- Haskell-Cafe - Haskell.org

Howto debug erros occuring just by linking to non-Haskell libraries
by Mads Lindstrøm 01 Feb '09

01 Feb '09

Hi Haskeleers I am trying to track down the cause of an error occurring in the Linux version of wxHaskell. The error occurs before the main function is executed. That is, it occurs if one imports the wxHaskell libraries, and it occurs even if one do not execute any wxHaskell function. Specifically, GLib complains that a initialization-function has not been called. My guess is, that it has something to do with the wxWidgets (and gtk or glib) libraries wxHaskell links to. Some people have suggested it may be an error in the way GHC links with C libraries. But that is all guesswork, I would need something more solid if I were to file GHC bugreport. Here is a simple Haskell program to illustrate the problem: module Main where import Graphics.UI.WX main = print "sdfjkl" and when we compile and execute this program we get: (process:13986): GLib-GObject-CRITICAL **: gtype.c:2240: initialization assertion failed, use IA__g_type_init() prior to this function (process:13986): Gdk-CRITICAL **: gdk_cursor_new_for_display: assertion `GDK_IS_DISPLAY (display)' failed (process:13986): GLib-GObject-CRITICAL **: gtype.c:2240: initialization assertion failed, use IA__g_type_init() prior to this function (process:13986): Gdk-CRITICAL **: gdk_cursor_new_for_display: assertion `GDK_IS_DISPLAY (display)' failed "sdfjkl" So even if I do not call any wxHaskell functions, just by linking to wxHaskell, I get these errors. As Jeroen Janssen reports here http://www.mail-archive.com/wxhaskell-users@lists.sourceforge.net/msg00540.… , he is experiencing the same error, but his wxPython programs works. Thus, wxHaskell (or GHC or ...) must do something different. Could this error be related to the order which external libraries are loaded in? If so, do anybody know how to specify the load order? Can anybody help med with a good approach for debugging this error? Greetings, Mads Lindstrøm

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Panic with GTK2HS 0.10.0 RC under Vista with GHCi 6.10.1; GHCi or GTK bug?
by Peter Verswyvelen 01 Feb '09

01 Feb '09

Often when trying to run my GTK2HS application the first time with GHCi I get : panic! (the 'impossible' happened) (GHC version 6.10.1 for i386-unknown-mingw32): loadObj: failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This only occurs when I forgot to set my current directory correctly; then GHCi gives an error since it can't find modules GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer ... linking ... done. Loading package base ... linking ... done. Boxes.hs:23:17: Could not find module `NM8.GUI.Layout': Use -v to see a list of the files searched for. Failed, modules loaded: none. If I then correctly set my current directory using the :cd command, and try again, I get the panic crash. When I start GHCi again and immediately set the correct current directory, it works fine. I haven't tried to isolate the problem, but maybe others have experienced this problem? It's not really a show-stopper, just but a bit annoying

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ANN: regex-xmlschema
by Uwe Schmidt 01 Feb '09

01 Feb '09

I'm pleased to announce (yet another) package for processing text with regular expressions: regex-xmlschema The W3C XML Schema specification (http://www.w3.org/TR/xmlschema11-2/#regexs) defines a language for regular expressions. This language is used in the XML Schema spec when defining the data type library part. This regex-xmlschema package contains a complete implementation of this spec. It is implemented with the technique of derivations of regular expression. Main features are: * full support of Unicode including all Unicode code blocks and character properties * a purely functional interface * 100% Haskell, no other packages except parsec needed * cabal build file * extensions for intersection, set difference, exclusive or and interleave of regular sets (regular expressions), * extensions for subexpression matches * functions for matching, for grep like searching, for stream like editing (sed like) and for tokenizing. With this package, it becomes rather easy to build lightweight tokenizers e.g. for colourizing arbitrary programming languages, like hscolor does it for Haskell. The package is available from Hackage: "http://hackage.haskell.org/cgi-bin/hackage-scripts/package/regex-xmlschema", there's a darcs repo for the latest source: "http://darcs2.fh-wedel.de/hxt/regex/" and a wiki page, describing the extension and giving some examples for using the library: "http://www.haskell.org/haskellwiki/Regular_expressions_for_XML_Schema" Cheers, Uwe -- Uwe Schmidt FH Wedel http://www.fh-wedel.de/~si/

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can't build testpack
by Ezekiel Smithburg 01 Feb '09

01 Feb '09

this is the error message i get: ezekiel-smithburgs-macbook-pro-15% runhaskell Setup.* build Preprocessing library testpack-1.0.0... Building testpack-1.0.0... [1 of 3] Compiling Test.QuickCheck.Instances ( src/Test/QuickCheck/Instances.hs, dist/build/Test/QuickCheck/Instances.o ) [2 of 3] Compiling Test.QuickCheck.Tools ( src/Test/QuickCheck/Tools.hs, dist/build/Test/QuickCheck/Tools.o ) [3 of 3] Compiling Test.HUnit.Tools ( src/Test/HUnit/Tools.hs, dist/build/Test/HUnit/Tools.o ) src/Test/HUnit/Tools.hs:28:36: Class `Control.Exception.Exception' used as a type In the type `Control.Exception.Exception' In the type `Control.Exception.Exception -> IO a -> IO ()' In the type `String -> Control.Exception.Exception -> IO a -> IO ()' what should i do? need this in order to build hdbc 2.0, which i'm hoping solves a problem i was having earlier (memory leak).

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Re: [Haskell-cafe] can't build testpack
by Ezekiel Smithburg 01 Feb '09

01 Feb '09

tried that version, it gets rid of that error message but now i have this one: ezekiel-smithburgs-macbook-pro-15% cabal --flag=split-base configure -p Configuring testpack-1.0.0... ezekiel-smithburgs-macbook-pro-15% cabal build Preprocessing library testpack-1.0.0... Building testpack-1.0.0... [1 of 3] Compiling Test.QuickCheck.Instances ( src/Test/QuickCheck/Instances.hs, dist/build/Test/QuickCheck/Instances.o ) [2 of 3] Compiling Test.QuickCheck.Tools ( src/Test/QuickCheck/Tools.hs, dist/build/Test/QuickCheck/Tools.o ) [3 of 3] Compiling Test.HUnit.Tools ( src/Test/HUnit/Tools.hs, dist/build/Test/HUnit/Tools.o ) src/Test/HUnit/Tools.hs:23:7: Could not find module `System.Random': Perhaps you haven't installed the profiling libraries for package random-1.0.0.1? Use -v to see a list of the files searched for. i'll start reading the cabal user guide and see if i can figure it out on my own, but i figure progress on this should be up on the list so if someone else has this problem, they can find this and solve it on their own. also, if someone else can figure it out before i do, that's cool too. thanks for your help so far! On Sat, Jan 31, 2009 at 8:14 PM, Krzysztof Skrzętnicki <gtener(a)gmail.com>wrote: > Ok, sorry for the confusion, I should have checked it before: testpack > doesn't really need base-4, it needs base-3.The right dependency line is > (for both 6.10.1 and 6.8.3): > > Build-Depends: base >= 3 && < 4 , containers, random > > I really need to get some sleep... > > All best > > Christopher Skrzętnicki > > > On Sun, Feb 1, 2009 at 03:07, Krzysztof Skrzętnicki <gtener(a)gmail.com>wrote: > >> Trying to follow Ezekiel's steps I bumped into this: >> >> >>> >> D:\biblioteki\testpack-1.0.0>cabal configure >> Configuring testpack-1.0.0... >> >> D:\biblioteki\testpack-1.0.0>cabal build >> Preprocessing library testpack-1.0.0... >> Building testpack-1.0.0... >> [1 of 3] Compiling Test.QuickCheck.Instances ( >> src\Test\QuickCheck\Instances.hs, dist\build\Test\QuickCheck\Instances.o ) >> [2 of 3] Compiling Test.QuickCheck.Tools ( src\Test\QuickCheck\Tools.hs, >> dist\build\Test\QuickCheck\Tools.o ) >> [3 of 3] Compiling Test.HUnit.Tools ( src\Test\HUnit\Tools.hs, >> dist\build\Test\HUnit\Tools.o ) >> >> src\Test\HUnit\Tools.hs:28:36: >> Class `Control.Exception.Exception' used as a type >> In the type `Control.Exception.Exception' >> In the type `Control.Exception.Exception -> IO a -> IO ()' >> In the type `String >> -> Control.Exception.Exception -> IO a -> IO ()' >> >> D:\biblioteki\testpack-1.0.0>cabal install >> Resolving dependencies... >> Configuring testpack-1.0.0... >> Preprocessing library testpack-1.0.0... >> Building testpack-1.0.0... >> [3 of 3] Compiling Test.HUnit.Tools ( src\Test\HUnit\Tools.hs, >> dist\build\Test\HUnit\Tools.o ) >> C:\ghc\ghc-6.10.1\bin\ar.exe: creating dist\build\libHStestpack-1.0.0.a >> Installing library in C:\Program Files\Haskell\testpack-1.0.0\ghc-6.10.1 >> Registering testpack-1.0.0... >> Reading package info from "dist\\installed-pkg-config" ... done. >> Writing new package config file... done. >> <<< >> >> In short: "cabal configure && cabal build" fails, whereas "cabal install" >> builds fine. Looks like a bug in cabal-install. Am I right? >> >> All best >> >> Christopher Skrzętnicki >> >> >> >> On Sun, Feb 1, 2009 at 03:01, Krzysztof Skrzętnicki <gtener(a)gmail.com>wrote: >> >>> testpack builds fine for me. In the original .cabal file there are >>> following lines: >>> >>> >>> >>> If flag(splitBase) >>> Build-Depends: base >= 3, containers, random >>> Else >>> Build-Depends: base < 3 >>> <<< >>> >>> Now that I think about it you didn't actually said what is your GHC >>> version. >>> Knowing that you can replace lines above with one line that matches your >>> specific configuration. >>> >>> GHC 6.8.3 : >>> Build-Depends: base >= 4, containers, random >>> GHC 6.10.1 : >>> Build-Depends: base >= 3, containers, random >>> >>> Please take care to restore and modify the original file. >>> >>> I think you should read Cabal user guide. This will save your time in the >>> future: >>> http://www.haskell.org/ghc/docs/latest/html/Cabal/index.html >>> >>> I *hope* those changes will fix your installation. I can't really test >>> it, because testpack build fine with my version of cabal: >>> >>> C:\Documents and Settings\Metharius>cabal install testpack --reinstall >>> Resolving dependencies... >>> 'testpack-1.0.0' is cached. >>> Configuring testpack-1.0.0... >>> Preprocessing library testpack-1.0.0... >>> Building testpack-1.0.0... >>> [1 of 3] Compiling Test.QuickCheck.Instances ( >>> src\Test\QuickCheck\Instances.hs, dist\build\Test\QuickCheck\Instances.o ) >>> [2 of 3] Compiling Test.QuickCheck.Tools ( src\Test\QuickCheck\Tools.hs, >>> dist\build\Test\QuickCheck\Tools.o ) >>> [3 of 3] Compiling Test.HUnit.Tools ( src\Test\HUnit\Tools.hs, >>> dist\build\Test\HUnit\Tools.o ) >>> C:\ghc\ghc-6.10.1\bin\ar.exe: creating dist\build\libHStestpack-1.0.0.a >>> Installing library in C:\Program Files\Haskell\testpack-1.0.0\ghc-6.10.1 >>> Registering testpack-1.0.0... >>> Reading package info from "dist\\installed-pkg-config" ... done. >>> Writing new package config file... done. >>> >>> C:\Documents and Settings\Metharius>cabal install -w >>> c:\ghc\ghc-6.8.3\bin\ghc testpack --reinstall >>> Resolving dependencies... >>> 'testpack-1.0.0' is cached. >>> Configuring testpack-1.0.0... >>> Preprocessing library testpack-1.0.0... >>> Building testpack-1.0.0... >>> [1 of 3] Compiling Test.QuickCheck.Instances ( >>> src/Test/QuickCheck/Instances.hs, dist\build/Test/QuickCheck/Instances.o ) >>> [2 of 3] Compiling Test.QuickCheck.Tools ( src/Test/QuickCheck/Tools.hs, >>> dist\build/Test/QuickCheck/Tools.o ) >>> [3 of 3] Compiling Test.HUnit.Tools ( src/Test/HUnit/Tools.hs, >>> dist\build/Test/HUnit/Tools.o ) >>> C:\ghc\ghc-6.10.1\bin\ar.exe: creating dist\build\libHStestpack-1.0.0.a >>> Installing library in C:\Program Files\Haskell\testpack-1.0.0\ghc-6.8.3 >>> Registering testpack-1.0.0... >>> Reading package info from "dist\\installed-pkg-config" ... done. >>> Saving old package config file... done. >>> Writing new package config file... done. >>> >>> Perhaps it may also be the difference of installing with "cabal install" >>> and "runhaskell Setup build". >>> >>> All best >>> >>> Christopher Skrzętnicki >>> >>> >>> 2009/2/1 Ezekiel Smithburg <tehgeekmeister(a)gmail.com> >>> >>>> oddly, when i do that, i'm back to the original error message. and >>>> sorry, i didn't understand what you meant, apparently. >>>> >>>> >>>> On Sat, Jan 31, 2009 at 7:41 PM, Krzysztof Skrzętnicki < >>>> gtener(a)gmail.com> wrote: >>>> >>>>> >>>>> 2009/2/1 Ezekiel Smithburg <tehgeekmeister(a)gmail.com> >>>>> >>>>>> solution to that problem: >>>>>> >>>>>> deleted the lines from "If flag(splitBase)" on and changed base in >>>>>> Build-Depends to base >= 4. >>>>>> >>>>> >>>>> Well, this is exactly what I suggested in the first place: >>>>> >>>>> > This error is due to usage of old base package in version 3.> In >>>>> .cabal file add dependency on base-4, in form "base >= 4". >>>>> >>>>> Regarding second qustion: >>>>> >>>>> > random 1.0.0.1 is installed, i've verified that. what does this >>>>> error mean? >>>>> >>>>> It means that .cabal file fails to specify dependancy on random >>>>> package. Add dependancy on "random" package next to "base>=4". This should >>>>> help. >>>>> >>>>> All best >>>>> >>>>> Christopher Skrzętnicki >>>>> >>>> >>>> >>> >> >

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Buttons and Clicks - State Monad
by guenni68 31 Jan '09

31 Jan '09

Hi, in this piece here http://moonpatio.com/fastcgi/hpaste.fcgi/view?id=1083#a1083 I'm trying to create a button that, every time when clicked, increases a counter by one and does a putStrLn of the counters current value. I'm trying to write this without any use of IORef but merely using the state monad. Can anybody show me how to do this? Günther The UI Code is wxHaskell

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Haskell Weekly News: Issue 103 - January 31, 2009
by Brent Yorgey 31 Jan '09

31 Jan '09

--------------------------------------------------------------------------- Haskell Weekly News http://sequence.complete.org/hwn/20090131 Issue 103 - January 31, 2009 --------------------------------------------------------------------------- Welcome to issue 103 of HWN, a newsletter covering developments in the [1]Haskell community. Announcements HDBC v2.0 now available. John Goerzen [2]announced that [3]HDBC v2.0 is now available. Simultaneously, [4]HDBC-sqlite3, [5]HDBC-postgresql, and [6]HDBC-odbc v2.0 have also been uploaded to Hackage. A guide to new features and migration can be [7]found here. Extensible and Modular Generics for the Masses: emgm-0.2. Sean Leather [8]announced the second major release of [9]Extensible and Modular Generics for the Masses (EMGM), a library for generic programming in Haskell using type classes and a sum-of-products view. Improvements over emgm-0.1 include type representation derivation using Template Haskell, documentation improvements, a bimap function, and more. incremental-sat-solver. Sebastian Fischer [10]announced the [11]incremental-sat-solver library, which provides an implementation of the [12]Davis-Putnam-Logemann-Loveland algorithm for the Boolean satisfiability problem. It not only allows solving Boolean formulas in one go, but also adding constraints and query bindings of variables incrementally. data-spacepart - space partitioning data structure[s] (initial release). Corey O'Connor [13]announced the [14]data-spacepart package, the goal of which is to be a collection of space partitioning data structures. Currently, there is only a simple quadtree implementation. Wired 0.2. Emil Axelsson [15]announced a new release of [16]Wired. The most important news in this release is that it now contains a 45nm cell library, which means that you can use Wired to create and analyze modern VLSI designs today! CFP Haskell Symposium 2009. Stephanie Weirich [17]announced a call for papers for the [18]2009 Haskell Symposium in Edinburgh, Scotland. The deadline for submissions is May 8. testpack (first release). John Goerzen [19]announced the release of [20]testpack, a collection of a few utilities for tests: some tools to convert QuickCheck properties into HUnit test cases, and various shortcuts and tools to increase verbosity while running tests in both QuickCheck and HUnit. convertible (first release). John Goerzen [21]announced a new package, [22]convertible. At its heart, it's a very simple typeclass that's designed to enable a reasonable default conversion between two different types without having to remember a bunch of functions. The return type from this conversion is "Either ConvertError a", and conversions are expected to do sanity checking (such as bounds checking when converting to types like Int), so as to produce neither garbage nor exceptions as part of the conversion process. The package also includes instances of the Convertible typeclass for common type conversions. working with numeric types as well as dates and times. Notably, it has code to convert between System.Time types and their Data.Time siblings, and vice versa, a capability I found annoyingly lacking in the standard library. Progress with IDE. Juergen Nicklisch-Franken [23]announced that the [24]Leksah 0.4.0 pre-release is now available. Current features include a Haskell customized editor with candy, project management support based on Cabal, a visual editor for Cabal files, navigation aids, a module browser, session support, and more. Hayoo! beta 0.3. Timo B. [25]announced the next beta version 0.3 of [26]Hayoo!, the Haskell API search engine with find-as-you-type and suggestions. Hayoo! now works even if your browser does not support JavaScript. DecisionTree 0.0. Adrian Neumann [27]announced the [28]DecisionTree package, which provides an implementation of the ID3 algorithm and can be used to classify data with discrete valued attributes. orchid-0.0.7. Sebastiaan Visser [29]announced a new release of [30]Orchid, just another Haskell Wiki. This release features a number of improvements, including a [31]filestore backend, searching, deleting and renaming support, and more. Check out the [32]demo. gitit 0.5. John MacFarlane [33]announced the latest release of [34]Gitit, the multitalented distributed wiki written in Haskell. This release uses the [35]filestore library and hence also supports a darcs backend, and also features optimizations, better search, better diffs, and more. You can check out a [36]running example. filestore 0.1. Gwern Branwen [37]announced [38]filestore 0.1, which provides a uniform, abstract, generic interface for storing versioned files on disk. It allows calling programs to use generic commands to store strings or binary data and perform various queries, such as 'what files are in this repository?' or 'what were the contents of this file at revision XXXXXXX?' or 'give me a diff of this file between revision XXXXXXX and revision YYYYYYY.' Because the interface is abstract, the calling program is insulated from the messy details of the backend (which might be a VCS or a database). Darcs and Git are fully supported. There are plans for a SQLite backend. Scurry :: A cross platform (if you put your mind to it) P2P VPN. John Van Enk [39]announced the release of [40]Scurry, a P2P VPN application written in Haskell (and a little C). Discussion Why binding to existing widget toolkits doesn't make any sense. Achim Schneider began an interesting [41]discussion on the proper approach to GUI toolkits in Haskell. Laws and partial values. Henning Thielemann began [42]a long thread on the semantics of laws (such as the monoid laws). Blog noise [43]Haskell news from the [44]blogosphere. * Sebastian Fischer: [45]Using SmallCheck to Shatter an Audacious Claim. * Xmonad: [46]Quad head xmonad. * Darcs: [47]darcs weekly news #15. * Osfameron: [48]More longest paths, and sick folds.. * Eric Kow (kowey): [49]haskell-ji. * Jeff Heard: [50]Control.Monad.IfElse. * Conal Elliott: [51]What is automatic differentiation, and why does it work?. * Luke Palmer: [52]Fun with PiSigma. * Neil Mitchell: [53]Small scripts with Haskell. * LHC Team: [54]Release notes.. * LHC Team: [55]Thoughts on a new code generator. * Xmonad: [56]contribs review: ThreeColumnsMiddle, CenteredMaster, Mosaic. * Osfameron: [57]There's the nub (snippet in Perl and Haskell). * Malcolm Wallace: [58]codec implementations. * Sebastian Fischer: [59]Fun with Infinite Global Constants. Just-in-time, memoized binomial coefficients. * Chris Done: [60]Some libgd changes. * Luke Palmer: [61]A world without orphans. Luke muses on the benefits to be gained by outlawing orphan instances. * Creighton Hogg: [62]Fear of releasing code. * LHC Team: [63]Thoughts on a new code generator. * Don Stewart (dons): [64]What is Haskell good for?. Lots of things, if this tag cloud has anything to say about it. * Arch Haskell News: [65]Haskell wiki stack in Arch. * Conal Elliott: [66]Comparing formulations of higher-dimensional, higher-order derivatives. * Conal Elliott: [67]Fostering creativity by relinquishing the obvious. * Arch Haskell News: [68]Arch Haskell News: Jan 11 2009. * Dan Piponi (sigfpe): [69]Fast incremental regular expression matching with monoids. A very cool article showing how to use fingertrees storing memoized automaton transition functions to do fast incremental regular expression matching (or, in general, fast incremental lexing). Quotes of the Week * lilac: is happy with his infinite type. it's ducks all the way across and down. * Gracenotes: You are likely to be eaten by a poset * RossMellgren: Apparently 64-bit GHC is sufficiently advanced to be indistinguishable from magic. * cjb: It's all fun and games until somebody loses an IOVar. * sigfpe: If I took some Ritalin, maybe I could write an entire book on Haskell and algebra. * ddarius: Nothing is evaluated until it is. About the Haskell Weekly News New editions are posted to [70]the Haskell mailing list as well as to [71]the Haskell Sequence and [72]Planet Haskell. [73]RSS is also available, and headlines appear on [74]haskell.org. To help create new editions of this newsletter, please see the information on [75]how to contribute. Send stories to byorgey at cis dot upenn dot edu. The darcs repository is available at darcs get [76]http://code.haskell.org/~byorgey/code/hwn/ . References 1. http://haskell.org/ 2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51664 3. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HDBC 4. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HDBC%2Dsqlite3 5. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HDBC%2Dpostgresql 6. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HDBC%2Dodbc 7. http://software.complete.org/software/wiki/hdbc/NewIn20 8. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51646 9. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/emgm 10. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51564 11. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/incremental-sat-… 12. http://en.wikipedia.org/wiki/DPLL_algorithm 13. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51505 14. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/data-spacepart 15. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51484 16. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Wired 17. http://article.gmane.org/gmane.comp.lang.haskell.general/16818 18. http://haskell.org/haskell-symposium/2009/ 19. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51482 20. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/testpack 21. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51481 22. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/convertible 23. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51475 24. http://www.leksah.org/ 25. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51450 26. http://holumbus.fh-wedel.de/hayoo 27. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51407 28. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/DecisionTree 29. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51395 30. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/orchid 31. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/filestore 32. http://funct.org/wiki/ 33. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51392 34. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/gitit 35. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/filestore 36. http://gitit.johnmacfarlane.net/ 37. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51388 38. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/filestore 39. http://article.gmane.org/gmane.comp.lang.haskell.cafe/51364 40. http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Scurry 41. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/51478 42. http://thread.gmane.org/gmane.comp.lang.haskell.cafe/51299 43. http://planet.haskell.org/ 44. http://haskell.org/haskellwiki/Blog_articles 45. http://www-ps.informatik.uni-kiel.de/~sebf/haskell/smallcheck-experience.ht… 46. http://xmonad.wordpress.com/2009/01/31/quad-head-xmonad/ 47. http://blog.darcs.net/2009/01/darcs-weekly-news-15.html 48. http://greenokapi.net/blog/2009/01/31/more-longest-paths-and-sick-folds/ 49. http://koweycode.blogspot.com/2009/01/haskell-ji.html 50. http://vis.renci.org/jeff/?p=96 51. http://conal.net/blog/posts/what-is-automatic-differentiation-and-why-does-… 52. http://lukepalmer.wordpress.com/2009/01/28/fun-wth/ 53. http://neilmitchell.blogspot.com/2009/01/small-scripts-with-haskell.html 54. http://lhc-compiler.blogspot.com/2009/01/release-notes.html 55. http://lhc-compiler.blogspot.com/2009/01/thoughts-on-new-code-generator.html 56. http://xmonad.wordpress.com/2009/01/27/contribs-review-threecolumnsmiddle-c… 57. http://greenokapi.net/blog/2009/01/27/theres-the-nub-snippet-in-perl-and-ha… 58. http://feeds.feedburner.com/~r/malcolm/~3/523603226/codec-implementations.h… 59. http://www-ps.informatik.uni-kiel.de/~sebf/haskell/infinite-constants.html 60. http://chrisdone.com/blog/2009/01/26/Some-libgd-changes 61. http://lukepalmer.wordpress.com/2009/01/25/a-world-without-orphans/ 62. http://abstractabsurd.blogspot.com/2009/01/fear-of-releasing-code.html 63. http://lhc-compiler.blogspot.com/2009/01/thoughts-on-new-code-generator.html 64. http://donsbot.wordpress.com/2009/01/24/what-is-haskell-good-for/ 65. http://archhaskell.wordpress.com/2009/01/25/haskell-wiki-stack-in-arch/ 66. http://conal.net/blog/posts/comparing-formulations-of-higher-dimensional-hi… 67. http://conal.net/blog/posts/fostering-creativity-by-relinquishing-the-obvio… 68. http://archhaskell.wordpress.com/2009/01/11/arch-haskell-news-jan-11-2009/ 69. http://sigfpe.blogspot.com/2009/01/fast-incremental-regular-expression.html 70. http://www.haskell.org/mailman/listinfo/haskell 71. http://sequence.complete.org/ 72. http://planet.haskell.org/ 73. http://sequence.complete.org/node/feed 74. http://haskell.org/ 75. http://haskell.org/haskellwiki/HWN 76. http://code.haskell.org/~byorgey/code/hwn/

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Re[Haskell-cafe] cursive referencing
by Belka 31 Jan '09

31 Jan '09

Hello! I'm puzzled, if in Haskell it's possible to create a (pure) data structure, consisting of 2 substructures referencing each other: ------------------------- data AA = AA { someData1 :: SomeData1 bb :: BB } data BB = BB { someData2 :: SomeData2 aa :: AA } f :: SomeData1 -> SomeData2 -> AA f somedata1 somedata2 = ?????????? -- Always True: ghci> f == aa $ bb f True ------------------------- Any ideas? Belka -- View this message in context: http://www.nabble.com/Recursive-referencing-tp21722002p21722002.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.

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GHCi Memory Leak in Windows Vista
by spam.andir＠gmail.com 31 Jan '09

31 Jan '09

Hi all! Environment: Windows Vista + SP1, GHC 6.10.1. Description: If use ghci.exe and run separate ghc.exe compiler process, memory leak in ghci occurred. After exhausting available memory Vista has no responding. Steps for reproduce: 1) After run GHCi, process list has 2 processes: ghci.exe (a), ghc.exe (b), 2) Then I run separated compilation process 20 times: Command Line: for /L %i in (1,1,20) do ghc -fforce-recomp -O --make "problem.hs" -o "problem.exe" Sample Haskell Program listing (problem.hs): main :: IO () main = do print $ [x | x <- [1..]] putStrLn "Hello, world!" 3) In process list (taskmgr.exe) I can see some processor activity and increasing value of "Memory (Private Working Set)" for process (b). 4) After run "Memory (Private Working Set)" increased about 100Mb. Best regards.

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darcs-client on ghc 6.10.1
by Phil 30 Jan '09

30 Jan '09

Hi, Was wondering if anyone knew if darcs-server is still maintained? The author¹s e-mail address bounces. The Haskell client is broken in ghc 6.10. I have a straightforward fix for it: phil$ darcs whatsnew hunk ./client/build 2 -ghc -Wall -O2 -o darcs-client -package network Http.hs DarcsClient.hs +ghc -Wall -O2 -o darcs-client.exe -package base-3.0.3.0 -package network Http.hs DarcsClient.hs Phil.

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