March 2013 - Haskell-Cafe

Trouble installing and using Chart/cairo on windows 7
by Arnaud Bailly 04 Mar '13

04 Mar '13

Hello, I am trying to install timeplot and splot on a windows 7 host, using Haskell platform 2012.2.0.0, and I have troubles installing HSChart. First difficulties were installing cairo, which requires Gtk+ libraries and headers. I installed those using a Gtk+-bundle, first in c:\Program Files\. I had to move to d:\soft (eg. a directory without spaces) to be able to install cairo. Then I tried to install Chart and at first failed with a cryptic 'Exit Failure 1' error from cabal. I succeeded when I redirected cabal output to a file, eg: cabal install > out 2<&1 whereas a plain 'cabal install' failed. Then I managed to install splot and timeplot. I then tried to use Chart to draw a simple chart, following http://hackage.haskell.org/packages/archive/Chart/0.16/doc/html/Graphics-Re… it hang forever with a CPU at 100%. Suggestions are more than welcomed. Regards, Arnaud

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ANN: pipes-network-0.1.0 - Stream your network sockets using the pipes and pipes-safe libraries
by Renzo Carbonara 04 Mar '13

04 Mar '13

I'm happy to announce the release of pipes-network 0.1.0. The pipes-network package allows using network sockets together with the pipes and pipes-safe libraries, for streaming purposes. Currently, just TCP sockets are supported. http://hackage.haskell.org/package/pipes-network-0.1.0 The package is split into two halves: one “Safe” half that can be used if proxies need to safely and timely acquire and release new sockets within a pipeline, using the facilities provided by the pipes-safe package; and another simpler and faster half that doesn't depend on pipes-safe, but it also doesn't provide any means for safely acquiring and releasing new sockets within a pipeline itself. There's plenty of documentation and some examples in the Haddocks. Many thanks to Gabriel Gonzalez, author of pipes, for discussing the design of the library with me; and to Paolo Capriotti, author of a previous pipes-network version, for his original work and for handing me the maintenance of this package. ¡Enjoy your TCP streams! Regards, Renzo Carbonara.

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building darcs failed (Unable to link against the iconv library)
by Dmitry Malikov 04 Mar '13

04 Mar '13

Trying to install darcs with cabal-install: Linking /tmp/darcs-2.8.4-12051/darcs-2.8.4/dist/setup/setup ... Configuring darcs-2.8.4... checking whether to use -liconv... setup: Unable to link against the iconv library. Failed to install darcs-2.8.4 cabal: Error: some packages failed to install: What is actually going on here? Iconv libraries already installed with libc6 package. Running ubuntu, cabal-install-1.16.0.2. -- Best regards, dmitry malikov !

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ANN: Nomyx 0.1 beta, the game where you can change the rules
by Corentin Dupont 03 Mar '13

03 Mar '13

Hello everybody! I am very happy to announce the beta release [1] of Nomyx, the only game where You can change the rules. This is an implementation of a Nomic [2] game in Haskell (I believe the first complete implementation). In a Nomyx game you can change the rules of the game itself while playing it. The players can submit new rules or modify existing ones, thus completely changing the behaviour of the game through time. The rules are managed and interpreted by the computer. They must be written in the Nomyx language, which is a subset of Haskell. At the beginning, the initial rules are describing: - how to add new rules and change existing ones. For example a unanimity vote is necessary to have a new rule accepted. - how to win the game. For example you win the game if you have 5 rules accepted. But of course even that can be changed! Here is a video introduction and first tutorial of the game: http://vimeo.com/58265498 The game is running here: www.nomyx.net:8000/Nomyx I have set up a forum where players can learn about Nomyx and discuss the rules they intend to propose: www.nomyx.net/forum As this is the first beta release of the game, I'm looking for beta testers :) Although I tested it quite a lot, I'm sure a lot of bugs remains, especially in multiplayer. So if you are interested in testing Nomyx, please go to this forum thread and we'll set up a small team to start a match! http://www.nomyx.net/forum/viewtopic.php?p=5 Comments/contributions are very highly welcome! There is still a lot to do. As for now, the game is not completely securised. It is easy to break it by submitting rules containing malicious code. I'm working on it. If you'd like to do security testing, please do it locally on your own machine and send me a bug report :). Cheers, Corentin [1] http://hackage.haskell.org/package/Nomyx [2] www.nomic.net

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Proposal: TypeDirectedNameResolution
by Johannes Waldmann 03 Mar '13

03 Mar '13

While browsing Haskell-Prime I found this: http://hackage.haskell.org/trac/haskell-prime/wiki/TypeDirectedNameResoluti… This is not some April Fool's day hoax? Because, it might actually turn Haskell into a somewhat usable (and marketable) language ... well, you know what I mean. Is there 'ghc -XTypeDirectedNameResolution' yet? - J.W.

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ANNOUNCE: netpbm
by Niklas Hambüchen 03 Mar '13

03 Mar '13

I'm happy to announce a new library, "netpbm", a full implementation of the netpbm image formats (PPM, PGM, PBM) in pure Haskell. The P*N formats describe themselves as "as easy as possible"; they mainly consist of dimensions + uncompressed data and are used especially in between graphics programs, e.g. between ImageMagick and its ghostscript part as well as in ffmpeg. There are six formats (bitmap, greyscale, color, each of them coming in binary and ASCII variants). This parses all of them. The main focus of this library is *pedantic* adherence to the spec (http://netpbm.sourceforge.net/doc/pbm.html) - in fact I claim that all implementations out there do not properly implement the spec correctly, not even the netpbm project itself. I have not properly verified this yet, but my library can parse valid PPM files that don't display in my image viewer (which is built on top of the C library in question). To be honest, one cannot really blame anybody for this since netpbm allows pretty insane things (such as comments inside numeric literals) and its claim to be simple is absolutely hilarious. haskell-netpbm is backed by an extensive test suite that checks its compatibility with images created by common programs (GIMP, convert), public data sets, and random pictures I found on the Internet. It is built using attoparsec. You can find it on http://hackage.haskell.org/package/netpbm Any contributions in form of code, tests images or claims that I don't implement the spec right are highly welcome at https://github.com/nh2/haskell-netpbm Please note that I just finished the implementation and that I will clean up (break) the API in the next release, but I found it made sense to announce it as early as possible now that the format implementation is complete. Niklas

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ANN: sandi 0.2 - reasonbly fast data encoding library
by Magnus Therning 02 Mar '13

02 Mar '13

I've just uploaded sandi version 0.2[1] to Hackage. Sandi is a data encoding library. It's aimed to be the successor of dataenc, my old data encoding library. Currently the following encodings are supported: - base16 - base32 - base32 hex - base64 - base64 url - base85 - quoted printable - uu - xx - yenc The main changes since the previous release: - Added benchmarks using criterion. - Modified API to make it better suited for piecemeal decoding by making decoding of base16, qp, and yenc accept correct but incomplete input. - Add a completely new API to allow using sandi with conduit. [1]: http://hackage.haskell.org/package/sandi-0.2 -- Magnus Therning OpenPGP: 0xAB4DFBA4 email: magnus(a)therning.org jabber: magnus(a)therning.org twitter: magthe http://therning.org/magnus

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Re: [Haskell-cafe] Parser left recursion
by Paul Callaghan 02 Mar '13

02 Mar '13

Hi Another alternative is this Haskell library: https://github.com/paulcc/xsaiga This is a combinator library which is suitable for mid-scale NLP work, so handles left recursion and (high amounts of) ambiguity to produce a packed result (which can be decoded to a list of results if required). It uses a technique similar to Danielsson's for termination. The technical details (incl papers) can be found on http://cs.uwindsor.ca/~hafiz/xsaiga/pub.html, particularly in the IWPT paper http://cs.uwindsor.ca/~hafiz/pub/iwpt-07.pdf I'd be interested to see a GLL impl for Haskell, particularly for comparison with the above. Did Roman C. publish some code for this a while back? Paul On Wed, Feb 27, 2013 at 9:50 AM, Paul Callaghan <paulcc.two(a)gmail.com> wrote: > Another alternative is this Haskell library: https://github.com/paulcc/xsaiga > > This is a combinator library which is suitable for mid-scale NLP work, > so handles left recursion and (high amounts of) ambiguity to produce a > packed result (which can be decoded to a list of results if required). > It uses a technique similar to Danielsson's for termination. > > The technical details (incl papers) can be found on > http://cs.uwindsor.ca/~hafiz/xsaiga/pub.html, particularly in the IWPT > paper http://cs.uwindsor.ca/~hafiz/pub/iwpt-07.pdf > > I'd be interested to see a GLL impl for Haskell, particularly for > comparison with the above. Did Roman C. publish some code for this a > while back? > > Paul > > On Tue, Feb 26, 2013 at 7:43 PM, Dominique Devriese > <dominique.devriese(a)cs.kuleuven.be> wrote: >> 2013/2/26 Martin Drautzburg <Martin.Drautzburg(a)web.de>: >>> I wonder if I can enforce the nonNr property somehow, i.e. enforce the rule >>> "will not consider the same nonterminal again without having consumed any >>> input". >> >> You might be interested in this paper: >> >> Danielsson, Nils Anders. "Total parser combinators." ACM Sigplan >> Notices. Vol. 45. No. 9. ACM, 2010. >> >> Regards, >> Dominique >> >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe(a)haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe

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Re: [Haskell-cafe] Announce: Leksah 0.13.2.0 (still a bit experimental)
by Hamish Mackenzie 01 Mar '13

01 Mar '13

12.10 uses webkit 1.10 so the -fwebkit1.8 was probably tripping it up. I have updated webkit so that webkit 1.8 is detected automatically and updated the .travis.yml file. Please try again. On 23 Feb 2013, at 06:20, alejandro.bello67(a)gmail.com wrote: > I compiled Leksah 0.13.2 using Ubuntu 12.04 (I followed the instructions on .travis.yml). It was OK, but when I tried to compile with Ubuntu 12.10, I got the following error: > > Building webkit-0.12.5... > Preprocessing library webkit-0.12.5... > gtk2hsC2hs: Errors during expansion of binding hooks: > > webkit1.8/Graphics/UI/Gtk/WebKit/DOM/File.chs:17: (column 14) [ERROR] > >>> Unknown identifier! > Cannot find a definition for `webkit_dom_file_get_file_name' in the header file. > webkit1.8/Graphics/UI/Gtk/WebKit/DOM/File.chs:23: (column 16) [ERROR] > >>> Unknown identifier! > Cannot find a definition for `webkit_dom_file_get_file_size' in the header file. > > Can you help me, please? > > Alejandro T. Bello Ruiz > > > -- > You received this message because you are subscribed to the Google Groups "leksah" group. > To unsubscribe from this group and stop receiving emails from it, send an email to leksah+unsubscribe(a)googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > >

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Galois is hiring!
by Jason Dagit 01 Mar '13

01 Mar '13

Galois is hiring! We're looking for functional programmers, formal methods practitioners, and project leads, with a variety of positions open at all professional experience levels. For more information on the job openings and Galois in general, see: http://corp.galois.com/careers I've written before about what makes Galois a great organization to be a part of: http://blog.codersbase.com/2012/03/life-at-galois.html Thanks, Jason

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