<div>Welcome to issue 220 of the HWN, an issue covering crowd-sourced bits</div><div>of information about Haskell from around the web. This issue covers the</div><div>week of March 18 to 24, 2012.</div><div><br></div><div>

Quotes of the Week</div><div><br></div><div>&nbsp; &nbsp;* shachaf: Type classes are a scary story that you tell new</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Haskellers so they can go to sleep at night.</div><div><br></div><div>&nbsp; &nbsp;* acowley: Parametric polymorphism is the inspiring story you tell</div>

<div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; them to get them riled up and raring to go.&nbsp;</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; It&#39;s like Braveheart for programmers.</div><div><br></div><div>&nbsp; &nbsp;* monochrom: the purpose of types is to ban more programs</div>

<div><br></div><div>&nbsp; &nbsp;* rostayob: I was a type constructor, then I took an arrow in the</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;kind</div><div><br></div><div>&nbsp; &nbsp;* shachaf: @let otherfoolish = not otherwise</div><div><br></div><div>&nbsp; &nbsp;* flebron: Monoidal objects in the monoidal category of endofunctors</div>

<div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; on a category. I took a small detour through tensor&nbsp;</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; products to understand monoidal categories better, with</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one example of such a product.</div><div>&nbsp; &nbsp; &nbsp;mauke: I have no idea what you just said</div>

<div><br></div><div>&nbsp; &nbsp;* weexplat: starts a proposal to replace launchMissiles with</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;atomicDestroyBiosphere</div><div><br></div><div>&nbsp; &nbsp;* monochrom: rumour: SPJ will write a thick book &quot;A New Science of</div>

<div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Kind&quot;</div><div><br></div><div>&nbsp; &nbsp;* JonathanShapiro: [on abandoning BitC] &quot;And I *still* don&#39;t believe</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; in monads. :-)&quot;</div><div><br></div><div>Top Reddit Stories</div>

<div><br></div><div>&nbsp; &nbsp;* Starting the Mezzo Haskell Book</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://yesodweb.com">yesodweb.com</a>, Score: 58, Comments: 28</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [1] <a href="http://goo.gl/pOSlR">http://goo.gl/pOSlR</a></div>

<div>&nbsp; &nbsp; &nbsp;Original: [2] <a href="http://goo.gl/ecy4O">http://goo.gl/ecy4O</a></div><div><br></div><div>&nbsp; &nbsp;* First patches for iPhone cross compiler against GHC head</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://haskell.org">haskell.org</a>, Score: 55, Comments: 27</div>

<div>&nbsp; &nbsp; &nbsp;On Reddit: [3] <a href="http://goo.gl/OOAai">http://goo.gl/OOAai</a></div><div>&nbsp; &nbsp; &nbsp;Original: [4] <a href="http://goo.gl/p7C3L">http://goo.gl/p7C3L</a></div><div><br></div><div>&nbsp; &nbsp;* Retrospective thoughts on BitC by its author, and why type classes didn&#39;t work for him</div>

<div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://coyotos.org">coyotos.org</a>, Score: 44, Comments: 22</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [5] <a href="http://goo.gl/0sL80">http://goo.gl/0sL80</a></div><div>&nbsp; &nbsp; &nbsp;Original: [6] <a href="http://goo.gl/5pCp2">http://goo.gl/5pCp2</a></div>

<div><br></div><div>&nbsp; &nbsp;* Google Summer of Code 2012 - Haskell.org is participating</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://haskell.org">haskell.org</a>, Score: 42, Comments: 11</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [7] <a href="http://goo.gl/9EwzD">http://goo.gl/9EwzD</a></div>

<div>&nbsp; &nbsp; &nbsp;Original: [8] <a href="http://goo.gl/XqcUJ">http://goo.gl/XqcUJ</a></div><div><br></div><div>&nbsp; &nbsp;* Conduits vs. Pipes. Using Void as an Input or Output type can reduce the number of concepts (source, sink, conduit) from 3 to 1 (pipe).</div>

<div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://twanvl.nl">twanvl.nl</a>, Score: 34, Comments: 50</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [9] <a href="http://goo.gl/bc8RB">http://goo.gl/bc8RB</a></div><div>&nbsp; &nbsp; &nbsp;Original: [10] <a href="http://goo.gl/eb7oz">http://goo.gl/eb7oz</a></div>

<div><br></div><div>&nbsp; &nbsp;* Announcing conduit 0.3</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://yesodweb.com">yesodweb.com</a>, Score: 33, Comments: 9</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [11] <a href="http://goo.gl/JrgV0">http://goo.gl/JrgV0</a></div>

<div>&nbsp; &nbsp; &nbsp;Original: [12] <a href="http://goo.gl/OsDl7">http://goo.gl/OsDl7</a></div><div><br></div><div>&nbsp; &nbsp;* Haskell for embedded domain-specific languages (Functional Programming eXchange 2012)</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://skillsmatter.com">skillsmatter.com</a>, Score: 31, Comments: 4</div>

<div>&nbsp; &nbsp; &nbsp;On Reddit: [13] <a href="http://goo.gl/pSREX">http://goo.gl/pSREX</a></div><div>&nbsp; &nbsp; &nbsp;Original: [14] <a href="http://goo.gl/1azVh">http://goo.gl/1azVh</a></div><div><br></div><div>&nbsp; &nbsp;* Domain theory course</div>
<div>
&nbsp; &nbsp; &nbsp;Domain: <a href="http://cs.nott.ac.uk">cs.nott.ac.uk</a>, Score: 31, Comments: 5</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [15] <a href="http://goo.gl/5VHyG">http://goo.gl/5VHyG</a></div><div>&nbsp; &nbsp; &nbsp;Original: [16] <a href="http://goo.gl/o2pRC">http://goo.gl/o2pRC</a></div>

<div><br></div><div>&nbsp; &nbsp;* ANNOUNCE: options, an easy-to-use command-line option parser</div><div>&nbsp; &nbsp; &nbsp;Domain: self.haskell, Score: 29, Comments: 21</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [17] <a href="http://goo.gl/s6ktw">http://goo.gl/s6ktw</a></div>

<div>&nbsp; &nbsp; &nbsp;Original: [18] <a href="http://goo.gl/s6ktw">http://goo.gl/s6ktw</a></div><div><br></div><div>&nbsp; &nbsp;* A Case Study in Creating Rich Internet Apps in Haskell (Silk at FP eXchange 2012)</div><div>&nbsp; &nbsp; &nbsp;Domain: <a href="http://skillsmatter.com">skillsmatter.com</a>, Score: 22, Comments: 18</div>

<div>&nbsp; &nbsp; &nbsp;On Reddit: [19] <a href="http://goo.gl/ZdtDq">http://goo.gl/ZdtDq</a></div><div>&nbsp; &nbsp; &nbsp;Original: [20] <a href="http://goo.gl/Ta2HQ">http://goo.gl/Ta2HQ</a></div><div><br></div><div>&nbsp; &nbsp;* It just occurred to me that (lift .) defines a functor...</div>

<div>&nbsp; &nbsp; &nbsp;Domain: self.haskell, Score: 22, Comments: 15</div><div>&nbsp; &nbsp; &nbsp;On Reddit: [21] <a href="http://goo.gl/GMzPt">http://goo.gl/GMzPt</a></div><div>&nbsp; &nbsp; &nbsp;Original: [22] <a href="http://goo.gl/GMzPt">http://goo.gl/GMzPt</a></div>

<div><br></div><div><br></div><div>Top StackOverflow Questions</div><div><br></div><div>&nbsp; &nbsp;* Haskell platform: nested functions and optimization</div><div>&nbsp; &nbsp; &nbsp;votes: 15, answers: 2</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [23] <a href="http://goo.gl/nreIr">http://goo.gl/nreIr</a></div>

<div><br></div><div>&nbsp; &nbsp;* newtype with RankNTypes</div><div>&nbsp; &nbsp; &nbsp;votes: 14, answers: 2</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [24] <a href="http://goo.gl/UT9DV">http://goo.gl/UT9DV</a></div><div><br></div><div>&nbsp; &nbsp;* Pattern Matching - Prolog Vs Haskell</div>

<div>&nbsp; &nbsp; &nbsp;votes: 13, answers: 4</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [25] <a href="http://goo.gl/3hZV1">http://goo.gl/3hZV1</a></div><div><br></div><div>&nbsp; &nbsp;* How does this definition of ArrowLoop.loop work?</div><div>&nbsp; &nbsp; &nbsp;votes: 13, answers: 2</div>

<div>&nbsp; &nbsp; &nbsp;Read on SO: [26] <a href="http://goo.gl/ocSCM">http://goo.gl/ocSCM</a></div><div><br></div><div>&nbsp; &nbsp;* Data.Set : does it always know best?</div><div>&nbsp; &nbsp; &nbsp;votes: 12, answers: 2</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [27] <a href="http://goo.gl/NUjkB">http://goo.gl/NUjkB</a></div>

<div><br></div><div>&nbsp; &nbsp;* Building a histogram with haskell, many times slower than with python</div><div>&nbsp; &nbsp; &nbsp;votes: 11, answers: 3</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [28] <a href="http://goo.gl/kbh5i">http://goo.gl/kbh5i</a></div>

<div><br></div><div>&nbsp; &nbsp;* What is the scope of let when used without in?</div><div>&nbsp; &nbsp; &nbsp;votes: 11, answers: 2</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [29] <a href="http://goo.gl/bNwna">http://goo.gl/bNwna</a></div><div><br></div><div>
&nbsp; &nbsp;* Strange &ldquo;half to even&rdquo; rounding in different languages [closed]</div>
<div>&nbsp; &nbsp; &nbsp;votes: 11, answers: 3</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [30] <a href="http://goo.gl/lnPch">http://goo.gl/lnPch</a></div><div><br></div><div>&nbsp; &nbsp;* Practical reasons for ˇhurch Encoding</div><div>&nbsp; &nbsp; &nbsp;votes: 10, answers: 1</div>

<div>&nbsp; &nbsp; &nbsp;Read on SO: [31] <a href="http://goo.gl/xYoef">http://goo.gl/xYoef</a></div><div><br></div><div>&nbsp; &nbsp;* Can the FFI deal with arrays? If so, how?</div><div>&nbsp; &nbsp; &nbsp;votes: 9, answers: 3</div><div>&nbsp; &nbsp; &nbsp;Read on SO: [32] <a href="http://goo.gl/d4R3H">http://goo.gl/d4R3H</a></div>

<div><br></div><div><br></div><div>Until next time,</div><div>Daniel Santa Cruz</div><div><br></div><div>References</div><div><br></div><div>&nbsp; &nbsp;1. <a href="http://www.yesodweb.com/blog/2012/03/start-mezzo-haskell">http://www.yesodweb.com/blog/2012/03/start-mezzo-haskell</a></div>

<div>&nbsp; &nbsp;2. <a href="http://www.reddit.com/r/haskell/comments/r9xdq/starting_the_mezzo_haskell_book/">http://www.reddit.com/r/haskell/comments/r9xdq/starting_the_mezzo_haskell_book/</a></div><div>&nbsp; &nbsp;3. <a href="http://www.haskell.org/pipermail/iphone/2012-March/000120.html">http://www.haskell.org/pipermail/iphone/2012-March/000120.html</a></div>

<div>&nbsp; &nbsp;4. <a href="http://www.reddit.com/r/haskell/comments/r3ge7/first_patches_for_iphone_cross_compiler_against/">http://www.reddit.com/r/haskell/comments/r3ge7/first_patches_for_iphone_cross_compiler_against/</a></div>

<div>&nbsp; &nbsp;5. <a href="http://www.coyotos.org/pipermail/bitc-dev/2012-March/003300.html">http://www.coyotos.org/pipermail/bitc-dev/2012-March/003300.html</a></div><div>&nbsp; &nbsp;6. <a href="http://www.reddit.com/r/haskell/comments/rbk7z/retrospective_thoughts_on_bitc_by_its_author_and/">http://www.reddit.com/r/haskell/comments/rbk7z/retrospective_thoughts_on_bitc_by_its_author_and/</a></div>

<div>&nbsp; &nbsp;7. <a href="http://www.haskell.org/pipermail/haskell-cafe/2012-March/100247.html">http://www.haskell.org/pipermail/haskell-cafe/2012-March/100247.html</a></div><div>&nbsp; &nbsp;8. <a href="http://www.reddit.com/r/haskell/comments/r5h81/google_summer_of_code_2012_haskellorg_is/">http://www.reddit.com/r/haskell/comments/r5h81/google_summer_of_code_2012_haskellorg_is/</a></div>

<div>&nbsp; &nbsp;9. <a href="http://twanvl.nl/blog/haskell/conduits-vs-pipes">http://twanvl.nl/blog/haskell/conduits-vs-pipes</a></div><div>&nbsp; 10. <a href="http://www.reddit.com/r/haskell/comments/rbgvz/conduits_vs_pipes_using_void_as_an_input_or/">http://www.reddit.com/r/haskell/comments/rbgvz/conduits_vs_pipes_using_void_as_an_input_or/</a></div>

<div>&nbsp; 11. <a href="http://www.yesodweb.com/blog/2012/03/announcing-conduit-0-3">http://www.yesodweb.com/blog/2012/03/announcing-conduit-0-3</a></div><div>&nbsp; 12. <a href="http://www.reddit.com/r/haskell/comments/r6wdh/announcing_conduit_03/">http://www.reddit.com/r/haskell/comments/r6wdh/announcing_conduit_03/</a></div>

<div>&nbsp; 13. <a href="http://skillsmatter.com/podcast/scala/haskell-for-embedded-domain-specific-languages">http://skillsmatter.com/podcast/scala/haskell-for-embedded-domain-specific-languages</a></div><div>&nbsp; 14. <a href="http://www.reddit.com/r/haskell/comments/r22d6/haskell_for_embedded_domainspecific_languages/">http://www.reddit.com/r/haskell/comments/r22d6/haskell_for_embedded_domainspecific_languages/</a></div>

<div>&nbsp; 15. <a href="http://www.cs.nott.ac.uk/~gmh/domains.html">http://www.cs.nott.ac.uk/~gmh/domains.html</a></div><div>&nbsp; 16. <a href="http://www.reddit.com/r/haskell/comments/r250h/domain_theory_course/">http://www.reddit.com/r/haskell/comments/r250h/domain_theory_course/</a></div>

<div>&nbsp; 17. <a href="http://www.reddit.com/r/haskell/comments/rbpmb/announce_options_an_easytouse_commandline_option/">http://www.reddit.com/r/haskell/comments/rbpmb/announce_options_an_easytouse_commandline_option/</a></div>

<div>&nbsp; 18. <a href="http://www.reddit.com/r/haskell/comments/rbpmb/announce_options_an_easytouse_commandline_option/">http://www.reddit.com/r/haskell/comments/rbpmb/announce_options_an_easytouse_commandline_option/</a></div>

<div>&nbsp; 19. <a href="http://skillsmatter.com/podcast/home/silkapp-a-case-study-in-creating-rich-internet-apps-in-haskell/js-3880">http://skillsmatter.com/podcast/home/silkapp-a-case-study-in-creating-rich-internet-apps-in-haskell/js-3880</a></div>

<div>&nbsp; 20. <a href="http://www.reddit.com/r/haskell/comments/r1xey/a_case_study_in_creating_rich_internet_apps_in/">http://www.reddit.com/r/haskell/comments/r1xey/a_case_study_in_creating_rich_internet_apps_in/</a></div>
<div>
&nbsp; 21. <a href="http://www.reddit.com/r/haskell/comments/raxsk/it_just_occurred_to_me_that_lift_defines_a_functor/">http://www.reddit.com/r/haskell/comments/raxsk/it_just_occurred_to_me_that_lift_defines_a_functor/</a></div>

<div>&nbsp; 22. <a href="http://www.reddit.com/r/haskell/comments/raxsk/it_just_occurred_to_me_that_lift_defines_a_functor/">http://www.reddit.com/r/haskell/comments/raxsk/it_just_occurred_to_me_that_lift_defines_a_functor/</a></div>

<div>&nbsp; 23. <a href="http://stackoverflow.com/questions/9757515/haskell-platform-nested-functions-and-optimization">http://stackoverflow.com/questions/9757515/haskell-platform-nested-functions-and-optimization</a></div><div>

&nbsp; 24. <a href="http://stackoverflow.com/questions/9779301/newtype-with-rankntypes">http://stackoverflow.com/questions/9779301/newtype-with-rankntypes</a></div><div>&nbsp; 25. <a href="http://stackoverflow.com/questions/9780779/pattern-matching-prolog-vs-haskell">http://stackoverflow.com/questions/9780779/pattern-matching-prolog-vs-haskell</a></div>

<div>&nbsp; 26. <a href="http://stackoverflow.com/questions/9856342/how-does-this-definition-of-arrowloop-loop-work">http://stackoverflow.com/questions/9856342/how-does-this-definition-of-arrowloop-loop-work</a></div><div>&nbsp; 27. <a href="http://stackoverflow.com/questions/9755851/data-set-does-it-always-know-best">http://stackoverflow.com/questions/9755851/data-set-does-it-always-know-best</a></div>

<div>&nbsp; 28. <a href="http://stackoverflow.com/questions/9772098/building-a-histogram-with-haskell-many-times-slower-than-with-python">http://stackoverflow.com/questions/9772098/building-a-histogram-with-haskell-many-times-slower-than-with-python</a></div>

<div>&nbsp; 29. <a href="http://stackoverflow.com/questions/9777399/what-is-the-scope-of-let-when-used-without-in">http://stackoverflow.com/questions/9777399/what-is-the-scope-of-let-when-used-without-in</a></div><div>&nbsp; 30. <a href="http://stackoverflow.com/questions/9829769/strange-half-to-even-rounding-in-different-languages">http://stackoverflow.com/questions/9829769/strange-half-to-even-rounding-in-different-languages</a></div>

<div>&nbsp; 31. <a href="http://stackoverflow.com/questions/9806729/practical-reasons-for-hurch-encoding">http://stackoverflow.com/questions/9806729/practical-reasons-for-hurch-encoding</a></div><div>&nbsp; 32. <a href="http://stackoverflow.com/questions/9854782/can-the-ffi-deal-with-arrays-if-so-how">http://stackoverflow.com/questions/9854782/can-the-ffi-deal-with-arrays-if-so-how</a></div>

<div><br></div>