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Re: [Haskell-cafe] pqueue - repository and maintainer (taking over)
by Louis Wasserman 29 May '15

29 May '15

No, it's not; I never did put it up on github. On Wed, May 27, 2015 at 11:18 PM Tobias Brandt <tob.brandt(a)gmail.com> wrote: > I have an open pull request for this issue since February: > https://github.com/bumptech/haskell-pqueue/pull/2 > > But I don't even know whether this is the official repository. > > On Wed, May 27, 2015 at 10:01 PM lennart spitzner < > lsp(a)informatik.uni-kiel.de> wrote: > >> Greetings, >> >> Regarding the pqueue package: >> >> 1) Does anyone have any (additional) contact details for the current >> maintainer/author, Louis Wasserman? >> 2) Is the package's repository available anywhere? The darcs link >> listed in the package 404s. >> 3) I would be willing to take over for basic maintenance if the >> current maintainer is unavailable. >> >> The pqueue package does not compile with ghc-7.10. Fixing requires >> just some quick changes (i have a working version locally). The last >> upload for the package is from 2012, but the author's github account >> lowasser shows some more recent activity. Yet I have not received a >> reply to my e-mail from six weeks ago. >> >> Lennart >> > _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe(a)haskell.org >> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe >> >

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Libraries Mailing Problem?
by Dominic Steinitz 29 May '15

29 May '15

Is there something wrong with the libraries mailing list? There doesn’t seem to have been any traffic since 18 May: https://mail.haskell.org/pipermail/libraries/2015-May/date.html <https://mail.haskell.org/pipermail/libraries/2015-May/date.html> Dominic Steinitz dominic(a)steinitz.org http://idontgetoutmuch.wordpress.com

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International Conference on Live Coding, 13-15 July, Registration open
by alex 28 May '15

28 May '15

First International Conference on Live Coding ICSRiM, School of Music, University of Leeds 13th-15th July 2015 http://iclc.livecodenetwork.org/ We are happy to announce that registration for ICLC2015 is now open. Live coding turns programming languages into live interfaces, allowing us to directly manipulate computation via its notation. Live coding has great potential, being used for example to create improvised music and visuals, to allow developers to collaborate in new ways, to better understand computational models by making fundamental changes to them on-the-fly, and to find new ways to learn and teach programming. Since the beginning of the TOPLAP movement in 2003 (building on an extensive but hidden pre-history), live coding has grown fast, attracting interest from many people in artistic, creative, scientific, educational, business and mixed contexts. After a good number of international events, the time is right to bring these people together for an academic conference, exchanging ideas and techniques, and enjoying dozens of peer reviewed papers and performances. The conference will also open up the field for people new to live coding, so they may develop and contribute their own perspectives on this emerging field. Join us! Registration is £80 (£50 concessions) for the three day conference including lunches, evening events, and more. See the website for details of the developing programme: http://iclc.livecodenetwork.org/ And register here, completing both the on-line payment and registration forms: http://iclc.livecodenetwork.org/registration.html ICLC is organised by the Live Coding Research Network, which is funded by the Arts and Humanities Research Council. -- http://yaxu.org/

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no Web-Security component in Haskell?
by Thomas Koch 28 May '15

28 May '15

Hallo, I did not found anything comparable to Spring Security[1][2] (Java) or Symfony Security[3] (PHP) in Haskell. Both components are used in web applications to grant or deny access to resources based on roles, ACLs or custom voters. A naive strategy would be to port the concepts of both components, which are very similar, to Haskell. They represent a lot of accumulated knowledge from many experts about web security. Or are there better ways to do web security in a powerful language like Haskell? Regards, Thomas Koch [1] http://projects.spring.io/spring-security [2] http://docs.spring.io/autorepo/docs/spring-security/3.1.7.RELEASE/apidocs [3] http://api.symfony.com/master/Symfony/Component/Security/Core/SecurityConte…

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Taking over protocol-buffers package
by Kostiantyn Rybnikov 28 May '15

28 May '15

Hi Chris and Cafe! I've sent Chris an email couple days ago, this is another one to have haskell-cafe CCed in order to request maintainership of protocol-buffers package. Stefan Wehr actually tried to contact Chris long time ago, and thus you can see current "riak" package depends upon protocol-buffers-fork package, created to add support for GHC 7.8. I'd like to incorporate work from protocol-buffers-fork, add support for GHC 7.10, and also move project to GitHub and add some README with at least basic tutorial. Thanks! Awaiting few weeks now :)

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how to organize a parallel parser/compiler
by Maurizio Vitale 28 May '15

28 May '15

hello haskell-cafe, suppose you have a compiler pipeline roughly similar to (from write you a Haskell <http://dev.stephendiehl.com/fun/007_path.html> ): modl :: FilePath -> L.Text -> CompilerM () modl fname = parseP fname >=> dataP >=> groupP >=> renameP >=> desugarP >=> inferP >=> evalP and suppose you have a language where you can compile multiple files and compilation must be made _as if_ files were concatenated together in the order given on the command line (there might be side effects that affect parsing of subsequent files); still in the average case there're no dependencies and files could be compiled in parallel (or some of the dependencies can be handled at the AST level as one can prove they don't affect parsing but only aspects of the AST that can be patched). What are good strategies for dealing with this and rerun some of the parseP functions (and in the simplest solution the complete pipeline after it). The strategy I have in mind now doesn't mix well with the above pipeline, so I'd like to see if there're alternative solutions. Basically, what I have in mind is: - each parse function gets a file, something to watch on for the result of the previous parse (let's say an MVar, or some variation of speculation <https://hackage.haskell.org/package/speculation> , not sure yet) and an input environment (same for everybody). It produces an AST + what he's sensitive to (e.g. what would have affected the parsing) and what he generates that the next guy must be sensitive to. - before producing the 'what it generates part', it must be sure to have completed a valid parse, so he'll wait on the input MVar to know that the previous files have been parsed properly and that whatever side effects it caised wouldn't affect parsing. This wait will be done on a thread that doesn't count towards the parallelism limit as it is presumably cheap and we don't really serialize the parsing. [a similar question related to the above pipeline would be how do I fit in any kind of global transformation pass] Is there any library or other ideas on how to combine multiple pipelines where we want to run them with maximum parallelism but the outcome of (even a partial step of) one pipeline can invalidate and require to rerun others? Thanks for any idea, Maurizio

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ZeroMQ Thread Safety
by David Turner 28 May '15

28 May '15

Hi all, According to the ZeroMQ docs[1]: "Individual ØMQ sockets are not thread safe except in the case where full memory barriers are issued when migrating a socket from one thread to another." The Haskell ZeroMQ binding [2] is a fairly thin wrapper around the C API, and in particular doesn't seem to do much to enforce thread safety as described above. My question: do I need to use bound threads to call functions on sockets to ensure that all the foreign calls happen on the same OS thread, or is it the case that two consecutive foreign calls in a single Haskell thread have a "full memory barrier" between them if they end up being called from different OS threads? Thanks in advance, David [1] http://api.zeromq.org/4-0:zmq [2] http://hackage.haskell.org/package/zeromq4-haskell

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Account for the Haskell Wiki
by Alois Cochard 27 May '15

27 May '15

Hi, I would like a user account to access the Haskell wiki. Desired username: 'aloiscochard' Cheers -- *Λ\ois* http://twitter.com/aloiscochard http://github.com/aloiscochard

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ClassyPrelude vs. Haskell.Language.Interpreter
by Mike Meyer 27 May '15

27 May '15

No answer on -beginners, so I'm trying -cafe. I'm trying to run interpreted code via ClassyPrelude, and getting some results that make me suspect a bug in the Prelude's type system. Or maybe the interpreter. Anyway, here's a bit of code that works as expected: {-# LANGUAGE NoImplicitPrelude #-} import ClassyPrelude import Language.Haskell.Interpreter main :: IO () main = do fun <- runInterpreter $ makeFun "reverse" case fun of Left e -> print e Right f -> readFile "/etc/motd" >>= hPut stdout . f makeFun expr = do set [languageExtensions := [NoImplicitPrelude]] setImportsQ [("ClassyPrelude", Nothing)] interpret expr (as :: Text -> Text) I don't think I can simplify this any further. It works as expected, and also works as expected, and prints out the contents of /etc/motd reversed. However, if you change the type signature in the last line from Text -> Text to LText -> Ltext (to get lazy text), you get no output. But if you change the function in the first line after main from "reverse" to "id", it works. So far, it might be an issue with lazy IO. However, change the type signature in the last line to LText -> Text. In this case, there is no output for either value of the expression. I expect an error in this case, as neither id nor reverse should be able to have the type LText -> Text! So, is there something I missed in either ClassyPrelude or the Interpreter? Or is this a subtle interaction, in which case can someone suggest a workaround? Or have I found a bug in one of the two?

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Re: [Haskell-cafe] Installing ghc-mod on Windows
by Anakreontas 26 May '15

26 May '15

I think cabal reported errors regarding the header files where in fact the problem was that it could not find a c compiler. I tried to install QuickCheck and the primitives package required by QuickCheck failed to install with errors related to header files. After installing gcc, primitives and QuickCheck installed without errors. On Tuesday, May 26, 2015 at 11:18:30 AM UTC+1, Anakreontas wrote: > > ... continued from previous message > .. even with command cabal install --extra-include-dirs=include cabal > still reports an error. > The header file is useful for older ghc versions that the one I have so > removing the dependency on the header resolved the problem. > > On Tue, May 26, 2015 at 11:16 AM, Anakreontas Mentis < > anakreonmejdi(a)gmail.com> wrote: > >> I installed the MinGHC distribution but it did not solve the problem. >> >> To install ghc-mod I had to: >> 1) cabal install ghc-mod >> to install what cabal can build without errors. >> 2) Modify the cabal file of ansiterminal according to Roman's advice. It >> installed successfully. >> 3) Modify the cabal file of lifted-base where I removed the Include-dirs >> and Includes directives and all references to inlinable.h from the source >> files. >> cabal reports that it can not find the header file or it is damaged. >> The file exists in the include directory but even with >> >> On Fri, May 22, 2015 at 7:58 PM, Michal Antkiewicz < >> mantkiew(a)gsd.uwaterloo.ca> wrote: >> >>> There used to be a big warning "don't download just the ghc. Use the >>> platform. " before. >>> >>> Nowadays, it's best to get MinGHC from >>> >>> https://www.haskell.org/downloads/windows >>> >>> this distribution is best, it'll allow you build the network package and >>> other things like the ansi-terminal, etc. >>> >>> Get the 32bit installer. >>> >>> Michał >>> >>> On Fri, May 22, 2015 at 2:10 PM, <anakreonmejdi(a)gmail.com> wrote: >>> >>>> Hello. >>>> I don't know the MinGHC release. To install ghc I downloaded a windows >>>> install program from https://www.haskell.org/ghc/. >>>> >>>> >>>> Michal Antkiewicz <mantkiew(a)gsd.uwaterloo.ca> writes: >>>> >>>> > Hi, >>>> > >>>> > are you using msys and MinGHC? >>>> > >>>> > For now, I clone ghc-mod @ master and just cabal install it (with >>>> MinGHC >>>> > 0.7.10 and cabal 1.22) within msys. It has not been released yet. >>>> > >>>> > Michał >>>> > >>>> > On Fri, May 22, 2015 at 12:09 PM, Roman Cheplyaka <roma(a)ro-che.info> >>>> wrote: >>>> > >>>> >> On 22/05/15 18:06, Anakreontas wrote: >>>> >> > I tried to instal ghc-mod on Windows with cabal. Two dependencies >>>> fail >>>> >> > to compile because of missing native libraries. >>>> >> > ansi-terminal requires kernel32 and >>>> >> > lifted-base requires inlinable.h. >>>> >> > >>>> >> > Have you solved a similar problem? In Linux it would be easy to >>>> install >>>> >> > the native libraries but in Windows I do not know which programs I >>>> >> > should install and where to find them. >>>> >> >>>> >> You should be able to install ansi-terminal by patching its cabal >>>> file, >>>> >> see https://github.com/feuerbach/ansi-terminal/issues/6 >>>> >> >>>> >> Once again, I'm asking Windows users and developers for their input >>>> on >>>> >> this issue. >>>> >> >>>> >> Roman >>>> >> >>>> >> >>>> >> _______________________________________________ >>>> >> Haskell-Cafe mailing list >>>> >> Haskell-Cafe(a)haskell.org >>>> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe >>>> >> >>>> >> >>>> >>>> -- >>>> >>> >>> >> >

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