General News

Welcome to issue 100 of HWN, a newsletter covering developments in the Haskell community.

Welcome to the 100th (!) issue of the Haskell Weekly News, suitably published on your friendly neighborhood HWN editor's 1000th birthday (base 3). If you ever have content to be included in the HWN (announcements, blog posts, major life news) or a suggestion on how the HWN could be more useful to you as a window into the goings-on of the Haskell community, please don't hesitate to send it along, using the contact information at the end of each issue.

Announcements

Haskell BLAS bindings version 0.7. Patrick Perry announced the release of version 0.7 of the blas package, Haskell bindings to the BLAS (Basic Linear Algebra Subprograms) library. According to Patrick, this release is "a major milestone---it is finally the library with all of the features that I want."

X Haskell Bindings. Antoine Latter announced a preview release of the X Haskell Bindings. The goal of the library is to provide low-level access to the X11 protocol, in the spirit of the X C Bindings.

Data.TCache 0.5.5. Alberto G. Corona announced the 0.5.5 release of the TCache package, a transactional data cache with configurable persistence. This version adds the the capability to safely handle transactions, and incrementally serialize many data types simultaneously in the same piece of code.

haskell-src-exts 0.4.8. Niklas Broberg announced a new release (0.4.8) of the haskell-src-exts package. This is a bug-fix release in the wake of the flurry of bug reports due to hlint.

bytestring-trie 0.1.2 (bugfix). wren ng thornton announced a bugfix release for bytestring-trie, efficient finite maps from (byte)strings to values. This release fixes a bug in alterBy, and adds an Eq instance.

wxHaskell 0.11.1. Jeremy O'Donoghue announced the release of wxHaskell 0.11.1, a Haskell binding for the wxWidgets GUI library. The main highlights include support for XRC resource files, support for wxWidgets 2.8.x and GHC 6.10, and preliminary support for Cabal and Hackage.

cabal2doap 0.1. Greg Heartsfield announced the release of Cabal2doap, which generates Description of a Project (DOAP) XML/RDF data representing a Haskell project. This should make it possible for semantic web project aggregation sites to find and index Haskell projects.

Jobs

Jane Street is hiring functional programmers. Yaron Minsky reminded everyone that Jane Street is still hiring! Jane Street now has over 30 OCaml developers, and is actively looking to hire more in Tokyo, London and New York.

PhD, postdoc, and engineering positions at HATS. CFP announced the availability of 10 PhD, postdoc, and engineering positions within the HATS project (Highly Adaptable and Trustworthy Software using Formal Models), a new Integrated Project funded by the European Union, within the programme "Future and Emerging Technologies" (FET). The goal of HATS is a tool-supported framework and formal methodology for the development of long-lived and trustworthy software systems.

Hypothetical Haskell job in New York. Tony Hannan asked how many would be interested in applying to a hypothetical Haskell job in New York, assuming his boss can be convinced to use Haskell.

Blog noise

• Lennart Augustsson (augustss): LLVM arithmetic.

• GHC / OpenSPARC Project: Bootstrapping 6.

• Patrick Perry: New Haskell BLAS bindings!.

• Clemens Fruhwirth: Liskell standalone.

• The GHC Team: Benchmarking recent improvements in parallelism.

• Galois, Inc: Tech Talk: OpenTheory: Package Management for Higher Order Logic Theories.

• Eric Kow (kowey): fold diagram revisited?.

• GHC / OpenSPARC Project: Bootstrapping 5.

• Lennart Augustsson (augustss): LLVM.

• Sebastian Fischer: Monadic and Queue-Based Tree Search.

• Philip Wadler: Well-typed programs can't be blamed.

• GHC / OpenSPARC Project: Bootstrapping 4.

• Manuel M T Chakravarty: GPU Kernels as Data-Parallel Array Computations in Haskell..

• GHC / OpenSPARC Project: Bootstrapping 3.

• Tom Schrijvers: Monadic Constraint Programming.

• Conal Elliott: Another angle on functional future values.

• >>> Greg Heartsfield: Cabal2doap.

• Christopher Lane Hinson: MaybeArrow?.

• GHC / OpenSPARC Project: Bootstrapping 2.

• Darcs: darcs 2.2.0pre2 ready for testing!.

• Alson Kemp: Sad about Import Cycles.

• GHC / OpenSPARC Project: Bootstrapping.

• gamr7: Accessing Recursive Haskell Data Structures from C/Python.

Quotes of the Week

• jml: A wise man once said, "the program isn't debugged until the last user is dead".
• pumpkin: OMG I <3 RECORD SYNTAX
• Olathe: <Olathe> > floor (1.0/0.0) <lambdabot> 179769... <Olathe> But you can see that Haskell can calculate the maximum Integer.
• lilac: <drdozer> gha! I'm drowning in the haskell number hierarchy again <lilac> drdozer: magic 8-ball says 'add calls to fromIntegral'
• monopoly: do not exit IO. go directly to the REPL, do not pass any parameters or continuations.
• EvilTerran: [on category theory] the same place of nightmares that spawned zygohistomorphic prepromorphisms :P

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 99 of HWN, a newsletter covering developments in the Haskell community.

Happy new year to all! May 2009 be a year full of joy, family, friends, professional success, much Haskell hacking, and a minimal number of rabid weasels. Just in case.

Announcements

#haskell IRC channel reaches 600 users. Don Stewart announced that 7 years after its inception, under the guiding hand of Shae Erisson (aka shapr), the #haskell IRC channel on freenode has reached 600 concurrent users!

citeproc-hs-0.2. andrea rossato announced the release of citeproc-hs-0.2, a Haskell implementation of the Citation Style Language, which adds a Bibtex like citation and bibliographic formatting and generation facility to pandoc. This version adds support for citation collapsing, a wrapper around hs-bibutils, and some API documentation.

hs-bibutils-0.1. andrea rossato announced the first release of hs-bibutils, Haskell bindings to Chris Putnam's bibutils. Bibutils is a library and a set of bibliographic utilities to interconvert between various bibliography database formats using a common MODS-format XML intermediate.

Haskell koans. Gwern Branwen issued an RFK (Request for Koans), following the success of his CFH (Call for Haiku).

[ANN] Haskell web server + wiki: salvia-0.0.4 + orchid-0.0.6. Sebastiaan Visser announced the release of three new packages: salvia, a lightweight modular web server framework; orchid, a(nother) wiki written in Haskell, using Darcs as a versioning back-end and Salvia as the application server; and orchid-demo, a simple demo application using Salvia and Orchid to serve an example darcs repository. You can play around with an online demo.

gitit-0.4.1, recaptcha-0.1. John MacFarlane announced the release of gitit-0.4.1, a wiki program that stores pages in a git repository. This release adds support for (optional) captchas, using the reCAPTCHA service. The reCAPTCHA code has been packaged as a separate library on Hackage, recaptcha.

monte-carlo-0.2, gsl-random-0.2.3. Patrick Perry announced the release of a new version of the monte-carlo package. The new version includes a more general type class, MonadMC, which allows all the functions to work in both MC and MCT monads; functions to sample from discrete distributions, and functions to sample subsets. There is also a quick tutorial.

Reading group for Programming Collective Intelligence. Creighton Hogg announced that he would like to start a small group for the O'Reilly book Programming Collective Intelligence, to work through translating some of the examples to Haskell. Email Creighton if you are interested in participating.

Maintaining laziness. Henning Thielemann announced that he has written a tutorial on how to make functions lazy and how to test whether they are actually lazy.

Request for feedback: Understanding Haskell Monads. Ertugrul Soeylemez requested feedback on a new monad tutorial.

Discussion

How do we decide on the new logo?. Fritz Ruehr began a discussion of how to go about choosing a winner of the Great 2009 Haskell Logo Contest. Weigh in if you care!

Jobs

Two Positions as Associate Professor in Software Engineering at Chalmers University. Koen Claessen announced the availability of two positions as Associate Professor at Chalmers University in Gothenburg, Sweden, within the division of Software Engineering and Technology at the department of Computer Science and Engineering. The application deadline is January 12, 2009.

Blog noise

• GHC / OpenSPARC Project: Bootstrapping.

• Dan Piponi (sigfpe): Rewriting Monadic Expressions with Template Haskell.

• GHC / OpenSPARC Project: Fighting dependencies.

• GHC / OpenSPARC Project: A new year and a new project.

• Alson Kemp: 2009: The Year Of Hackage.

• Patrick Perry: Monte Carlo Poker Odds.

• Joachim Breitner: Handling explicit and implicit recursion in Haskell data.

• Luke Palmer: Domain Convergence.

• Eric Kow (kowey): riot is almost a Haskell mail client.

• John Goerzen (CosmicRay): Real World Haskell update.

• Alson Kemp: A Plea For "cabal install".

• Alson Kemp: Cyptol on Slashdot.

Quotes of the Week

• lilac: <bohdan> how do I see the number of reductions required to calculate something? <lilac> bohdan: the usual method is to ask Cale to reduce it by hand :)
• conal: If it's purely functional, how do you *do* anything? You don't ;-)
• ddarius: The opposite ends of CS meet in the Haskell world.
• EvilTerran: forcedYet :: a -> Bool; forcedYet x = x `seq` True -- :P
• bmh: I dream in folds. One day I'll dream in monads.
• sclv: dreaming is a monad.

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 98 of HWN, a newsletter covering developments in the Haskell community.

Happy holidays! An exciting HWN for you this week, including a number of cool new libraries, the public release of Cryptol, a Haskell logo contest, and the second most awesome GHC bug ever (see augustss's quote at the end of the Quotes section for the most awesome GHC bug ever).

Announcements

Hieroglyph 0.85. Jeff Heard announced that the Thingie library has been renamed Hieroglyph, and now has support for displaying images on the Cairo canvas.

Cryptol now freely available. Don Stewart announced that Cryptol, the language of cryptography, is now available to the public! Cryptol is a domain specific language for the design, implementation and verification of cryptographic algorithms, developed over the past decade by Galois for the United States National Security Agency. It has been used successfully in a number of projects, and is also in use at Rockwell Collins, Inc. Cryptol is implemented in Haskell.

Control.Monad.IfElse. Jeff Heard announced the Control.Monad.IfElse module, which provides useful anaphoric and monadic versions of if-else and when.

llvm-0.4.0.1. Lennart Augustsson announced version 0.4.0.1 of the release that is quite incompatible with the old 0.0.2 release.) Haskell LLVM bindings. LLVM is a virtual machine and the bindings allow you to generate code for this virtual machine. This code can then be executed by a JIT or written to a file for further processing by the LLVM tools.

bytestring-trie 0.1.0. wren ng thornton announced the release of bytestring-trie 0.1.0, an efficient finite map from (byte)strings to values. The implementation is based on big-endian patricia trees, like Data.IntMap.

RWH book club. Don Stewart announced that Matt Podwysocki has set up a Real World Haskell book club, a mailing list on google groups with already some 200 members discussing typical new user Haskell questions. Feel free to join if you like talking about Haskell, or teaching new users.

Thingie-0.80. Jeff Heard announced the release of Thingie, a library for creating 2D visualizations in a purely functional manner. It supports static visualizations and animation, and like most vis libraries, can probably do games as well as simple viz graphics.

typehash version 1.3. Lennart Augustsson announced the release of the typehash library, which allows you to produce a unique identifier (a cryptographic hash) for a type. This is useful if you save values of some type to a file (text, binary, whatever format you wish) and then when you read it back in again you want to verify that the type you want to read is the one you actually wrote. The library also supports type codes, which encode the complete structure of a type and can be used for finer comparison than just equality.

uvector-algorithms 0.1. Dan Doel announced the release of uvector-algorithms, a library of algorithms (mostly sorting) for the mutable arrays defined in uvector. It has several varieties of sorting, including introsort (quicksort which falls back on heapsort in bad cases), heapsort, a simple top- down merge sort and a radix sort. Also exposed are the operations that allow you to use the arrays as heaps and a combinator for safely using these mutable array algorithms to sort immutable arrays. All algorithms have been painstakingly profiled and optimized.

Data.List.Split. Brent Yorgey announced the release of Data.List.Split, which provides a wide range of strategies and a unified combinator framework for splitting lists with respect to some sort of delimiter.

Hoogle with more libraries. Neil Mitchell announced that Hoogle will now search lots of the libraries present on hackage!

HLint 1.0. Neil Mitchell announced the re-release of HLint, a tool for making suggestions to improve your Haskell code. Previously this tool was called Dr Haskell and depended on a working installation of Yhc; now it depends on GHC 6.10.1.

rangemin-1.0. Louis Wasserman announced the release of rangemin, a library for efficiently preprocessing an array to find minimum elements of subranges of the array in constant time.

Discussion

length of module name affecting performance??. Daniel Gorín reported a GHC bug where in certain cases, changing the name of a module to something longer results in a 2x-3x performance hit! Strange but true.

Time for a new logo?. Don Stewart proposed a competition to produce a new Haskell logo! Submissions should go on the wiki page; the deadline for logo submissions is December 31.

Pattern combinators. Andrew Wagner started a thread turning a paper on pattern-matching in Haskell into actual code for hackage.

Coroutines. Ryan Ingram posted some interesting code showing how to implement coroutines with session types.

Type wildcards. Eyal Lotem proposed a 'type wildcards' extension to the language.

Blog noise

• Galois, Inc: Cryptol, the language of cryptography, now available.

• Dan Piponi (sigfpe): The Mother of all Monads.

• Real-World Haskell: Pat Eyler Interviews the Real World Haskell Team.

• Philip Wadler: Unsafe.

• Conrad Parker: Release: HOgg 0.4.1.

• ezekiel smithburg: fast string appending/concatenation in haskell.

• Brent Yorgey: Data.List.Split.

• Alson Kemp: Turbinado: Implementing a poor-man's wiki.

• Luke Palmer: Reactive spaces.

• Conal Elliott: Smarter termination for thread racing.

• Real-World Haskell: RWH on Twitter.

• >>> Muharem Hrnjadovic: My new favourite book.

• Alson Kemp: Turbinado update.

• Philip Wadler: Type Safe Pattern Combinators, by Morten Rhiger.

• Osfameron: Crossword puzzles in Haskell.

• Brent Yorgey: QuickCheck rocks my socks.

• >>> Matt Youell: If programming languages were martial arts.

• >>> Sebastian Fischer: Haskell idioms I did not understand before hacking them on my own.

• Alson Kemp: Thinking about Haskell: You Know Lazy Evaluation; You Just Don't Know It.

• >>> Brian McCallister: Real World Haskell, for Jon.

• Ivan Lazar Miljenovic: RWH Arrives Down Under!.

• >>> Thomas ten Cate: XMonad with Ubuntu, dvorak, Pidgin and Skype.

• >>> Jeremy Frens: PE Problem #3 in All Languages.

• Jeremy Shaw: Data Migration with HApps-Data.

• Chris Done: Haskell Formlets: Composable web form construction and validation.

• Real World Haskell: Haskell around the world.

• Dougal Stanton: A brief look at fingertrees.

Quotes of the Week

• luqui: no!!! I was building a joke, but then I sent it before I thought of one.
• roconnor: We put up a clothes line and made a turing machine by hand at a party once ... that is the sort of parties I go to.
• cjs: In what other language could I have learned so much about Win32 programming (summary: basically, the Windows 3.0 API but with all sorts of hacks to deal with having more than one thread in the system), and come out having *enjoyed* myself? Praise to the Lord!
• PaulJohnson: A paradox of the Haskell world is that, while the language is Vulcan, the community around it is dominated by Warm Fuzziness. Clearly the two are not mutually exclusive.
• Botje: Caleskell even has unsafeSolveHaltingProblem?
• Taejo: * Taejo needs to write Sitar Hero in Yampa
• dons: it is safer for incompetent people to be working in Haskell than C++.
• mpeter: the quality of my code increased drastically when i realized i should stop telling the computer to do things which were stupid.
• byorgey: <Cale> RandomT/Random are effectively state monads. (in fact, they're thin candy shells around StateT/State.) <byorgey> "newtype: melts in the compiler, not in your hands"
• quicksilver: [on classes having the same name as constructs in other languages] it's like having a laxative called "after dinner mint", and people being upset when they were looking for something nice to eat after dinner.
• quicksilver: #haskell is a loquacracy!
• quicksilver: It's also the same thing as the Yoneda lemma. That's the thing about maths. Everything is actually the same.
• hugo: i feel like i was drugged with imperative programming, and now im in rehab.
• chrisdone: yo dawg we heard you like haskell so we installed a lambdabot in your ghci so you can monad while you monad
• augustss: ghc had a bug once where it deleted the source file if it had a type error. Quite sensible, I think.

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 97 of HWN, a newsletter covering developments in the Haskell community.

Lots of neat blog posts and funny quotes this week. Don't forget to keep adding haiku to the wiki, and don't miss Alex McLean (yaxu)'s streaming livecoding performance tonight!

Announcements

Spam on HaskellWiki. Ashley Yakeley asked what people would like to do about the increasing amounts of spam on the Haskell wiki, and offered some suggestions.

The Timber compiler 1.0.2. Johan Nordlander announced the first public release of the Timber compiler. Timber is a modern language for building event-driven systems, based around the notion of reactive objects. It is also a purely functional language derived from Haskell, although with a strict evaluation semantics. To try it out, just grab the timberc package on Hackage.

Retrospective on 2008?. Don Stewart proposed the idea of a 2008 retrospective. How would you choose the 10 best new libraries, applications, blog posts, etc. of 2008?

a haskell_proposals subreddit. Jason Dusek announced a subreddit for Haskell library proposals. The idea is that Web 2.0 will help us to allocate our collective talents more efficiently when it comes to extensions (and perhaps clue us in when our pet project is something people really want).

permutation-0.2. Patrick Perry announced a new version of the permutation library, which includes data types for storing permutations. It implements pure and impure types, the latter which can be modified in-place. The main utility of the library is converting between the linear representation of a permutation to a sequence of swaps. This allows, for instance, applying a permutation or its inverse to an array with O(1) memory use.

Data.List.Split. Brent Yorgey announced the creation of a wiki page for Data.List.Split, a hypothetical module containing implementations of every conceivable way of splitting lists known to man, so we no longer have to (1) argue about the 'one true' interface for a 'split' function, or (2) be embarrassed when people ask why there isn't a split function in the standard libraries. Please add code or comments! At some point it will be uploaded as a new module to Hackage.

Announcing Haskell protocol-buffers version 1.2.2. Chris Kuklewicz announced new versions of protocol-buffers, protocol-buffers-descriptor, and hprotoc.

Discussion

A curious monad. Andrew Coppin exhibited an interesting Storage monad, which (it turns out) is similar to ST. An enlightening discussion if you want to understand how ST works and the motivation behind it.

Origins of '$'. George Pollard asked about the origins of the $ operator (low-precedence function application) in the standard libraries, leading to some interesting history and general discussion about notation.

Blog noise

• Jamie Brandon: Zombified GMap. Jamie is determined to get his SoC generalized map library released!

• Philip Wadler: Informatics 1 - Fancy Dress and Competition.

• >>> Eduard - Gabriel Munteanu: Learning Haskell, part 2.

• Martin Sulzmann: Equality, containment and intersection among regular expressions via symbolic manipulation.

• Neil Mitchell: mapM, mapM_ and monadic statements.

• Alson Kemp: A HAML parser for Haskell.

• Chris Done: More Haskell blogging.

• Twan van Laarhoven: Knight in n, part 4: tensors. Part four of Twan's enlightening series on computing knight moves.

• Alex McLean: Saturday night stream. All the cool kids will be watching Alex's streaming livecoding performance TONIGHT, using (among other things) a tool implemented in Haskell.

• David Sankel: Synchronous Events.

• Lennart Augustsson: The OCaml code again.

• Lennart Augustsson: Abstracting on, suggested solutions.

• Lennart Augustsson: The abstraction continues.

• Conal Elliott: Functional interactive behavior.

• Conal Elliott: Trimming inputs in functional reactive programming.

• Mikael Vejdemo Johansson (Syzygy-): J, or how I learned to stop worrying and love the matrix.

• Conal Elliott: Why classic FRP does not fit interactive behavior.

• Clifford Beshers: Functional Programming Marketing.

• Lennart Augustsson: A somewhat failed adventure in Haskell abstraction.

• >>> Joey Hess: haskell and xmonad.

• Andy Gill: The Timber compiler 1.0.2.

• Manuel M T Chakravarty: Not a particularly good article, but....

• >>> Chris Double: Random and Binary IO using Iteratees.

• >>> Chris Double: Not a Tutorial on HAppS.

• "FP Lunch": The new GHC API.

• Luke Palmer: Compact data types.

• Neil Mitchell: F# from a Haskell perspective.

• Real-World Haskell: RWH Now In Store.

• >>> Sebastian Fischer: Constraint Functional-Logic Programming.

• >>> fhtr: Hexagons with Haskell.

• >>> Eduard - Gabriel Munteanu: Learning Haskell.

• Bryan O'Sullivan: Functional programmers on Twitter.

• Martin Sulzmann: Parallel Join Patterns with Guards and Propagation.

• Martin Sulzmann: Multi-set rewrite rules with guards and a parallel execution scheme.

• Martin Sulzmann: STM with control: Communication for retrying transactions.

• Martin Sulzmann: Concurrent Goal-Based Execution of Constraint Handling Rules.

• >>> talkingCode: Haskell, GTK and Multi-Threading.

• >>> Gianfranco Alongi: QuickCheck(ing) the code I C - source.

Quotes of the Week

• quicksilver: Baughn: glFlush? the 80s called, they want your programs back?
• gwern: the best way to optimize a program is to make it lazier or stricter.
• ksf: Perl is obfuscated by design, haskell is designed by obfuscation.
• conal: omg -- i can print right from emacs again. praise be to Linux!
• mmorrow: [I] didn't realize what it really said until after i @remembered it
• blackh: Haskell is great because of all the wonderful things you can't do with it.
• JustinBogner: gitit's 46 dependencies convinced me to install cabal-install, and now I couldn't be happier!
• Anonymous: I'd love to explain to you how to write hello world in Haskell, but first let me introduce you to basic category theory.
• lilac: @type \o-> look at my muscles <lambdabot> forall t nice muscles. t -> nice -> muscles
• ook: (:[])
• oink: <^(oo)^>
• mmorrow: {-# RULES "HAI; CAN HAS STDIO?" id = unsafePerformIO (system "killall -9 breathingMachine && xeyes &" >> return id) #-}
• gwern: We will be welcomed as liberators! I estimate that we will need 50000 haskellers at most and will be able to wind up the occupation quickly

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 96 of HWN, a newsletter covering developments in the Haskell community.

Announcements

Haskell haikus. Gwern Branwen announced that he has collected all known haikus about Haskell and put them on a wiki page. Add more!

Platforms that GHC supports. Simon Peyton-Jones linked to a new page clearly articulating what platforms GHC supports, and what platforms its maintainers would like it to support. If you're interested and willing to help sponsor a "Tier 2" platform, let them know!

Using Data Parallel Haskell. Manuel Chakravarty announced a new wiki page with documentation for Data Parallel Haskell.

DrHylo 0.0.1. Hugo Pacheco announced the release of DrHylo, a tool for deriving hylomorphisms from a restricted Haskell syntax. It is based on the algorithm first presented in the paper Deriving Structural Hylomorphisms From Recursive Definitions at ICFP'96 by Hu, Iwasaki, and Takeichi. The generated code can be run with Pointless Haskell, allowing the visualization of the recursion trees of Haskell functions.

pointless-haskell 0.0.1. Hugo Pacheco announced the release of Pointless Haskell, a library for point-free programming with recursion patterns defined as hylomorphisms, inspired in ideas from the PolyP library. The re-implementation of the library using type functions (in opposition to classes with functional dependencies) enables a type-level view of data types as the fixed points of functors and provides a better experience to the users in terms of code sanity. The library also features the visualization of the intermediate data structure of hylomorphisms with GHood.

Projects that depend on the vty package?. Corey O'Connor asked whether there are any other projects that depend on the vty package. If so, let him know! The package also has a new trac and wiki.

haskell-src-exts 0.4.4. Niklas Broberg announced the release of haskell-src-exts 0.4.4, which adds support for pragmas.

ChristmasTree 0.1. S. Doaitse Swierstra announced the release of the ChristmasTree package, which stands for "Changing Haskell's Read Implementation Such That by Manipulating Abstract Syntax Trees it Reads Expressions Efficiently".

TTTAS. S. Doaitse Swierstra announced the release of TTTAS, a library for typed transformations of typed abstract syntax.

GHood. Hugo Pacheco announced that GHood, a graphical backend for the lightweight Hood Haskell debugger, has now been released as a Cabal package.

Discussion

Animated line art. Andrew Coppin asked for ideas on writing Haskell to generate some animations.

Jobs

Scala job in Boston writing quantitative finance software. Paul Chiusano announced that ClariFI is looking to hire developers with a strong background in functional programming to do a mixture of Scala and Java programming. ClariFI is a small company (about 15 developers) that specializes in software for quantitative investment management. This position is for the Boston office. If you're interested, send him an email.

Blog noise

• Bryan O'Sullivan: Functional programmers on Twitter.

• Conal Elliott: Sequences, segments, and signals.

• >>> Gianfranco Alongi: QuickCheck(ing) the code i C.

• Edward Kmett: The Pointed-Set Comonad.

• Twan van Laarhoven: Knight in n, part 3: rings.

• "The GHC Team": Explicit Stack Traces.

• Real-World Haskell: The Real World Haskell Book Club.

• Real-World Haskell: Real World Haskell: Now in Brazil.

• >>> Matt Hellige: Pointless fun.

• Chung-chieh Shan: The pointed-set monad.

• Holumbus: Status Update.

• Paul R Brown: .editrc Tidbit for ghci.

• Roman Cheplyaka: DPH docs and project status.

• David Sankel: Introducing Reactive: Behaviors.

• Manuel M T Chakravarty: How to use Data Parallel Haskell..

• Conal Elliott: Prettier functions for wrapping and wrapping.

• Twan van Laarhoven: Knight in n, part 2: combinatorics.

• Yi: Prototypes: Encoding OO-style inheritance in Haskell.

• "Osfameron": Functional Pe(a)rls v2 (now with Monads!) at the London Perl Workshop 2008.

• Conal Elliott: Sequences, streams, and segments.

• Conal Elliott: Early inspirations and new directions in functional reactive programming.

• Clemens Fruhwirth: XMonad GridSelect.

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 95 of HWN, a newsletter covering developments in the Haskell community.

Real World Haskell is finally here! Read it online, and/or get your own dead tree copy. Better yet, get two copies, one for yourself and one for a friend. The fifteenth Haskell Communities and Activities Report is also here---check out all the exciting stuff being worked on in the Haskell world!

Announcements

HCAR. Janis Voigtlaender announced the 15th edition of the Haskell Communities and Activities Report (HCAR) is now available!

Not quite another Haskell tutorial, but .... Janis Voigtlaender announced that he submitted his Habilitation thesis last week. The first few chapters of it try to give an introduction to Haskell with emphasis on types and reasoning principles.

hledger 0.2. Simon Michael announced version 0.2 of [http://joyful.com/hledger hledger, a minimal haskell clone of John Wiegley's "ledger" text-based accounting tool.

darcs zlib error workaround. Eric Kow outlined workarounds and future plans for a darcs bug relating to broken CRCs in gzipped patch files. You should read this if you have installed darcs 2.1.2 via the Cabal build method.

Turbinado 0.2. Alson Kemp announced version 0.2 of Turbinado, an easy-to-use, fast web application framework.

Fun with type functions. Simon Peyton-Jones requests examples of compelling use cases for type functions: "can you tell us about the most persuasive, fun application you've encountered, for type families or functional dependencies? Simple is good. It doesn't have to be elaborate: just something that does something useful you could not have done otherwise."

Jobs

PhD Positions in Language-based Security at Chalmers. Andrei Sabelfeld announced the availability of PhD student positions in programming language-based security in the Department of Computer Science and Engineering at Chalmers University of Technology, Sweden. The application deadline is January 30, 2009.

FP Jobs. Julien Sylvestre announced several new permanent positions, based in Paris, with MLstate -- an IT company whose functional programming approach to SaaS and cloud computing has been recently recognized by the French Ministry of Research Innovation Award.

Blog noise

• Dan Piponi (sigfpe): An Approach to Algorithm Parallelisation. Dan illustrates a clever, general framework for parallelizing some not-so-obviously-parallelizable algorithms, based on linear operations over rings.

• Real-World Haskell: First European Orders Now Landing.

• Braden Shepherdson: Pimp Your XMonad #3: Prompt. Braden continues his series on getting the most out of your xmonad configuration with a post describing the Prompt family of extensions.

• Real-World Haskell: Amazon orders now arriving.

• Real-World Haskell: Orders Now Arriving on the US West Coast.

• Luke Palmer: Relative time FRP. A new, more elegant semantics for FRP -- relative time instead of absolute time?

• JP Moresmau: Predictable random for testing.

• Osfameron: London Perl Workshop tomorrow!.

• >>> Phil Ratzsch: Initial Haskell Impressions.

• Chung-chieh Shan: Metalinguistics.

• Alex McLean: Babble. A simple vocable synthesiser that runs in a web browser, written in HaXe.

• Jonathan Tang: Sum types vs. typeclasses.

• Magnus Therning: Re: Redesigning GHC's build system. Magnus's response to a recent post about redoing GHC's build system.

• Real-World Haskell: Real World Haskell is shipping!.

• Twan van Laarhoven: Knight in n, part 1: moves. Twan explores knight-move problems in Haskell.

• Conal Elliott: Semantic editor combinators. An elegant explanation of semantic editor combinators -- a principled framework for building up ways to "edit" components of structured values.

• David Sankel: Why is the Reactive Behavior tutorial taking so long? splitB.

• Chung-chieh Shan: Bowling balls. A nice solution to the bowling-ball problem in Haskell.

• >>> Cory: Developing in "impractical" languages.

• Chris Double: Dynamic Compilation and Loading of Modules in Haskell. A mini-tutorial on using the GHC API.

• Ashish Hanwadikar: More on Haskell DSL. A Haskell DSL for replacing 'make'.

• Luke Palmer: Screw laziness (w.r.t. Fran semantics).

Quotes of the Week

• quicksilver: I ACCIDENTALLY THE WHOLE VERB
• dons: [on ghc's new code generation] <byorgey> so how's the new code gen better? <dons> it's got 98% less dumbs.
• adu: source code is transient, dreams are forever.
• monochrom: n is the nth English letter.
• nomeata: Ah, it seems I'm creating a tuple with more than 62 elements somewhere...
• dons: we had 15 years building ivory towers - time to throw rocks from the top!

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 94 of HWN, a newsletter covering developments in the Haskell community.

Lots of interesting reading this week! Martin Escardo writes about finite search over infinite search spaces expressed as a monad; Conal Elliott writes about the unambiguous choice operator and merging partial values; Luke Palmer on restricted data types and Udon, his system for universal distributed object management; a post about incremental parsing in Yi; Ryan Ingram on parametric higher-order abstract syntax; Issue #12 of the Monad.Reader; and much more!

Announcements

The Monad.Reader - Issue 12: Summer of Code Special. Wouter Swierstra announced Issue 12 of the Monad.Reader, featuring articles by Max Bolingbroke, Roman Cheplyaka, and Neil Mitchell describing their Summer of Code projects.

Turbinado V0.1. Alson Kemp announced the release of Turbinado, an MVC web framework for Haskell.

EEConfig-1.0. Bartosz Wojcik announced the release of EEConfig, a simple library for reading parameters from a configuration file.

Discussion

Proof of a multi-threaded application. Silviu Andrica asked about the possibility of proving the correctness of a multi-threaded application written in Haskell, leading to a discussion of STM, model checking, and related issues.

Monadic bind with associated types + PHOAS?. Ryan Ingram wrote about using parametric higher-order abstract syntax to get the benefits of HOAS (using the embedding language to express binding and substitution) while still being able to inspect or optimize the resulting expressions.

Blog noise

• Ashish Hanwadikar: More on Haskell DSL.

• Real-World Haskell: Real World Haskell in the Wild!.

• Conal Elliott: Merging partial values.

• John Goerzen (CosmicRay): If Programming Languages Were Christmas Carols.

• Conal Elliott: Functional concurrency with unambiguous choice.

• >>> Martin Escardo: A Haskell monad for infinite search in finite time.

• The GHC Team: Redesigning GHC's build system.

• Luke Palmer: Restricted Data Types.

• Yi: Incremental Parsing in Yi.

• Roman Cheplyaka: The Monad Reader, SoC special.

• Darcs: camp irregular news #1.

• Eric Kow (kowey): iterative committing.

• >>> Joey Hess: a year of haskell (not really).

• FP Lunch: The origin of species.

• Luke Palmer: Udon Sketch #2.

• John Goerzen (CosmicRay): Real World Haskell Update.

• Real-World Haskell: When will you see us on bookstore shelves?.

• Paul Potts: Reading Real World Haskell.

• Darcs: darcs 2.1.2 released!.

• Darcs: darcs weekly news #12.

• Russell O'Connor: Haskell Lesson.

• Conal Elliott: Enhancing a Zip.

• Conal Elliott: Proofs for left fold zipping.

• >>> Andrew Birkett: Why do they call it: Referentially transparent.

• >>> Andrew Birkett: Why do they call it: Referentially transparent (II).

Quotes of the Week

• dons: instance Ord OCaml, oh wait. hang on. OCaml can't do that.
• BONUS: as you can see, one of the best parts of Haskell is #haskell.
• ddarius: head [] :: FlyingMonkeys

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 93 of HWN, a newsletter covering developments in the Haskell community.

Community News

Congratulations to Ganesh (aka Heffalump) and Amanda on the birth of Alexander Suresh Kerr Sittampalam!

Announcements

bustle-0.1. Will Thompson announced the release of Bustle, a tool to show diagrams of D-Bus traffic for profiling purposes. It consists of a small C executable to log traffic, and a Gtk+ application which draws diagrams using Cairo.

haskell-src-exts 0.4.1. Niklas Broberg announced a new major release of the haskell-src-exts package, an extension of the standard haskell-src package which handles most common syntactic extensions to Haskell. The new release features a cleaned up AST and names without ugly disambiguation prefixes.

darcs 2.1.1rc2. Eric Kow (kowey) announced the release of darcs 2.1.1rc2, which adds support for GHC 6.10.1. It also includes a Windows bug fix. If you're using GHC 6.10.1 or Windows, give it a try and let the darcs development team know how it works.

hpapi 0.1 release. Michael D. Adams announced the first release of hpapi, Performance API (PAPI) bindings for Haskell. PAPI provides access to various CPU counters such as cache-miss, instruction and pipeline stall counts.

Workflow-0.1. Alberto G. Corona announced the release of Workflow, a library for transparent execution of computations across shutdowns and restarts.

Reactive library (FRP) and mailing list. Conal Elliott announced the release of Reactive, a library for functional reactive programming (FRP), similar to the original Fran but with a more modern interface (using standard type classes) and a hybrid push/pull implementation. It is designed to be used in a variety of contexts, such as interactive 2D and 3D graphics, graphical user interfaces, web services, and automatic recompilation/re-execution. There is also now a mailing list and a feature/bug tracker.

ANN (sorta): OpenGL with extra type safety. Neal Alexander announced a modification of the hOpenGL (and GLFW) source tree to force extra type checking on its various IO actions using the -XGeneralizedNewtypeDeriving extension. The main motivation was for writing concurrent OpenGL applications; the second motivation was to enforce static type checking on commands that can only be executed in certain OpenGL contexts (sending vertex data for example). Hopefully the code will be uploaded to Hackage as a separate package soon.

FieldTrip library (functional 3D) and mailing list. Conal Elliott announced the release of FieldTrip, a library for functional 3D graphics. It is intended for building static, animated, and interactive 3D geometry, efficient enough for real-time synthesis and display. FieldTrip also has a mailing list and a feature/bug tracker.

gitit 0.2 release - wiki using HAppS, git, pandoc. John MacFarlane announced the upload of an early version of gitit, a Haskell wiki program, to HackageDB. Gitit uses HAppS as a webserver, git for file storage, pandoc for rendering the (markdown) pages, and highlighting-kate for highlighted source code. You can try it out here. Comments and patches welcome.

Discussion

Proof that Haskell is RT. Andrew Birkett asked whether there exists a formal proof that the Haskell language is referentially transparent. Such a thing cannot exist, since Haskell has no formally defined semantics, but an interesting discussion about referential transparency and semantics ensued anyway.

What *not* to use Haskell for. Dave Tapley asked how people answer the question, "what does Haskell not do well?" Unfortunately, it seems that there is no good answer to this question and the thread degenerated into a discussion of all the great things you can do with Haskell. If only Haskell sucked more.

Blog noise

• Braden Shepherdson: Pimp Your XMonad #2: SmartBorders. The second in Braden's series on customising xmonad explains how to use the NoBorders extension to get rid of window borders when you don't want them.

• Real-World Haskell: Real World Haskell Electronic Edition Now On Sale.

• Conal Elliott: More beautiful fold zipping.

• >>> Stephen: Endless Cavern. A procedurally-generated tessellated-cavern flying game.

• Twan van Laarhoven: Arrays without bounds. Unbounded arrays (with O(1) amortized access) in Haskell!

• "The GHC Team": Comparing concurrent linked-list implementations in Haskell.

• Ketil Malde: 454 sequencing and parsing the SFF binary format.

• Tom Schrijvers: Type Invariants for Haskell. Tom, Louis-Julien Guillemette, and Stefan Monnier's paper on Type Invariants for Haskell, which was recently accepted at PLPV'09.

• Conal Elliott: Another lovely example of type class morphisms. Conal elaborates on Max Rabkin's recent post on composable folds.

• Real-World Haskell: Beautiful Parallelism: Harnessing Multicores with Haskell. Don Stewart will be talking about programming mainstream multicore systems with Haskell at SC'08 next week in Austin, Texas.

• Luke Palmer: Sketch of Udon (Version Control/Packaging system). Luke sketches a high-level design for a distributed storage system that could be used as the basis for solving a number of interesting problems.

• Galois, Inc: Galois awarded NASA research contract.

• Mark Jason Dominus: Representing ordinal numbers in the computer and elsewhere.

• The GHC Team: Bootstrapping cabal-install.

• Jason Dagit: Phantom Types, Existentials and Controlling Unification -- Part 1.

• Ben Moseley: Why does Functional Programming matter?.

Quotes of the Week

• BMeph: In a functional world, students would ask how that index shadowing works in those funny 'for' statements...
• digit: i'm almost annoyed at how brilliant xmonad is.
• _pizza_: i think Haskell is undoubtedly the world's best programming language for discovering the first few dozen numbers in the Fibonacci sequence over IRC.
• adu: let uncat3 [] = [] ; uncat3 xs = (let (ys, zs) = splitAt 3 xs in ys : uncat3 zs) ; getFrom x y = map (x !!) $ map (fromIntegral . ((\x -> fromIntegral $ foldl (.|.) (0::Word8) (zipWith (\c n -> if c then bit n else (0::Word8)) x [0..2])) :: [Bool] -> Int)) $ reverse . uncat3 . reverse . concat . map (((\x -> map (testBit x) [7,6..0]) :: Word8 -> [Bool]) . fromIntegral . ord) $ y in getFrom " HWdelor" "e\184-\235"
• Beelsebob: ((:[]) "pigs eat") <^(++)^> ((:[]) " robot monkies")

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 92 of HWN, a newsletter covering developments in the Haskell community.

GHC 6.10 is released!! Go forth and drool over its new features. Be sure to have the editline libraries (libedit-dev on Debian/Ubuntu, for example) installed before you try building it.

Announcements

GHC version 6.10.1. Ian Lynagh announced the release of GHC version 6.10.1! This new major release features a number of significant changes, including wild-card patterns, punning, and field disambiguation in record syntax; generalised quasi-quotes; generalised SQL-like list comprehensions; view patterns; a complete reimplementation of type families; parallel garbage collection; a new extensible exception framework; a more user-friendly API; included Data Parallel Haskell (DPH); and more! See the full release notes for more information.

new community.haskell.org features: webspace, mailing lists. Ian Lynagh announced that the community server, http://community.haskell.org/, has two new features for hosted projects: project webspace, and project mailing lists.

GHC blog. Simon Marlow has set up a GHC blog. This is for all things related to GHC, particularly people working on GHC to blog about what they're up to. If you want a write-bit, sign up for a wordpress account, let Simon know your account name, and blog away! The GHC blog should be syndicated on Planet Haskell soon.

Haddock 2.4.0. David Waern announced a new release of Haddock, the Haskell documentation tool. This is a later version than the one shipped with GHC 6.10.1, which is version 2.3.0. That version will not be released on Hackage since it only builds with GHC 6.10.1 (by accident, actually). Besides adding back support for earlier GHC versions, this release contains some more fixes and support for HTML frames.

htags-1.0. David Sankel announced the htags package, a tag file generator to enable extra functionality in editors like vim. It expands upon hasktags by using a full Haskell 98 parser and options for recursion.

Haskell Quick Reference (1-page PDF). Malcolm Wallace sent a 1-page Haskell quick reference prepared for a recent Haskell tutorial. Permission is granted for anyone to distribute it more widely as they wish, in the hope that it might be useful. Editable sources can be passed along if anyone would like to extend it.

Proposal for associated type synonyms in Template Haskell. Thomas van Noort submitted a proposal for adding associated type synonyms to Template Haskell. Comments are welcomed.

announce [("InfixApplicative", 1.0), ("OpenGLCheck", 1.0), ("obj", 0.1)]. Thomas Davie announced the upload of a few packages to Hackage which he has produced while working at Anygma. obj-0.1 is a library for loading and writing obj 3D models; OpenGLCheck-1.0 is a micro-package containing instances of Arbitrary for the data structures provided in Graphics.Rendering.OpenGL; and InfixApplicative-1.0 is a second micro-package containing a pair of functions (<^) and (^>) which can be used to provide an infix version of liftA2 applied to an operator.

Graphalyze-0.5 and SourceGraph-0.3. Ivan Lazar Miljenovic announced the latest versions of Graphalyze and SourceGraph, which fix a couple of bugs in the previous versions.

zlib and bzlib 0.5 releases. Duncan Coutts announced updates to the zlib and bzlib packages, featuring a slightly nicer extended API. The simple API that most packages use is unchanged. There is also a new parameter to control the size of the first output buffer; this lets applications save memory when they happen to have a good estimate of the output size.

Discussion

Efficient parallel regular expressions. Martijn van Steenbergen asked about efficiently running multiple regular expressions in parallel, leading to an interesting discussion of regular expressions and various parsing methods and libraries.

Problems with strictness analysis?. Patai Gergely started an informative discussion about strictness, laziness, strictness analysis, and compiler optimization. If you don't know a lot about these topics but would like to learn, this thread is a good starting point!

Jobs

1-year postdoc position in Chalmers Functional Programming group. John Hughes announced a position for a post-doctoral researcher with the Chalmers Functional Programming Group, with a one-year tax-free stipend funded by Intel. The funded project will develop a Domain Specific Language (DSL) for high level modelling, design and analysis of hardware and microarchitectures.

Blog noise

• Edward Kmett: Still Alive. Edward is still alive but sadly lost a few recursion scheme posts. =(

• >>> Max Rabkin: Beautiful folding. A very cool post about composable folds!

• Eric Kow (kowey): timesheet helper.

• Philip Wadler: A bizarre function over streams.

• David Sankel: Introducing Reactive: Events. A very readable introduction to the Reactive library. I look forward to reading more!

• "FP Lunch": Numbers vs Sets.

• Mark Jason Dominus: Addenda to recent articles 200810.

• Darcs: darcs weekly news #11.

• >>> Ken G.: Haskell?. Ken shares some thoughts on Real World Haskell.

• Real-World Haskell: Some early reviews.

• David Sankel: freeglut + Windows + HOpenGL + HGLUT.

• GHC mutterings: GHC 6.10.1 is out!.

• Chung-chieh Shan: Cognitive jobs.

• London Haskell Users Group: Duncan Coutts: The Haskell Platform. The abstract for Duncan's talk at the London HUG.

• Well-Typed.Com: GHC 6.10.1 released!.

• Well-Typed.Com: Haskell Platform talk at the London Haskell Users Group.

• Mark Wassell: GIS with Haskell 1.

• >>> phoenix: Haskell Tricks: Indexing a List. Getting the index of an element satisfying a predicate by zipping.

• JP Moresmau: Haskell for counting votes!. JP illustrates five different voting methods with some Haskell implementations.

• Ivan Lazar Miljenovic: Graph Theoretic Analysis of Relationships within Discrete Data.

• Braden Shepherdson: Pimp Your XMonad #1: Status bars. The first in a planned series of articles on not-so-well-known ways to extend your xmonad configuration.

• >>> Cory: Euler and Haskell. Cory just started learning Haskell (a "fun, slightly ridiculous language") via Project Euler.

• >>> Sadek Drobi: Code Safety and Correctness is a matter of Mindset Cultured by the Language.

• Well-Typed.Com: zlib and bzlib package updates.

• >>> Bryan St. Amour: Haskell Solution To The Farmer Problem.

• >>> Nathan Hartman: Haskell, Lambert, and the Clarke Ellipsoid. Nathan has started porting a map projection library to Haskell.

• David Sankel: Analysis of lazy-stream programs..

Quotes of the Week

• Cory: Any language which makes frequent use of monads, functors and has a wikibook describing its relation to category theory is the result of an evil genius (or several, to be precise).
• mmorrow: in langs with dependent types, you can just map numbers directly to types instead of having to ride a unicycle along a tightrope while battling an unruly gang of monkeys with knives.
• conal: -fsemantics-shemantics
• roconnor: all sorts of wonderful things could be done if we are less anal about bottoms. No pun intended.

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .

Welcome to issue 91 of HWN, a newsletter covering developments in the Haskell community.

Announcements

blas version 0.6. Patrick Perry announced a new version of the Haskell BLAS bindings, now with support for the ST monad!

darcs hacking sprint #1 (report). Eric Y. Kow summarized the progress made during the darcs hacking sprint last weekend. Looks like exciting stuff! Much more detail and links can be found in Eric's original email.

LAST CALL: Haskell Communities and Activities Report. Janis Voigtlaender is extending the submission deadline for the 15th edition of the Haskell Community and Activities Report by a few days. If you haven't already, please write an entry for your new project or update your old entry.

Data.TCache 0.5.1. Alberto G. Corona announced the release of Data.TCache, which implements a transactional cache with configurable persistence. It tries to simulate Hibernate for Java or Rails for Ruby; the main difference is that transactions are done in memory trough STM.

multirec-0.1. Andres Loeh announced the release of the multirec package, which provides a mechanism to talk about fixed points of systems of datatypes that may be mutually recursive. On top of this representations, generic functions such as the fold or the Zipper can then be defined.

Making 'Super Nario Bros.' in Haskell. Korcan Hussein linked to a super mario brothers clone which was written in Haskell!

Chart-0.9. Tim Docker announced the 0.9 release of the Chart library, a library for drawing 2D charts.

Publication of InputYourData.com + Project Announcement. Enzo Haussecker announced the publication of InputYourData.com, an online tool, written in Haskell, for financial, mathematical and scientific calculations. Enzo also described an idea to create a similar website where web applications are created by the user. If you are intrigued by this project and have substantial experience in designing Haskell-based web applications, please send Enzo your resume and a brief summery of why you are interested.

Blog noise

• Mark Jason Dominus: Atypical Typing. Mark describes his OOPSLA talk about Haskell's type system.

• Eric Kow (kowey): official darcs blog!.

• Ben Moseley: 2 Minute intro to Associated Types / Type Families.

• Ivan Lazar Miljenovic: Honours + LXDE. Ivan discusses the status of his Haskell-oriented Mathematics Honours thesis.

• Jason Dagit: Darcs Hacking Sprint - Summary from Portland Team.

• Eric Kow (kowey): darcs hacking sprint - Team Brighton Day 2.

• Dan Piponi (sigfpe): Operads and their Monads.

Quotes of the Week

• lispy: I just wanted to make sure that this was illegal first
• quicksilver: it doesn't entirely help that SQL is a series of broken standards layered over very poor decisions by large corporations
• Baughn: SingInTime> hello world <Baughn> SingInTime: Type mismatch: Expected type: IRC [a], inferred type: IO ()

About the Haskell Weekly News

New editions are posted to the Haskell mailing list as well as to the Haskell Sequence and Planet Haskell. RSS is also available, and headlines appear on haskell.org.

To help create new editions of this newsletter, please see the information on how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get http://code.haskell.org/~byorgey/code/hwn/ .