November 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

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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

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haskell.org migration complete
by Ian Lynagh 09 Dec '10

09 Dec '10

Hi all, The haskell.org server migration is now complete. Please let us know if you have any problems. Thanks Ian

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ANNOUNCE: genprog-0.1
by Jan Snajder 08 Dec '10

08 Dec '10

Dear Haskellers, I am pleased to announce the release of genprog-0.1, a genetic programming library. Genetic programming is an evolutionary technique, inspired by biological evolution, to evolve programs for solving specific problems. A genetic program is represented by a value of an algebraic datatype and associated with a custom-defined fitness value indicating the quality of the solution. Starting from a randomly generated initial population of genetic programs, the genetic operators of selection, crossover, and mutation are used to evolve programs of increasingly better quality. genprog-0.1 is available from Hackage at: http://hackage.haskell.org/package/genprog An example of how to use the library is included in the documentation. Cheers, Jan

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ANNOUNCE: GHC version 7.0.1
by Ian Lynagh 07 Dec '10

07 Dec '10

============================================================= The (Interactive) Glasgow Haskell Compiler -- version 7.0.1 ============================================================= The GHC Team is pleased to announce a new major release of GHC. Since the 6.12 branch we are delighted that more than 60 people have contributed patches to GHC or the accompanying libraries and utilities. There have been a number of significant changes since the last major release, including: * GHC now defaults to the Haskell 2010 language standard * -fglasgow-exts is now deprecated, in favour of the individual extension flags * On POSIX platforms, there is a new I/O manager based on epoll/kqueue/poll, which allows multithreaded I/O code to scale to a much larger number (100k+) of threads * GHC now includes an LLVM code generator which, for certain code, can bring some nice performance improvements * The type checker has been overhauled, which means it is now able to correctly handle interactions between the type systemextensions * The inliner has been overhauled, which should in general give better performance while reducing unnecessary code-size explosion * Large parts of the runtime system have been overhauled, including fixing several instances of pathological performance when there are large numbers of threads * Due to changes in the runtime system, if you are using Control.Parallel.Strategies from the parallel package, please upgrade to at least version 2 (preferably version 3) * The full Haskell import syntax can now been used to bring modules into scope in GHCi * GHC now comes with a more recent mingw bundled on Windows, which includes a fix for windres on Windows 7 * There is a new -fno-ghci-sandbox flag, which stops GHCi running computations in a separate thread; in particular, this works around an issue running GLUT from GHCi on OS X The full release notes are here: http://new-www.haskell.org/ghc/docs/7.0.1/html/users_guide/release-7-0-1.ht… How to get it ~~~~~~~~~~~~~ The easy way is to go to the web page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in the native package format for many platforms, and the source distribution is available from the same place. Packages will appear as they are built - if the package for your system isn't available yet, please try again later. Background ~~~~~~~~~~ Haskell is a standard lazy functional programming language; the current language version is Haskell 98, agreed in December 1998 and revised December 2002. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces (C, whatever). GHC is distributed under a BSD-style open source license. A wide variety of Haskell related resources (tutorials, libraries, specifications, documentation, compilers, interpreters, references, contact information, links to research groups) are available from the Haskell home page (see below). On-line GHC-related resources ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Relevant URLs on the World-Wide Web: GHC home page http://www.haskell.org/ghc/ GHC developers' home page http://hackage.haskell.org/trac/ghc/ Haskell home page http://www.haskell.org/ Supported Platforms ~~~~~~~~~~~~~~~~~~~ The list of platforms we support, and the people responsible for them, is here: http://hackage.haskell.org/trac/ghc/wiki/Contributors Ports to other platforms are possible with varying degrees of difficulty. The Building Guide describes how to go about porting to a new platform: http://hackage.haskell.org/trac/ghc/wiki/Building Developers ~~~~~~~~~~ We welcome new contributors. Instructions on accessing our source code repository, and getting started with hacking on GHC, are available from the GHC's developer's site run by Trac: http://hackage.haskell.org/trac/ghc/ Mailing lists ~~~~~~~~~~~~~ We run mailing lists for GHC users and bug reports; to subscribe, use the web interfaces at http://www.haskell.org/mailman/listinfo/glasgow-haskell-users http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs There are several other haskell and ghc-related mailing lists on www.haskell.org; for the full list, see http://www.haskell.org/mailman/listinfo/ Some GHC developers hang out on #haskell on IRC, too: http://www.haskell.org/haskellwiki/IRC_channel Please report bugs using our bug tracking system. Instructions on reporting bugs can be found here: http://www.haskell.org/ghc/reportabug

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ANN: HaLVM 1.0: the Haskell Lightweight Virtual Machine
by Adam Wick 30 Nov '10

30 Nov '10

Galois, Inc. is pleased to announce the immediate release of the Haskell Lightweight Virtual Machine (or HaLVM), version 1.0. The HaLVM is a port of the GHC runtime system to the Xen hypervisor, allowing programmers to create Haskell programs that run directly on Xen's "bare metal." Internally, Galois has used this system in several projects with much success, and we hope y'all will have an equally great time with it. What might you do with a HaLVM? Pretty much anything you want. :) Explore designs for operating system decomposition, examine new notions of mobile computation with the HaLVM and Xen migration, or find interesting network services and lock them inside small, cheap, single-purpose VMs. The HaLVM is the result of many years of effort, by many people inside Galois. Although it is not yet totally bug-free, we have decided that broad adoption wins over perfection and thus we are releasing it for general review. As such, there will be some rough edges, and we urge you to read the documentation to understand the platforms we test on. We are releasing the HaLVM under a non-restrictive BSD3 license. You can find it here: http://halvm.org We welcome user feedback, feature requests, bug notices, patches, and feature additions; see the page above for guidelines on getting involved. Finally, we'd like to give many things to the GHC and Xen communities, without which this work would not be possible. If you have any questions or concerns, please don't hesitate to contact the HaLVM's maintainers at halvm-devel(a)community.galois.com. Have a lovely day! - Adam

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TLDI 2011 Call for participation
by Stephanie Weirich 30 Nov '10

30 Nov '10

********************************************************************* CALL FOR PARTICIPATION TLDI 2011 ACM SIGPLAN Workshop on Types in Language Design and Implementation 25 January 2011 Austin, TX, USA To be held in conjunction with POPL 2011 http://www.mpi-sws.org/~dreyer/tldi2011/ ********************************************************************* IMPORTANT DATES Deadline for student travel grant applications: December 17, 2010 Hotel reservation deadline: December 21, 2010 Notification of student travel awards: December 27, 2010 Early registration deadline: December 31, 2010 VENUE TLDI'11 and all POPL'11 affiliated events will take place at the Omni Austin Hotel in downtown Austin, TX. REGISTRATION To register for TLDI'11, follow the link from the POPL 2011 page, at https://regmaster3.com/2011conf/POPL11/register.php 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. WORKSHOP PROGRAM Session 1: Invited Talk (9:30 - 10:30) Type Design Patterns for Computer Mathematics Georges Gonthier (Microsoft Research, Cambridge) Break (10:30-11:00) Session 2 (11:00-12:30) Singleton: A General-Purpose Dependently-Typed Assembly Language Simon Winwood and Manuel Chakravarty A Type and Effect System for Deadlock Avoidance in Low-Level Languages Prodromos Gerakios, Nikolaos Papaspyrou and Konstantinos Sagonas Extended Alias Type System using Separating Implication Toshiyuki Maeda, Haruki Sato and Akinori Yonezawa Lunch (12:30-14:30) Session 3: Invited Talk (14:30-15:30) Type Safety from the Ground Up Chris Hawblitzel (Microsoft Research, Redmond) Break (15:30-16:00) Session 4 (16:00-17:30) AuraConf: A Unified Approach to Authorization and Confidentiality Jeffrey Vaughan Information Flow Enforcement in Monadic Libraries Dominique Devriese and Frank Piessens The Essence of Monotonic State Alexandre Pilkiewicz and François Pottier

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haskell.org downtime: Tuesday Nov 30th
by Ian Lynagh 29 Nov '10

29 Nov '10

Hi all, We plan to have some haskell.org downtime on Tuesday Nov 30th, while we migrate to the new server. If you think something is missing from http://new-www.haskell.org/ then please let us know as soon as possible! Thanks Ian

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ANNOUNCE: iteratee-compress 0.1.2
by Maciej Piechotka 28 Nov '10

28 Nov '10

Iteratee-compress provides compressing and decompressing enumerators including flushing. Currently only gzip is provided but at bzip and LZMA are planned. This is bug-fixing release Changes from previous version: - Fix infinite loop/segfault bug - Fix bug in which part of the output was lost - Support for iteratee 0.5 and 0.6 Next goals: - BZip support - LZMA support - Generic interface for flushing To think about: - Should inner iteratee be able to request flushing? Regards

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ANNOUNCE: iteratee-compress 0.1.2
by Maciej Piechotka 28 Nov '10

28 Nov '10

Iteratee-compress provides compressing and decompressing enumerators including flushing. Currently only gzip is provided but at bzip and LZMA are planned. This is bug-fixing release Changes from previous version: - Fix infinite loop/segfault bug - Fix bug in which part of the output was lost Next goals: - BZip support - LZMA support - Generic interface for flushing To think about: - Should inner iteratee be able to request flushing? Regards

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