Welcome to issue 214 the HWN, a newsletter covering stories, questions, and remarks seen around the web during the week of January 29 to February 4, 2012. You can find the HTML version at: http://contemplatecode.blogspot.com/2012/02/haskell-weekly-news-issue-214.ht... Quotes of the Week * Jafet: [on memoising an O(n) algorithm:] This is like trying to save work in a police investigation by having each detective determine whether another detective has already removed all evidence from his area by walking through it to search for evidence in the area. * CodeWeaver: keep in mind encryption's only as good as how much you trust that the implementors got it right. * cmccann: length [1..10^20] lambdabot: mueval-core: Time limit exceeded cmccann: looks like 10^20 is infinity * elliott: race condition waiting to happen * elliott: o'reilly publishes attoparsec tutorial: exactly the same as their parsec tutorial, but 10^-18th the size * rwbarton: Num works for Float/Double, it's Float/Double that doesn't work for Num * ddarius: Space isn't that big. * Brent Yorgey: > Sometimes, I suspect that Haskell not only makes easier of the hard > things for imperative programming languages but also makes harder of > some easy things. This is true. But usually these are things that you don't *want* to be easy, like shooting yourself in the kidney. (But these features are often described in ways that make them sound great, like "flexible usage of bullet-placement tools".) Inserting arbitrary print statements into the middle of some code is difficult for a reason. Top Reddit Stories * GHC 7.4.1 is out. Here's the release notes Domain: haskell.org, Score: 107, Comments: 59 On Reddit: [1] http://goo.gl/su4jl Original: [2] http://goo.gl/Nstve * Coming soon, to a bookstore near you Domain: yesodweb.com, Score: 82, Comments: 16 On Reddit: [3] http://goo.gl/6gZXg Original: [4] http://goo.gl/zSW1l * ImplicitCAD is a Programmatic CAD Tool/3D Modelling Engine in Haskell. Also my first big Haskell project. Feedback, advice? Domain: github.com, Score: 63, Comments: 23 On Reddit: [5] http://goo.gl/YHMRa Original: [6] http://goo.gl/39rc3 * Using monadic effects to reverse a merge sort Domain: github.com, Score: 42, Comments: 4 On Reddit: [7] http://goo.gl/dVuyp Original: [8] http://goo.gl/jL9qj * Exciting changes coming to conduit 0.2 Domain: yesodweb.com, Score: 38, Comments: 7 On Reddit: [9] http://goo.gl/neyW2 Original: [10] http://goo.gl/1ikN5 * Vectorisation without Replication in Data Parallel Haskell Domain: disciple-devel.blogspot.com, Score: 35, Comments: 4 On Reddit: [11] http://goo.gl/iJ4OD Original: [12] http://goo.gl/uMp4S * If software purity in functional languages is such an awesome idea, why are we still writing Python, Ruby or Java? Domain: self.haskell, Score: 33, Comments: 136 On Reddit: [13] http://goo.gl/F0QCY Original: [14] http://goo.gl/F0QCY * Released Data.Array.Accelerate 0.9.0.0 — the Haskell array library for GPUs Domain: justtesting.org, Score: 32, Comments: 3 On Reddit: [15] http://goo.gl/NqUwp Original: [16] http://goo.gl/JYTQ4 * Fun With -XPolyKinds : Polykinded Folds Domain: typesandotherdistractions.com, Score: 24, Comments: 1 On Reddit: [17] http://goo.gl/daxL8 Original: [18] http://goo.gl/u9gHi * Introduction to using acid-state, IxSet and data-lens as a native Haskell, noSQL, RAM-cloud database Domain: happstack.com, Score: 23, Comments: 21 On Reddit: [19] http://goo.gl/9bliO Original: [20] http://goo.gl/ZGXyW * Can't wait for the Haskell Platform? -- Compiling GHC 7.4.1 from source has never been easier. Domain: blog.jasonknight.us, Score: 21, Comments: 8 On Reddit: [21] http://goo.gl/IKjm6 Original: [22] http://goo.gl/dgMF2 * Generating random functions Domain: mainisusuallyafunction.blogspot.com, Score: 20, Comments: 6 On Reddit: [23] http://goo.gl/DB4f6 Original: [24] http://goo.gl/aOAPo * How to deal with undesired values when designing types Domain: self.haskell, Score: 19, Comments: 28 On Reddit: [25] http://goo.gl/aPCbQ Original: [26] http://goo.gl/aPCbQ * Guarded Pipes or How to write Conduit.List Combinators in Pipes. Domain: pcapriotti.wordpress.com, Score: 17, Comments: 16 On Reddit: [27] http://goo.gl/vo8ip Original: [28] http://goo.gl/mhnfH * UHC JavaScript Backend Project Page (Work in Progress) Domain: uu-computerscience.github.com, Score: 16, Comments: 0 On Reddit: [29] http://goo.gl/42xXs Original: [30] http://goo.gl/Cz8R6 Top StackOverflow Questions * What are the rules about concurrently accessing a persistent database votes: 17, answers: 1 Read on SO: [31] http://goo.gl/m3QhB * Functions don't just have types: They ARE Types. And Kinds. And Sorts. Help put a blown mind back together votes: 15, answers: 2 Read on SO: [32] http://goo.gl/fKjQR * Defining polymorphic constants in Haskell votes: 12, answers: 2 Read on SO: [33] http://goo.gl/3H3ke * Do guarded pipes behave the same as pipes using await? votes: 12, answers: 2 Read on SO: [34] http://goo.gl/Mf3HQ * What is the purpose of the IdentityT transformer? votes: 11, answers: 2 Read on SO: [35] http://goo.gl/L7Syk * call/cc implementation? votes: 10, answers: 5 Read on SO: [36] http://goo.gl/tfLLz * Understanding bind function in Haskell votes: 9, answers: 4 Read on SO: [37] http://goo.gl/amtSd * How to show that a monad is a functor and an applicative functor? votes: 8, answers: 2 Read on SO: [38] http://goo.gl/Cg0EQ * Avoiding lift with Monad Transformers votes: 7, answers: 2 Read on SO: [39] http://goo.gl/fBhCz * Container element types votes: 7, answers: 1 Read on SO: [40] http://goo.gl/UfZnG Until next time, Daniel Santa Cruz References 1. http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/release-7-4-1.html 2. http://www.reddit.com/r/haskell/comments/p886g/ghc_741_is_out_heres_the_rele... 3. http://www.yesodweb.com/blog/2012/01/coming-soon 4. http://www.reddit.com/r/haskell/comments/p4hpt/coming_soon_to_a_bookstore_ne... 5. https://github.com/colah/ImplicitCAD 6. http://www.reddit.com/r/haskell/comments/p9jzh/implicitcad_is_a_programmatic... 7. https://github.com/DanBurton/Blog/blob/master/Literate%20Haskell/recovery.lh... 8. http://www.reddit.com/r/haskell/comments/p2kar/using_monadic_effects_to_reve... 9. http://www.yesodweb.com/blog/2012/01/conduit-changes-0-2 10. http://www.reddit.com/r/haskell/comments/p1iu0/exciting_changes_coming_to_co... 11. http://disciple-devel.blogspot.com/2012/02/vectorisation-without-replication... 12. http://www.reddit.com/r/haskell/comments/p7f6u/vectorisation_without_replica... 13. http://www.reddit.com/r/haskell/comments/pavb1/if_software_purity_in_functio... 14. http://www.reddit.com/r/haskell/comments/pavb1/if_software_purity_in_functio... 15. http://justtesting.org/released-dataarrayaccelerate-0900-the-haskell 16. http://www.reddit.com/r/haskell/comments/p5sij/released_dataarrayaccelerate_... 17. http://www.typesandotherdistractions.com/2012/02/fun-with-xpolykinds-polykin... 18. http://www.reddit.com/r/haskell/comments/p8djh/fun_with_xpolykinds_polykinde... 19. http://www.happstack.com/docs/crashcourse/AcidState.html 20. http://www.reddit.com/r/haskell/comments/p75ko/introduction_to_using_acidsta... 21. http://blog.jasonknight.us/2012/02/how-to-install-ghc-741-in-ubuntu-from.htm... 22. http://www.reddit.com/r/haskell/comments/pabfi/cant_wait_for_the_haskell_pla... 23. http://mainisusuallyafunction.blogspot.com/2012/02/generating-random-functio... 24. http://www.reddit.com/r/haskell/comments/p89fq/generating_random_functions/ 25. http://www.reddit.com/r/haskell/comments/p5lv0/how_to_deal_with_undesired_va... 26. http://www.reddit.com/r/haskell/comments/p5lv0/how_to_deal_with_undesired_va... 27. http://pcapriotti.wordpress.com/2012/02/02/an-introduction-to-guarded-pipes/ 28. http://www.reddit.com/r/haskell/comments/p8g55/guarded_pipes_or_how_to_write... 29. http://uu-computerscience.github.com/uhc-js/ 30. http://www.reddit.com/r/haskell/comments/p1nqh/uhc_javascript_backend_projec... 31. http://stackoverflow.com/questions/9055214/what-are-the-rules-about-concurre... 32. http://stackoverflow.com/questions/9074261/functions-dont-just-have-types-th... 33. http://stackoverflow.com/questions/9088821/defining-polymorphic-constants-in... 34. http://stackoverflow.com/questions/9145656/do-guarded-pipes-behave-the-same-... 35. http://stackoverflow.com/questions/9122825/what-is-the-purpose-of-the-identi... 36. http://stackoverflow.com/questions/9050725/call-cc-implementation 37. http://stackoverflow.com/questions/9074284/understanding-bind-function-in-ha... 38. http://stackoverflow.com/questions/9098247/how-to-show-that-a-monad-is-a-fun... 39. http://stackoverflow.com/questions/9054731/avoiding-lift-with-monad-transfor... 40. http://stackoverflow.com/questions/9078168/container-element-types