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? Announcements 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 length. 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_... 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... 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_haskel... Original: http://blog.virtucal.com/cyclical/2010/10/14/my-experience-learning-haskell.... * 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_excepti... 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_co... 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_impr... Original: http://www.serpentine.com/blog/2010/10/15/unicode-text-performance-improveme... * 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... Original: http://www.serpentine.com/blog/2010/10/11/like-a-coding-challenge-check-out-... * 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-... * 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=dG8tcVhBdzRSS1lkdVV6U281emt... Top StackOverflow Questions * When is memoization automatic in GHC Haskell? Question (votes: 14, answers: 3) http://stackoverflow.com/questions/3951012/when-is-memoization-automatic-in-... * Why is my code using monadic lists from the List package so slow? Question (votes: 12, answers: 3) http://stackoverflow.com/questions/3916444/why-is-my-code-using-monadic-list... * Haskell: lift vs liftIO Question (votes: 8, answers: 2) http://stackoverflow.com/questions/3921237/haskell-lift-vs-liftio * Can anyone suggest a good constraint library for Haskell? Question (votes: 8, answers: 2) http://stackoverflow.com/questions/3926656/can-anyone-suggest-a-good-constra... * Library function to compose a function with itself n times Question (votes: 6, answers: 4) http://stackoverflow.com/questions/3911060/library-function-to-compose-a-fun... * Evaluation of a small math type language that supports one variable Question (votes: 5, answers: 1) http://stackoverflow.com/questions/3906231/evaluation-of-a-small-math-type-l... * What's the difference of a “class” in Haskell and in an “abstract class” in OO language? Question (votes: 5, answers: 4) http://stackoverflow.com/questions/3938779/whats-the-difference-of-a-class-i... * Haskell and State Question (votes: 5, answers: 4) http://stackoverflow.com/questions/3944170/haskell-and-state * Can Haskell guard on abstract data types in a polymorphic function? Question (votes: 5, answers: 3) http://stackoverflow.com/questions/3944756/can-haskell-guard-on-abstract-dat... 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 References 1. http://haskell.org/ 2. http://twitter.com/#!/donsbot/haskellers 3. http://groups.google.com/group/haskell-cafe/browse_thread/thread/c0071547638... 4. http://groups.google.com/group/haskell-cafe/browse_thread/thread/ff95d6c78de... 5. http://groups.google.com/group/haskell-cafe/msg/d9d227b0f38bcf51 6. http://groups.google.com/group/haskell-cafe/browse_thread/thread/fc86bd03d09... 7. http://groups.google.com/group/haskell-cafe/browse_thread/thread/4ba5741441d... 8. http://groups.google.com/group/haskell-cafe/browse_thread/thread/7982f0ad3bc... 9. http://groups.google.com/group/haskell-cafe/browse_thread/thread/2440a1683fe... 10. http://groups.google.com/group/haskell-cafe/browse_thread/thread/f0a05dd5b58... 11. http://groups.google.com/group/haskell-cafe/browse_thread/thread/38185e7ba65... 12. http://groups.google.com/group/haskell-cafe/browse_thread/thread/7ba4b3b0386... 13. http://www.cs.kent.ac.uk/people/staff/sjt/JFP/available.html 14. http://groups.google.com/group/haskell-cafe/browse_thread/thread/81707fea2b1... 15. http://groups.google.com/group/haskell-cafe/browse_thread/thread/a7c7b569dd5... 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/