Welcome to issue 266 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
week of April 7 to 27, 2013.

Quotes of the Week

   * hpc: the dirty secret of haskell programmers is that their power
     does not come from their PhD, but their bowtie

   * tibbe: I think I have implemented a reverse state monad by mistake.
     The numbers suggest I'm getting the values tunneled back from the
     future. :/

   * SaulGorn: A formalist is one who cannot understand a theory unless
     it is meaningless.

   * cmccann: laziness by default is a shortcoming. eagerness by default
     is a bigger shortcoming.

   * monochrom: #haskell-blah has brilliant people too. for example me.

   * limo: OK, guys was nice meeting you and now I'm a proud owner of a
     GHCi icon on my desktop

   * otters: lens law #1: the implementation must be shorter than the
     type

   * MartinDeMello: Any sufficiently well-commented Lisp program
     contains an ML program in its comments.

   * tgeeky: whatever man. Jesus only had twelve or so deciples, lens
     has 80!

   * SatnamSingh: I always thought that category theory was something
     that happened to other people. (#ICFP)

   * cmccann: see the thing is tabs are good for indentation. haskell
     doesn't use indentation, it uses alignment. it is not indenting. it
     is ASCII art.

   * JohnVonNeumann: In mathematics you don't understand things. You
     just get used to them.

   * edwardk: you can view Yoneda f as enforced fmap fusion and
     Codensity f as enforced bind fusion.

Top Reddit Stories

   * Functors, applicatives, and monads in pictures
     Domain: adit.io, Score: 136, Comments: 67
     On Reddit: [1] http://goo.gl/xRC6K
     Original: [2] http://goo.gl/QcfqM

   * What I Wish I Knew When Learning Haskell, Stephen Diehl 
     [39 slides, Left/Rgt-arrow key to back/advance]
     Domain: dev.stephendiehl.com, Score: 119, Comments: 37
     On Reddit: [3] http://goo.gl/T8uzi
     Original: [4] http://goo.gl/eZTA0

   * git clone in Haskell from the bottom up
     Domain: stefan.saasen.me, Score: 86, Comments: 6
     On Reddit: [5] http://goo.gl/Al86J
     Original: [6] http://goo.gl/nWSXV

   * Vinyl: Modern Records for Haskell
     Domain: jonmsterling.com, Score: 56, Comments: 27
     On Reddit: [7] http://goo.gl/pSUph
     Original: [8] http://goo.gl/ra0Jb

   * Follow-up: Web Woes for Haskell
     Domain: self.haskell, Score: 49, Comments: 9
     On Reddit: [9] http://goo.gl/PJZEA
     Original: [10] http://goo.gl/PJZEA

   * What does “coalgebra” mean in the context of programming? (StackOverflow)
     Domain: stackoverflow.com, Score: 45, Comments: 23
     On Reddit: [11] http://goo.gl/nMqBF
     Original: [12] http://goo.gl/UH2Wl

   * The Mother of all Monads - School of Haskell
     Domain: self.haskell, Score: 42, Comments: 27
     On Reddit: [13] http://goo.gl/XO7mQ
     Original: [14] http://goo.gl/XO7mQ

   * Why do all the Haskell Web Frameworks rely on Template Haskell?
     Domain: self.haskell, Score: 40, Comments: 59
     On Reddit: [15] http://goo.gl/v5p6F
     Original: [16] http://goo.gl/v5p6F

   * Job opening for Haskell developer in Nijmegen (NL)
     Domain: self.haskell, Score: 39, Comments: 6
     On Reddit: [17] http://goo.gl/Uzqs8
     Original: [18] http://goo.gl/Uzqs8

   * Tutorial: Building a Sample Application with Haskell Snap, PostgreSQL, 
     and the PostgreSQL Simple Snaplet
     Domain: janrain.com, Score: 39, Comments: 17
     On Reddit: [19] http://goo.gl/TAM6J
     Original: [20] http://goo.gl/37Nry

   * Haskell for all: Defaults
     Domain: haskellforall.com, Score: 38, Comments: 20
     On Reddit: [21] http://goo.gl/7NYex
     Original: [22] http://goo.gl/FqiuW

   * Haskell for all: pipes-concurrency-1.0.0: Reactive programming
     Domain: haskellforall.com, Score: 38, Comments: 23
     On Reddit: [23] http://goo.gl/DaSaZ
     Original: [24] http://goo.gl/eGw3F

   * Haskell in Ipython
     Domain: github.com, Score: 38, Comments: 7
     On Reddit: [25] http://goo.gl/Y7DEP
     Original: [26] http://goo.gl/324JX

   * A taste of Curry (Wolfgang Jeltsch)
     Domain: jeltsch.wordpress.com, Score: 38, Comments: 0
     On Reddit: [27] http://goo.gl/Ijh6Y
     Original: [28] http://goo.gl/17Ry1

   * Complete and Easy Bidirectional Typechecking for Higher-Rank Polymorphism
     Domain: semantic-domain.blogspot.co.uk, Score: 37, Comments: 21
     On Reddit: [29] http://goo.gl/Yv9RY
     Original: [30] http://goo.gl/qW1Qq

   * Template Haskell on impossible architectures (x-post from r/programming)
     Domain: joeyh.name, Score: 37, Comments: 14
     On Reddit: [31] http://goo.gl/m1Jvp
     Original: [32] http://goo.gl/GqiAR

   * inefficient Ackermann implementation not obvious how to improve
     Domain: stackoverflow.com, Score: 37, Comments: 20
     On Reddit: [33] http://goo.gl/CEaOT
     Original: [34] http://goo.gl/JploA

   * Haskell for all: pipes and io-streams
     Domain: haskellforall.com, Score: 37, Comments: 20
     On Reddit: [35] http://goo.gl/fmLhr
     Original: [36] http://goo.gl/8BoLg

   * Build applications with Shake build system
     Domain: lethalman.blogspot.it, Score: 35, Comments: 5
     On Reddit: [37] http://goo.gl/MZBLj
     Original: [38] http://goo.gl/bP7lK

   * What’s in a number? criterion edition
     Domain: serpentine.com, Score: 34, Comments: 6
     On Reddit: [39] http://goo.gl/cfVMa
     Original: [40] http://goo.gl/hqBfW

   * Announcing postgresql-simple 0.3.1
     Domain: blog.melding-monads.com, Score: 34, Comments: 5
     On Reddit: [41] http://goo.gl/LEuEv
     Original: [42] http://goo.gl/jrn5v

   * LGtk: Lens-based Gtk Interface
     Domain: people.inf.elte.hu, Score: 32, Comments: 64
     On Reddit: [43] http://goo.gl/SC7kn
     Original: [44] http://goo.gl/FfYeE

   * Introduction to QuickCheck testing (new FP complete SoH tutorial)
     Domain: fpcomplete.com, Score: 32, Comments: 7
     On Reddit: [45] http://goo.gl/2BnS6
     Original: [46] http://goo.gl/6DKRG

   * Introduction to Haskell, Lecture 12 is Live (Category Theory). 
     This is the last lecture in this series. Thank you for your support!
     Domain: shuklan.com, Score: 31, Comments: 4
     On Reddit: [47] http://goo.gl/to9jd
     Original: [48] http://goo.gl/JZYSv

Top StackOverflow Questions

   * What does “coalgebra” mean in the context of programming?
     votes: 134, answers: 3
     Read on SO: [49] http://goo.gl/UH2Wl

   * Ackermann very inefficient with Haskell/GHC
     votes: 39, answers: 7
     Read on SO: [50] http://goo.gl/JploA

   * How to concisely express function iteration?
     votes: 21, answers: 3
     Read on SO: [51] http://goo.gl/OknK3

   * Does the GHC garbage collector have any special 
     optimisations for large objects?
     votes: 16, answers: 1
     Read on SO: [52] http://goo.gl/p1zvM

   * Parallel computations with fast randomness and purity?
     votes: 16, answers: 4
     Read on SO: [53] http://goo.gl/O3FzX

   * Idiomatic Scala translation of Kiselyov's zippers?
     votes: 15, answers: 1
     Read on SO: [54] http://goo.gl/TCBaL

   * Singleton types in Haskell
     votes: 14, answers: 1
     Read on SO: [55] http://goo.gl/u3867

   * Encoding correctness constraints directly into the Haskell type system?
     votes: 14, answers: 2
     Read on SO: [56] http://goo.gl/in0xv

   * Monad transformers with identity monad
     votes: 12, answers: 2
     Read on SO: [57] http://goo.gl/hx2Ic

   * Extensible Haskell Type Classes
     votes: 12, answers: 4
     Read on SO: [58] http://goo.gl/zdYpL

   * GADT's failed exhaustiveness checking
     votes: 12, answers: 2
     Read on SO: [59] http://goo.gl/GIFDu

   * QuickCheck: Arbitrary instances of nested data structures 
     that generate balanced specimens
     votes: 11, answers: 1
     Read on SO: [60] http://goo.gl/WH3FV

   * What is this special functor structure called?
     votes: 11, answers: 1
     Read on SO: [61] http://goo.gl/cKt7o

Until next time,
[62]+Daniel Santa Cruz

References

   1. http://adit.io/posts/2013-04-17-functors,_applicatives,_and_monads_in_pictures.html
   2. http://www.reddit.com/r/haskell/comments/1co0s5/functors_applicatives_and_monads_in_pictures/
   3. http://dev.stephendiehl.com/hask/
   4. http://www.reddit.com/r/haskell/comments/1cbjqm/what_i_wish_i_knew_when_learning_haskell_stephen/
   5. http://stefan.saasen.me/articles/git-clone-in-haskell-from-the-bottom-up/
   6. http://www.reddit.com/r/haskell/comments/1ch3l2/git_clone_in_haskell_from_the_bottom_up/
   7. http://www.jonmsterling.com/posts/2013-04-06-vinyl-modern-records-for-haskell.html
   8. http://www.reddit.com/r/haskell/comments/1buh5y/vinyl_modern_records_for_haskell/
   9. http://www.reddit.com/r/haskell/comments/1cy58c/followup_web_woes_for_haskell/
  10. http://www.reddit.com/r/haskell/comments/1cy58c/followup_web_woes_for_haskell/
  11. http://stackoverflow.com/questions/16015020/what-does-coalgebra-mean-in-the-context-of-programming
  12. http://www.reddit.com/r/haskell/comments/1cht4v/what_does_coalgebra_mean_in_the_context_of/
  13. http://www.reddit.com/r/haskell/comments/1cyajx/the_mother_of_all_monads_school_of_haskell/
  14. http://www.reddit.com/r/haskell/comments/1cyajx/the_mother_of_all_monads_school_of_haskell/
  15. http://www.reddit.com/r/haskell/comments/1czxvj/why_do_all_the_haskell_web_frameworks_rely_on/
  16. http://www.reddit.com/r/haskell/comments/1czxvj/why_do_all_the_haskell_web_frameworks_rely_on/
  17. http://www.reddit.com/r/haskell/comments/1clkjb/job_opening_for_haskell_developer_in_nijmegen_nl/
  18. http://www.reddit.com/r/haskell/comments/1clkjb/job_opening_for_haskell_developer_in_nijmegen_nl/
  19. http://janrain.com/blog/tutorial-building-a-sample-application-with-haskell-snap-postgresql-and-the-postgresql-simple-snaplet
  20. http://www.reddit.com/r/haskell/comments/1d5c38/tutorial_building_a_sample_application_with/
  21. http://www.haskellforall.com/2013/04/defaults.html
  22. http://www.reddit.com/r/haskell/comments/1c2g1r/haskell_for_all_defaults/
  23. http://www.haskellforall.com/2013/04/pipes-concurrency-100-reactive.html?m=1
  24. http://www.reddit.com/r/haskell/comments/1cc6fe/haskell_for_all_pipesconcurrency100_reactive/
  25. https://github.com/creswick/ihaskell-notebook
  26. http://www.reddit.com/r/haskell/comments/1d0151/haskell_in_ipython/
  27. http://jeltsch.wordpress.com/2013/04/27/a-taste-of-curry/
  28. http://www.reddit.com/r/haskell/comments/1d8n51/a_taste_of_curry_wolfgang_jeltsch/
  29. http://semantic-domain.blogspot.co.uk/2013/04/thanks-to-olle-fredriksson.html
  30. http://www.reddit.com/r/haskell/comments/1c50t3/complete_and_easy_bidirectional_typechecking_for/
  31. http://joeyh.name/blog/entry/Template_Haskell_on_impossible_architectures/
  32. http://www.reddit.com/r/haskell/comments/1cm4n1/template_haskell_on_impossible_architectures/
  33. http://stackoverflow.com/questions/16115815/ackermann-very-inefficient-with-haskell-ghc
  34. http://www.reddit.com/r/haskell/comments/1cq3r4/inefficient_ackermann_implementation_not_obvious/
  35. http://www.haskellforall.com/2013/04/pipes-and-io-streams.html
  36. http://www.reddit.com/r/haskell/comments/1ct65e/haskell_for_all_pipes_and_iostreams/
  37. http://lethalman.blogspot.it/2013/04/build-vala-applications-with-shake.html
  38. http://www.reddit.com/r/haskell/comments/1bv703/build_applications_with_shake_build_system/
  39. http://www.serpentine.com/blog/2013/04/13/whats-in-a-number-criterion-edition/
  40. http://www.reddit.com/r/haskell/comments/1cauc5/whats_in_a_number_criterion_edition/
  41. http://blog.melding-monads.com/2013/04/27/announcing-postgresql-simple-0-3-1/
  42. http://www.reddit.com/r/haskell/comments/1d8mf1/announcing_postgresqlsimple_031/
  43. http://people.inf.elte.hu/divip/LGtk.html
  44. http://www.reddit.com/r/haskell/comments/1cemr2/lgtk_lensbased_gtk_interface/
  45. https://www.fpcomplete.com/user/pbv/an-introduction-to-quickcheck-testing
  46. http://www.reddit.com/r/haskell/comments/1cus3k/introduction_to_quickcheck_testing_new_fp/
  47. http://shuklan.com/haskell/lec12.html
  48. http://www.reddit.com/r/haskell/comments/1c00tj/introduction_to_haskell_lecture_12_is_live/
  49. http://stackoverflow.com/questions/16015020/what-does-coalgebra-mean-in-the-context-of-programming
  50. http://stackoverflow.com/questions/16115815/ackermann-very-inefficient-with-haskell-ghc
  51. http://stackoverflow.com/questions/16010778/how-to-concisely-express-function-iteration
  52. http://stackoverflow.com/questions/16186488/does-the-ghc-garbage-collector-have-any-special-optimisations-for-large-objects
  53. http://stackoverflow.com/questions/16248600/parallel-computations-with-fast-randomness-and-purity
  54. http://stackoverflow.com/questions/15940473/idiomatic-scala-translation-of-kiselyovs-zippers
  55. http://stackoverflow.com/questions/16017294/singleton-types-in-haskell
  56. http://stackoverflow.com/questions/16207008/encoding-correctness-constraints-directly-into-the-haskell-type-system
  57. http://stackoverflow.com/questions/15946633/monad-transformers-with-identity-monad
  58. http://stackoverflow.com/questions/15967167/extensible-haskell-type-classes
  59. http://stackoverflow.com/questions/16225281/gadts-failed-exhaustiveness-checking
  60. http://stackoverflow.com/questions/15959357/quickcheck-arbitrary-instances-of-nested-data-structures-that-generate-balanced
  61. http://stackoverflow.com/questions/16123588/what-is-this-special-functor-structure-called
  62. https://plus.google.com/105107667630152149014/about