Welcome to issue 271 of the HWN, an issue covering crowd-sourced bits

of information about Haskell from around the web. This issue covers the

week of June 9 to 11, 2013.

Quotes of the Week

* cmccann: also please note that "malign" remains one of my best

function names ever

* dolio: Peak file descriptors is a myth.

* mami: i think my brain rewired for higher typesystem compatibility

in my sleep

* elliott: it's impure but only depending on the environment! which

is to say it is impure.

* johnw: lens makes one into a mutating ninja

* applicativ: een my language we say Z for one

* DavidJacobs: Code is like poetry; most of it shouldn't have been

written.

* merijn: If I could program with arbitrary real world side effects

I'd use "unsafeStabComputerUser" if someone attempted that

* shachaf: Hackage going down regularly is part of the rustic charm

of Haskell!

* shachaf: JavaScript is the best example of a domain-specific

language. Because of the same-origin policy.

* chrisdone: [on being invited to help with idris development] dude

i've already got 20 yaks lined up waiting to be shaved, don't send

me a whole truck full

* shachaf: edwardk isn't benevolent or malevolent. edwardk is more of

a simple mechanical process tending toward maximal complexity.

* AndrejBauer: When have you ever heard a category theorist say: I

want to prove this diagram commutesâLet's suppose it doesn't.

Top StackOverflow Questions

* How to compare two functions for equivalence, as in (λx.2*x) == (λx.x+x)?

votes: 15, answers: 2

Read on SO: [31] http://goo.gl/A6YDd

* Should I use typeclasses or not?

votes: 15, answers: 2

Read on SO: [32] http://goo.gl/EOV1M

* Is there something like `map2 :: (i -> a) -> (i -> b) -> [i] -> [(a,b)]`?

votes: 11, answers: 2

Read on SO: [33] http://goo.gl/WZyEy

* Why isn't GeneralizedNewtypeDeriving a Safe Haskell?

votes: 11, answers: 1

Read on SO: [34] http://goo.gl/on6Fc

* It's not a monad, but what is it?

votes: 10, answers: 0

Read on SO: [35] http://goo.gl/sm9gR

* Writing efficient iterative loop for ST monad

votes: 10, answers: 0

Read on SO: [36] http://goo.gl/WAAwA

* Getting multiple results from map with “lens”

votes: 10, answers: 2

Read on SO: [37] http://goo.gl/zqX8E

* How to run Frege programs on Android?

votes: 10, answers: 2

Read on SO: [38] http://goo.gl/XlSCN

* Are there problems that can't be solved efficiently without arrays? [duplicate]

votes: 9, answers: 0

Read on SO: [39] http://goo.gl/Z5j9a

* Haskell: How to organize a group of functions that all take the same arguments

votes: 9, answers: 4

Read on SO: [40] http://goo.gl/z64H7

Until next time,

[41]+Daniel Santa Cruz

References

1. http://www.haskell.org/haskellwiki/Functor-Applicative-Monad_Proposal

2. http://www.reddit.com/r/haskell/comments/1gsejt/applicative_monad_is_coming/

3. http://homotopytypetheory.org/book/

4. http://www.reddit.com/r/haskell/comments/1gr3uw/the_homotopy_type_theory_book_is_now_available/

5. http://adit.io/posts/2013-06-10-three-useful-monads.html

6. http://www.reddit.com/r/haskell/comments/1g3a7e/three_useful_monads/

7. https://www.fpcomplete.com/blog/2013/06/beta-sign-up

8. http://www.reddit.com/r/haskell/comments/1giy7l/beta_sign_up_for_fp_complete_new_ide/

9. http://izbicki.me/blog/hlearns-code-is-shorter-and-clearer-than-wekas

10. http://www.reddit.com/r/haskell/comments/1g4v7u/hlearn_implements_more_with_6_trivial_lines_of/

11. http://www.reddit.com/r/haskell/comments/1g5k80/top_secret_school_of_haskell_articles_leaked/

12. http://www.reddit.com/r/haskell/comments/1g5k80/top_secret_school_of_haskell_articles_leaked/

13. https://www.fpcomplete.com/user/bartosz/understanding-algebras

14. http://www.reddit.com/r/haskell/comments/1g2g3s/falgebra_tutorial/

15. http://www.reddit.com/r/haskell/comments/1g1mvx/john_carmack_on_haskell_today/

16. http://www.reddit.com/r/haskell/comments/1g1mvx/john_carmack_on_haskell_today/

17. http://justtesting.org/post/53175916852/data-flow-fusion-with-series-expressions-in-haskell

18. http://www.reddit.com/r/haskell/comments/1gi5m1/data_flow_fusion_with_series_expressions_in/

19. http://akgupta.ca/blog/2013/05/14/so-you-still-dont-understand-hindley-milner/

20. http://www.reddit.com/r/haskell/comments/1g0ueo/so_you_still_dont_understand_hindleymilner_part_1/

21. https://news.ycombinator.com/item?id=5893442

22. http://www.reddit.com/r/haskell/comments/1gknfs/ask_hn_any_downsides_of_programming_in_haskell/

23. https://www.youtube.com/watch?v=Fqi0Xu2Enaw

24. http://www.reddit.com/r/haskell/comments/1glw2o/fp_complete_haskell_introduction/

25. https://github.com/keera-studios/keera-posture

26. http://www.reddit.com/r/haskell/comments/1gr044/fix_your_posture_with_haskell/

27. https://github.com/gasche/icfp2013-papers#readme

28. http://www.reddit.com/r/haskell/comments/1gg2xf/preprint_list_for_icfp13_papers_additional_links/

29. https://github.com/ghc/ghc/commit/569b26526403df4d88fe2a6d64c7dade09d003ad

30. http://www.reddit.com/r/haskell/comments/1gu2yl/ghc_now_with_closed_type_families/

31. http://stackoverflow.com/questions/17045941/how-to-compare-two-functions-for-equivalence-as-in-x-2x-x-xx

32. http://stackoverflow.com/questions/17100036/should-i-use-typeclasses-or-not

33. http://stackoverflow.com/questions/17074424/is-there-something-like-map2-i-a-i-b-i-a-b

34. http://stackoverflow.com/questions/17137111/why-isnt-generalizednewtypederiving-a-safe-haskell

35. http://stackoverflow.com/questions/17034427/its-not-a-monad-but-what-is-it

36. http://stackoverflow.com/questions/17126923/writing-efficient-iterative-loop-for-st-monad

37. http://stackoverflow.com/questions/17144334/getting-multiple-results-from-map-with-lens

38. http://stackoverflow.com/questions/17222383/how-to-run-frege-programs-on-android

39. http://stackoverflow.com/questions/17128103/are-there-problems-that-cant-be-solved-efficiently-without-arrays

40. http://stackoverflow.com/questions/17176829/haskell-how-to-organize-a-group-of-functions-that-all-take-the-same-arguments

41. https://plus.google.com/105107667630152149014/about