# Haskell Weekly News: October 17, 2009

Welcome to issue 136 of HWN, a newsletter covering developments in the Haskell community.

Over the last week, fpisfun from reddit announced a new subreddit for simple, direct applications of Haskell to common problems which normally might be solved by a perl script or bit of bash. There are a number of examples already there, and the numbers keep growing. It's not just command-line utilities either, there is also this post on calculating the bend needed for a bay window curtainrod. There is plenty of great material if you're new to Haskell and looking for some basic examples of different simple projects, examples of using monads and functors appropriately, or just want to see some 'real' programs in Haskell, it's worth a look!

Also, a small correction, due to some issues with the tools, unicode characters get replaced with their ASCII 'equivalents' so that an 'e' with an umlaut becomes an 'e' character. Thanks to Wolfram Kahl for pointing out that this change is not as innocent as I thought, apologies thusly to Guenther Schmidt (I'm told thats a better approximation of the correct spelling) for the error, I apologize in advance for any other similar errors. I'm working on improving the unicode support in the tools, but it's a nasty bug to catch.

This was a long editorial, so I won't take any more of your time, Haskellers, the Haskell Weekly News!

#### Announcements

*Call for Contributions - Haskell Communities
and Activities Report, November 2009 edition*. voigt
called
for contributions to the November 2009 issue of the Haskell Communities
and Activities Report. See post for details.

*Call for Participation: VSTTE 2009*. Jean-Christophe Filliatre
announced
a call for participation for the VSTTE Workshop.

*WFLP 2010 Call for papers*. Pablo Nogueira
announced
a call for papers for the 2010 WFLP.

*BAHUG Next meeting: October 21st at MIT (32G-882)*. Ravi Nanavati
announced
the next meeting of the Boston Area Haskell User's Group. Which will be
in the CSAIL Reading Room at MIT. This editor hopes to actually make it
to this one, so maybe I'll see you there!

*fp-southwales, the South Wales Functional Programming User
Group*. Andy Gimblett
announced
the formation of fp-southwales, a user group for anybody interested in
functional programming in the area of south Wales, UK.

*The Monad.Reader (14) - Call for copy*. Brent Yorgey
announced
the call for copy for the next issue of `The Monad.Reader`, Issue #14

*Extensions to Vec uploaded (useful for GPipe programs)*. Tobias
Bexelius
announced
two extensions to the Vec package: Vec-Transform and
Vec-Boolean. Vec-Transform provides some 4x4 transform matrices such as
perspective projection and rotation. Vec-Boolean provides Data.Boolan
instances for the Vec data types.

*Bindings to FFMpeg library*. Vasyl Pasternak
announced
the next release of the hs-ffmpeg library. Downloadable from Hackage
along with the ffmpeg-tutorials, which show capabilities of this
library. The installation process is a bit tricky so Vasyl put up a blog
post which describes the installation process.

*Haskell Hackathon in Zurich, Switzerland*. Johan Tibell
announced
a Hackathon in Zurich, to be held in March in the Google office. No concrete
date has been decided, but if your interested, make sure to add your name here.

*Reverse Dependencies in Hackage (demo)*. Roel van Dijk
announced
his patch to add reverse-dependencies to Hackage, see the linked post
for information on where to see an example version of hackage.

#### Discussion

*Relational Algebra*. Guenther Schmidt
asked
about whether or not a EDSL for relational algebra in Haskell.

*GHC devs*. Andrew Coppin
asked
about how many GHC Developers there are, and was somewhat surprised with
the answer.

*Fuzzy Logic / Linguistic Variables*. Neal Alexander
demonstrated
an implementation of fuzzy logic taken from the book: 'Programming Game AI
by Example' by Mat Buckland. In the book, the code was in C++, rewriting
it in Haskell made for much more succint, readable code.

*Graph Library Using Associated Types*. Lajos Nagy
asked
about using Associated types in a Graph library.

*Is proof by testing possible?* Muad'Dib
asked
us Haskell Mentat's about whether it was possible to prove a function
correct in a finite number of tests. The discussion brought forth not only
answers but some /very cool/ results about the application of compactness
(in the topological sense) to testing.

#### Blog noise

Haskell news from the blogosphere. Blog posts from people new to the Haskell community are marked with >>>, be sure to welcome them!Don Stewart (dons):

*LACSS 2009: Domain Specific Languages and Haskell*.FP Lunch:

*Factorising folds for faster functions*.Mikael Vejdemo Johansson (Syzygy-):

*[MATH 198] Lecture 4 and a question for the community*. More of Syzygy's lectures on category theory, Syzygy also asks about what it means to 'integrate' a datatype.Neil Brown:

*Emulating Shared Mutable Variables with Message-Passing Processes*.Galois, Inc:

*Tech Talk: Writing Linux Kernel Modules with Haskell*.Galois, Inc:

*Domain Specific Languages for Domain Specific Problems*.FP-Syd:

*Sydney FP Group: FP-Syd #18.*.Neil Brown:

*The octopus, the boids and GHC 6.12.1rc1*.Brent Yorgey:

*Call for submissions: Monad.Reader issue 15*.Brent Yorgey:

*diagrams 0.2.1, and future plans*.Don Stewart (dons):

*Self-optimizing data structures: using types to make lists faster*.Martijn van Steenbergen:

*Context Synonyms*.Joachim Breitner:

*arbtt: Now with Documentation*.Dan Piponi (sigfpe):

*Vectors, Invariance, and Math APIs*.Creighton Hogg:

*How to teach Category Theory?*.

#### Quotes of the Week

*sproingie*: How do you beta-reduce a problem like Maria*Baughn*: There's also the language, Quine, whose interpreter is implemented as a symlink to /bin/cat*benmachine*: [on the best editor] opinions vary. from correct opinions i.e. mine to other ones. [editor's comment: Obviously, this question is settled, the best editor is *garbled*]*pozic*: statistics. a wonderful tool to control people.*FunctorSalad*: I think the 'asks', 'gets' etc family of names is sort of cute, like the program is talking about itself in the third person*mmorrow:*: Right, that's just beggin for a State monad.

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