   the Haskell Platform, and replacing it with something more modern.


   PhD position in Nottingham. vxc [28]announced the availability of a new
   PhD position in the Functional Programming Laboratory at the University
   of Nottingham. The topic of research for the project is "Programming
   and Reasoning with Infinite Structures": it consists in the theoretical
   study and development of software tools for coinductive types and
   structured corecursion.

Blog noise

   [29]Haskell news from the [30]blogosphere. Blog posts from people new
   to the Haskell community are marked with >>>, be sure to welcome them!
     * Leif Frenzel: [31]EclipseFP is going to be reloaded.
     * Tom Schrijvers: [32]Dictionaries: Eager or Lazy Type Class
       Witnesses?. Can type class dictionaries be optimized by treating
       them strictly?
     * Real-World Haskell: [33]RWH Now In The Kindle Store.
     * JP Moresmau: [34]Adding a Writer Monad transformer.
     * Ketil Malde: [35]Using a phantom type to label different kinds of
     * Ivan Lazar Miljenovic: [36]Functions All The Way Down. Ivan's talk
       on lambda calculus.
     * Thomas M. DuBuisson: [37]Fun with Distributed Hash Tables.
       Distributed hash tables in Haskell.
     * Darcs: [38]darcs joins the Software Freedom Conservancy.
     * Mark Wassell: [39]Just Grapefruit. Mark's first impressions of the
       Grapefruit library.
     * Roman Cheplyaka: [40]LambdaCube accepted to JSSP. Jane Street is
       funding development of the LambdaCube 3D rendering engine.
     * >>> Joel Neely: [41]BuilderBuilder: The Model in Haskell.
     * Brandon Simmons: [42]directory-tree module released.
     * >>> Sadek Drobi: [43]Paul Hudak on Haskell. An interview with Paul
     * >>> dayvan cowboy: [44]Blast from the past: a stochastic monad in
     * Matthew Podwysocki: [45]Type Classes Are The Secret Sauce .
     * Remco Niemeijer: [46]Programming Praxis - Priority Queues. A
       priority queue implementation using a leftist heap.
     * >>> Y. Liang: [47]A Lambda Calculus Interpreter in Haskell.

Quotes of the Week

     * seydar: what's the nick of the drug addict who wrote learn you a
       haskell? and i mean that in the best possible way.
     * roconnor: String is kinda a poor data type for strings.
     * kyevan: I had a haskell-related dream last night. Sorta. I was
       beaten up by some kids because I tried to go somewhere my type
       didn't match, apparently.
     * edwardk: Haskell 98 is the Windows 98 of standards ;)
     * PhilipWadler: I'm delighted to learn that "a monad is a monoid in
       the category of endofunctors"---anyone know where I can find a good
     * David Leimbach: Don't play with your monads... eventually you'll go

About the Haskell Weekly News

   New editions are posted to [48]the Haskell mailing list as well as to
   [49]the Haskell Sequence and [50]Planet Haskell. [51]RSS is also
   available, and headlines appear on [52]haskell.org.

   To help create new editions of this newsletter, please see the
   information on [53]how to contribute. Send stories to byorgey at cis
   dot upenn dot edu. The darcs repository is available at darcs get
   [54]http://code.haskell.org/~byorgey/code/hwn/ .


   1. http://haskell.org/
   2. http://haddock2009.wordpress.com/
   3. http://www.haskell.org/haddock/
   4. http://eclipsefp.wordpress.com/
   5. http://just-bottom.blogspot.com/
   6. http://nibrofun.blogspot.com/
   7. http://web.mornfall.net/tag/darcs.html
   8. http://darcs.net/
   9. http://article.gmane.org/gmane.comp.lang.haskell.libraries/11120
  10. http://trac.haskell.org/haskell-platform/
  11. http://article.gmane.org/gmane.comp.lang.haskell.general/17194
  12. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/OpenGL
  13. http://article.gmane.org/gmane.comp.lang.haskell.general/17193
  14. http://www.cs.nott.ac.uk/~gmh/book.html
  15. http://article.gmane.org/gmane.comp.lang.haskell.general/17182
  16. http://www.cs.chalmers.se/~emax/bookshelf/Manual.shelf.html
  17. http://article.gmane.org/gmane.comp.lang.haskell.cafe/58615
  18. http://haskelldb.sourceforge.net/
  19. http://article.gmane.org/gmane.comp.lang.haskell.cafe/58589
  20. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/RESTng
  21. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/redHandlers
  22. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/yuiGrid
  23. http://article.gmane.org/gmane.comp.lang.haskell.cafe/58581
  24. http://article.gmane.org/gmane.comp.lang.haskell.cafe/58522
  25. http://haskell.org/haskellwiki/Simonpj/Talk:FunWithTypeFuns
  26. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/58560
  27. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/58430
  28. http://article.gmane.org/gmane.comp.lang.haskell.cafe/58526
  29. http://planet.haskell.org/
  30. http://haskell.org/haskellwiki/Blog_articles
  31. http://cohatoe.blogspot.com/2009/05/eclipsefp-is-going-to-be-reloaded.html
  32. http://tomschrijvers.blogspot.com/2009/05/dictionaries-eager-or-lazy-type-class.html
  33. http://www.realworldhaskell.org/blog/2009/05/15/rwh-now-in-the-kindle-store/
  34. http://jpmoresmau.blogspot.com/2009/05/adding-writer-monad-transformer.html
  35. http://blog.malde.org/index.php/2009/05/14/using-a-phantom-type-to-label-different-kinds-of-sequences/
  36. http://ivanmiljenovic.wordpress.com/2009/05/14/functions-all-the-way-down/
  37. http://tommd.wordpress.com/2009/05/13/fun-with-distributed-hash-tables/
  38. http://blog.darcs.net/2009/05/darcs-joins-software-freedom.html
  39. http://www.poundstone.org/blog/?p=165
  40. http://physics-dph.blogspot.com/2009/05/lambdacube-accepted-to-jssp.html
  41. http://joelneely.wordpress.com/2009/05/09/builderbuilder-the-model-in-haskell/
  42. http://coder.bsimmons.name/blog/2009/05/directory-tree-module-released/
  43. http://www.infoq.com/interviews/paul-hudak-haskell-Qcon-SF-08
  44. http://dayvancowboy.org/2009/05/08/blast-from-the-past-a-stochastic-monad-in-haskell/
  45. http://codebetter.com/blogs/matthew.podwysocki/archive/2009/05/08/type-classes-are-the-secret-sauce.aspx
  46. http://bonsaicode.wordpress.com/2009/05/05/programming-praxis-priority-queues/
  47. http://yiopposite.blogspot.com/2009/05/lambda-calculus-interpreter-in-haskell.html
  48. http://www.haskell.org/mailman/listinfo/haskell
  49. http://sequence.complete.org/
  50. http://planet.haskell.org/
  51. http://sequence.complete.org/node/feed
  52. http://haskell.org/
  53. http://haskell.org/haskellwiki/HWN
  54. http://code.haskell.org/~byorgey/code/hwn/

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