January 2011 - 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

PhD studentships in Nottingham
by Graham Hutton 31 Jan '11

31 Jan '11

+------------------------------------------------------------------+ PhD Studentships in Functional Programming School of Computer Science University of Nottingham, UK The Functional Programming Lab (FP Lab) in the School of Computer Science at the University of Nottingham is seeking to appoint up to two new PhD students, starting on 1st October 2011. The topics for the studentships are open, but will be within the general area of functional programming. The studentships are for 3.5 years, include a maintenance grant of 13,590 UK pounds per year and UK/EU tuition fees, and are open to UK and EU applicants. Particularly strong candidates from outside the EU may also be considered, subject to additional funds being available. Applicants will require a first-class Honours degree (or equivalent) in Computer Science, Mathematics, and/or Physics, experience in functional programming, and an aptitude for mathematical subjects. A higher degree (e.g. Masters) would be desirable. Additionally, experience in one or more of the following will be particularly welcome: formal semantics, type theory, program verification, theorem provers, domain-specific languages, languages for physical modelling, programming language implementation and tools. Successful applicants will work under the supervision of Dr Graham Hutton or Dr Henrik Nilsson in the FP Lab in Nottingham, a leading centre for research on functional programming. The group currently comprises 5 academic staff, 1 research fellow, and 10 PhD students. In order to apply, please submit the following to Dr Graham Hutton (gmh(a)cs.nott.ac.uk) or Dr Henrik Nilsson (nhn(a)cs.nott.ac.uk) by 1st March 2011: an up-to-date copy of your CV (including the results of all your University examinations to date) along with a brief covering letter that describes your experience in functional programming, your reasons for wishing to pursue a PhD in this area, and any ideas you have regarding possible research directions. Note: applicants to the FP Lab should follow the procedure above, rather than applying directly to the School or University, e.g. in response to a general advert for PhD studentships. Closing date for applications: 1st March 2011. +------------------------------------------------------------------+

1 0

Literate Haskell editing with Emacs and MMM: the $ operator
by Julian Gilbey 30 Jan '11

30 Jan '11

I've been editing literate (LaTeX-based) Haskell code using Emacs and MMM-mode, using the instructions posted in http://www.haskell.org/pipermail/haskell/2006-April/017855.html There's one annoyance, however: the $ operator in Haskell code ends up being interpreted as the beginning of math mode, completely messing up any font-lock colo(u)ring. Has anyone else found this, and has anyone come up with a good solution? Thanks, Julian

2 2

ANNOUNCE: jhc 0.7.7 is out.
by John Meacham 30 Jan '11

30 Jan '11

Announcing jhc 0.7.7! This release fixes a large number of bugs that cropped up when compiling haskell out in the wild as well as adds some more features. A major one being the garbage collector is enabled by default. http://repetae.net/computer/jhc/ Changes: (including some changes from the unannounced 0.7.6 release) * The Garbage Collector is now enabled by default. * new standard libraries * transformers * parsec * QuickCheck * report proper errors with line numbers for various issues with compiled code. * New option '-C' that compiles to C code and stops, useful for targeting other platforms or building shared libraries. * Nintendo Wii added as target (thanks to Korcan Hussein) * Fix major performance bug that kept WRAPPERs from being inlined in certain places. * Typechecking speed greatly increased. * monomorphism-restriction flag is now respected * empty class contexts now work * unicode in haskell source supported now * Type Defaulting now works properly * RULES parse like ghc now for compatibility * 'do' 'where' on same indent now parses * Build system fixes and cleanups * irrefutable lambda pattern bindings desugar properly now. * GHC parsing regression tests have been ported to jhc, helped find and fix many bugs. * Certain optimizations would discard RULES, these have been fixed. * Removed quadratic behavior in optimizer, speeds things up noticibly. * Garbage collector improvements, caches are pre-initialized. * Fix shiftL/R implementations for built in types. * All Num, Real, and Integral magic removed from compiler. This is a very good thing. * improved help messages John

2 1

Internships at MSR Cambridge, summer 2011 and later
by Simon Marlow 28 Jan '11

28 Jan '11

Hi folks, If you're a postgraduate and would like to spend 12 weeks in Cambridge working on a GHC or Haskell-related project, then apply for an internship: we have open slots starting in July this year and later. We've had many successful intern projects over the years. Lots more information here: http://hackage.haskell.org/trac/ghc/wiki/Internships The earliest available slot is the popular July-September summer slot, and for that you would need to have an application in by *Wednesday Feb 16*. However, we can also be flexible about start dates, and if you wanted to start later than July then you have more time to get an application in. By all means apply if you're interested in coming later in the year. Don't forget to email either Simon or myself if you intend to apply. This is very important: otherwise your application gets lost in the system. Cheers, Simon

1 0

MGS 2011
by Venanzio Capretta 28 Jan '11

28 Jan '11

MIDLANDS GRADUATE SCHOOL in the Foundations of Computing Science University of Nottingham, 11-15 April 2011 http://www.cs.nott.ac.uk/~vxc/mgs/mgs.html The Midlands Graduate School (MGS) in the Foundations of Computing Science is a collaboration between researchers at the Universities of Birmingham, Leicester, Nottingham and Sheffield. It was established in 1999. The MGS has two main goals: to provide PhD students with a sound basis for research in the mathematical and practical foundations of computing and to give PhD students the opportunity to make contact with established researchers in the field and their peers who are at a similar stage in their research careers. This year, the MGS is at the University of Nottingham. It will start on 11 April and finish on 15 April. This year the school offers the following courses. Core courses: "Functional Programming" by Henrik Nilsson "Category Theory" by Thorsten Altenkirch "Typed Lambda Calculi" by Andrzej Murawski Advanced courses: "Coalgebra" by Paul Blain Levy "Game Semantics and Applications" by Dan Razvan Ghica "Game Theory, Topology and Proof Theory for Functional Programming" by Martín Escardó "Process Calculi for Protocol Verification" by Eike Ritter "Mechanized Theorem Proving" by Georg Struth In addition there will be an invited course given by Professor Andrew M Pitts. We invite graduate students in computer science and related fields to participate. Applicants from industry who want to strengthen their theoretical background are also welcome. The deadline for registration is 18 March 2011. More details and information on how to register are on the school web page. -- Venanzio Capretta School of Computer Science University of Nottingham, UK http://www.cs.nott.ac.uk/~vxc/

1 0

A few days to go before the old server goes down
by Henk-Jan van Tuyl 27 Jan '11

27 Jan '11

1 0

Call for Copy: Monad.Reader Issue 18
by Brent Yorgey 27 Jan '11

27 Jan '11

Whether you're an established academic or have only just started learning Haskell, if you have something to say, please consider writing an article for The Monad.Reader! The submission deadline for Issue 18 will be: **Friday, April 1, 2011** This will be a normal issue -- but don't forget to also submit your Haskell poems and short stories by February 18 for inclusion in the special poetry and fiction edition [1]! The Monad.Reader ~~~~~~~~~~~~~~~~ The Monad.Reader is a electronic magazine about all things Haskell. It is less formal than journal, but somehow more enduring than a wiki-page. There have been a wide variety of articles: exciting code fragments, intriguing puzzles, book reviews, tutorials, and even half-baked research ideas. Submission Details ~~~~~~~~~~~~~~~~~~ Get in touch with me if you intend to submit something -- the sooner you let me know what you're up to, the better. Please submit articles for the next issue to me by e-mail (byorgey at cis.upenn.edu) Articles should be written according to the guidelines available from http://themonadreader.wordpress.com/contributing/ Please submit your article in PDF, together with any source files you used. The sources will be released together with the magazine under a BSD license. If you would like to submit an article, but have trouble with LaTeX please let me know and we'll work something out. [1] http://themonadreader.wordpress.com/2011/01/19/call-for-copy-special-poetry…

1 0

Haskell Weekly News: Issue 166 - January 26, 2011
by Daniel Santa Cruz 27 Jan '11

27 Jan '11

Welcome to issue 166 of the HWN, a newsletter covering developments in the [1]Haskell community. This release covers the week of January 16 to 22, 2011. Announcements Sukit Tretriluxana [2]proudly announced version 1.0 of SiteBridge. He also included a short introductory video. Mark Wright [3]annouced the release of a Haskell binding to ANTLR LL(*) parser generator C runtime library. Jasper Van der Jeugt [4]inveted everyone to the 6th Ghent Functional Group Meeting to be held on Feb 17, 2011 in the Technicum Building (Sint-Pietersnieuwstraat 41, 9000 Gent) of Ghent University. I know I'm not the only one who wishing I could attend!. Quotes of the Week * Guy Steele: Although Fortress is originally designed as an object-oriented framework in which to build an array-style scientific programming language, [...] as we've experimented with it and tried to get the parallelism going we found ourselves pushed more and more in the direction of using immutable data structures and a functional style of programming. [...] If I'd known seven years ago what I know now, I would have started with Haskell and pushed it a tenth of the way toward Fortran instead of starting with Fortran and pushing it nine tenths of the way toward Haskell. * geheimdienst:ah, yes. now we have to make a lambdacat captioned "kittehs no bery gud at speling. we says leksah fur lexer and monad fur moniod in catagory of ennobunktors" * mreh:some jerk said to me over my shoulder once, if you're doing functional programming, why do you have all those assignments? * revenantphx:You don't need category theory to understand Haskell, though you may need it to understand #haskell. * tolkad:haskell isn't even turing complete without infinite memory * monochrom:C-c C-p was the secret command for sending a report to the kgb * Draconx|Laptop:Rice's theorem: Let P be an interesting problem that you want to solve with a computer. Haha, you're screwed! * monochrom:one ring to rule them all! and in your monad >>= them! Top Reddit Stories * Haskell's Own DLL Hell Domain: cdsmith.wordpress.com, Score: 51, Comments: 27 On Reddit: http://www.reddit.com/r/haskell/comments/f3lh5/haskells_own_dll_hell/ Original: http://cdsmith.wordpress.com/2011/01/16/haskells-own-dll-hell/ * [CCC] On how Haskell’s Arrows are NOT just function compositions with a fancier name Domain: ro-che.info, Score: 40, Comments: 4 On Reddit: http://www.reddit.com/r/haskell/comments/f3e06/ccc_on_how_haskells_arrows_a… Original: http://ro-che.info/ccc/12.html * Announcing the Warp web server (benchmarks inside) Domain: docs.yesodweb.com, Score: 36, Comments: 12 On Reddit: http://www.reddit.com/r/haskell/comments/f4bn8/announcing_the_warp_web_serv… Original: http://docs.yesodweb.com/blog/announcing-warp/ * The ABCs of semantics Domain: haskell.org, Score: 33, Comments: 0 On Reddit: http://www.reddit.com/r/haskell/comments/f4v8f/the_abcs_of_semantics/ Original: http://www.haskell.org/pipermail/haskell-cafe/2011-January/088315.html * Thoughts on node.js and Haskell Domain: moreindirection.blogspot.com, Score: 33, Comments: 10 On Reddit: http://www.reddit.com/r/haskell/comments/f6o5i/thoughts_on_nodejs_and_haske… Original: http://moreindirection.blogspot.com/2011/01/thoughts-on-nodejs.html * A low level performance comparison of simple operations on unboxed integer arrays between Haskell/GHC (6.12.1) and OCaml (3.12.0) (and also C) [originally on Proggit] Domain: lix.polytechnique.fr, Score: 32, Comments: 16 On Reddit: http://www.reddit.com/r/haskell/comments/f3yf8/a_low_level_performance_comp… Original: http://www.lix.polytechnique.fr/~kaustuv/expo/incr_uarray/ * The Butterfly Effect in Cabal Domain: cdsmith.wordpress.com, Score: 29, Comments: 8 On Reddit: http://www.reddit.com/r/haskell/comments/f4179/the_butterfly_effect_in_caba… Original: http://cdsmith.wordpress.com/2011/01/17/the-butterfly-effect-in-cabal/ * Painless NP-complete problems: an embedded DSL for SMT solving Domain: donsbot.wordpress.com, Score: 27, Comments: 2 On Reddit: http://www.reddit.com/r/haskell/comments/f3fp6/painless_npcomplete_problems… Original: http://donsbot.wordpress.com/2011/01/16/painless-np-complete-problems-an-em… * Merging SMT solvers and programming languages Domain: corp.galois.com, Score: 26, Comments: 3 On Reddit: http://www.reddit.com/r/haskell/comments/f4r5r/merging_smt_solvers_and_prog… Original: http://corp.galois.com/blog/2011/1/18/merging-smt-solvers-and-programming-l… * Tell Haskellers: GHC's Trac now has source code browsing (courtesy of Git) Domain: hackage.haskell.org, Score: 26, Comments: 3 On Reddit: http://www.reddit.com/r/haskell/comments/f6391/tell_haskellers_ghcs_trac_no… Original: http://hackage.haskell.org/trac/ghc/browser Top StackOverflow Questions * Criticize simple monad votes: 11, answers: 1 Read on SO: http://stackoverflow.com/questions/4765260/criticize-simple-monad * Parsing function in haskell votes: 8, answers: 1 Read on SO: http://stackoverflow.com/questions/4711893/parsing-function-in-haskell * Possible optimizations in Haskell that are not yet implemented in GHC? votes: 7, answers: 1 Read on SO: http://stackoverflow.com/questions/4720499/possible-optimizations-in-haskel… * Is there a Haskell/ML-like compiler to C? votes: 6, answers: 3 Read on SO: http://stackoverflow.com/questions/4722439/is-there-a-haskell-ml-like-compi… * How to find the longest word in list? votes: 5, answers: 4 Read on SO: http://stackoverflow.com/questions/4708028/how-to-find-the-longest-word-in-… About the Haskell Weekly News You can find an html version of this newsletter at: http://contemplatecode.blogspot.com/2011/01/haskell-weekly-news-issue-166.h… To help create new editions of this newsletter, please send stories to dstcruz(a)gmail.com. I'm in dire need of finding good "quotes of the week". If you happen to come across any, please don't hesitate to send it along. Until next time, Daniel Santa Cruz References 1. http://haskell.org/ 2. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/85348 3. http://permalink.gmane.org/gmane.comp.lang.haskell.general/18437 4. http://permalink.gmane.org/gmane.comp.lang.haskell.cafe/85519

1 0