- Haskell-Cafe - Haskell.org

haddock - error
by Andrew U. Frank 22 Jan '10

22 Jan '10

the problem with me getting no haddock output whatsoever was that i had not reconfigured cabal after replacing haddock 2.4 by 2.5 (by installing it with cabal). it would be helpful if there were an error message - but i can clearly see that this is difficult to achieve in this case. thanks for the help!

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Re: Is Haskell capable of matching C in string processing performance?
by John Lato 22 Jan '10

22 Jan '10

> From: Heinrich Apfelmus <apfelmus(a)quantentunnel.de> > Don Stewart wrote: >> jmillikin: >>> Here's the fastest Haskell version I could come up with. It discards >>> all error handling, validation, and correctness in the name of >>> performance, but still can't get anywhere near C: >>> http://hpaste.org/fastcgi/hpaste.fcgi/view?id=16423 >> >> Thanks for posting the code. >> >> You're not using bytestrings?? >> >> They were invented to deal with the problem of [Char] being a poor >> structure for large scale string processing, and you should have no >> problem getting C-like string performance. >> >> http://www.cse.unsw.edu.au/~dons/papers/CSL06.html > > In my limited experience, ByteStrings are great for reading data, but > not that good for writing data that is being generated on the fly. For > writing, good old difference lists or the Builder monoid / Put monad > from Data.Binary seem to be best. > If find that this is particularly true if you don't know the length of data to write in advance because it involves lots of new allocations and copying. Using Builder/Put is definitely a better approach. Out of curiousity, has anyone ever tried implementing a LinkedListString in C to check what its performance would be? I expect it would be pretty poor compared to standard strings. Cheers, John

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Re: [Haskell-cafe] hsql won't install due to system.time
by John Lato 22 Jan '10

22 Jan '10

Hello, Could this be a global/user install issue? That is, if the old-time package is installed per-user, and you're trying to install a package globally, the user-installed packages all show up as hidden, because they can't be dependencies of a global install. This shows up frequently because global installs are the default when doing "runghc Setup.hs install", but per-user installs are the default for cabal install. If you use both of these commands, you'll run into this sooner or later. You can run "ghc-pkg list" to get a listing of what's installed where. If "old-time" is only in the local database, you should reinstall it into the global database (or install everything globally). Cheers, John > From: Brian Denheyer <briand(a)aracnet.com> > > Database/HaskellDB/HSQL.hs:25:7: > Could not find module `System.Time': > it is a member of the hidden package `old-time-1.0.0.3' > it is a member of the hidden package `old-time-1.0.0.2' > Use -v to see a list of the files searched for. > > old-time-1.0.0.2 is installed (via cabal). > > Suggestions on how to fix this or which haskell db (for sqlite3) package > will actually install greatly appreciated. > > I get a lot of failures in hackages which involve that dreaded "hidden > package" message. Anybody care to enlighten us mere mortals as to why > it seems to occur so frequently (at least for me). > > Brian >

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problems installing ghc-6.12.1-x86_64
by Andrew Polonsky 22 Jan '10

22 Jan '10

Dear all, Help!! I am trying to build 6.12 on a fresh 64-bit Ubuntu, with no GHC installed yet. The compiler itself builds happily, but when I try to "make install" the Haskell platform, I eventually get the error Setup: GLUT-2.1.1.2: dependency "OpenGL-2.2.1.1-b638210d1627880d532e3b035b53bcd2" doesn't exist (use --force to override) I can't even install cabal, because it requires having the ghc6 package, which is not installed. And bootstrapping cabal-install requires parsec and network, which also require ghc6. When I finally install ghc6 (why should I have to anyway?), it still thinks I am on 6.12, and ./bootstrap.sh can't find parsec with that number. Is there anyway to break out of this non-terminating reduction? Is YI solvable? :'"( Andrew

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ANNOUNCE: Haskell XML Toolbox Version 8.5.0
by Uwe Schmidt 22 Jan '10

22 Jan '10

Haskell XML Toolbox 8.5.0 I would like to announce a new version of the Haskell XML Toolbox. The main change in this release is the separation of the XPath module and the XSLT module into separate packages hxt-xpath and hxt-xslt. So the base package becomes a bit smaller. Installation shouldn't become more complex because of the easy install with cabal and hackage. A second major change concerns the XPath module. The internal data structures, especially the XPath node-sets, have been refactored for runtime efficiency. So even complex XPath expressions with ambiguous paths to single nodes run in acceptable time. The source repositories have been converted to the git version control system. There is a single git repository for all HXT packages at "http://git.fh-wedel.de/repos/hxt.git" More information and also downloads can be found at http://www.fh-wedel.de/~si/HXmlToolbox/index.html There's also a copy of all packages on Hackage. Please email comments, bugs, etc. to hxmltoolbox(a)fh-wedel.de or si(a)fh-wedel.de Uwe -- University of Applied Sciences, Wedel, Germany http://www.fh-wedel.de/~si/index.html

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ssh ports for monk and nun?
by Alistair Bayley 22 Jan '10

22 Jan '10

Trying to get ssh working via putty from behind my company firewall. Had some success in the past with sourceforge because they had ssh daemons listening on ports 80 and 443, to aid prisoners like myself. Does anyone know if the monk (darcs.haskell.org) and nun (code.haskell.org) servers accept ssh on ports other than 22? Thanks, Alistair

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haddock - 'could not find link destination"
by Andrew U. Frank 22 Jan '10

22 Jan '10

i try to use haddock for documentation, but have no success. no output is produced. i assume i make some stupid mistake (not having used haddock before) help is appreciated! thank you andrew ------------------------------- i get the following error: $ haddock Hadtest2.hs Warning: Main: could not find link destinations for: GHC.Types.Int GHC.Base.String Hadtest2.hs is a simplistic test program with some parts copied from the haddock manual: module Main (square, this) where -- | a constant this :: String this = "this" -- |The 'square' function squares an integer. square :: Int -> Int square x = x * x main = do putStrLn $ "test " ++ show (square 4) return () --

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Cannot rebuild GHC 6.12.1 due to Cabal type conflict
by James Britt 22 Jan '10

22 Jan '10

Hey all. I recently wanted to rebuild GHC 6.12.1 from source (from a downloaded tarball). After the first install from that source I went and updated Cabal (from a tarball grabbed from Hackage). When I now try to do a rebuild of GHC, I get this error compiler/main/Packages.lhs:233:63: Couldn't match expected type `InstalledPackageInfo_ String' against inferred type `Cabal-1.8.0.2:Distribution.InstalledPackageInfo.InstalledPackageInfo_ m' Expected type: [InstalledPackageInfo_ String] Inferred type: [Cabal-1.8.0.2:Distribution.InstalledPackageInfo.InstalledPackageInfo_ m] In the second argument of `map', namely `conf' In the first argument of `return', namely `(map installedPackageInfoToPackageConfig conf)' make[1]: *** [compiler/stage1/build/Packages.o] Error 1 make[1]: *** Waiting for unfinished jobs.... make: *** [all] Error 2 (also here: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=16380#a16380) I'm running the build like this: make distclean sh boot ./configure --enable-shared make -j 2 but (I'm guessing) it's looking at the already-installed Cabal libs and not liking what it's getting. Any ideas on how to get past this? Thanks, James Britt -- www.jamesbritt.com - Playing with Better Toys www.ruby-doc.org - Ruby Help & Documentation www.rubystuff.com - The Ruby Store for Ruby Stuff www.neurogami.com - Smart application development

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Haskell on Ideone!
by Sphere Research Labs 22 Jan '10

22 Jan '10

Hi, test Haskell on ideone.com, see the example: http://ideone.com/bbloQ9r0 regards, Ideone Team

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Haskell Platform
by Rafael Gustavo da Cunha Pereira Pinto 21 Jan '10

21 Jan '10

Hi folks, How are the efforts on Haskell Platform for GHC 6.12.1 going? I'm considering joining those brave heroes. Where can I apply? Rafael Gustavo da Cunha Pereira Pinto

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