January 2009 - Haskell-Cafe

IFL 2009: Call for Papers
by IFL 2009 15 Jan '09

15 Jan '09

Call for Papers IFL 2009 Seton Hall University SOUTH ORANGE, NJ, USA http://tltc.shu.edu/blogs/projects/IFL2009/ The 21st IFL symposium, IFL 2009, will be held for the first time in the USA. The hosting institution is Seton Hall University in South Orange, NJ, USA and the symposium dates are September 23-25, 2009. It is our goal to make IFL a regular event held in the USA. The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2009 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming. Following the IFL tradition, IFL 2009 will use a post-symposium review process to produce a formal proceedings which we expect to be published by Springer in the Lecture Notes in Computer Science series. All participants in IFL 2009 are invited to submit either a draft paper or and extended abstract describing work to be presented at the symposium. These submissions will be screened by the program committee chair to make sure they are within the scope of IFL and will appear in the draft proceedings distributed at the symposium. Submissions appearing in the draft proceedings are not peer-reviewed publications. After the symposium, authors will be given the opportunity to incorporate the feedback from discussions at the symposium and will be invited to submit a revised full arcticle for the formal review process. These revised submissions will be reviewed by the program committee using prevailing academic standards to select the best articles that will appear in the formal proceedings. TOPICS IFL welcomes submissions describing practical and theoretical as well as submissions describing applications and tools. If you are not sure if your work is appropriate for IFL 2009, please contact the PC chair at ifl2009(a)shu.edu. Topics of interest include, but are not limited to: language concepts type checking contracts compilation techniques staged compilation runtime function specialization runtime code generation partial evaluation (abstract) interpretation generic programming techniques automatic program generation array processing concurrent/parallel programming concurrent/parallel program execution functional programming and embedded systems functional programming and web applications functional programming and security novel memory management techniques runtime profiling and performance measurements debugging and tracing virtual/abstract machine architectures validation and verification of functional programs tools and programming techniques PAPER SUBMISSIONS Prospective authors are encouraged to submit papers or extended abstracts to be published in the draft proceedings and to present them at the symposium. All contributions must be written in English, conform to the Springer-Verlag LNCS series format and not exceed 16 pages. The draft proceedings will appear as a technical report of the Department of Mathematics and Computer Science of Seton Hall University. IMPORTANT DATES Registration deadline August 15, 2009 Presentation submission deadline August 15, 2009 IFL 2009 Symposium September 23-25, 2009 Submission for review process deadline November 1, 2009 Notification Accept/Reject December 22, 2009 Camera ready version January 15, 2010 PROGRAM COMMITTEE Peter Achten University of Nijmegen, The Netherlands Jost Berthold Philipps-Universität Marburg, Germany Andrew Butterfield University of Dublin, Ireland Robby Findler Northwestern University, USA Kathleen Fisher AT&T Research, USA Cormac Flanagan University of California at Santa Cruz, USA Matthew Flatt University of Utah, USA Matthew Fluet Toyota Technological Institute at Chicago, USA Daniel Friedman Indiana University, USA Andy Gill University of Kansas, USA Clemens Grelck University of Amsterdam/Hertfordshire, The Netherlands/UK Jurriaan Hage Utrecht University, The Netherlands Ralf Hinze Oxford University, UK Paul Hudak Yale University, USA John Hughes Chalmers University of Technology, Sweden Patricia Johann University of Strathclyde, UK Yukiyoshi Kameyama University of Tsukuba, Japan Marco T. Morazán (Chair) Seton Hall University, USA Rex Page University of Oklahoma, USA Fernando Rubio Universidad Complutense de Madrid, Spain Sven-Bodo Scholz University of Hertfordshire, UK Manuel Serrano INRIA Sophia-Antipolis, France Chung-chieh Shan Rutgers University, USA David Walker Princeton University, USA Viktória Zsók Eötvös Loránd University, Hungary PETER LANDIN PRIZE The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honored article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 euros.

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Comments from OCaml Hacker Brian Hurt
by Andrzej Jaworski 15 Jan '09

15 Jan '09

If you called your girlfriend "Kitten" and on a mountain trip she broke her leg would cry/phone for help to treat your Kitten or would you use a stupid high-brow term "woman"? Or perhaps you would rename "Washington Square" for " My Kitten Square" ? There are hundreds programming languages designed by hackers, that is why I have chosen Haskell...

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ANN: split-0.1.1 (doc bugfix; new functions wordsBy and linesBy)
by Brent Yorgey 15 Jan '09

15 Jan '09

Version 0.1.1 of the split library is now on Hackage, which provides a wide range of strategies and a unified combinator framework for splitting lists with respect to some sort of delimiter. This version: * fixes a couple Haddock bugs that were preventing the documentation from building on Hackage, and * adds two new convenience functions suggested by Neil Mitchell, wordsBy and linesBy, such that words === wordsBy isSpace lines === linesBy (=='\n'). Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/split darcs: http://code.haskell.org/~byorgey/code/split -Brent

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ANN: hs-dotnet, version 0.3.0
by Sigbjorn Finne 15 Jan '09

15 Jan '09

Hi, the first public release of hs-dotnet is now available - a pragmatic take on interoperating between Haskell (via GHC) and .NET. For downloads and (some) info, see: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hs-dotnet http://haskell.forkIO.com/dotnet Feedback most welcome, both on what's there and what you would like to see better handled/supported next. enjoy --sigbjorn

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Re: Issues with posix-realtime package
by Galchin, Vasili 15 Jan '09

15 Jan '09

Hi Manlio, I am the author of this package. Let me think about what you have said. Regards, Vasili

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Re: [Haskell-cafe] Looking for Haskellers on Windows
by Günther Schmidt 14 Jan '09

14 Jan '09

Hi Kyra, and again, thanks for taking the effort. Kyra I've tried any sort of values to any sort of columns. I tried "insert into somesinglecolumntable (someNumbercolumn) values (?)" [toSql 5] ... and so on. So I'm not certain at all the error message does actually give the right clue. It just blows no matter what. What does work though is this: run dbc "insert into sometable (someVarcharcolumn) values ('some string value')" [] This would be a workaround for my app, but I hope I can do better. Günther Am 10.01.2009, 17:01 Uhr, schrieb kyra <kyrab(a)mail.ru>: > Günther Schmidt wrote: >> Hi Kyra, >> thanks for your reply. >> The problem I was facing is using an MS-Access backend with HDBC-ODBC. >> I try to export data to MS-Access and I can't get it to work. Otherwise >> HDBC works fine in other parts of my app but with MS-Access it blows up. >> I did of course post this on the haskell-cafe list first, but no >> response and the HDBC package maintainer himself was unable to help too >> since he's not using Windows. > > I've looked at Your problem now. What is the type of that single field > in 'mytable'? Google shows numerous similar cases, e.g. for date or memo > fields, that Access don't accept varchars and require longvarchars for. > > I'm in no way an Access expert. > > Cheers, > Kyra -- Erstellt mit Operas revolutionärem E-Mail-Modul: http://www.opera.com/mail/

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Stack Overflow, tail recursion and CPS
by Günther Schmidt 14 Jan '09

14 Jan '09

Hi all, I get a stack overflow when I want to insert a huge, lazy list into a Map. I have changed the insertion algo to use foldl to make it tail-recursive but still get a stack overflow as the "insert" remains lazy. Could CPS be a solution in these cases? Günther

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Re: [Haskell-cafe] Stack Overflow, tail recursion and CPS
by Günther Schmidt 14 Jan '09

14 Jan '09

Hi Eugene, tried that, but since the action to be evaluated is the insertion into a structure that won't work. The strictness here doesn't go deep enough, it stopps short. Günther Am 14.01.2009, 18:27 Uhr, schrieb Eugene Kirpichov <ekirpichov(a)gmail.com>: > Use foldl' ? > > 2009/1/14 Günther Schmidt <redcom(a)fedoms.com>: >> Hi all, >> >> I get a stack overflow when I want to insert a huge, lazy list into a >> Map. >> >> I have changed the insertion algo to use foldl to make it >> tail-recursive but >> still get a stack overflow as the "insert" remains lazy. >> >> Could CPS be a solution in these cases? >> >> Günther >> >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe(a)haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> -- Erstellt mit Operas revolutionärem E-Mail-Modul: http://www.opera.com/mail/

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HEADS UP: finalizer changes coming in GHC 6.10.2
by Simon Marlow 14 Jan '09

14 Jan '09

By popular demand, GHC 6.10.2 will support finalizers that are actually guaranteed to run, and run promptly. There aren't any API changes: this happens for finalizers created using newForeignPtr as normal. However, there's a catch. Previously it was possible to call back into Haskell from a finalizer (finalizers are C functions), by using foreign import "wrapper" or foreign export. According to the FFI spec, whether this is allowed or not is "system dependent". In GHC 6.10.1 and earlier it was allowed, but in 6.10.2 and later it is not. The reason being that C finalizers are now executed directly by the GC, when the runtime is not in a position to handle callbacks. You can still have fully-fledged Haskell finalizers if you want: we have Foreign.Concurrent.newForeignPtr for that purpose. But those finalizers are not subject to the same promptness guarantees that you get with C finalizers - they run in a separate thread, and are not guaranteed to be run at program exit. We'll make sure this is documented prominently in the 6.10.2 release notes, but I thought a heads-up would be a good idea right now as it turns out that there are existing libraries (e.g. LLVM) that will be affected. Cheers, Simon

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Recursive modules, GHC /= Report?
by Mauricio 14 Jan '09

14 Jan '09

Hi, Here: http://www.haskell.org/onlinereport/modules.html I read: "Modules may reference other modules via explicit import declarations, each giving the name of a module to be imported and specifying its entities to be imported. Modules may be mutually recursive." However, I get this from GHC: --- Module imports form a cycle for modules: main:Main imports: Control.Concurrent.MVar GtkMostrarConfig GtkLerECG Graphics.UI.Gtk main:GtkMostrarConfig imports: Control.Concurrent.MVar Graphics.UI.Gtk Main --- Aren't cycles of modules just recursive modules? Why wasn't that allowed? Thanks, Maurício

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