[Haskell-cafe] Haskell Weekly News: Issue 155 - October 20, 2010

Daniel Santa Cruz dstcruz at gmail.com
Wed Oct 20 18:00:45 EDT 2010

   Welcome to issue 155 of the HWN, a newsletter covering developments in
   the [1]Haskell community in the week of October 10 - 16.

   This time around we again have 87 posts to HackageDB. Instead of
   posting the individual packages, we get to see and celebrate the 43
   people behind these efforts.

   Want to keep a close eye on the haskellers that lurk twitter? Don
   Steward made [2]a twitter list of tweeting haskellers! Let him know if
   you'd like to be added to the list.

   There were a total of 24 new stories posted to the Haskell Reddit
   channel, 27 new questions taged with Haskell in StackOverflow, and 408
   messages posted to Haskell-Cafe.

   So, what was hot last week?


   Gregory Crosswhite is pleased to [3]announce the release of a family of
   packages for type-level natural numbers. He also [4]announced
   tagged-list, a package which provides fixed-length lists that are
   tagged with a phantom type-level natural number corresponding to the

   Janis Voigtlander [5]announced that it is time to collect contributions
   for the 19th edition of the Haskell Communities & Activities Report.
   The submission deadline is November 1, 2010.

   Alexander Solla [6]announced his new "Facts" library. The Facts
   hierarchy is meant to contain commonly used, relatively static facts
   about the "real world."

   Kevin Jardine [7]announced polyToMonoid: a library that supplies two
   very general polyvariadic functions that can map their arguments into
   any monoid you specify.

   Simon Hengel [8]announced a new version of DocTest. DocTest now uses
   Haddock for parsing of comments.

Interesting Threads on Haskell-Cafe

   Michael Snoyman [9]reported that Haskellers.com has become popular a
   lot falter that he anticipated. Read up on what changes are planned for
   Haskellers.com. Michael is very interested in some help with running
   the site.

   Jacek Generowicz [10]asked how to deal with dynamic dispatch on
   extensible sets of types.

   Uwe Schmidt [11]replied to a question about why HXT uses arrows as
   opposed to using monads. Good comments followed.

   Jason Dusek [12]asked if there is a way to write a Haskell data
   structure that is necessarily only one or two or seventeen items long;
   but that is nonetheless statically guaranteed to be of finite length?
   Twenty-three messages followed.

   Simon Thompson [13]annouced the availability of books for review for
   the Journal of Functonial Programming.

   Andrew Copping [14]summarized a report produced by Google Szwitzerland
   on taking a Python system and rewriting bits of it in Haskell, some of
   which is now in production use.

   Ben Franksen [15]ranted about the current "Haskell Blurb" on the first
   paragraph of haskell.org. Quite the read to end the week :)

Top Reddit Stories

  * Using Haskell’s ‘newtype’ in C
    Domain: blog.nelhage.com
    Score: 37, Comments: 5
    On Reddit: http://www.reddit.com/r/haskell/comments/dptzh/using_haskells_newtype_in_c/
    Original: http://blog.nelhage.com/2010/10/using-haskells-newtype-in-c/

  * The Haskell theme: consistent visual branding for Haskell
    Domain: haskell.org
    Score: 34, Comments: 11
    On Reddit: http://www.reddit.com/r/haskell/comments/dqiej/the_haskell_theme_consistent_visual_branding_for/
    Original: http://www.haskell.org/pipermail/haskell-cafe/2010-October/084781.html

  * Haskellers: Survey results and new site features
    Domain: haskellers.com
    Score: 22, Comments: 6
    On Reddit: http://www.reddit.com/r/haskell/comments/dr37b/haskellers_survey_results_and_new_site_features/
    Original: http://www.haskellers.com/news/1/

  * My Experience Learning Haskell
    Domain: blog.virtucal.com
    Score: 21, Comments: 6
    On Reddit: http://www.reddit.com/r/haskell/comments/drgcz/my_experience_learning_haskell/
    Original: http://blog.virtucal.com/cyclical/2010/10/14/my-experience-learning-haskell.html

  * Invertible monads for exception handling and memory allocations
    Domain: docs.yesodweb.com
    Score: 21, Comments: 0
    On Reddit: http://www.reddit.com/r/haskell/comments/drkdj/invertible_monads_for_exception_handling_and/
    Original: http://docs.yesodweb.com/blog/invertible-monads-exceptions-allocations/

  * Accelerating Haskell Array Codes with Multicore GPUs
    Domain: justtesting.org
    Score: 19, Comments: 0
    On Reddit: http://www.reddit.com/r/haskell/comments/dq1yo/accelerating_haskell_array_codes_with_multicore/
    Original: http://justtesting.org/accelerating-haskell-array-codes-with-multico

  * Unicode text performance improvements
    Domain: serpentine.com
    Score: 17, Comments: 1
    On Reddit: http://www.reddit.com/r/haskell/comments/drinz/unicode_text_performance_improvements/
    Original: http://www.serpentine.com/blog/2010/10/15/unicode-text-performance-improvements/

  * Like a coding challenge? Check out Code Quarterly!
    Domain: serpentine.com
    Score: 16, Comments: 9
    On Reddit: http://www.reddit.com/r/haskell/comments/dpjgv/like_a_coding_challenge_check_out_code_quarterly/
    Original: http://www.serpentine.com/blog/2010/10/11/like-a-coding-challenge-check-out-code-quarterly/

  * C9 Lecture: Ralf Lämmel on Monads
    Domain: channel9.msdn.com
    Score: 16, Comments: 0
    On Reddit: http://www.reddit.com/r/haskell/comments/dq614/c9_lecture_ralf_lämmel_on_monads/
    Original: http://channel9.msdn.com/Shows/Going+Deep/C9-Lectures-Dr-Ralf-Lmmel-AFP-The-Quick-Essence-of-Functional-Programming

  * Take the Haskellers.com survey
    Domain: spreadsheets.google.com
    Score: 15, Comments: 3
    On Reddit: http://www.reddit.com/r/haskell/comments/dq7xj/take_the_haskellerscom_survey/
    Original: https://spreadsheets.google.com/viewform?formkey=dG8tcVhBdzRSS1lkdVV6U281emtRMWc6MQ

Top StackOverflow Questions

  * When is memoization automatic in GHC Haskell?
    Question (votes: 14, answers: 3)

  * Why is my code using monadic lists from the List package so slow?
    Question (votes: 12, answers: 3)

  * Haskell: lift vs liftIO
    Question (votes: 8, answers: 2)

  * Can anyone suggest a good constraint library for Haskell?
    Question (votes: 8, answers: 2)

  * Library function to compose a function with itself n times
    Question (votes: 6, answers: 4)

  * Evaluation of a small math type language that supports one variable
    Question (votes: 5, answers: 1)

  * What's the difference of  a “class” in Haskell and in an “abstract
class” in OO language?
    Question (votes: 5, answers: 4)

  * Haskell and State
    Question (votes: 5, answers: 4)

  * Can Haskell guard on abstract data types in a polymorphic function?
    Question (votes: 5, answers: 3)

 Quotes of the Week

   * pumpkin: sounds like a lot of work! it's easier for me to just
     bitch about it
   * OlegKiselyov: Haskell is inconsistent in yet another way.
   * monochrom: just add #! /usr/bin/runghc to your haskell file. then
     type errors occur at runtime only.
   * IIcke: [haskell] is like wearing a corset, at the beginning is
     annoying, but then your tits look bigger and the world becomes a
     better place

Contributors to HackageDB

   Who contributed, and how many uploads did they make?

   MichaelSnoyman (14), BryanOSullivan (11), GregoryCrosswhite (5),
   AndyStewart (5), GregoryCollins (4), JosePedroMagalhaes (3),
   StephenBlackheath (2), SjoerdVisscher (2), PaulTalaga (2), MichaelZuo (2),
   DanielDiaz (2), ConalElliott (2), AristidBreitkreuz (2),
   AlexanderSolla (2), YuriyIskra (1), VivianMcPhail (1), TristanSkudlik (1),
   TonyMorris (1), StephenTetley (1), SimonHengel (1), ReinierLamers (1),
   OlegBelozeorov (1), NeilMitchell (1), MaxBolingbroke (1),
   MatthiasBartsch (1), MatthewSottile (1), MasatakeDaimon (1),
   MarkSnyder (1), ManuelChakravarty (1), LeePike (1), KiYungAhn (1),
   KevinJardine (1), JustinBailey (1), IlyaPortnov (1), GeoffHulette (1),
   EugeneKirpichov (1), DonaldStewart (1), DanielSeidel (1), DanielSchoepe (1),
   CarlHowells (1), BenFranksen (1), ArieMiddelkoop (1), AlexSuraci (1)

About the Haskell Weekly News

   New editions are posted to [16]the Haskell mailing list as well as to
   [17]the Haskell Sequence and [18]Planet Haskell. [19]RSS is also
   available, and headlines appear on [20]haskell.org.

   To help create new editions of this newsletter, please send stories to
   dstcruz * at * gmail * dot * com. The code used to produce this version
   of the newsletter is not yet publicly available, as it is a complete
   hack designed to get things started again.

   Until next time,
   Daniel Santa Cruz


   1. http://haskell.org/
   2. http://twitter.com/#!/donsbot/haskellers
   3. http://groups.google.com/group/haskell-cafe/browse_thread/thread/c0071547638d7cb0
   4. http://groups.google.com/group/haskell-cafe/browse_thread/thread/ff95d6c78ded677f
   5. http://groups.google.com/group/haskell-cafe/msg/d9d227b0f38bcf51
   6. http://groups.google.com/group/haskell-cafe/browse_thread/thread/fc86bd03d091c4bf
   7. http://groups.google.com/group/haskell-cafe/browse_thread/thread/4ba5741441d7bb33
   8. http://groups.google.com/group/haskell-cafe/browse_thread/thread/7982f0ad3bc9ce1d
   9. http://groups.google.com/group/haskell-cafe/browse_thread/thread/2440a1683fe3e739
  10. http://groups.google.com/group/haskell-cafe/browse_thread/thread/f0a05dd5b58dc3d2
  11. http://groups.google.com/group/haskell-cafe/browse_thread/thread/38185e7ba6509563/c6063929f39a7197?#c6063929f39a7197
  12. http://groups.google.com/group/haskell-cafe/browse_thread/thread/7ba4b3b0386fb3d6
  13. http://www.cs.kent.ac.uk/people/staff/sjt/JFP/available.html
  14. http://groups.google.com/group/haskell-cafe/browse_thread/thread/81707fea2b1568ee
  15. http://groups.google.com/group/haskell-cafe/browse_thread/thread/a7c7b569dd524934
  16. http://www.haskell.org/mailman/listinfo/haskell
  17. http://sequence.complete.org/
  18. http://planet.haskell.org/
  19. http://sequence.complete.org/node/feed
  20. http://haskell.org/

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