Daniel Santa Cruz | 24 Jan 04:49 2013

Haskell Weekly News: Issue 255

Welcome to issue 255 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
weeks of January 06 to 19, 201.

Quotes of the Week

   * ky3: Indexed monads are just categories in the category of
     endofunctors, what's the problem?

   * tac: I guess I'm just living in a fantasy world where the docs tell
     you how to use such a basic API :P

   * shachaf: 3.0 is an edwardk phase, not just a version number. It's
     like Picasso's Blue Period.

   * cmccann: Clearly the reason why edwardk uses Haskell now is because
     every C++ compiler has a restraining order against him.

   * shachaf: I'm not sure what your question is, but maybe lens is the

   * cmccann: * cmccann has concluded that lenses are just a category
     whose objects are english prepositions and whose morphisms are all

   * shachaf: Some people, when asking about a problem in #haskell, get
     a link to okmij.org. Now they have two problems.

   * quicksilver: It returns undefined for convenience. I'm not really
     sure it's that convenient, but that's why.

   * edwardk: cmccann: let me get this straight you are saying that
     someone [mm_freak] who by their very nick admits to being a freak
     did something freakish?

Top Reddit Stories

   * LiquidHaskell: Refinement Types in Haskell via SMT
     Domain: goto.ucsd.edu, Score: 71, Comments: 22
     On Reddit: [1] http://goo.gl/PE2nf
     Original: [2] http://goo.gl/P3Gm9

   * Hakyll 4.0 released
     Domain: jaspervdj.be, Score: 59, Comments: 19
     On Reddit: [3] http://goo.gl/IQAXq
     Original: [4] http://goo.gl/AbLnM

   * When Haskell is faster than C
     Domain: paulspontifications.blogspot.co.uk, Score: 52, Comments: 23
     On Reddit: [5] http://goo.gl/3rj8J
     Original: [6] http://goo.gl/N2cbA

   * I'm teaching an introductory 12-week class on Haskell. 
     Join in for a journey!
     Domain: reddit.com, Score: 45, Comments: 15
     On Reddit: [7] http://goo.gl/TsnQ5
     Original: [8] http://goo.gl/EMMVR

   * Subtractable values are torsors
     Domain: ro-che.info, Score: 42, Comments: 15
     On Reddit: [9] http://goo.gl/4IcMp
     Original: [10] http://goo.gl/6YJrY

   * Chordify: extract chord sequences from MP3's using HarmTrace
     Domain: chordify.net, Score: 42, Comments: 8
     On Reddit: [11] http://goo.gl/8J7rA
     Original: [12] http://goo.gl/ySfR5

   * Getting Started with Haskell
     Domain: bob.ippoli.to, Score: 41, Comments: 8
     On Reddit: [13] http://goo.gl/4Evnb
     Original: [14] http://goo.gl/nzg9o

   * Using AngularJS with Haskell Snap
     Domain: nurpax.github.com, Score: 40, Comments: 19
     On Reddit: [15] http://goo.gl/SH8e1
     Original: [16] http://goo.gl/0lSyN

   * Down with kinds: adding dependent heterogeneous equality to to FC
     Domain: cis.upenn.edu, Score: 38, Comments: 14
     On Reddit: [17] http://goo.gl/iEvyI
     Original: [18] http://goo.gl/cH0Eo

   * Fixing GADTs : Generic recursion schemes for GADTs using fixed 
     points of higher-order functors
     Domain: timphilipwilliams.com, Score: 38, Comments: 25
     On Reddit: [19] http://goo.gl/dEMq9
     Original: [20] http://goo.gl/vnjhp

   * What's the importance of Category Theory in Haskell? Is it worth 
     really studying?
     Domain: self.haskell, Score: 37, Comments: 60
     On Reddit: [21] http://goo.gl/T430r
     Original: [22] http://goo.gl/T430r

   * Parsing Markdown with Parsec: How Pandoc does it
     Domain: youtube.com, Score: 35, Comments: 13
     On Reddit: [23] http://goo.gl/TN9TJ
     Original: [24] http://goo.gl/zpX7f

   * Clckwrks, from the creator of Happstack, is developing into a clean 
     alternative to Wordpress
     Domain: clckwrks.com, Score: 34, Comments: 7
     On Reddit: [25] http://goo.gl/L9WXx
     Original: [26] http://goo.gl/FZRpU

   * pipes-safe-1.0 - Resource management and exception handling for pipes
     Domain: haskellforall.com, Score: 32, Comments: 27
     On Reddit: [27] http://goo.gl/HeLWz
     Original: [28] http://goo.gl/1hTFc

Top StackOverflow Questions

   * values, types, kinds,… as an infinite sequence?
     votes: 36, answers: 1
     Read on SO: [29] http://goo.gl/lyyYc

   * Why is this a useful warning in Haskell when pattern matching? 
     “Defined but not used”
     votes: 17, answers: 3
     Read on SO: [30] http://goo.gl/iQLFq

   * Why are getArgs and getProgName IO actions?
     votes: 16, answers: 3
     Read on SO: [31] http://goo.gl/5ZPYO

   * Can GADTs be used to prove type inequalities in GHC? [duplicate]
     votes: 14, answers: 2
     Read on SO: [32] http://goo.gl/fDdha

   * Applying Denotational Semantics to design of Programs [migrated]
     votes: 14, answers: 0
     Read on SO: [33] http://goo.gl/KLOCX

   * Examples where compiler-optimized functional code performs better 
     than imperative code
     votes: 14, answers: 1
     Read on SO: [34] http://goo.gl/Fzqdx

   * Why is there only one non-strict function from Int to Int?
     votes: 12, answers: 2
     Read on SO: [35] http://goo.gl/KXcAy

   * Dependency injection in Haskell: solving the task idiomatically
     votes: 12, answers: 3
     Read on SO: [36] http://goo.gl/xTcYc

   * What does a Haskell comment starting with `{- |` generally mean?
     votes: 11, answers: 1
     Read on SO: [37] http://goo.gl/zNikw

   * Is operational really isomorphic to a free monad?
     votes: 10, answers: 3
     Read on SO: [38] http://goo.gl/AJlgH

Until next time,
[39]+Daniel Santa Cruz


Haskell mailing list
Haskell <at> haskell.org
Daniel Santa Cruz | 31 Jan 03:39 2013

Haskell Weekly News: Issue 256

Welcome to issue 256 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
weeks of January 20 to 26, 2013.

Quotes of the Week

   * elliott: cmccann: unfortunately it is too perfect an abstraction to
           be useful.

   * SamanthaD: shachaf: you're one of those dirty imperative communists
      who want the state to dictate everything!

   * monochrom: I refuse camel case and mark zuckerberg. same level. not

   * mauke: a newtype is like an existing type but wearing glasses and a
         fake mustache and a sign saying "you've never seen me before"

Top Reddit Stories

   * Taking magic out of GHC or: Tracing compilation by transformation 
     (intro to Core transformations, inlining,..
     Domain: ics.p.lodz.pl, Score: 59, Comments: 2
     On Reddit: [1] http://goo.gl/lJmsb
     Original: [2] http://goo.gl/IbJ5O

   * Introduction to Haskell IO
     Domain: haskellforall.com, Score: 57, Comments: 26
     On Reddit: [3] http://goo.gl/fPky4
     Original: [4] http://goo.gl/Xymbr

   * The longest type signature I have ever seen (package Nussinov78)
     Domain: i.imgur.com, Score: 48, Comments: 26
     On Reddit: [5] http://goo.gl/ePwNs
     Original: [6] http://goo.gl/B74yW

   * There is now a patch for the GHC runtime system which implements a 
     scheduler which can handle threads with priorities.
     Domain: hackage.haskell.org, Score: 47, Comments: 12
     On Reddit: [7] http://goo.gl/22XgH
     Original: [8] http://goo.gl/8iC8w

   * Success story: novice haskeller moves console cursor with 
     “netwire” FRP library
     Domain: danbst.wordpress.com, Score: 43, Comments: 8
     On Reddit: [9] http://goo.gl/dm8ga
     Original: [10] http://goo.gl/Ue7pK

   * Haskell as pseudo code
     Domain: arxiv.org, Score: 33, Comments: 2
     On Reddit: [11] http://goo.gl/JL8Mf
     Original: [12] http://goo.gl/5D4zV

   * Generalizing do notation
     Domain: self.haskell, Score: 28, Comments: 19
     On Reddit: [13] http://goo.gl/teYAD
     Original: [14] http://goo.gl/teYAD

   * Tutorial: Up-front Unit Testing in Haskell
     Domain: github.com, Score: 26, Comments: 21
     On Reddit: [15] http://goo.gl/kjzYJ
     Original: [16] http://goo.gl/oB2jg

   * The Design of a Practical Proof Checker for a Lazy Functional Language [PDF]
     Domain: people.cs.missouri.edu, Score: 26, Comments: 
     On Reddit: [17] http://goo.gl/sj5Aj
     Original: [18] http://goo.gl/eEUOj

   * Introduction to Haskell, Lecture 2 is Live
     Domain: shuklan.com, Score: 24, Comments: 4
     On Reddit: [19] http://goo.gl/1nUVv
     Original: [20] http://goo.gl/rCbfx

   * Hugs in your browser
     Domain: tryhaskell.org, Score: 24, Comments: 21
     On Reddit: [21] http://goo.gl/zNtex
     Original: [22] http://goo.gl/wMPPW

   * Free functors - the reason Free and operational are not equivalent
     Domain: self.haskell, Score: 24, Comments: 12
     On Reddit: [23] http://goo.gl/E7qe7
     Original: [24] http://goo.gl/E7qe7

   * Scribbling, smudging and smearing with Haskell
     Domain: self.haskell, Score: 22, Comments: 108
     On Reddit: [25] http://goo.gl/KBw0V
     Original: [26] http://goo.gl/KBw0V

   * Touch and Keyboard API (announcing Elm 0.7.1)
     Domain: elm-lang.org, Score: 20, Comments: 3
     On Reddit: [27] http://goo.gl/OhFaH
     Original: [28] http://goo.gl/rV9bU

   * (re)implementing the generalised Functor strength function using lenses.
     Domain: statusfailed.com, Score: 20, Comments: 3
     On Reddit: [29] http://goo.gl/gEYHr
     Original: [30] http://goo.gl/TDX2A

Top StackOverflow Questions

   * Can using UndecidableInstances pragma locally have global consequences 
     on compilation termination?
     votes: 20, answers: 1
     Read on SO: [31] http://goo.gl/PcQF1

   * Why doesn't GHC Haskell support overloaded record parameter names?
     votes: 14, answers: 1
     Read on SO: [32] http://goo.gl/BJ71T

   * How much does it cost for Haskell FFI to go into C and back?
     votes: 14, answers: 2
     Read on SO: [33] http://goo.gl/kUCKn

   * Compile unsafe Haskell
     votes: 13, answers: 1
     Read on SO: [34] http://goo.gl/nGaCX

   * Why GADT/existential data constructors cannot be used in lazy patterns?
     votes: 12, answers: 2
     Read on SO: [35] http://goo.gl/zhpCh

   * Correct design for Haskell exception handling
     votes: 11, answers: 2
     Read on SO: [36] http://goo.gl/zeWoH

   * How to use phase control of inlining in haskell?
     votes: 10, answers: 0
     Read on SO: [37] http://goo.gl/dyuGI

   * Looking for resources that help testing a Haskell implementation for 
     standard conformance
     votes: 9, answers: 1
     Read on SO: [38] http://goo.gl/DL7vY

   * Generate a C struct based on a complex Haskell type
     votes: 8, answers: 1
     Read on SO: [39] http://goo.gl/7E8OT

   * How to structure a Haskell project?
     votes: 7, answers: 1
     Read on SO: [40] http://goo.gl/J4GuA

   * Difference between two functions creating a singleton list
     votes: 7, answers: 3
     Read on SO: [41] http://goo.gl/ZXzw0

Until next time,
Daniel Santa Cruz


Haskell mailing list
Haskell <at> haskell.org
Daniel Santa Cruz | 7 Feb 02:30 2013

Haskell Weekly News: Issue 257

Welcome to issue 257 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
week of January 27 to February 02, 2013.

Quotes of the Week

   * shachaf: Everyone forgets about Agda Lovelace, the first

   * applicative: I have my new ghc and am reinstalling my feeble world

   * wuttf: My world is starting to feel like isToyLanguage x = x /=

   * PenguinOfDoom: Being enlightened gentlemen, we split all
     programming languages into two groups, sucks and doesn't-suck and
     put all of them into the first group.

   * Taneb: lens has got to be the only library with more contributors
     than people who know how it works

   * shachaf: I like to put all my application's modules under GHC.*
     That's because I use the GHC API, and I want them not to conflict.

Top Reddit Stories

   * The FP Complete School of Haskell goes beta
     Domain: fpcomplete.com, Score: 84, Comments: 45
     On Reddit: [1] http://goo.gl/dEEyU
     Original: [2] http://goo.gl/0eKLt

   * My reaction to: How To Exclude Women From Your Technical Community: A Tutorial
     Domain: self.haskell, Score: 75, Comments: 145
     On Reddit: [3] http://goo.gl/dVnVv
     Original: [4] http://goo.gl/dVnVv

   * Edward Yang: The GHC scheduler
     Domain: blog.ezyang.com, Score: 72, Comments: 1
     On Reddit: [5] http://goo.gl/pkCmD
     Original: [6] http://goo.gl/SP1s3

   * GHC HEAD now has support for named holes; an extension of -XTypeHoles. Feedback welcome!
     Domain: github.com, Score: 44, Comments: 32
     On Reddit: [7] http://goo.gl/87Pbw
     Original: [8] http://goo.gl/cqX9N

   * LiquidHaskell - Safely Catching A List By Its Tail
     Domain: goto.ucsd.edu, Score: 44, Comments: 2
     On Reddit: [9] http://goo.gl/uxU64
     Original: [10] http://goo.gl/9aS35

   * ProseDoc: A literate programming tool for Haskell inspired by docco
     Domain: shangaslammi.github.com, Score: 43, Comments: 12
     On Reddit: [11] http://goo.gl/x4YGE
     Original: [12] http://goo.gl/sM4bN

   * ANNOUNCE: GHC version 7.6.2
     Domain: haskell.org, Score: 39, Comments: 16
     On Reddit: [13] http://goo.gl/BS6Sm
     Original: [14] http://goo.gl/RPF00

   * What you consider "advanced" Haskell topics?
     Domain: self.haskell, Score: 34, Comments: 45
     On Reddit: [15] http://goo.gl/JRgzG
     Original: [16] http://goo.gl/JRgzG

   * How to write unmaintainable Haskell code
     Domain: github.com, Score: 34, Comments: 49
     On Reddit: [17] http://goo.gl/V0nxC
     Original: [18] http://goo.gl/G8wNv

   * Introduction to Haskell, Lecture 3 is Live (Types and Typeclasses)
     Domain: shuklan.com, Score: 32, Comments: 5
     On Reddit: [19] http://goo.gl/JyH81
     Original: [20] http://goo.gl/bve7N

   * Proposal: A trivial Cabal package signing utility for use with Hackage
     Domain: github.com, Score: 32, Comments: 61
     On Reddit: [21] http://goo.gl/R2l9g
     Original: [22] http://goo.gl/IpYSo
Top StackOverflow Questions

   * Haskell/GHC UndecidableInstances - example for non-terminating type check?
     votes: 19, answers: 2
     Read on SO: [23] http://goo.gl/KX8oj

   * Efficient parallel strategies
     votes: 15, answers: 2
     Read on SO: [24] http://goo.gl/aDnW2

   * Is it possible to implement MonadFix for `Free`?
     votes: 15, answers: 2
     Read on SO: [25] http://goo.gl/uKOrO

   * Do Haskell imports have side effects?
     votes: 15, answers: 1
     Read on SO: [26] http://goo.gl/sjltX

   * What monads can be expressed as Free over some functor?
     votes: 10, answers: 1
     Read on SO: [27] http://goo.gl/Q8MF9

   * What is the point of having a lazy/strict version of Writer?
     votes: 10, answers: 1
     Read on SO: [28] http://goo.gl/InUsm

   * Why can applicative functors have side effects, but functors can't?
     votes: 9, answers: 4
     Read on SO: [29] http://goo.gl/LxUi5

   * How to write fixed point build rules in Shake, e.g. Latex
     votes: 9, answers: 1
     Read on SO: [30] http://goo.gl/Ef82G

   * Event handling in Netwire compared to conventional FRP frameworks
     votes: 9, answers: 2
     Read on SO: [31] http://goo.gl/mA4Kc

Until next time,
Daniel Santa Cruz


Haskell mailing list
Haskell <at> haskell.org
Daniel Santa Cruz | 14 Feb 02:17 2013

Haskell Weekly News: Issue 258

Welcome to issue 258 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
week of February 03 to 09, 2013.

Quotes of the Week

   * shachaf: The trouble with the lens rabbit hole is that there are a
           few of us here at the bottom, digging.

   * monochrom: "a monad is like drinking water from a bottle without
      human mouth touching bottle mouth"

Top Reddit Stories

   * GHCi 7.4.2 is finally working on ARM
     Domain: luzhuomi.blogspot.com, Score: 49, Comments: 15
     On Reddit: [1] http://goo.gl/yBh9o
     Original: [2] http://goo.gl/Kgx9R

   * Implementation of a Java Just In Time Compiler in Haskell
     Domain: blog.wien.tomnetworks.com, Score: 41, Comments: 15
     On Reddit: [3] http://goo.gl/BjpX3
     Original: [4] http://goo.gl/f1Qrh

   * I/O is pure
     Domain: chris-taylor.github.com, Score: 32, Comments: 41
     On Reddit: [5] http://goo.gl/pYMXz
     Original: [6] http://goo.gl/9xeKd

   * Introduction to Haskell, Lecture 4 is Live (Pattern matching and Guards)
     Domain: shuklan.com, Score: 28, Comments: 7
     On Reddit: [7] http://goo.gl/wvFO6
     Original: [8] http://goo.gl/sKF5C

   * What makes comonads important?
     Domain: self.haskell, Score: 20, Comments: 41
     On Reddit: [9] http://goo.gl/CqS7Z
     Original: [10] http://goo.gl/CqS7Z

   * OdHac, the Haskell Hackathon in Odessa
     Domain: haskell.org, Score: 18, Comments: 2
     On Reddit: [11] http://goo.gl/ZumYI
     Original: [12] http://goo.gl/Pfuaq

   * NYC Haskell Meetup Video: Building a Link Shortener with Haskell and Snap
     Domain: vimeo.com, Score: 18, Comments: 3
     On Reddit: [13] http://goo.gl/j42PG
     Original: [14] http://goo.gl/RRgsl

   * Evaluation-State Assertions in Haskell
     Domain: joachim-breitner.de, Score: 18, Comments: 6
     On Reddit: [15] http://goo.gl/lMMT1
     Original: [16] http://goo.gl/7eLI5

   * A post about computational classical type theory
     Domain: queuea9.wordpress.com, Score: 17, Comments: 14
     On Reddit: [17] http://goo.gl/r8DOO
     Original: [18] http://goo.gl/UIxIY

   * parellella has a forum board for haskell. anyone working in this direction?
     Domain: forums.parallella.org, Score: 13, Comments: 5
     On Reddit: [19] http://goo.gl/BSfRd
     Original: [20] http://goo.gl/qLnG0

   * Haskell Lectures - University of Virginia (Nishant Shukla)
     Domain: shuklan.com, Score: 13, Comments: 3
     On Reddit: [21] http://goo.gl/CxTPI
     Original: [22] http://goo.gl/JkhXz

   * NYC Haskell Meetup Video: Coding and Reasoning with Purity, Strong Types and Monads
     Domain: vimeo.com, Score: 13, Comments: 2
     On Reddit: [23] http://goo.gl/MmGZb
     Original: [24] http://goo.gl/Vj63w

   * Introducing fixed-points via Haskell
     Domain: apfelmus.nfshost.com, Score: 9, Comments: 34
     On Reddit: [25] http://goo.gl/UuCc1
     Original: [26] http://goo.gl/SCVJc

Top StackOverflow Questions

   * Is spoon unsafe in Haskell?
     votes: 19, answers: 2
     Read on SO: [27] http://goo.gl/6RDku

   * What general structure does this type have?
     votes: 17, answers: 4
     Read on SO: [28] http://goo.gl/2GV0V

   * Why aren't Nums Ords in Haskell?
     votes: 14, answers: 2
     Read on SO: [29] http://goo.gl/8Hrkn

   * Why does cabal install reinstall packages already in .cabal/lib
     votes: 12, answers: 1
     Read on SO: [30] http://goo.gl/yMXCh

   * Free Monad of a Monad
     votes: 12, answers: 2
     Read on SO: [31] http://goo.gl/kpV2q

   * Haskell pattern match “diverge” and ⊥
     votes: 11, answers: 2
     Read on SO: [32] http://goo.gl/VeRUJ

   * How can one make a private copy of Hackage
     votes: 11, answers: 2
     Read on SO: [33] http://goo.gl/ZNAwL

   * Recursion Schemes in Agda
     votes: 9, answers: 1
     Read on SO: [34] http://goo.gl/xtmqr

Until next time,
+Daniel Santa Cruz


Haskell mailing list
Haskell <at> haskell.org