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darcs hacking sprint #1 (report)
by Eric Y. Kow 31 Oct '08

31 Oct '08

Dear Haskellers, I thought some of you might be interested in our report from the darcs hacking sprint, held on 25-26 October. See also the blog version of it at http://blog.darcs.net/2008/10/darcs-hacking-sprint-1-report.html (it has photos). So how did that darcs hacking sprint go? Well, we had a lot of fun and we got a lot of work done, so I think we can safely say that it was a great success! What next? The sprint participants found themselves with a lot of good work started that we simply couldn't put down, so we have continued hacking into the week, turning many of our good starts into more concrete progress. There is still a lot of work to do so we want to make sure we keep that momentum going! The big challenge right now is to get all of the patches reviewed and merged back into darcs.net. Unfortunately, this is creating a delay in the usual patch review process as we clear our backlog. In the meantime, please continue sending your patches! Thanks very much to David Roundy for his advice before the sprint and cheerful handling of this patch influx; Galois, the University of Brighton and Université de Paris 7 for graciously hosting our three venues; and especially to everybody who participated or joined #darcs to cheer us on :-) The next sprint will be held in conjunction with the Haskell Hackathon, March 2009 in Utrecht, Netherlands. So see you in six months! Overview -------- Total sprint patches : 234 Patches produced - during the sprint itself : 178 - as follow-up work : 56 Patches sent and - accepted into darcs.net : 43 - awaiting review : 191 ("during" defined as 25-27 October 2008 at 08:00 UTC) Site reports ------------ * Team Portland: - report: http://lists.osuosl.org/pipermail/darcs-users/2008-October/015082.html - pictures: http://blog.codersbase.com/2008/10/28/darcs-hacking-sprint-summary-from-por… * Team Brighton: - report: http://lists.osuosl.org/pipermail/darcs-users/2008-October/015122.html - pictures: http://koweycode.blogspot.com/2008/10/darcs-hacking-sprints-some-pictures.h… - pictures: http://koweycode.blogspot.com/2008/10/darcs-hacking-sprint-team-brighton-da… * Team Paris: - report: http://lists.osuosl.org/pipermail/darcs-users/2008-October/015215.html What we worked on ----------------- Warm up tasks ============= * Warn the user when the patch name looks like a command line option - http://bugs.darcs.net/issue395 - Participants: Reinier Lamers (Team Paris) - Status: Accepted! * Warn when tags are too short (length name <2) - http://bugs.darcs.net/issue1000 - Participants: Christian Kellerman - Status: Accepted! Optimisations ============= * Solved stack overflow when doing whatsnew on very large lines - http://bugs.darcs.net/issue1017 - Participants: Ganesh Sittampalam (Team Brighton) - Status: awaiting review * Smarter slurpies for faster directory lookups - http://bugs.darcs.net/issue711 - Participants: Ganesh Sittampalam (Team Brighton) - Status: awaiting review * Avoiding lstats in darcs whatsnew - http://bugs.darcs.net/issue390 - Participants: Reinier Lamers (Team Paris) - Status: needs tweaking * Bytestring optimisations - Participants: Don Stewart (Team Portland) - Status: awaiting review Performance-related features ============================ * Filecache to improve darcs annotate and darcs changes performance - Participants: Benedikt Schmidt - Status: still hacking! * Packs - http://wiki.darcs.net/index.html/Packs_Specification - Participants: Nicolas Pouillard, Florent Becker (Team Paris) - Status: plan is fleshed out; implementation started in branch * "Chunky" hunk representation - Participants: Ian Lynagh (Team Brighton) - Status: needs volunteer to start porting from camp to darcs * Global cache: enabled by default and more portable - http://bugs.darcs.net/issue839 - Participants: Simon Michael - Status: Accepted! * Networking performance (Team Paris) - Used tcpdump to examine network performance problems - New issues filed: * http://bugs.darcs.net/issue1167 - darcs-transfer mode versions * http://bugs.darcs.net/issue1168 - ssh pipelining * http://bugs.darcs.net/issue1170 - Nagle's algorithm - Participants: Team Paris - Status: needs implementation! Improved Windows support ======================== * Bugs fixed: - newline endings on Windows for HTTP module. - http://bugs.darcs.net/issue774 - fix character echo on win32. - http://bugs.darcs.net/issue1023 - bracket file writing to prevent windows permission errors. - http://bugs.darcs.net/issue784 - fix file handle leak and check for exceptions on process running. * Participants: Salvatore Insalaco * Status: Accepted! Infrastructure and cleanups =========================== * Code cleanups - Added language pragmas in all files - Removed OldFastPackedString - Replaced FastPackedStrings api in favor of Data.ByteString api - Participants: Don Stewart and Jason Dagit (Team Portland) - Status: awaiting review * Documentation cleanups - Use .lhs only for truly literate files - Migrate .tex to reST in preparation for user manual overhaul - Participants: Trent Buck - Status: awaiting review * Cabalisation - Participants: Duncan Coutts (Team Portland) * Makefile simplifications and cleanups (for doc) - Participants: Trent Buck * Makefile improvements (make ci, make darcs_p) - Participants: Simon Michael, Eric Kow (Team Brighton) - Status: make ci is accepted! make darcs_p awaiting review * Benchmarking suite - Participants: Eric Kow (Team Brighton) - Status: usable as of Wednesday, needs visualisation Camp ==== * http://projects.haskell.org/camp * Progress... - developed "chunky" hunk representation and tests! - got libcurl working under Windows with Cabal - primitive interactive patch selection implemented - Repository type rather than FilePath for repos * Participants: Ian Lynagh (Team Brighton) -- Eric Kow <http://www.nltg.brighton.ac.uk/home/Eric.Kow> PGP Key ID: 08AC04F9

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Re: [darcs-users] Poll: Do you need to be able to build darcs from source on GHC 6.6?
by Juliusz Chroboczek 31 Oct '08

31 Oct '08

> Also, note that Lenny has 6.8, and it is scheduled to become stable Real > Soon Now. That's irrelevant. Lenny going stable will not cause my servers to automatically get upgraded. FWIW, the experimental server is scheduled to switch to lenny in the summer of 2009. There is no ETA for the production servers, which tend to be managed more conservatively still. Juliusz

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Cabal packaging problem - Build-Depends name for Network.Curl.Download?
by Brian Troutwine 31 Oct '08

31 Oct '08

Hello all, I'm having a small bit of trouble using cabal to package a program I'm calling aule. I cannot build the program using cabal but can compile it using ghc directly. Here's my aule.config: Name: Aule Version: 0.2.0 Cabal-Version: >= 1.2 Build-type: Simple Author: Brian L. Troutwine Maintainer: goofyheadedpunk(a)gmail.com Stability: alpha Executable aule Build-Depends: base, network, bytestring, download-curl Main-Is: Main.hs Hs-Source-Dirs: src ghc-options: -Wall -O2 If I decend into src/ the result is as follows. blt@doritos:~/aule/src $ ghc -Wall -O2 --make Main.hs [1 of 1] Compiling Main ( Main.hs, Main.o ) Linking Main ... If I attempt to use cabal the result is the following. blt@doritos:~/aule $ runhaskell Setup.hs configure --prefix=$HOME Configuring Aule-0.2.0... Setup.hs: At least the following dependencies are missing: download-curl -any I've attempted variations on the download-curl name, as well. Also, download-curl was install using the nifty cabal-install tool. I run Ubuntu 8.04 with ghc 6.8.2. Thanks, Brian

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Re: Problems with Windows
by Felix Martini 30 Oct '08

30 Oct '08

Hi John, You don't have to compile hsc2hs yourself. It is part of the standard GHC installation. Cabal should be able to find it. You can check if it does by running runghc Setup.hs configure -v when configuring a package. Compiling network-2.2.0.0 against parsec-3.0.0 with msys/mingw worked fine for me. So if Cabal cannot find hsc2hs you could reinstall GHC or otherwise try to compile network-2.2.0.0 with msys. Regards, Felix

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LAST CALL: Haskell Communities and Activities Report
by Janis Voigtlaender 30 Oct '08

30 Oct '08

Dear Haskellers, It is not yet too late to contribute to the 15th edition of the HC&A Report. In fact, I will wait for a few more days. If you haven't already, please write an entry for your new project or update your old entry. Please mail your entries to hcar(a)haskell.org in plain text or LaTeX format. More information can be found in the original Call for Contributions at http://www.haskell.org/pipermail/haskell/2008-October/020651.html I look forward to receiving your contributions. Thanks a lot, Janis (current editor) -- Dr. Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:voigt@tcs.inf.tu-dresden.de

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RE: [Haskell] Making 'Super Nario Bros.' in Haskell‏
by Eli Ford 30 Oct '08

30 Oct '08

That’s great -- easy to follow, even though I can’t read the comments. ^^ It’s not possible for actors to ‘watch’ each other in this system, correct? For instance, if one actor holds a reference to another, it will keep that old version of the actor alive, but it won’t see when the actor moves. This game doesn’t seem to need actors that watch each other, but it’s very common in games. I’ve been using IORefs for that purpose, but I like how pure the Mario game is. Is there a better way than IORefs? ________________________________ From: haskell-bounces(a)haskell.org [mailto:haskell-bounces@haskell.org] On Behalf Of Korcan Hussein Sent: Wednesday, October 29, 2008 4:57 PM To: haskell(a)haskell.org Subject: [Haskell] Making 'Super Nario Bros.' in Haskell‏ Hi I haven't seen this posted any where so I'm sorry in advance if this has been mentioned already but I came across this recent video on youtube: http://uk.youtube.com/watch?v=gVLFGQGRsDw it's a mario clone written in haskell with a link to source code repository (http://svn.coderepos.org/share/lang/haskell/nario/) I thought that it maybe useful to some people. Trustworthiness: Vendor reliability: Privacy: Child safety: ________________________________ For the best free wallpapers from MSN Click here! <http://wallpapers.msn.com/?ocid=%5bB001MSN42A0716B%5d>

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Hugs GraphicsUtils "legacy" code
by Galchin, Vasili 30 Oct '08

30 Oct '08

Hello, What is the suggested migration path from the Hugs GraphicsUtils to contemporary Haskell?? Thanks, Vasili

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[Somewhat OT] Speed
by Andrew Coppin 30 Oct '08

30 Oct '08

Hi guys. This isn't specifically to do with Haskell, but... does anybody have any idea roughly how fast various CPU operations are? For example, is integer arithmetic faster or slower than floating-point? Is addition faster or slower than multiplication? How much slower are the trigonometric functions? etc. Does using 8-bit integers make arithmetic any faster than using wider values? Does anybody have a good resource for this kind of information?

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Problems with Windows
by John Van Enk 30 Oct '08

30 Oct '08

Hello All, I'm trying to reinstall network-2.2.0.0 against Parsec 3 in Windows. Well, this is really hard/impossible to do. Here's what I've done so far: 1) After bashing my face against my desk for a while, I got cabal-install installed in windows. 2) cabal install network --reinstall 3) This freaks out because I don't have hsc2hs installed, but it doesn't tell me that, it just complains about something having to do with sizeof. 4) I figure out that I need hsc2hs installed, and i put cabal-install to use fetching it for me. 5) cabal-install fails because hsc2hs needs the process and directory packages, but they aren't exposed by the cabal file (at least in the version sitting on hackage, I assume this is the right one to use). 6) I give up on using cabal-install to get hsc2hs, so i download the targz for hsc2hs directly. 7) I fix the .cabal file to include process and directory 8) runhaskell Setup configure: >runhaskell Setup configure Configuring hsc2hs-0.67.20061107... Warning: No 'build-type' specified. If you do not need a custom Setup.hs or ./configure script then use 'build-type: Simple'. 9) runhaskell Setup build: Everything works fine. 10) runhaskell Setup install: Everything works fine. 11) Go back to try and install network-2.2.0.0 again with cabal-install. 12) Gets past the sizeof/hsc2hs errors, but then chokes on spaces in build path names: Preprocessing library network-2.2.0.0... gcc.exe: Files\Haskell\parsec-2.1.0.1\ghc-6.8.3: No such file or directory linking dist\build\Network\BSD_hsc_make.o failed command was: C:\ghc\ghc-6.8.3\gcc.exe -BC:\ghc\ghc-6.8.3\gcc-lib -IC:\ghc\ghc-6.8.3\include\mingw -LC:\Program Files\Haskell\parsec-2.1.0.1\ghc-6.8.3 -LC:\ghc\ghc-6.8.3/lib\base-3.0.2.0 -lwsock32 -lmsvcrt -lkernel32 -luser32 -lshell32 -LC:\ghc\ghc-6.8.3 -LC:\ghc\ghc-6.8.3/gcc-lib -lm -lgmp -lwsock32 dist\build\Network\BSD_hsc_make.o -o dist\build\Network\BSD_hsc_make.exe cabal: Error: some packages failed to install: network-2.2.0.0 failed during the building phase. The exception was:exit: ExitFailure 1 13) And this is where I finally gave up and came here. Does any one have any insight into: 1) Why cabal doesn't check for hsc2hs during a configure 2) How I can rebuild network-2.2.0.0 on my Windows box without sacrificing a goat to Bill Gates/GHC Gods? Thanks. /jve

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Re: [Haskell] How to get the binary respentation of the Int/Double.
by Ryan Ingram 29 Oct '08

29 Oct '08

Actually, this is a good question, at least as relating to floating point values. Is there a primitive to view the machine representation of floats? I'm thinking of functions like: reinterpretFloatAsWord :: Float -> Word32 reinterpretWordAsFloat :: Word32 -> Float reinterpretDoubleAsWord :: Double -> Word64 reinterpretWordAsDouble :: Word64 -> Double There are decodeFloat and encodeFloat in the RealFloat class, but these seem to be a bit heavy for inner-loop usage, especially when you are just going to paste the values back together into a word immediately anyways. Are the precision of Float and Double specified by the standard? There's actually lots of nice tricks you can do with these functions; for example, if you know you have a floating point value between 0 and 2^23-1, you can convert it to integer with a floating point add and an integer mask: > magic = 0x00800000 :: Float -- 2^23 > magicMask = 0x007fffff :: Word32 -- 2^23 - 1 > fastFloatToInt23 :: Float -> Word32 > fastFloatToInt23 x = reinterpretFloatAsWord (x + magic) .&. magicMask The add sets the exponent of the float to +23 and arranges it so the low bit of the float corresponds to "1", rounding if necessary. Then you can interpret the result as an integer and mask off the exponent and sign bit from the float, leaving you with just the integer value. This relies on the representation of IEEE single-precision floats, of course. These sorts of tricks come have in handy when working on graphics code; often I've found myself wanting to index into an array with the nearest value after some floating point computation. Texture mapping hardware does this conversion all the time, for example, and sometimes it's useful to emulate that behavior in software. -- ryan On Tue, Oct 28, 2008 at 10:08 AM, Brandon S. Allbery KF8NH <allbery(a)ece.cmu.edu> wrote: > On 2008 Oct 28, at 10:38, haihualin wrote: >> >> I am wondering how to get the binary respentation of the Int/Double. >> So I can save the integer as the binary data so that the C program can >> read it from the file. > > > The Binary package on Hackage (http://hackage.haskell.org) allows you to > serialize Haskell data in any form including C-compatible binary output. > > -- > brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery(a)kf8nh.com > system administrator [openafs,heimdal,too many hats] allbery(a)ece.cmu.edu > electrical and computer engineering, carnegie mellon university KF8NH > > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell >

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