- Haskell - Haskell.org

ANN: vty-4.2.1.0
by Corey O'Connor 28 Dec '09

28 Dec '09

http://hackage.haskell.org/package/vty 4.2.1.0 * GHC 6.12.1 support * API changes: * Attr record accessor fore_color changed to attr_fore_color * Attr record accessor back_color changed to attr_back_color * Attr record accessor style changed to attr_style * Added an "inline" display attribute changing DSL: * put_attr_change applies a display attribute change immediately to a terminal * For instance, can be used to change the display attrbiutes of text output via putStrLn and putStr. EX: "put_attr_change $ back_color red" will set the background color to red. * Changes do not apply to a Picture output via output_picture. * See Graphics.Vty.Inline * Moved all IO actions into any monad an instance of MonadIO Short example of Graphics.Vty.Inline: import Graphics.Vty import Graphics.Vty.Inline main = do t <- terminal_handle putStr "Not styled. " put_attr_change t $ back_color red >> apply_style underline putStr " Styled! " put_attr_change t $ default_all putStrLn "Not styled." release_terminal t return () Cheers, Corey O'Connor

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ANN: stm-io-hooks-0.6.0
by Peter Robinson 27 Dec '09

27 Dec '09

A new announcement, as the interface has changed quite a bit (e.g. 'onRetry' is gone) and previous versions had a rare but annoying bug due to the unpredictability of 'unsafeIOToSTM'. >From the package description: ----- This library provides an STM monad with commit and retry IO hooks. A retry-action is run (at least once) if the transaction retries, while commit-actions are executed iff the transaction commits. The AdvSTM monad also gives some atomicity guarantees for commit-actions: * When a TVar is modified in a transaction and this transaction commits, the update remains invisible to other threads until the corresponding onCommit action is run. * If the onCommit action throws an exception, the original values of the modified TVars are restored. Note: This library was inspired by the AdvSTM monad on the Haskell Wiki (see http://haskell.org/haskellwiki/?title=New_monads/MonadAdvSTM) Feedback is welcome! -----

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ANNOUNCE: CPython / libpython bindings
by John Millikin 27 Dec '09

27 Dec '09

CPython, the primary implementation of the Python language, has a C API for embedding Python into applications and writing extension modules[1]. The cpython[2] package is a binding to this API. It's not a complete binding yet -- there's a couple areas where I haven't figured out how to represent the C-ish idioms -- so it's not yet possible to do things like implement extension modules[3], run code directly from a file[4], or compile Python strings to code[4]. Hackage can't build docs because it doesn't have the Python development libraries installed, so I've uploaded them to <http://ianen.org/haskell/bindings/cpython/api-documentation/>. If you encounter any build errors, or have wishes / ideas on which parts of the API to add to the binding, please say so. I will add parts as I figure them out, but wanted to get a working version out ASAP so people can play with it. [1] http://docs.python.org/3.1/c-api/ [2] http://hackage.haskell.org/package/cpython/ [3] http://docs.python.org/3.1/c-api/module.html#initializing-c-modules [4] http://docs.python.org/3.1/c-api/veryhigh.html

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ANNOUNCE: graphviz-2999.8.0.0
by Ivan Lazar Miljenovic 26 Dec '09

26 Dec '09

I am pleased to announce the latest release of my graphviz [1] library, which provides bindings and helper functions for use with the Graphviz [2] suite of graph visualisation programs. [1] http://hackage.haskell.org/package/graphviz [2] http://www.graphviz.org/ For the most part, this release has a compatible API with the 2999.7.0.0 version; the only exceptions to this are the runGraphviz and runGraphvizCommand functions in Data.GraphViz.Commands; I released after the last release that it might be useful to have these return the filenames of the files created rather than just indicating success, especially when using addExtension (from the same module) to add the correct extension to a provided filename. The rest of the changes to this release are: * Added support for generalised DotGraphs; this optional representation removes the restriction of ordering of Dot statements. This allows for greater flexibility of how to specify Dot code. As an offshoot from this, most relevant functions now utilise a new DotRepr class that work with both DotGraphs and the new GDotGraphs; this shouldn't affect any code already in use. * With the prompting of Noam Lewis, the augmentation functions have been revamped in two ways: - Now contains support for multiple edges. - The ability to perform "manual" augmentation if greater control is desired. * Add a preview function to quickly render and visualise an FGL graph using the Xlib canvas. * Added a pseudo-inverse of the FGL -> Dot functions (a graph is created, but the original node and edge labels are unrecoverable). * The Printing and Parsing modules have been moved (from Data.GraphViz.Types to Data.GraphViz). In the near future, this library is also likely to contain support for record shapes for graph nodes thanks to Minh Thu. If you want/require any additional features in graphviz, you too can do what countless (well, OK, not actually countless per-se) people like Noam and Thu have done: bug me to do it or send me a patch! ;-) (I hope that I don't have to make yet another release soon fixing an obvious flaw as soon as I actually start using this release myself...) -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com IvanMiljenovic.wordpress.com

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ANNOUNCE: hecc-0.2
by Marcel Fourné 25 Dec '09

25 Dec '09

Hi again, this is the second release of hecc, the Elliptic Curve Cryptography Library for Haskell, to be found at http://hackage.haskell.org/package/hecc There are only some smaller changes since the first release **3... * license change to the more common BSD3 * proper benchmarking * speed improvements * timing-attack resistant default point multiplication * simple key generation (given a generator on the curve used) En Detail: There are now 2 algorithms for point multiplication, the classic double-and-add (dnadd) and a montgomery ladder(montgladder). Dnadd varies in speed between 200us (degenerate case: long rows of zeroes) and 4.6ms while montgomery ladder (almost, see **1) always takes its 4.6ms. **2 Notes: **1 except when multiplying by binary numbers with trailing long rows of zeroes (e.g. 2^254), in which case it also takes 200us (cache?... anybody got more ideas how to fix this?) **2 Test HW: 2.4Ghz Core2, accompanying src/bench.hs, projective coordinates used **3 (due to an annoyingly complicated fracture of my main hand) This library still uses plain Haskell, in case anybody wants to ask... ;-) Still considered alpha, so beware of dragons! Almost enjoying holidays, welcoming feedback, Marcel -- Marcel Fourné OpenPGP-Key-ID: 0x74545C72 A good library is preferable to a tool, except when you just need that one tool.

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ghc-6.12.1 binary package for OpenSolaris b129
by Michael Lee 23 Dec '09

23 Dec '09

If anyone is interested in a binary package of ghc-6.12.1 for OpenSolaris, one can find said package at http://code.google.com/p/opensolaris-lang/. Please let me know how it works out for you. Thanks, -m

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Final Call for Participation: TLDI'10
by Andrew Kennedy 22 Dec '09

22 Dec '09

********************************************************************* FINAL CALL FOR PARTICIPATION TLDI 2010 ACM SIGPLAN Workshop on Types in Language Design and Implementation 23 January 2010 Madrid, Spain To be held in conjunction with POPL 2010 http://research.microsoft.com/~akenn/tldi2010/ ********************************************************************* IMPORTANT DATES Early registration deadline for POPL: December 22, 2009 (TODAY!) Hotel reservation deadline: December 28, 2009 (Monday) VENUE TLDI'10 and all POPL'10 affiliated events will take place at the Melia Castilla Hotel, Madrid. REGISTRATION To register for TLDI'10, follow the link from the POPL 2010 page, at http://www.cse.psu.edu/popl/10/ SCOPE The role of types and proofs in all aspects of language design, compiler construction, and software development has expanded greatly in recent years. Type systems, type-based analyses and type-theoretic deductive systems have been central to advances in compilation techniques for modern programming languages, verification of safety and security properties of programs, program transformation and optimization, and many other areas. The ACM SIGPLAN Workshop on Types in Language Design and Implementation brings researchers together to share new ideas and results concerning all aspects of types and programming, and is now an annual event. INVITED SPEAKER Matthias Felleisen, Northeastern University, Boston PRELIMINARY PROGRAM ---------------------- Opening remarks: 9:20-9:30 Invited talk 9:30-10:30 *** Adding Types to Untyped Languages Matthias Felleisen, Northeastern University, Boston ---------------------- ** Session I 11:00-12:30 *** Effects for Cooperable and Serializable Threads Jaeheon Yi and Cormac Flanagan *** Race-free and Memory-safe Multithreading: Design and Implementation in Cyclone Prodromos Gerakios, Nikolaos Papaspyrou and Konstantinos Sagonas *** Distributed programming with distributed authorization Kumar Avijit, Anupam Datta and Robert Harper ---------------------- ** Session II 2:30-4:00 *** let should not be generalized Dimitrios Vytiniotis, Simon Peyton Jones and Tom Schrijvers *** Pointwise Generalized Algebraic Data Types Chuan-kai Lin and Tim Sheard *** Verifying Event-Driven Programs using Ramified Frame Properties Neelakantan Krishnaswami, Lars Birkedal and Jonathan Aldrich ---------------------- ** Session III 4:30-5:30 *** Lightweight Linear Types in System F^o Karl Mazurak, Jianzhou Zhao and Steve Zdancewic *** F-ing Modules Andreas Rossberg, Claudio Russo and Derek Dreyer ---------------------- GENERAL CHAIR Andrew Kennedy, Microsoft Research, Cambridge PROGRAM CHAIR Nick Benton, Microsoft Research, Cambridge PROGRAM COMMITTEE Gilles Barthe, IMDEA Software, Spain Viviana Bono, University of Torino, Italy Giorgio Ghelli, University of Pisa, Italy Dan Grossman, University of Washington, USA Atsushi Igarashi, Kyoto University, Japan Conor McBride, University of Strathclyde, UK Jeremy Siek, University of Colorado at Boulder, USA Zhong Shao, Yale University, USA Matthieu Sozeau, Harvard University, USA Chris Stone, Harvey Mudd College, USA Kristian Støvring, ITU Copenhagen, Denmark

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Haskell Web News: Looking back on 2009
by Don Stewart 21 Dec '09

21 Dec '09

The Haskell Web News is a monthly summary of the hottest news about the Haskell programming language, as found in our online communities. If you want to catch up with what’s been happening in Haskell, this might be the journal for you. In this edition, we look back on the major events of 2009. http://haskellwebnews.wordpress.com/2009/12/20/the-year-in-haskell/ -- Don

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ANN: Happstack 0.4.1
by Jeremy Shaw 21 Dec '09

21 Dec '09

Happstack 0.4.1 STABLE is now available. We recommend that all users of Happstack update to 0.4.1 immediately. Migration from Happstack 0.3 should be trivial. There was one race condition in happstack-state which could cause a state event to fail under heavy congestion. Happstack is the Haskell Application Server Stack. It is a scalable framework for developing web applications. It is similar in purpose to Django, RoR, Turbogears, Grails, Seaside, etc. Using less buzzwords, it is a collection of libraries which can be used to develop a self-contained server application which does not require SQL or Apache (though it can integrate with both). It includes: * an HTTP server * a rich DSL for deconstructing HTTP Requests and generating Responses * HTML/XML/etc templating via HStringTemplate, HSP, or Text.XHtml * a persistent data store based on user defined Haskell data types with ACID properties and state migration * and more!! Happstack's modular nature means it is easy to integrate unrelated 3rd party modules such as Pandoc, or to add support for an alternative templating system. Additionally, it does not exclude you from using SQL, or supporting other protocols besides HTTP. HOMEPAGE: http://www.happstack.com/ SUPPORTED PLATFORMS: Happstack supports GHC 6.8, 6.10, and 6.12, under GNU/Linux, FreeBSD, OS X, and Windows. GHC 6.12 currently requires a minor patch to HJScript. Details here: http://groups.google.com/group/haskell-server-pages/browse_thread/thread/56… INSTALL: 1. ensure that ~/.cabal/bin is in your $PATH 2. cabal update 3. cabal install happstack * see SUPPORTED PLATFORMS for information about GHC 6.12 NOTABLE CHANGES: For a complete list of changes see: http://www.patch-tag.com/r/mae/happstack/snapshots/all/history Removed: * happstack-contrib has been completely removed. If you were using something in it, please complain on the mailing list. * removed Happstack.Server.S3 -- newer, better maintained S3 libraries are on hackage now * removed unsupported spread-based multimaster support fileServe: * now with sendfile() support! On supported platforms sendfile allows files to be served from the disk to the network in a zero-copy fashion. This means faster transfers, less memory and CPU usage, and no file handle leaks. (hopefully). sendfile uses native sendfile() support on Linux, Windows, OS X, and FreeBSD. Other platforms will use a sendfile emulation mode. We recommend that you use sendFile instead of sendFileStrict or sendFileLazy, unless you have specific needs and know some reason why you must use sendFileStrict or sendFileLazy. * FileServe internals majorly refactored. FileServe now provides a modular way of building your own fileServe-like functions. Also includes functions for serving a single file instead of the contents of a directory. * added more complete list of mime-types * automatically redirect from foo to foo/ if foo is a directory * filter . and .. from request path, but allow filenames and directories which start with . happstack-server: * ServerMonad instance for ErrorT * Added ServerMonad, FilterMonad, and WebMonad for XMLGenT * Added secure flag to cookies. Defaults to False. * fix supportsIPv6 to work with newer versions of network library * simpleHTTPWithSocket + bindPort for H.S.SimpleHTTP (you can use this to start the server as root, bind to the socket, and then drop privileges.) * Fixed Accept-Encoding parser to accepts encodings with a - in them. Added additional tests to acceptEncodingParserTest * fix so basicAuth sets correct response code and headers. * SimpleHTTP: added trailingSlash. Guard which checks that Request URI ends with a / * decode body of PUT requests not just POST * added ifModifiedSince guard * added host and withHost guards to SimpleHTTP (similar to dir and path, but for the requested hostname) other: * happstack-state: Correct an embarrassing race condition bug. * happstack-data: Exported getSafeGet and getSafePut * happstack: add state transition code to guestbook (add email to form, handler, and state), and tar of example _local state before transition experimental: * happstack-state: now has experimental replication support using Amazon Web Services. This support is disabled by default. This feature is highly experimental, may not work, and may even be completely removed in future versions (though, hopefully not). THANKS: Alex Jacobson David Himmelstrup / Lemmih Matthew Elder / mae Antoine Latter Erik Hesselink Pasqualino 'Titto' Assini Nils / McManiaC Thomas Hartman Creighton Hogg / wchogg John MacFarlane Jochem Berndsen / koeien MightByte And everyone who filed bug reports, tested RC1 and RC2, and anyone else I missed.

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Call for Participation - PEPM'10 (co-located with POPL'10)
by Janis Voigtländer 19 Dec '09

19 Dec '09

=============================================================== CALL FOR PARTICIPATION ACM SIGPLAN 2010 Workshop on Partial Evaluation and Program Manipulation (PEPM'10) Madrid, January 18-19, 2010 (Affiliated with POPL'10) http://www.program-transformation.org/PEPM10 =============================================================== Abstracts of all papers and presentations are available from the above web site. INVITED TALKS: * Lennart Augustsson (Standard Chartered Bank, UK) Title: O, Partial Evaluator, Where Art Thou? * Jeremy G. Siek (University of Colorado at Boulder, USA) Title: General Purpose Languages Should be Metalanguages. CONTRIBUTED TALKS: * Nabil el Boustani and Jurriaan Hage. Corrective Hints for Type Incorrect Generic Java Programs. * Johannes Rudolph and Peter Thiemann. Mnemonics: Type-safe Bytecode Generation at Run Time. * Elvira Albert, Miguel Gomez-Zamalloa and German Puebla. PET: A Partial Evaluation-based Test Case Generation Tool for Java Bytecode. * Martin Hofmann. Igor II - an Analytical Inductive Functional Programming System. * José Pedro Magalhães, Stefan Holdermans, Johan Jeuring and Andres Löh. Optimizing Generics Is Easy! * Michele Baggi, María Alpuente, Demis Ballis and Moreno Falaschi. A Fold/Unfold Transformation Framework for Rewrite Theories extended to CCT. * Hugh Anderson and Siau-Cheng Khoo. Regular Approximation and Bounded Domains for Size-Change Termination. * Évelyne Contejean, Pierre Courtieu, Julien Forest, Andrei Paskevich, Olivier Pons and Xavier Urbain. A3PAT, an Approach for Certified Automated Termination Proofs. * Fritz Henglein. Optimizing Relational Algebra Operations Using Generic Equivalence Discriminators and Lazy Products. * Adrian Riesco and Juan Rodriguez-Hortala. Programming with Singular and Plural Non-deterministic Functions. * Martin Hofmann and Emanuel Kitzelmann. I/O Guided Detection of List Catamorphisms. * Andrew Moss and Dan Page. Bridging the Gap Between Symbolic and Efficient AES Implementations. * Christopher Brown and Simon Thompson. Clone Detection and Elimination for Haskell. * Stefan Holdermans and Jurriaan Hage. Making "Stricterness" More Relevant. * Arun Lakhotia, Davidson Boccardo, Anshuman Singh and Aleardo Manacero Júnior. Context-Sensitive Analysis of Obfuscated x86 Executables. * Xin Li and Mizuhito Ogawa. Conditional Weighted Pushdown Systems and Applications. * Ivan Lazar Miljenovic. The SourceGraph Program. * Florian Haftmann. From Higher-Order Logic to Haskell: There and Back Again. SPECIAL FEATURE: * Andy Gill, Garrin Kimmell and Kevin Matlage. Capturing Functions and Catching Satellites. IMPORTANT DATES: * Early registration deadline: December 22, 2009 * Hotel registration deadline: December 28, 2009

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