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Postdoc in Functional Programming at Chalmers
by John Hughes 19 Oct '10

19 Oct '10

The Functional Programming group at Chalmers is recruiting a postdoctoral researcher for a two year position, starting as soon as possible. The position is funded by a project in property-based testing with QuickCheck, with an emphasis specifically on language terms as test data. We're looking for someone with a PhD with a strong Functional Programming component. Experience with automated test case generation, whether with QuickCheck or other tools, and with formal specifications, is a merit. Full details (including how to apply) are on the web here: http://www.chalmers.se/cse/EN/news/vacancies/positions/post-doc-position-in… John Hughes

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Help-me read file
by Gilmara Pompelli 18 Oct '10

18 Oct '10

Hello I have a file with 100 lists, with 100 ints. I have to read the file and apply the map and sort functions on lists. II did it to read file: learquivo :: FilePath -> IO ([[Int]]) learquivo s = do conteudo <- readFile s return (read conteudo) But now applying the sort, the error appears: <interactive>:1:5: Couldn't match expected type `[a]' against inferred type `IO [[Int]]' how can I fix? Thanks

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New blog on Disciple/DDC development
by Ben Lippmeier 16 Oct '10

16 Oct '10

The blog is at: http://disciple-devel.blogspot.com/ more about the project here: http://trac.haskell.org/ddc/ Ben.

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ANNOUNCE: language-c-comments 0.1 package
by Geoff Hulette 08 Oct '10

08 Oct '10

Dear Haskell, Announcing the initial (0.1) release of the 'language-c-comments' package. If you need to grab the comments from a C source file, well now you can. Features: * Robust parsing of both single- and multi-line comments; * Handles obscure corner cases, e.g. http://hpaste.org/40456/a_valid_c_comment; * Comments include their position within the file, using the file position type from language-c for easy integration with that package; * Tested on the Linux kernel. Suggestions, feature requests, and bug reports welcome. Also, I may expand this package out into a full C preprocessor parser to complement language-c and enable source-to-source C translations that preserve the original formatting. If you have an opinion on what such a package should look like, I would be interested to hear about it. Cheers, -geoff

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ANNOUNCE: HaskellDB 2.0: Scrap your SQL strings
by Justin Bailey 08 Oct '10

08 Oct '10

What is it? ======== The HaskellDB library lets you generate SQL queries without writing any actual SQL. Unlike other query generating libraries, you choose the abstraction level. Queries can be built out of independent fragments, just like your programs. Leave hand-written, string-based, SQL libraries behind and check out HaskellDB. Where to get it? ============ You can get it from Hackage (http://hackage.haskell.org/package/haskelldb) or by using cabal (cabal install haskelldb). You also need drivers for your specific database. HaskellDB currently supports the HDBC family of drivers. First, download haskelldb-hdbc (http://hackage.haskell.org/package/haskelldb-hdbc) then get the appropriate package for your database: * ODBC: haskelldb-hdbc-odbc (http://hackage.haskell.org/package/haskelldb-hdbc-odbc) * Postgres: haskelldb-hdbc-postgresql (http://hackage.haskell.org/package/haskelldb-hdbc-postgresql) * Sqllite: haskelldb-hdbc-sqlite3 (http://hackage.haskell.org/package/haskelldb-hdbc-sqlite3) Documentation, Mailing List, Source, etc ======================= Go to http://trac.haskell.org/haskelldb for detailed information. What's New? ========= * New query capabilities: stored procedures, CASTs, query parameters, constants, and more. * Postgres SQL improvements. * Bug fixes around AND and OR associativity. * Query optimization improvements around aggregate expressions. * More tests. Details ===== Back in June 2009, Bjorn Bringert passed maintainership of HaskellDB to me. I've been working this summer to get a release out, which included: * Adding an examples/ directory to the source distribution. * Archiving and consolidating information to http://trac.haskell.org/haskelldb. * Accepting patches for various issues. I have used a lot of ORM & SQL-wrapper libraries during my career and HaskellDB is the first that I've found which does not require you to eventually break the abstraction. Learning to use the the library was a fun challenge but not one that many people are willing to take, when they can easily write SQL by hand. If the library was easier to get started with, I think it would be much more widely used. Help me get HaskellDB better documentation! If you are using HaskellDB and want to help: go to http://trac.haskell.org/haskelldb and write an article, write a blog post, get in touch with me, etc. When I saw that Rails 3.0 uses the "ARel" gem (based on the relational algebra) I groaned - Haskell has had that forever! We need to get the word out! Why 2.0? -------------- Last year Brian Bloniarz contributed an awesome patch which replaced HaskellDB's home-grown record system with the HList library by Oleg Kiselyov (and colleagues). I intended to work with the library for awhile and get a 1.0 release out. Unfortunately, HList proved too daunting for GHC and for me. Compile times went way up, and I could not isolate it enough to give GHC HQ a repro case. Even worse, HList required too many Oleg units for me to comprehend. I could usually fix compile errors, but found myself struggling to extend HaskellDB's functionality. In the end I felt I needed to back the patch out. I really hated to lose some of the functionality but in the end maintainability won out. At that point I had pushed a few patches with a v1.0 cabal file, so I thought it best to make this release 2.0. Who am I? --------------- I started using HaskellDB in early 2009. I use it more as a query-generating library than for executing SQL statements. I have written a largish system for generating a data-access layer in PHP from query descriptions in HaskellDB. Yes, I'm using Haskell to write PHP ... dirty! Unmaintained & Unrelated Packages ----------------------------------------------------- A couple of haskelldb related packages on Hackage are not maintained by me: * haskelldb-hdbc-mysql - This project was created and uploaded independent of me. Contact the author for specifics. However, the haskelldb-hdbc-odbc library is maintained by me and can be used to talk to MySQL. * HSQL (haskelldb-hsql, etc) - I cannot get this backend to compile on my platform. HSQL seems unmaintained so I have let the drivers decay. You'll notice I have not uploaded new packages or changed their version dependencies. * haskelldb-flat and haskelldb-dynamic - Both of these packages have suffered serious bitrot and are not maintained any longer.

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CFP MSCS Issue: Dependently Typed Programming
by Conor McBride 07 Oct '10

07 Oct '10

(s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)- >(p:P s)* OPEN CALL FOR PAPERS for a Special Issue of MATHEMATICAL STRUCTURES in COMPUTER SCIENCE in association with the workshop DEPENDENTLY TYPED PROGRAMMING 2010 editors: Thorsten Altenkirch (Nottingham), Conor McBride (Strathclyde) 2011 timeline: submission Jan 31; notification May 31; final version June 30 (s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)->(p:P s)*(s:S)- >(p:P s)* Thorsten Altenkirch and Conor McBride are delighted to invite contributions to a Special Issue of the journal Mathematical Structures in Computer Science (Cambridge University Press), in association with the Workshop on Dependently Typed Programming, which we organised on 9 and 10 July 2010 in Edinburgh, as part of FLoC, associated with LiCS. The workshop had a packed programme of exciting developments, reflecting the strength of work on this topic at this time. More recent workshops and conferences have exhibited a significant contribution from researchers in this area. We are grateful to Editor-in-Chief Giuseppe Longo and to Editor Eugenio Moggi for the opportunity to reflect these welcome developments in the pages of MSCS, and we encourage researchers to consider submitting a paper. submission deadline: January 31 2011 notification: May 31 2011 final versions due: June 30 2011 We invite full journal articles concerning Dependently Typed Programming or related topics, from authors at work in this area. Submissions are particularly welcome from but not limited to contributors to the workshop, and the same journal-standard peer review process will apply in any case. Please feel free to address any enquiries about scope and suitability to the guest editors, Thorsten Altenkirch (University of Nottingham) and Conor McBride (University of Strathclyde). Submissions should usually not exceed 35 pages. Authors should adhere to the guidelines issued by Cambridge University Press for MSCS contributors: http://assets.cambridge.org/MSC/MSC_ifc.pdf. These include directions to the relevant LaTeX resources. We very much look forward to hearing from you. Thorsten and Conor

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ANNOUNCE : shaker 0.4.1
by Anthonin Bonnefoy 04 Oct '10

04 Oct '10

Hi all, I am pleased to announce the release of shaker 0.4.1 Shaker is an interactive build tool which allow to simply compile or launch test on a haskell project and provides some interesting features like continuous action. With continuous action, an action (compile or test) will be automatically executed when a source modification is detected. All configuration are made via cabal; Shaker will read cabal configuration to discover source directories, compilation options and targets to compile. More details on http://hackage.haskell.org/package/shaker What's new since 0.3 : * Integration of test-framework for test execution * Better exception handling * File changes are now correctly reloaded for continuous testing * Test action now use arguments to filter test by their names * Created test-module to execute tests on a specific module Suggestions, feedbacks and bug reports are welcome. Cheers, Anthonin

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TLDI 2011: Final CALL FOR PAPERS
by Stephanie Weirich 04 Oct '10

04 Oct '10

TLDI 2011 FINAL CALL FOR PAPERS The Sixth ACM SIGPLAN Workshop on Types in Language Design and Implementation Austin, Texas, USA Tuesday, January 25, 2011 (Co-located with POPL 2011) http://www.mpi-sws.org/~dreyer/tldi2011/ Submission Deadline: October 11, 2010 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. TLDI 2011 is the sixth workshop in the series and will be co-located with POPL in Austin, Texas in January 2011. Submissions for TLDI 2011 are invited on all interactions of types with language design, implementation, and programming methodology. This includes both practical applications and theoretical aspects. TLDI 2011 specifically encourages papers from a broad field of programming language and compiler researchers, including those working on object-oriented or dynamic languages, systems programming, mobile-code or security, as well as traditional fully-static type systems. Topics of interest include: * Typed intermediate languages and type-directed compilation * Type-based language support for safety and security * Types for interoperability * Type systems for system programming languages * Type-based program analysis, transformation, and optimization * Dependent types and type-based proof assistants * Types for security protocols, concurrency, and distributed computing * Type inference and type reconstruction * Type-based specifications of data structures and program invariants * Type-based memory management * Proof-carrying code and certifying compilation * Types and objects This is not meant to be an exhaustive list; papers on novel utilizations of type information are welcome. Authors concerned about the suitability of a topic are encouraged to inquire via electronic mail to the program chair prior to submission. Submission Guidelines: Authors should submit a full paper of no more than 12 pages (including bibliography and appendices) by Monday, October 11, 2010. The submission deadline and length limitations are firm. Submissions that do not meet these guidelines will not be considered. All submissions should be in standard ACM SIGPLAN conference format: two columns, nine-point font on a ten-point baseline. Detailed formatting guidelines are available on the SIGPLAN Author Information page, along with a LaTeX class file and template. Papers must be submitted electronically via the workshop website (http://www.mpi-sws.org/~dreyer/tldi2011/) in Adobe Portable Document Format (PDF) and must be formatted for US Letter size (8.5"x11") paper. Authors for whom this is a hardship should contact the program chair before the deadline. Submitted papers must adhere to the SIGPLAN Republication Policy. Submissions should contain original research not published or submitted for publication elsewhere. Publication: As in previous years, accepted papers will be published by the ACM and appear in the ACM digital library. A printed proceedings will be available at the workshop. Important Dates: - Submission deadline: October 11, 2010 (Monday), 21:00 Samoa-Apia Time - Notification: November 8, 2010 (Monday) - Final versions due: November 22, 2010 (Monday) - Workshop: January 25, 2011 (Tuesday) General Chair: Stephanie Weirich University of Pennsylvania sweirich at cis dot upenn dot edu Program Chair: Derek Dreyer Max Planck Institute for Software Systems (MPI-SWS) dreyer at mpi-sws dot org Program Committee: Thorsten Altenkirch (University of Nottingham) Fritz Henglein (University of Copenhagen) Michael Hicks (University of Maryland, College Park) Limin Jia (Carnegie Mellon University) Mark Jones (Portland State University) Neel Krishnaswami (Microsoft Research, Cambridge) Paul-André Melliès (CNRS & Université Paris Diderot) Aleks Nanevski (IMDEA Software, Madrid) Benjamin Pierce (University of Pennsylvania) Tachio Terauchi (Tohoku University) Sam Tobin-Hochstadt (Northeastern University) Steering Committee: Amal Ahmed (Indiana University) Nick Benton (Microsoft Research, Cambridge) Derek Dreyer (MPI-SWS) Robert Harper (Carnegie Mellon University, chair) Andrew Kennedy (Microsoft Research, Cambridge) Francois Pottier (INRIA Rocquencourt) Zhong Shao (Yale University) Stephanie Weirich (University of Pennsylvania)

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ANNOUNCE: plot 0.1 plotting package
by Alexander McPhail 29 Sep '10

29 Sep '10

Dear Haskell, Announcing the initial (0.1) release of the 'plot' and 'plot-gtk' packages. Released under the "release early, release often" philosophy. This package uses Cairo to render high quality graphs exportable as PNG, PS, PDF, and SVG. Features: * simple monadic interface to configure each figure and elements * title/subtitle * an array of plots in each figure with optional headers * configurable axes and ticks * configurable ranges * linear, log, semilog ranges * plot vectors or (Double -> Double) functions * line/point/linepoint/impulse/step/area plots * bar/histogram plots * optional error bars * mix and match data series types and formatting * fully configurable text elements * greyscale matrix visualisation The companion package 'plot-gtk' allows creation and incremental update of gtk-displayed plots from the ghci prompt and provides a 'plot' widget. Suggestions, feature requests, and bug reports welcome. Cheers, Vivian

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Re: [Haskell-cafe] ANNOUNCE: Utrecht Haskell Compiler (UHC), version 1.1.0
by Atze Dijkstra 26 Sep '10

26 Sep '10

John, UHC cannot compile itself: some of the used libraries use non-Haskell98 features still absent in UHC (e.g. functional dependencies). Runtime system comparison depends on what topic you want to compare on, otherwise UHC's runtime system just corresponds to what UHC supports, and thus obviously lacks what GHC does support and UHC does not (e.g. parallelism related features). regards, On 24 Sep, 2010, at 19:36 , John Van Enk wrote: > Can UHC self-host yet? How does the runtime compare to GHC's? I suppose I could just go look... :) > > On Wed, Sep 22, 2010 at 10:30 AM, Atze Dijkstra <atze(a)cs.uu.nl> wrote: > Utrecht Haskell Compiler -- second release 1.1.0 > ================================================ > > > The UHC team is happy to announce the second public release of the > Utrecht Haskell Compiler (UHC). UHC supports almost allmost all > Haskell98 and Haskell2010 features plus some experimental extensions. The > compiler runs on MacOSX, Windows (cygwin), and various Unix flavors. > > This second release has the following highlights relative to the > previous first release: > > * Supports most of the Haskell2010 features. > > * Generic deriving [1]. > > * UHC knows about packages, and Cabal version 1.9.3 and later have > basic support for UHC, so that Cabal can be used to build UHC packages. > > * For the default backend libraries are provided until including > package haskell98. > > * The runtime system is no longer dependent on Boehm garbage > collector, but uses UHCs own, a swap space collector allowing > parameterization with backend specifics. > > * More programs from the nofib test suite compile and run. > > * Many smaller and larger problems fixed. > > For more info see http://www.cs.uu.nl/wiki/UHC > > > Getting started & Download > -------------------------- > > UHC is available for download as source distribution via the UHC home > page: > > http://www.cs.uu.nl/wiki/UHC > > Here you will also find instructions to get started and the specifics > of what UHC can and cannot do. > > > Status of the implementation > ---------------------------- > > Over the past year much effort by many people has been put into > improving UHC, in particular to make it compile and run more library > modules and test programs. Although the UHC project is very much work in > progress overall reliability has improved, bugs have been fixed, and > some Hackage packages compile. > > > Warning > ------- > > Although we think that the compiler is stable enough to compile > substantial Haskell programs, we do not recommend yet to use it for any > serious development work in Haskell. We ourselves use the GHC as a > development platform! We think however that it provides a great platform > for experimenting with language implementations, language extensions, > etc. > > > Mailing lists > ------------- > > For UHC users and developers respectively: > > http://mail.cs.uu.nl/mailman/listinfo/uhc-users > http://mail.cs.uu.nl/mailman/listinfo/uhc-developers > > > Bug reporting > ------------- > > Please report bugs at: > > http://code.google.com/p/uhc/issues/list > > > The UHC Team > > > > [1] Jose Pedro Magalhaes, Atze Dijkstra, Johan Jeuring, and Andres Loeh. > A generic deriving mechanism for Haskell. > http://dreixel.net/research/pdf/gdmh_draft.pdf (see Section 7.1 for the > discussion on constrained datatypes) > > > > > - Atze - > > Atze Dijkstra, Department of Information and Computing Sciences. /|\ > Utrecht University, PO Box 80089, 3508 TB Utrecht, Netherlands. / | \ > Tel.: +31-30-2534118/1454 | WWW : http://www.cs.uu.nl/~atze . /--| \ > Fax : +31-30-2513971 .... | Email: atze(a)cs.uu.nl ............ / |___\ > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > - Atze - Atze Dijkstra, Department of Information and Computing Sciences. /|\ Utrecht University, PO Box 80089, 3508 TB Utrecht, Netherlands. / | \ Tel.: +31-30-2534118/1454 | WWW : http://www.cs.uu.nl/~atze . /--| \ Fax : +31-30-2513971 .... | Email: atze(a)cs.uu.nl ............ / |___\

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