Re: [Haskell-cafe] Observer pattern in haskell FRP

2012-11-27 Thread Nathan Hüsken
On 11/27/2012 07:12 AM, Ertugrul Söylemez wrote: Nathan Hüsken nathan.hues...@posteo.de wrote: When writing games in other (imperative) languages, I like to separate the game logic from the rendering. For this I use something similar to the observer pattern. [...] So I am wondering: Is

Re: [Haskell-cafe] cabal configure cabal build cabal install

2012-11-27 Thread kudah
On Tue, 27 Nov 2012 02:20:35 -0500 Albert Y. C. Lai tre...@vex.net wrote: When cabal build succeeds, it always says: (older) registering name-version (newer) In-place registering name-version That's what it says. But use ghc-pkg and other tests to verify that no registration whatsoever

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Gregory Collins
GHC has a stop the world garbage collector, meaning that while major GC is happening, the entire process must be halted. In my experience GC pause times are typically low, but depending the heap residency profile of your application (and the quantity of garbage being produced by it), this may not

Re: [Haskell-cafe] Observer pattern in haskell FRP

2012-11-27 Thread Ertugrul Söylemez
Nathan Hüsken nathan.hues...@posteo.de wrote: In fact it could be a (free) monad: myApp :: MyWire a (GameDelta ()) someDelta :: GameDelta () someDelta = do randomPos - liftA2 (,) getRandom getRandom replicateM_ 4 (addCreature randomPos)

[Haskell-cafe] Conduit and pipelined protocol processing using a threadpool

2012-11-27 Thread Nicolas Trangez
All, I've written a library to implement servers for some protocol using Conduit (I'll announce more details later). The protocol supports pipelining, i.e. a client can send a 'command' which contains some opaque 'handle' chosen by the client, the server processes this command, then returns some

Re: [Haskell-cafe] Problem with benchmarking FFI calls with Criterion

2012-11-27 Thread Janek S.
I tested the same code on my second machine - Debian Squeeze (kernel 2.6.32) with GHC 7.4.1 - and the results are extremely surprising. At first I was unable to reproduce the problem and got consistent runtimes of about 107us: benchmarking FFI/C binding mean: 107.3837 us, lb 107.2013 us, ub

[Haskell-cafe] 1st São Paulo Haskell Meeting [1° Encontro de Haskellers em São Paulo]

2012-11-27 Thread Felipe Almeida Lessa
Hey! I'd like to invite you to the 1st São Paulo Haskell Meeting! It's going to be something simple, we just want to meet each other and talk about Haskell =). We already have 9 people confirmed on the Google+ event [1], so come join us already! Cheers, PS: We still didn't set the place yet.

Re: [Haskell-cafe] Problem with benchmarking FFI calls with Criterion

2012-11-27 Thread Jake McArthur
I once had a problem like this. It turned out that my laptop was stepping the cpu clock rate down whenever it got warm. Disabling that feature in my BIOS fixed it. Your problem might be similar. On Nov 27, 2012 7:23 AM, Janek S. fremenz...@poczta.onet.pl wrote: I tested the same code on my

Re: [Haskell-cafe] Problem with benchmarking FFI calls with Criterion

2012-11-27 Thread Janek S.
Dnia wtorek, 27 listopada 2012, Jake McArthur napisał: I once had a problem like this. It turned out that my laptop was stepping the cpu clock rate down whenever it got warm. Disabling that feature in my BIOS fixed it. Your problem might be similar. I just check - I disabled frequency scaling

Re: [Haskell-cafe] Problem with benchmarking FFI calls with Criterion

2012-11-27 Thread Gregory Collins
Did you pass the option to criterion asking it to do a GC between trials? You might be measuring a GC pause. On Tue, Nov 27, 2012 at 2:41 PM, Janek S. fremenz...@poczta.onet.pl wrote: Dnia wtorek, 27 listopada 2012, Jake McArthur napisał: I once had a problem like this. It turned out that my

Re: [Haskell-cafe] Problem with benchmarking FFI calls with Criterion

2012-11-27 Thread Janek S.
Dnia wtorek, 27 listopada 2012, Gregory Collins napisał: Did you pass the option to criterion asking it to do a GC between trials? Yes. You might be measuring a GC pause. On Tue, Nov 27, 2012 at 2:41 PM, Janek S. fremenz...@poczta.onet.pl wrote: Dnia wtorek, 27 listopada 2012, Jake

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Johan Tibell
Kazu and Andreas, could this be IO manager related? On Monday, November 26, 2012, Jeff Shaw wrote: Hello, I've run into an issue that makes me think that when the GHC GC runs while a Snap or Warp HTTP server is serving connections, the GC prevents or delays TCP connections from forming. My

Re: [Haskell-cafe] Conduit and pipelined protocol processing using a threadpool

2012-11-27 Thread Michael Snoyman
I think the stm-conduit package[1] may be helpful for this use case. Each time you get a new command, you can fork a thread and give it the TBMChan to write to, and you can use sourceTBMChan to get a source to send to the client. Michael [1] http://hackage.haskell.org/package/stm-conduit On

Re: [Haskell-cafe] Observer pattern in haskell FRP

2012-11-27 Thread Heinrich Apfelmus
Nathan Hüsken wrote: Hey, When writing games in other (imperative) languages, I like to separate the game logic from the rendering. For this I use something similar to the observer pattern. With rendering I mean anything only related to how objects are drawn to the screen. Animation state for

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread timothyhobbs
Could you give us more info on what your constraints are?  Is it necessary that you have a certain number of connections per second, or is it necessary that the connection results very quickly after some other message is received? -- Původní zpráva -- Od: Johan Tibell

Re: [Haskell-cafe] Observer pattern in haskell FRP

2012-11-27 Thread Nathan Hüsken
On 11/27/2012 04:18 PM, Heinrich Apfelmus wrote: Nathan Hüsken wrote: Hey, When writing games in other (imperative) languages, I like to separate the game logic from the rendering. For this I use something similar to the observer pattern. With rendering I mean anything only related to how

Re: [Haskell-cafe] Conduit and pipelined protocol processing using a threadpool

2012-11-27 Thread Nicolas Trangez
Michael, On Tue, 2012-11-27 at 17:14 +0200, Michael Snoyman wrote: I think the stm-conduit package[1] may be helpful for this use case. Each time you get a new command, you can fork a thread and give it the TBMChan to write to, and you can use sourceTBMChan to get a source to send to the

Re: [Haskell-cafe] Portability of Safe Haskell packages

2012-11-27 Thread Amit Levy
FWIW, some very core libraries do this: http://hackage.haskell.org/packages/archive/bytestring/0.10.2.0/doc/html/src/Data-ByteString.html (see very top of linked source file) Perhaps a more general solution would be for GHC to take the internet explorer route and require a special javascript

[Haskell-cafe] ANNOUNCE: language-java 0.2.0

2012-11-27 Thread Vincent Hanquez
Hi Cafe, with the approval of Niklas, the original author and maintainer, i'll be maintaining language-java for now. I've uploaded a new version on hackage [1] with some minor improvements and the repository is now hosted on github [2]. Thanks Niklas for language-java ! [1]

Re: [Haskell-cafe] ANNOUNCE: language-java 0.2.0

2012-11-27 Thread Alfredo Di Napoli
Thanks for the effort! Now, what about some documentation? :P Cheers, A. On 27 November 2012 18:26, Vincent Hanquez t...@snarc.org wrote: Hi Cafe, with the approval of Niklas, the original author and maintainer, i'll be maintaining language-java for now. I've uploaded a new version on

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Jeff Shaw
Hello Timothy and others, One of my clients hosts their HTTP clients in an Amazon cloud, so even when they turn on persistent HTTP connections, they use many connections. Usually they only end up sending one HTTP request per TCP connection. My specific problem is that they want a response in

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Jason Dagit
On Tue, Nov 27, 2012 at 11:02 AM, Jeff Shaw shawj...@gmail.com wrote: Hello Timothy and others, One of my clients hosts their HTTP clients in an Amazon cloud, so even when they turn on persistent HTTP connections, they use many connections. Usually they only end up sending one HTTP request

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Jason Dagit
On Tue, Nov 27, 2012 at 11:17 AM, Jason Dagit dag...@gmail.com wrote: On Tue, Nov 27, 2012 at 11:02 AM, Jeff Shaw shawj...@gmail.com wrote: Hello Timothy and others, One of my clients hosts their HTTP clients in an Amazon cloud, so even when they turn on persistent HTTP connections, they

[Haskell-cafe] Real-time code in Haskell (Was: Can a GC delay TCP connection formation?)

2012-11-27 Thread Mike Meyer
On Tue, Nov 27, 2012 at 3:45 AM, Gregory Collins g...@gregorycollins.net wrote: If you have a hard real-time requirement then a garbage-collected language may not be appropriate for you. This is a common meme, but frankly, it isn't true. When writing real-time code, you just need to make sure

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Gershom Bazerman
On 11/27/12 2:17 PM, Jason Dagit wrote: Based on that I would check the FFI imports in your database library. In the best case (-threaded, 'safe', and thread-safe odbc), I think you'll find that N of these can run concurrently, but here your number of requests is likely to be much greater

Re: [Haskell-cafe] Real-time code in Haskell (Was: Can a GC delay TCP connection formation?)

2012-11-27 Thread timothyhobbs
What triggers GC in haskell?  We obviously aren't using Java's method of GC as needed(for good reasons, Java's method is terrible because you get slow downs when you need speed the most).  But we should be able to learn something from Java and have a gc::IO() method that one could call BEFORE a

Re: [Haskell-cafe] ANNOUNCE: language-java 0.2.0

2012-11-27 Thread Vincent Hanquez
On 11/27/2012 06:46 PM, Alfredo Di Napoli wrote: Thanks for the effort! Now, what about some documentation? :P Sure ! Fork away, and send pull requests :-) -- Vincent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org

Re: [Haskell-cafe] Real-time code in Haskell (Was: Can a GC delay TCP connection formation?)

2012-11-27 Thread Felipe Almeida Lessa
http://hackage.haskell.org/packages/archive/base/4.6.0.0/doc/html/System-Mem.html#v:performGC On Tue, Nov 27, 2012 at 5:52 PM, timothyho...@seznam.cz wrote: What triggers GC in haskell? We obviously aren't using Java's method of GC as needed(for good reasons, Java's method is terrible because

Re: [Haskell-cafe] Real-time code in Haskell (Was: Can a GC delay TCP connection formation?)

2012-11-27 Thread Roman Cheplyaka
* Mike Meyer m...@mired.org [2012-11-27 13:40:17-0600] Lazyness, on the other hand ... I haven't thought about. I suspect you need to force the evaluation of everything you're going to need before you start the critical region, but I wonder if that's enough? Has anyone out there investigated

Re: [Haskell-cafe] ANNOUNCE: language-java 0.2.0

2012-11-27 Thread Ömer Sinan Ağacan
Great, thanks for this great work! One of the things I _love_ about haskell and it's community is that language-x packages. I really love playing with source code and compiling to other languages. And working with Haskell, thanks to that language-x packages, make this a joy. And recently I also

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Jeff Shaw
On 11/27/2012 2:45 PM, Gershom Bazerman wrote: HDBC-odbc has long used the wrong type of FFI imports, resulting in long-running database queries potentially blocking all other IO. I just checked, and apparently a patch was made to the repo in September that finally fixes this [1], but

Re: [Haskell-cafe] Can a GC delay TCP connection formation?

2012-11-27 Thread Nicolas Wu
On Tue, Nov 27, 2012 at 9:45 PM, Jeff Shaw shawj...@gmail.com wrote: On 11/27/2012 2:45 PM, Gershom Bazerman wrote: HDBC-odbc has long used the wrong type of FFI imports, resulting in long-running database queries potentially blocking all other IO. I just checked, and apparently a patch was

Re: [Haskell-cafe] cabal configure cabal build cabal install

2012-11-27 Thread Albert Y. C. Lai
On 12-11-27 04:40 AM, kudah wrote: On Tue, 27 Nov 2012 02:20:35 -0500 Albert Y. C. Lai tre...@vex.net wrote: When cabal build succeeds, it always says: (older) registering name-version (newer) In-place registering name-version That's what it says. But use ghc-pkg and other tests to verify

[Haskell-cafe] Recursive timezone-loading function

2012-11-27 Thread David Thomas
https://github.com/dlthomas/tzcache A small bit of code, but seems likely to be useful enough that I figured I should share. I've a few notes/questions: 1) Does this already exist somewhere I missed? 2) It seems silly to make this its own library - any suggestions where it could be added? 3)

Re: [Haskell-cafe] Conduit and pipelined protocol processing using a threadpool

2012-11-27 Thread Michael Snoyman
On Tue, Nov 27, 2012 at 7:25 PM, Nicolas Trangez nico...@incubaid.comwrote: Michael, On Tue, 2012-11-27 at 17:14 +0200, Michael Snoyman wrote: I think the stm-conduit package[1] may be helpful for this use case. Each time you get a new command, you can fork a thread and give it the