August 2010 - Haskell

ANNOUNCE: ioctl 0.0.1
by Maciej Piechotka 13 Sep '15

13 Sep '15

A package for type-safe I/O control. Currently only ioctl is supported. Currently simply a extract from my tuntap fork TODO: - Return the integer as well as structure (will break the API) - Port for Windows Network.Socket.IOCtl (as soon as I manage to setup some sane environment on this platform) - Wrapping around DeviceIoControl Example (in hsc): data NotRead = NotRead instance NotRead Int where ioctlReq _ = #const FIONREAD notRead s = ioctlsocket' s NotRead Regards

2 1

Announcing Djinn, version 2004-12-11, a coding wizard
by Lennart Augustsson 07 Apr '11

07 Apr '11

Howdy, y'all! I've written a small program that takes a (Haskell) type and gives you back a function of that type if one exists. It's kind of fun, so I thought I'd share it. It's probably best explained with a sample session. calvin% djinn Welcome to Djinn version 2005-12-11. Type :h to get help. # Djinn is interactive if not given any arguments. # Let's see if it can find the identity function. Djinn> f ? a->a f :: a -> a f x1 = x1 # Yes, that was easy. Let's try some tuple munging. Djinn> sel ? ((a,b),(c,d)) -> (b,c) sel :: ((a, b), (c, d)) -> (b, c) sel ((_, v5), (v6, _)) = (v5, v6) # We can ask for the impossible, but then we get what we # deserve. Djinn> cast ? a->b -- cast cannot be realized. # OK, let's be bold and try some functions that are tricky to write: # return, bind, and callCC in the continuation monad Djinn> type C a = (a -> r) -> r Djinn> returnC ? a -> C a returnC :: a -> C a returnC x1 x2 = x2 x1 Djinn> bindC ? C a -> (a -> C b) -> C b bindC :: C a -> (a -> C b) -> C b bindC x1 x2 x3 = x1 (\ c15 -> x2 c15 (\ c17 -> x3 c17)) Djinn> callCC ? ((a -> C b) -> C a) -> C a callCC :: ((a -> C b) -> C a) -> C a callCC x1 x2 = x1 (\ c15 _ -> x2 c15) (\ c11 -> x2 c11) # Well, poor Djinn has a sweaty brow after deducing the code # for callCC so we had better quit. Djinn> :q Bye. To play with Djinn do a darcs get http://darcs.augustsson.net/Darcs/Djinn or get http://darcs.augustsson.net/Darcs/Djinn/Djinn.tar.gz Then just type make. (You need a Haskell 98 implementation and some libraries.) And then start djinn. For the curious, Djinn uses a decision procedure for intuitionistic propositional calculus due to Roy Dyckhoff. It's a variation of Gentzen's LJ system. This means that (in theory) Djinn will always find a function if one exists, and if one doesn't exist Djinn will terminate telling you so. This is the very first version, so expect bugs. :) Share and enjoy. -- Lennart

8 13

ANN: mute-unmute-0.2.0.0
by Krzysztof Skrzętnicki 01 Sep '10

01 Sep '10

* Hello! I'm pleased to announce a small utility program I wrote recently. Today I pushed version 0.2.0.0 of mute-unmute to Hackage, from with you can cabal-install it right now (following the usual 'update' step). What it does? It's simple: it will mute the sound when you lock your screen and unmute it back again when you unlock it. Why anyone would need such program? Well, this is a little bit more complicated. I work in "open space" kind of office. It can get quite noisy there. I often sit with headphones on, but when I walk away from my desk I put them down and lock my screen. Here comes uncomfortable moment: when I remove my headphones suddenly people around me who doesn't use their headphones now start to hear the music I listen to. And they don't always like it, so I manually mute the sound to make happy. But now, instead of doing this task by hand I have a program do it for me :-) Unfortunately this kind of programs tend to be pretty much platform specific. Current version supports the recent versions of Gnome and KDE, but needs ALSA. It's quite common setup, but if you happen to have a different one you can easily hack the code (it's very straightforward) and send me patches. Patches are always welcome. The source repo is on Github and released versions are on Hackage: Github: http://github.com/Tener/mute-unmute <http://github.com/Tener/mute-unmute#> Hackage: http://hackage.haskell.org/package/mute-unmute Example use: ~/ mute-unmute # first session, it will ask for configuration options mute-unmute: Creating config directory... mute-unmute: Mute config is missing... Mute sound card and press RETURN mute-unmute: Unmute config is missing... Unmute sound card and press RETURN mute-unmute: Session: UnixAbstract {addrPath = "/tmp/dbus-1tB1AEUcgg", addrGuid = Just "19ec85e3778816ad38a77bbf0000003f"} mute-unmute: Connected mute-unmute: Handler added: [MatchType Signal,MatchInterface "org.gnome.ScreenSaver",MatchMember "ActiveChanged",MatchPath "/org/gnome/ScreenSaver"] mute-unmute: Handler added: [MatchType Signal,MatchInterface "org.freedesktop.ScreenSaver",MatchMember "ActiveChanged",MatchPath "/ScreenSaver"] ^C ~/ mute-unmute # remembers previous options which can be changed by calling with --store switch mute-unmute: Session: UnixAbstract {addrPath = "/tmp/dbus-1tB1AEUcgg", addrGuid = Just "19ec85e3778816ad38a77bbf0000003f"} mute-unmute: Connected mute-unmute: Handler added: [MatchType Signal,MatchInterface "org.gnome.ScreenSaver",MatchMember "ActiveChanged",MatchPath "/org/gnome/ScreenSaver"] mute-unmute: Handler added: [MatchType Signal,MatchInterface "org.freedesktop.ScreenSaver",MatchMember "ActiveChanged",MatchPath "/ScreenSaver"] mute-unmute: Message {mType = Signal, mFlags = [NoReplyExpected], mSerial = 31, mPath = Just "/org/gnome/ScreenSaver", mInterface = Just "org.gnome.ScreenSaver", mMember = Just "ActiveChanged", mErrorName = Nothing, mReplySerial = Nothing, mDestination = Nothing, mSender = Just ":1.19", mBody = [Variant (True) {- b -}]} mute-unmute: Lock screen mute-unmute: Message {mType = Signal, mFlags = [NoReplyExpected], mSerial = 32, mPath = Just "/org/gnome/ScreenSaver", mInterface = Just "org.gnome.ScreenSaver", mMember = Just "ActiveChanged", mErrorName = Nothing, mReplySerial = Nothing, mDestination = Nothing, mSender = Just ":1.19", mBody = [Variant (False) {- b -}]} mute-unmute: Unlock screen ^C * You can get usage information with --help switch: *~/ mute-unmute --help *mute-unmute --store ask for mute and unmute configurations --store-mute ask for mute configuration --store-unmute ask for unmute configuration -d --daemon wait for screensaver state changes -h, -? --help show help There isn't much more I can say. I hope you find the program at least educational (as a simple example of DBus usage) if not useful. Best regards, Krzysztof Skrzętnicki

2 1

ANNOUNCE: iteratee-compress 0.1
by Maciej Piechotka 31 Aug '10

31 Aug '10

Iteratee-compress provides compressing and decompressing enumerators. Currently only gzip is provided but at least bzip is planned. Additionally more fine-control over stream (i.e. flushing) is planned. ---- Library currently depends on zlib haskell library only for sharing parameters data. However no zlib function is called (the needed functions are not exported) and the symbols it uses from necessity are deprecated. Would it be better to copy the parameters from zlib and drop the dependency? Please note also that the library do not bundle zlib (C) as zlib (Haskell) do.

2 2

ANNOUNCE: Industrial Haskell Group round 2
by Ian Lynagh 31 Aug '10

31 Aug '10

Hi all, The Industrial Haskell Group is now in the process of beginning the second round of the collaborative development scheme. If your company is interested in becoming a member of the IHG, please get in contact with us during the next month at info(a)industry.haskell.org To get an idea of what the IHG does and how it works, please see the website: http://industry.haskell.org/status and feel free to drop us an e-mail if you have any questions. -- Ian Lynagh, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

1 0

HLPP 2010 Call for participation
by Frederic Loulergue 28 Aug '10

28 Aug '10

Fourth International Workshop on High-level Parallel Programming and Applications (HLPP 2010) Baltimore, Maryland, September 25, 2010 Affiliated to ICFP 2010 http://www.icfpconference.org/icfp2010 Sponsored by ACM SIGPLAN Aims and Scope As processor and system manufacturers adjust their roadmaps towards increasing levels of both inter and intra-chip parallelism, so the urgency of reorienting the mainstream software industry towards these architectures grows. At present, popular parallel and distributed programming methodologies are dominated by low-level techniques such as send/receive message passing, or equivalently unstructured shared memory mechanisms. Higher-level, structured approaches offer many possible advantages and have a key role to play in the scalable exploitation of ubiquitous parallelism. This workshop provides a forum for discussion and research about such high-level approaches to parallel programming. Workshop Program 08:00-08:45: Continental Breakfast 09:00-10:00: Invited Talk Zhenjiang Hu (National Institute of Informatics) Calculational Parallel Programming 10:00-10:30: Break 10:30-12:00: Session "Skeletal Parallelism" Johan Enmyren and Christoph Kessler SkePU: A Multi-Backend Skeleton Programming Library for Multi-GPU Systems Kiminori Matsuzaki and Kento Emoto Lessons from Implementing the BiCGStab Method with SkeTo Library Oleg Lobachev and Rita Loogen Estimating Parallel Performance, A Skeleton-Based Approach 12:00-12:30: Session "Verification of High-Level Parallel Programs" Frédéric Gava and Jean Fortin BSP-Why: an intermediate language for deductive verification of BSP programs 12:30-02:00: Lunch 02:00-03:00: Invited Talk Phil Trinder (Heriot-Watt University) SymGrid-Par: A Standard Skeleton-Based Framework for Computational Algebra Systems 03:00-03:30: Break 03:30-04:30: Session "Bulk Synchronous Parallelism" Md. Mostofa Ali Patwary, Rob H. Bisseling and Fredrik Manne Parallel Greedy Graph Matching using an Edge Partitioning Approach Joel Falcou, Khaled Hammidouche and Daniel Etiemble Hybrid Bulk Synchronous Parallelism Library for Clustered SMP Architectures 04:30-05:00: Break Programme Committee Anne Benoit (ENS Lyon, France) Murray Cole (University of Edinburgh, UK) Alexandros Gerbessiotis (New Jersey Institute of Technology, USA) Christoph Kessler (Linköpings Universitet, Sweden) Herbert Kuchen (University of Muenster, Germany) Rita Loogen (University of Marburg, Germany) Frédéric Loulergue (University of Orléans, France), chair Kiminori Matsuzaki (Kochi University of Technology, Japan) Samuel Midkiff (Purdue University, USA) Susanna Pelagatti (University of Pisa, Italy) Sukyoung Ryu (Korea Advanced Institute of Science and Technology, Korea) Kazunori Ueda (Waseda University, Japan) ----- Fin du message transféré -----

1 0

ANNOUNCE: ListLike-1.0.2
by John Lato 27 Aug '10

27 Aug '10

Hello, I am pleased to announce that, with the permission of John Goerzon, I will be maintaining the ListLike package. John Goerzon has made many significant contributions to Haskell projects and the community, and I hope that I will be able to keep this package available to the high standard of his work. John Lato

1 0

MSFP - early registration: 30 August
by Venanzio Capretta 27 Aug '10

27 Aug '10

Early registration for MSFP closes on 30 August. To register, please use the ICFP registration page: https://regmaster3.com/2010conf/ICFP10/register.php Third Workshop on MATHEMATICALLY STRUCTURED FUNCTIONAL PROGRAMMING 25 September 2010, Baltimore, Maryland, USA A satellite workshop of ICFP 2010 PRESENTATION The workshop on Mathematically Structured Functional Programming is devoted to the derivation of functionality from structure. It is a celebration of the direct impact of Theoretical Computer Science on programs as we write them today. Modern programming languages, and in particular functional languages, support the direct expression of mathematical structures, equipping programmers with tools of remarkable power and abstraction. Monadic programming in Haskell is the paradigmatic example, but there are many more mathematical insights manifest in programs and in programming language design: Freyd-categories in reactive programming, symbolic differentiation yielding context structures, and comonadic presentations of dataflow, to name but three. This workshop is a forum for researchers who seek to reflect mathematical phenomena in data and control. The first MSFP workshop was held in Kuressaare, Estonia, in July 2006. Selected papers were published as a special issue of the Journal of Functional Programming (volume 19, issue 3-4). The second MSFP workshop was held in Reykjavik, Iceland as part of ICALP 2008. PROGRAM 9:00 - 10:00 Invited talk: Amy Felty, "Hybrid: Reasoning with Higher-Order Abstract Syntax in Coq and Isabelle" 10:00 - 10:30 break 10:30 - 11:00 Chantal Keller and Thorsten Altenkirch, "Normalization by hereditary substitutions" 11:00 - 11:30 Paul Tarau, "Hereditarily finite representations of natural numbers and self delimiting codes" 11:30 - 12:30 Tutorial: Adam Chlipala, "Foundational Program Verification in Coq with Automated Proofs" 12:30 - 2:00 lunch break 2:00 - 3:00 Invited talk: Martín Escardó, "What Tic-Tac-Toe, the Tychonoff Theorem, and the Double-Negation Shift have in common" 3:00 - 3:30 break 3:30 - 4:00 Kazuyuki Asada, "Arrows are Strong Monads" 4:00 - 4:30 Adam Gundry, Conor McBride and James McKinna, "Type inference in context" 4:30 - 5:00 break 5:00 - 6:00 Tutorial: Peter Morris, "Epigram Prime: A Demonstration" Workshop homepage: http://cs.ioc.ee/msfp/msfp2010/ Registration link: https://regmaster3.com/2010conf/ICFP10/register.php Local arrangements: http://www.icfpconference.org/icfp2010/local.html

1 0

FW: [TYPES/announce] CUFP 2010 Call for Participation
by Simon Peyton-Jones 27 Aug '10

27 Aug '10

Dear Haskellers CUFP should be a lot of fun this year. Do consider going. Simon Commercial Users of Functional Programming Workshop (CUFP) 2010 Call for Participation Sponsored by SIGPLAN Co-located with ICFP 2010 _________________________________________________________ 1 - 2 October 2010 Baltimore (MD), USA http://cufp.org/conference/schedule/2010 Reservation will be available through ICFP's website: http://www.icfpconference.org/icfp2010 _________________________________________________________ Functional programming languages have been a hot topic of academic research for over 35 years, and have seen an ever larger practical impact in settings ranging from tech startups to financial firms to biomedical research labs. At the same time, a vigorous community of practically-minding functional programmers has come into existence. CUFP is designed to serve this community. The annual CUFP workshop is a place where people can see how others are using functional programming to solve real world problems; where practitioners meet and collaborate; where language designers and users can share ideas about the future of their favorite language; and where one can learn practical techniques and approaches for putting functional programming to work. CUFP 2010 will feature three hour Functional Programming tutorials given by language experts on the first day and Experience and Technical Talks on day two. Attendees may attend either or both days. Talks Program, October 2nd 2010 Luke Hoban (Microsoft) Keynote: F#: Embracing Functional Programming in "Visual Studio 2010" Sally A Browning (Galois Inc) Cryptol, a DSL for Cryptographic Algorithms Marius Eriksen (Twitter) Scaling Scala at Twitter Michael Fogus (Science Applications International Corporation) Naïveté vs. Experience - or, How We Thought We Could Use Scala and Clojure, and How We Actually Did It Neal Glew & Leaf Petersen (Intel) Functional Language Compiler Experiences at Intel Warren Harris (Metaweb) Functional Programming at Freebase Warren A. Hunt, Jr. (U. of Texas) Eating One’s Own Dog Food Rusty Klophaus (Basho Technologies) Riak Core: Building Distributed Applications Without Shared State Howard Mansell (Credit Suisse) Eden: An F#/WPF frameworok for building GUI tools Erik Meijer (Microsoft) Reactive Extensions (Rx): Curing Your Asynchronous Programming Blues Tutorial Program, October 1st 2010 Morning: Clojure (Aaron Bedra) Building robust servers with Erlang (Martin Logan) High Performance Haskell (Johan Tibell) Afternoon: F# 2.0 - A day at the beach (Rick Minerich) Implementing web sites with Scala and Lift (David Pollak) Camlp4 and Template Haskell (Nicolas Pouillard, Jake Donham) There will be no published proceedings, as the meeting is intended to be more a discussion forum than a technical interchange. For more information, for more information, including presentation abstracts and the most recent schedule information, visit http://cufp.org See you there!

1 0

Haskell 2010 Call for Participation
by Jeremy.Gibbons＠comlab.ox.ac.uk 26 Aug '10

26 Aug '10

Haskell 2010 ACM SIGPLAN Haskell Symposium 2010 Baltimore MD, United States 30th September, 2010 CALL FOR PARTICIPATION http://www.haskell.org/haskell-symposium/2010/ The ACM SIGPLAN Haskell Symposium 2010 will take place on Thursday 30th September, co-located with the 2010 International Conference on Functional Programming (ICFP), in Baltimore, Maryland. The early registration deadline is 30th August. Accepted Papers "A generic deriving mechanism for Haskell", José Pedro Magalhães, Atze Dijkstra, Johan Jeuring and Andres Löh. "Hoopl: A Modular, Reusable Library for Dataflow Analysis and Transformation", Norman Ramsey, João Dias and Simon Peyton Jones. "A Systematic Derivation of the STG Machine Verified in Coq", Maciej Pirog and Dariusz Biernacki. "Species and Functors and Types, Oh My!", Brent Yorgey. "Experience Report: Using Hackage to Inform Language Design", J. Garrett Morris. "Concurrent Orchestration in Haskell", John Launchbury and Trevor Elliott. "Scalable Event Handling for GHC", Bryan O'Sullivan and Johan Tibell. "Seq no more: Better Strategies for Parallel Haskell", Simon Marlow, Patrick Maier, Hans-Wolfgang Loidl, Mustafa Aswad and Phil Trinder. "The performance of Haskell containers package", Milan Straka. "Nikola: Embedding Compiled GPU Functions in Haskell", Geoffrey Mainland and Greg Morrisett. "An LLVM Backend For GHC", David Terei and Manuel Chakravarty. "Supercompilation by Evaluation", Max Bolingbroke and Simon Peyton Jones. "Exchanging Sources Between Clean and Haskell - A Double-Edged Front End for the Clean Compiler", John van Groningen, Thomas van Noort, Peter Achten, Pieter Koopman and Rinus Plasmeijer. "Invertible syntax descriptions: Unifying parsing and pretty printing", Tillmann Rendel and Klaus Ostermann. Links * http://www.haskell.org/haskell-symposium, the permanent homepage of the Haskell Symposium. * http://www.haskell.org/haskell-symposium/2010, the 2010 Haskell Symposium web page. * http://www.icfpconference.org/icfp2010, the ICFP 2010 web page. * https://regmaster3.com/2010conf/ICFP10/register.php the ICFP (including Haskell Symposium) registration page. Programme Committee * Jeremy Gibbons, University of Oxford (chair) * James Cheney, University of Edinburgh * Duncan Coutts, Well-Typed LLP * Sharon Curtis, Oxford Brookes University * Fritz Henglein, Kobenhavns Universitet * Tom Schrijvers, Katholieke Universiteit Leuven * Chung-chieh Shan, Rutgers - The State University of New Jersey * Martin Sulzmann, Informatik Consulting Systems AG * Wouter Swierstra, Vector Fabrics * Peter Thiemann, Universitaet Freiburg * Andrew Tolmach, Portland State University * Malcolm Wallace, Standard Chartered Bank

1 0