- Glasgow-haskell-users

*****SPAM***** Annotation for unfolding wanted
by Georg Martius 28 Jul '07

28 Jul '07

Spam detection software, running on the system "h7568.serverkompetenz.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi, I was wondering why we don't have an annotation or pragma for function to tell the compiler that we need this particular recursive function to be unfolded. If the compiler cannot do this for some reason it should produce an error message to help you modifying your code. I have regularly problems that my code is either not strict enough or my functions are not unfolded. I find it annoying that this is a regular show stopper and consumes much time to fix. Here is an example: a search function for strings, which should return the index and the rest of the string after the first occurrence: search0 will not be unfolded by ghc -O. (I don't know why, it looks tail-recursive to me) whereas search1 is just fine. [...] Content analysis details: (7.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.1 FORGED_RCVD_HELO Received: contains a forged HELO 3.5 BAYES_99 BODY: Bayesian spam probability is 99 to 100% [score: 1.0000] 1.9 RCVD_IN_NJABL_DUL RBL: NJABL: dialup sender did non-local SMTP [87.172.170.59 listed in combined.njabl.org] 2.0 RCVD_IN_SORBS_DUL RBL: SORBS: sent directly from dynamic IP address [87.172.170.59 listed in dnsbl.sorbs.net] The original message was not completely plain text, and may be unsafe to open with some email clients; in particular, it may contain a virus, or confirm that your address can receive spam. If you wish to view it, it may be safer to save it to a file and open it with an editor.

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using Haskell readline package on Cygwin
by Amir E. Aharoni 28 Jul '07

28 Jul '07

Hi, I'm trying to build pugs ( http://www.pugscode.org/ ) on Cygwin. I have GHC 6.6.1 (installed from MSI). Pugs build routine tries to look for the readline package and fails: $ ghc-pkg describe readline ghc-pkg.exe: cannot find package readline I have GNU readline installed as a Cygwin package, but it looks like the readline package, which appears to be standard on other GHC-supported platforms, is not installed with GHC on Windows. This problem is mentioned in the GHC FAQ ( http://tinyurl.com/2lyjno ) but there is no solution; maybe there was supposed to be a link, but it is not there now. Is it possible to install the readline package manually? Thanks in advance. (Please excuse my cluelessness - i'm a GHC newbie.) -- Amir Elisha Aharoni my band: http://www.myspace.com/tzabari/ my blog: http://aharoni.wordpress.com/

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Is "-O currently also implies -fvia-C." still true?
by Thorkil Naur 27 Jul '07

27 Jul '07

Hello, The GHC User's Guide, Versio 6.6.1 (http://www.haskell.org/ghc/docs/latest/html/users_guide/options-optimise.ht…) says: -O currently also implies -fvia-C. I seem to remember some communication a while back that seemed to imply that this is no longer the case. So my question is: Is the quoted statement still true? Thanks and best regards Thorkil

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OPTIONS_GHC -iMyDir
by Greg Fitzgerald 24 Jul '07

24 Jul '07

I notice that some of GHC's command-line parameters do not work from within the OPTIONS_GHC pragma (6.6.1 on Windows). I can see how that makes sense for some parameters like "--make", but what about "-i" and "-v"? Is this intentional or a bug? Can't specify the include path: {-# OPTIONS_GHC -iMyDir #-} Can't compile a single file in 'verbose' mode: {-# OPTIONS_GHC -v #-} Thanks, Greg

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ForeignPtr and -threaded
by PHO 23 Jul '07

23 Jul '07

Hi, I have encountered a weird behavior of ForeignPtr. I want to know how to work around this. I am using GHC 6.6.1 on Darwin. [1] Foreign.Concurrent The following code prints "called" when it is linked with -threaded RTS, but it prints nothing when it isn't. import Foreign.Marshal.Alloc import qualified Foreign.Concurrent as Conc main = do mem <- mallocBytes 10 Conc.newForeignPtr mem $ print "called" [2] Foreign.ForeignPtr The following code prints nothing when it isn't linked with -threaded RTS, but when it is, it *sometimes* prints "called" but not always. import Foreign.Marshal.Alloc import Foreign.Ptr import Foreign.ForeignPtr foreign import ccall "wrapper" mkFinalizer :: (Ptr () -> IO ()) -> IO (FunPtr (Ptr () -> IO ())) main = do mem <- mallocBytes 10 fin <- mkFinalizer $ \ _ -> print "called" newForeignPtr fin mem _______________________________________________________ - PHO - http://ccm.sherry.jp/ OpenPGP public key: 1024D/1A86EF72 Fpr: 5F3E 5B5F 535C CE27 8254 4D1A 14E7 9CA7 1A86 EF72

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ghc-pkg: can't unregister - not found - describe works?
by Marc Weber 22 Jul '07

22 Jul '07

marc@localhost /pr/source/wxh/wxhaskell-0.9.4 $ ghc-pkg-wrapper-6.6.1 unregister wx ghc-pkg: cannot find package wx marc@localhost /pr/source/wxh/wxhaskell-0.9.4 $ ghc-pkg-wrapper-6.6.1 describe wx name: wx version: 0.10.1 license: AllRightsReserved [...] What does happen here? ghc-pkg-wrapper is just a simple script defining GHC_PACKAGE_PATH marc@localhost /pr/source/wxh/wxhaskell-0.9.4 $ ghc-pkg-wrapper-6.6.1 list /nix/store/q74q9piy9fsk4k7w1p3r3xc8wsm1z87m-ghc-6.6.1/lib/ghc-6.6.1/package.conf: Cabal-1.1.6.2, HUnit-1.1.1, QuickCheck-1.0.1, base-2.1.1, [...] /nix/store/fbj85ijnbc69bh19zi1a14p9idknb5g9-wxHaskell-0.10.1-pre20070124/nix-support/package.conf: wx-0.10.1, wxcore-0.10.1 Marc

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Re: rpm for RHEL4
by chuckanut 19 Jul '07

19 Jul '07

Thanks very much! I am just replying to the list so that someone else can take advantage of your work. On 7/7/07, Ronald Cole <ronald.cole(a)gmail.com> wrote: > I posted that I had ported the Fedora Core RPMs to RHEL4 and RHEL5 for both > i386 and x86_64 and was making them available from my site. I also asked > for it to be announced on the "distribution packages" page of haskell.org, > but that request seems to have fallen on deaf ears. > > Help yourself to my RPM packages at > <http://forte-intl.com/~ronald/haskell/ghc/ >. > > > On 7/6/07, chuckanut <chuckanut(a)gmail.com> wrote: > > > > Hi, > > > > I am looking for an rpm for Red Hat enterprise linux 4 for x86_64. > > Can anyone point me to such an rpm? I don't think the FC5 binary will > > work on EL4. > > > > Thanks > > _______________________________________________ > > Glasgow-haskell-users mailing list > > Glasgow-haskell-users(a)haskell.org > > > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users > > > >

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Why hide Distribution.Compat.FilePath, or what to use instead?
by Dimitry Golubovsky 17 Jul '07

17 Jul '07

Hi, I'm trying to bring HSFFIG in order and make it work with GHC 6.6 and the modern package structure. I have found out that the Distribution.Compat.FilePath module (which used to be System.FilePath in its former life) is hidden: programs/ffipkg.hs:11:7: Could not find module `Distribution.Compat.FilePath': it is hidden (in package Cabal-1.1.6.2) I cannot use the new FilePath package because it does not have function like exeExtension. Other functions (splitFileExt, parseSearchPath, joinFileName, join FileExt) probably have their analogs in the new package. What else can I use for exeExtension? Thanks. -- Dimitry Golubovsky Anywhere on the Web

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strange overlapping instance error
by Dave Herman 11 Jul '07

11 Jul '07

I'm a little mystified by an overlapping instance error I'm getting from GHC (I'm using v6.6.1 in Windows). Here's a simple test case that demonstrates the type error: ----- {-# OPTIONS_GHC -fglasgow-exts #-} module Overlap where class Needle a instance Needle String class Needle b => Haystack a b where find :: a -> [b] instance Needle a => Haystack a a where find a = [a] instance Haystack a b => Haystack [a] b where find xs = concatMap find xs data Tree = Leaf String | Node [Tree] instance Haystack Tree String where find (Leaf s) = find s find (Node ss) = concatMap find ss ----- The error is: overlap.hs:21:18: Overlapping instances for Haystack String String arising from use of `find' at overlap.hs:21:18-23 Matching instances: instance (Needle a) => Haystack a a -- Defined at overlap.hs:11:0 instance (Haystack a b) => Haystack [a] b -- Defined at overlap.hs:14:0 In the expression: find s In the definition of `find': find (Leaf s) = find s In the definition for method `find' Now, I understand that String is [Char], but since the proposition (Haystack Char String) is not true, I don't understand why the type checker is claiming that the second instance declaration matches. Thanks, Dave

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ghc 6.6 Debian packages
by Christian Maeder 11 Jul '07

11 Jul '07

Hi, our developers that have a debian system (i.e Ubuntu) and want to compile our sources with ghc complain that they have to install many extra library packages one after another. Compiling fails at various stages due to missing packages. Is there no way to provide all the extra libs in one debian package for ghc? Cheers Christian ii libghc6-fgl-dev 5.3-3 Haskell graph library for GHC ii libghc6-haskell-src-dev 1.0-3 Haskell module for manipulating Haskell sour ii libghc6-html-dev 1.0-3 Haskell html library for GHC ii libghc6-hunit-dev 1.1-3 Haskell unit testing framework for GHC ii libghc6-mtl-dev 1.0-3 Haskell monad transformer library for GHC ii libghc6-network-dev 2.0-3 Haskell network library for GHC ii libghc6-quickcheck-dev 1.0-3 Haskell automatic testing library for GHC

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