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Error in building profiling
by Marco Túlio Gontijo e Silva 09 Feb '09

09 Feb '09

Hello, I'm trying to package ghc-paths for debian, and I got to this: $ ./setup configure --enable-library-profiling --disable-library-vanilla Configuring ghc-paths-0.1.0.5... $ ./setup build Preprocessing library ghc-paths-0.1.0.5... Building ghc-paths-0.1.0.5... /usr/bin/ar: creating dist/build/libHSghc-paths-0.1.0.5_p.a /usr/bin/ld: dist/build/GHC/Paths.o: No such file: No such file or directory I thought this could be a problem with this package, but I've tried with mtl, and I got the same result: /usr/bin/ld: dist/build/Control/Monad/Cont.o: No such file: No such file or directory I'm using ghc6 6.10.1+dfsg1-5 and binutils 2.19-1~exp1. Greetings. -- marcot http://marcot.iaaeee.org/

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Data.Map: Enumerating ordered subset of keys
by Jared Updike 09 Feb '09

09 Feb '09

I would like to enumerate a subset of keys in a Map satisfying \ key >= key1 && key <= key2 but in the expected, reasonable amount of time (e.g. < O(log(n)) + O(m) for n total keys and m keys in the subset). (Or key > key1 and/or key < key2 or some such combination). Is there an appropriate idiom or combination of library functions to accomplish this, short of digging into the code for Data.Map and writing such a function for a forked version of Data.Map? For example I could try something like a Set.split of a Set.split of Map.keysSet of my original map, but will laziness magically do what I really want? which is to walk down the tree to key1 (or the nearest key > key1) and enumerate keys in order until key2 is reached? Data.Map almost looks like what I need if I can do this. Jared.

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Re: Haskell and Automation
by Guenther Schmidt 09 Feb '09

09 Feb '09

Dear Michael, sorry too, for not telling you sooner that meanwhile I found out how to get it working, I hope you did not spend too much time trying on your end. It had to do with the context in which these components are initialized. Once you switch to LocalProcess (as opposed to AnyProcess) in coCreateInstance everything works fine and rather smoothly. The defaults in createObject do not work for every kind of object that you do want to instantiate, certainly not Excel. Of course having an old, but still fairly current manual also helps. Good luck with your projects. Günther Michael Snoyman schrieb: > Gunther, > > Sorry for not getting back to you on your previous e-mail, I've been > swamped. > > The reason I didn't put up an example was specifically because of the > error you mention. I was hoping to get a chance to use the COM > bindings in Python to see if I got the same thing. For the life of me > I can't figure out how to get started with Excel and Haskell. Sorry I > can't be more useful at this time. > > Michael > > On Fri, Feb 6, 2009 at 6:56 PM, G?uenther Schmidt <redcom(a)fedoms.com > <mailto:redcom@fedoms.com>> wrote: > > Hi Michael, > > for some reason createObject "Excel.Application" throws an > "Interface not supported" error. > > Can you help me out here? > > Günther > >

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FFI binding to CGAL?
by Peter Verswyvelen 09 Feb '09

09 Feb '09

I was wandering of someone already made a FFI binding to http://www.cgal.org or something similar that does computational geometry?

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Does readFile "/proc/mounts" hang for you?
by David Fox 09 Feb '09

09 Feb '09

I posted a bug about this (http://hackage.haskell.org/trac/ghc/ticket/2971) but its so odd I had to ask here. Using ghc 6.10.1, both readFile "/proc/mounts" and Data.ByteString.Lazy.Char8.readFile "/proc/mounts" hang on an amd64 machine running Linux. Also, Data.ByteString.readFile "/proc/mounts" returns the empty string. Is this behavior present for others? On i386?

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The Haskell re-branding exercise
by Gwern Branwen 09 Feb '09

09 Feb '09

On Sat, Feb 7, 2009 at 1:34 PM, Don Stewart <dons(a)galois.com> wrote: > Oh, we had a long discussion about the need for condorcet voting, > not a system like the reddit which is prone to abuse. > > Also, it would be good to have the images inline. Perfect, please meet better. Better, perfect. Now get along you two! Since January 1st, we could've had hundreds or thousands of votes and easily compensated for any abuse. -- gwern

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threadDelay
by Immanuel Litzroth 09 Feb '09

09 Feb '09

Am I correct in assuming this program should run 100 secs? >import Control.Concurrent >main = do > threadDelay 100000 Why do I get the folling result then? ghc -threaded Main.hs -o delay time ./delay real 0m0.104s user 0m0.001s sys 0m0.002s Thanks in advance for all your wonderful comments, Immanuel

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Switching from Mercurial to Darcs
by Peter Verswyvelen 09 Feb '09

09 Feb '09

I'm trying to switch from HG to Darcs, but I'm failing miserably in getting the same productivity. I often do bad checkins with Darcs, merely because the amount of information I get from Darcs is overwhelming and I don't have time to read the details of the large set of commands. With Mercurial, here's my basic workflow: 1) hg st lists just the filenames of changed, deleted, new files (with a char prefix to show what kind of change it is). I only want to see the filenames, not the lines/content. If I want to see changes in the content, I use hg diff using a visual differ. My brain is not capable of making sense of the textual diff. 2) modify .hgignore to make sure only these files are added that are part of the project. I want this process to be automated, I don't want to check each time which files to add, since this is error prone. 3) hg addrem this adds new files and removes deleted files from local repos. forgetting to add files is a common problem, and is really tricky since no record is made of these files, so if after a couple of versions if a developer finds out a file was missing, the history is useless since you can't reconstruct the old content of that local file anymore, and often it's impossible to give the local file to the other developers since it might be changed. I actually would like to have an option that automatically adds/deletes files on each commit, as it is easier to delete a file after it is checked in, than it is to reconstruct an old version from a local file you forgot to add. 4) hg commit -m "message" this commits my changes locally. I always do this before pulling since then I'm sure my changes are saved in the case a merge goes wrong. 5) hg pull -u this pulls in changes, and updates and merges the files, using a visual merger of my preference. 6) hg commit -m "merged" hg push only needed if I did a merge and want to push that merge. 7) back to 1) It would be nice to know how to do this using darcs, or if a better way exists using darcs, that would be handy too :)

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Video phone application
by Jamie 09 Feb '09

09 Feb '09

Hello! I like to create H.323 (primarly) & SIP based video phone application that will run on Linux, Windows & Mac platforms and of course, written in Haskell. (Writing similar application in Haskell is not "reinventing the wheel" :) I did look/try various current H.323/SIP based video phone software that runs on Windows, Mac and Linux such as Ekiga, XMeeting, Linphone, Mirial and some others. Ekiga (despite version 3.x) is unstable, keeps crashing a lot on me. XMeeting (Mac) does not work good (choppy videos, dropped packets et al). So do Linphone. The best of the lot so far is Mirial Softphone, it has nice decent features to begin with, but there are lot more features I want to add. Please let me know if there is good H.323 based videophone software that I might miss (I think I have looked at all of them). Since my video phone application mainly focus more on deaf people thus strong emphasize on video part while all other (if not all) video softphone put stronger emphasize on audio part & traditional phone setup. Also it has to be primarly H.323 because I would say about over 95% or so of all deaf people (with high speed Internet access) use Sorenson VP-200 as their "main" videophone (Sorenson gives away VP-200 video phone device for free to all deaf people in USA in exchange for using Sorenson Video Relay Service which they make profit from). Sorenson VP-200 only supports H.323, H.263 video codec and G.711/G.723.1 audio codec. Being able to work with VP-200 well is this application's first step. Skype, ooVoo, SightSpeed, QuteCom, VZOchat, iChat AV and some others are excellent video phone/chat applications but they are not H.323 complaint so they are "out of question". It would take me a lot of time (more like forever) if I have to write my own H.323 protocol stack along with video/audio codecs as well the GUI in Haskell. So in order to write this application in timely manner (say one year from now or so) I will need external library/functions for H.323/SIP protocol stack, the audio/video codecs and the GUI. I have been contacting serveral companies that offer licensing of their H.323/SIP/codecs SDK/API/Libraries for my program to be able to access to those functions. Naturally all of them ues C/C++. Yes there are some free/open source ones such as h323plus.org, x264, ffmpeg and some others, but still all of them are written in C/C++. I think I am more likely to go for commercial libraries due to stability (least bugs), higher performance, better documentation and whole set of supported features. What do I ask to make sure those libraries/SDK would work well with Haskell? As for GUI, since I would like for this application to run on three popular platforms: Windows, Mac and Linux, so I think I would have to use Gtk+, wxWidgets or Qt which mean I would use Gtk2Hs, wxHaskell or qtHaskell. Even nicer is to use FRP GUI library such as Fruit, Grapefruit, wxFruit, et al. This application would need to support localization i.e. support different languages. What do you suggest for me to use one of middle level GUI library or even the higher level FRP GUI library (with localization support)? Fast and smooth video (i.e. 30 FPS) is the key for this application. As it stands now, looks like I'll write the "main program" entirely in Haskell, then use some kind of bindings to call to those C/C++ libraries for H.323, SIP, codecs, webcam/video camera I/O, video display, GUI et al. Any better ideas for doing this? I know it would be dream come true to see acclerated vector/raster based drawing primitives with FRP GUI on top written entirely in Haskell along with H.323, codecs et al being written in Haskell too (we may have to wait quite while for that), but we live in real world so I will have to learn to deal with what we have now and the workarounds. Thanks in advance! Jamie

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GHC 6.11 missing time package?
by Lyle Kopnicky 09 Feb '09

09 Feb '09

Hi folks, I'm getting ready to release a piece of software. Unfortunately due to a bug in GHC 6.10 on Windows it does not handle Ctrl+C properly. Since the bug has been fixed (thank you Simon Marlow), I figured I'd download a 6.11 build (I grabbed the 2009-01-29 version). Unfortunately, my project won't build with it because it's missing the time-1.1 package. This is sad because I had gone through the trouble to rewrite my use of oldtime to use time, thinking it was more future-proof. Is this an oversight in the nightly build, or is this package going out of GHC? Thanks, Lyle

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