Haskell Weekly News: Issue 214

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.

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. From (haskell.org), scored 107 with 59 comments.
• Coming soon, to a bookstore near you. From (yesodweb.com), scored 82 with 16 comments.
• ImplicitCAD is a Programmatic CAD Tool/3D Modelling Engine in Haskell. Also my first big Haskell project. Feedback, advice?. From (github.com), scored 63 with 23 comments.
• Using monadic effects to reverse a merge sort. From (github.com), scored 42 with 4 comments.
• Exciting changes coming to conduit 0.2. From (yesodweb.com), scored 38 with 7 comments.
• Vectorisation without Replication in Data Parallel Haskell. From (disciple-devel.blogspot.com), scored 35 with 4 comments.
• If software purity in functional languages is such an awesome idea, why are we still writing Python, Ruby or Java?. From (self.haskell), scored 33 with 136 comments.
• Released Data.Array.Accelerate 0.9.0.0 - the Haskell array library for GPUs. From (justtesting.org), scored 32 with 3 comments.
• Fun With -XPolyKinds : Polykinded Folds. From (typesandotherdistractions.com), scored 24 with 1 comments.
• Introduction to using acid-state, IxSet and data-lens as a native Haskell, noSQL, RAM-cloud database. From (happstack.com), scored 23 with 21 comments.
• Can't wait for the Haskell Platform? -- Compiling GHC 7.4.1 from source has never been easier.. From (blog.jasonknight.us), scored 21 with 8 comments.
• Generating random functions. From (mainisusuallyafunction.blogspot.com), scored 20 with 6 comments.
• How to deal with undesired values when designing types. From (self.haskell), scored 19 with 28 comments.
• Guarded Pipes or How to write Conduit.List Combinators in Pipes.. From (pcapriotti.wordpress.com), scored 17 with 16 comments.
• UHC JavaScript Backend Project Page (Work in Progress). From (uu-computerscience.github.com), scored 16 with 0 comments.

Top StackOverflow Questions

• What are the rules about concurrently accessing a persistent database votes: 17, answers: 1
• Functions don't just have types: They ARE Types. And Kinds. And Sorts. Help put a blown mind back together votes: 15, answers: 2
• Defining polymorphic constants in Haskell votes: 12, answers: 2
• Do guarded pipes behave the same as pipes using await? votes: 12, answers: 2
• What is the purpose of the IdentityT transformer? votes: 11, answers: 2
• call/cc implementation? votes: 10, answers: 5
• Understanding bind function in Haskell votes: 9, answers: 4
• How to show that a monad is a functor and an applicative functor? votes: 8, answers: 2
• Avoiding lift with Monad Transformers votes: 7, answers: 2
• Container element types votes: 7, answers: 1

Until next time,
Daniel Santa Cruz