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  • CodeIgniter's Scaffolding not working

    - by 01010011
    Hi, I keep getting a 404 Page Not Found whenever I try to access CodeIgniter's Scaffolding page in my browser, like so: localhost/codeignitor/index.php/blog/scaffolding/mysecretword I can access localhost/codeignitor/index.php/blog just fine. I followed CodeIgnitor's instructions in their "Create a blog in 20 minutes" by storing my database settings in the database.php file; and automatically connecting to the database by inserting "database" in the core array of the autoload.php; and I've added both parent::Controller(); and $this-load-scaffolding('myTableName') to blog's constructor. It still gives me this 404. Any suggestions?

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  • Java - SwingWorker - problem in done() method

    - by Yatendra Goel
    I am using javax.swing.SwingWorker for the first time. I want to update a JLabel from the interim result published by the swing worker as follows: publish("Published String"); Now to update the JLabel, I have coded the following: process(List<String> chunks) { if (chunks.size() > 0) { String text = chunks.get(chunks.size() - 1); label.setText(text); } } The above code works but my problem(or to be more specific, my doubt) is as follows: The above swing worker task is an annonymous inner class so it can access label field. But what if I want to make the swing worker class a non-inner class. Should I need to pass label as an argument to the constructor of swing worker class so that the process() method can access. Or Is there any other way? What approach does other developer follow to update UI components from the swing worker class' result when the swing worker class is not an inner class?

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  • Does my Dictionary must use locking mechanism?

    - by theateist
    Many threads have access to summary. Each thread will have an unique key for accessing the dictionary; Dictionary<string, List<Result>> summary; Do I need locking for following operations? summary[key] = new List<Result>() summary[key].Add(new Result()); It seems that I don't need locking because each thread will access dictionary with different key, but won't the (1) be problematic because of adding concurrently new record to dictionary with other treads?

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  • Is it possible to programmatically talk to MSN messenger / Live messenger?

    - by Ceilingfish
    Hi chaps, I've been researching how to interact with the MSN messenger / Live messenger service programmatically and I can't find any real documentation on this. The documentation for the Live services only seem to implement in Javascript (they're here: http://dev.live.com/Messenger/) It would be possible to reverse engineer this API to obtain the web services that it is actually using, but I am guessing that they didn't provide the sources for a reason (which means that those web services aren't meant for direct access). However I can't find any other official APIs that allow programmatic access (more specifically no APIs that mention sockets, web services, or a proper programming language like Java or .Net). Does anyone know if an API like that exists?

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  • Weird MySQL behavior, seems like a SQL bug

    - by Daniel Magliola
    I'm getting a very strange behavior in MySQL, which looks like some kind of weird bug. I know it's common to blame the tried and tested tool for one's mistakes, but I've been going around this for a while. I have 2 tables, I, with 2797 records, and C, with 1429. C references I. I want to delete all records in I that are not used by C, so i'm doing: select * from i where id not in (select id_i from c); That returns 0 records, which, given the record counts in each table, is physically impossible. I'm also pretty sure that the query is right, since it's the same type of query i've been using for the last 2 hours to clean up other tables with orphaned records. To make things even weirder... select * from i where id in (select id_i from c); DOES work, and brings me the 1297 records that I do NOT want to delete. So, IN works, but NOT IN doesn't. Even worse: select * from i where id not in ( select i.id from i inner join c ON i.id = c.id_i ); That DOES work, although it should be equivalent to the first query (i'm just trying mad stuff at this point). Alas, I can't use this query to delete, because I'm using the same table i'm deleting from in the subquery. I'm assuming something in my database is corrupt at this point. In case it matters, these are all MyISAM tables without any foreign keys, whatsoever, and I've run the same queries in my dev machine and in the production server with the same result, so whatever corruption there might be survived a mysqldump / source cycle, which sounds awfully strange. Any ideas on what could be going wrong, or, even more importantly, how I can fix/work around this? Thanks! Daniel

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  • Typical Hadoop setup for remote job submission

    - by Artii
    So I am still a bit new to hadoop and am currently in the process of setting up a small test cluster on Amazonaws. So my question relates to some tips on the structuring of the cluster so it is possible to work submit jobs from remote machines. Currently I have 5 machines. 4 are basically the Hadoop cluster with the NameNodes, Yarn etc. One machine is used as a manager machine( Cloudera Manager). I am gonna describe my thinking process on the setup and if anyone can chime in the points I am not clear with, that would be great. I was thinking what was the best setup for a small cluster. So I decided to expose only one manager machine and probably use that to submit all the jobs through it. The other machines will see each other etc, but not be accessible from the outside world. I am have conceptual idea on how to do this,but I am not sure how to properly go about doing this though, if anyone could point me in the right direction that would great. Also another big point is, I want to be able to submit jobs to the cluster through exposed machine from a client machine (might be Windows). I am not so clear on this setup as well. Do I need to have Hadoop installed on the machine in order to use the normal hadoop commands, and to write/submit jobs say from Eclipse or something similar. So to sum it up my questions are, Is this an ok setup for a small test cluster How can I go about using one exposed machine to submit/route jobs to the cluster, without having any of the Hadoop nodes on it. How do I setup a client machine to submit jobs to a remote cluster, and an example on how to do it on Windows. Also if there are any reason not to use Windows as a client machine in this setup. Thanks I would greatly appreciate any advice or help on this.

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  • E4X in ActionScript

    - by Brian Genisio
    Hey all, Looking at the E4X implementation in ActionScript, it occurs to me that they had to figure out how to do three things that I am not sure can be done within ActionScript regularly: Properties/Getters prefixed with @: var myAttribute = xmlPerson.@name; Nameless functions for filtering: xmlData.person.(/* predicate */) lambda syntax for predicates: xmlData.person.(@name == "Brian") So here is my question: Are these just one-off capabilities (much like Vector.<>) they put in just for E4X, therefore keeping out of reach for us? Or do we, as ActionScript developers, have access to these features? More specifically, I'd love to get access to the expression tree of that lambda predicate for my own code (not tied to the XML classes in any way). I figured out that this is called the "filter operator"... but I am not sure how to harness it. Not sure I can... since ActionScript does not allow for operator overloading :(

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  • Debugging an XBAP application with 64-bit browser

    - by Anne Schuessler
    We have an XBAP application that fails when opened in Internet Explorer 8 64 bit. We only get a pretty generic error which makes it hard to determine where the error is coming from. I'm trying to find a way to debug the application with IE 8 64 bit, but I haven't figured out how to do this. I can't set the 64 bit version as the standard browser and overwriting the browser path in the browsers.xml for Visual Studio doesn't work as well. It just gets overwritten as soon as I hit F5 to debug to point to the 32 bit IE. I have figured out how to start the application from Debug with the 64 bit browser by changing the Debug options from "Start browser with URL" to "Start external program" and setting the command line arguments to point to the bin folder. Unfortunately then the XBAP is looking for its config.deploy file which doesn't seem to be generated during regular debug. This doesn't happen when using "Start browser with URL" and the application doesn't seem to care for this file then. Does anybody know why there's a difference between "Start browser with URL" and "Start external program" in the Debug options which might cause this difference in behavior when Debug is started? Also, does anybody know how to successfully debug an XBAP with a 64-bit browser?

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  • Removing the email validation requirement - Login Toboggan

    - by Rob Orr
    I'm building a premium membership site where a visitor can purchase a role and gain access to the privileged content using ubercart. I've got all that working fine, but the last tiny snag that my client wants to remove is to remove the validation email requirement that's fired when someone signs up on the site in Login Toboggan (6.1.9). I've got nothing set that is forcing this extra step and I've come to believe that this may be a feature in Drupal (acquia distro 6.22) core for any user that registers. I was hoping that this module (login toboggan) would eliminate that step but I've not as of yet been able to do so. I can allow the newly registered user access by setting that in the module, but the notification and validation email requirement still remains. Can anyone recommend a way around this? I just want them to be able to come to the site purchase their membership without any validation/confirmation email. Is this possible? Thanks - Rob

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  • Jenkins and Visual Studio Online integration authentication

    - by user3120361
    right now I am trying to Setup Continuouse Integration - Delivery for a basic WCF Service, which will be hosted on a Microsoft Azure VM. The Project is Version Controlled through Visual Studio Online. So I installed Jenkins (also on the Azure VM), TFS plugin etc. and started the first Test Build: As Server URL I used "[VSO Adress]/DefaultCollection" and for Login purposes my Microsoft Account (I can Access VSO with that). The Problem is, when I run the Build I get the following error: Started by user Developer Building in workspace C:\Program Files (x86)\Jenkins\jobs\test\workspace [workspace] $ "C:\Program Files (x86)\TEE-CLC-11.0.0.1306\TEE-CLC-11.0.0\tf.cmd" workspaces -format:brief -server:[VSO Adress]/DefaultCollection ****" An error occurred: Access denied connecting to TFS server [VSO Adress] (authenticating as har****@*******o.com) FATAL: Executable returned an unexpected result code [100] ERROR: null Finished: FAILURE So my question is, whether it is generally possible to connect Jenkins and VSO that way and if so, which login credentials are needed

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  • NHibernate filters don't work with Session.Get

    - by Khash
    I'm trying to implement a Soft-deletable repository. Usually this can be easily done with a Delete Event listener. To filter out the deleted entities, I can add a Where attribute to my class mapping. However, I also need to implement two more methods in the repository for this entity: Restore and Purge. Restore will "undelete" entities and Purge will hard-delete them. This means I can't use Where attribute (since it block out soft-deleted entities to any access) I tried using filters instead. I can create a filter and enable or disable it within session to achieve the same result. But the problem is filters don't have any effect on Session.Get method (they only affect ICriteria based access). Any ideas as to how solve this problem? Thanks

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  • Accessing rails flash[:notice] in a model

    - by titaniumdecoy
    I am trying to assign a message to flash[:notice] in a model observer. This question has already been asked: Ruby on Rails: Observers and flash[:notice] messages? However, I get the following error message when I try to access it in my model: undefined local variable or method `flash' for #<ModelObserver:0x2c1742c> Here is my code: class ModelObserver < ActiveRecord::Observer observe A, B, C def after_save(model) puts "Model saved" flash[:notice] = "Model saved" end end I know the method is being called because "Model saved" is printed to the terminal. Is it possible to access the flash inside an observer, and if so, how?

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  • C++ std::stringstream seemingly causes thread to hang or die under SunOS

    - by stretch
    I have an application developed under Linux with GCC 4.2 which makes quite heacy use of stringstreams to wrap and unwrap data being sent over the wire. (Because the Grid API I'm using demands it). Under Linux everything is fine but when I deploy to SunOS (v5.10 running SPARC) and compile with GCC 3.4.6 the app hangs when it reaches the point at which stringstreams are used. In more detail: The main thread accepts requests from clients and starts a new pthread to handle each request. The child thread uses stringstreams to pack data. When the child thread gets to that point it seems to hang for a second and then die. The main thread is unaffected. Are there any known issues with stringstream and GCC 3.4.6 or SunOS or SPARCs? I didn't find anything yet... Can anyone suggest a better way to pack and unpack large amounts of data a strings or byte streams? Apologies for not posting code but this to me seems more involved than a simple syntax error. All the same, the thread crashes: std::stringstream mystringstream; //not here mystringstream << "some data: "; //but here That is, I can declare the stringstream but when I try to use it something goes wrong.

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  • flood fill algorithm

    - by user335593
    i want to implement the flood fill algorthm...so that when i get the x and y co-od of a point...it should start flooding from that point and fill till it finds a boundary but it is not filling the entire region...say a pentagon this is the code i am using void setpixel(struct fill fillcolor,int x,int y) { glColor3f(fillcolor.r,fillcolor.g,fillcolor.b); glBegin(GL_POINTS); glVertex2i(x,y); glEnd(); glFlush(); } struct fill getpixcol(int x,int y) { struct fill gotpixel; glReadPixels(x,y,1,1,GL_RGB,GL_UNSIGNED_BYTE,pick_col); gotpixel.r =(float) pick_col[0]/255.0; gotpixel.g =(float) pick_col[1]/255.0; gotpixel.b =(float) pick_col[2]/255.0; return(gotpixel); } void floodFill(int x, int y,struct fill fillcolor,struct fill boundarycolor) { struct fill tmp; // if ((x < 0) || (x >= 500)) return; // if ((y < 0) || (y >= 500)) return; tmp=getpixcol(x,y); while (tmp.r!=boundarycolor.r && tmp.g!=boundarycolor.g && tmp.b!=boundarycolor.b) { setpixel(fillcolor,x,y); setpixel(fillcolor,x+1,y); setpixel(fillcolor,x,y+1); setpixel(fillcolor,x,y-1); setpixel(fillcolor,x-1,y); floodFill(x-1,y+1,fillcolor,boundarycolor); floodFill(x-1,y,fillcolor,boundarycolor); floodFill(x-1,y-1,fillcolor,boundarycolor); floodFill(x,y+1,fillcolor,boundarycolor); floodFill(x,y-1,fillcolor,boundarycolor); floodFill(x+1,y+1,fillcolor,boundarycolor); floodFill(x+1,y,fillcolor,boundarycolor); floodFill(x+1,y-1,fillcolor,boundarycolor); } }

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  • Python, Ruby, and C#: Use cases?

    - by thaorius
    Hi everyone. For as long as I can remember, I've always had a "favorite" language, which I use for most projects, until, for some particular reason, there is no way/point on using it for project XYZ. At that point, I find myself rusty (and sometimes outdated) on other languages+libraries+toolchains. So I decided, I would just use some languages/libs/tools for some things, and some for other, effectively keeping them fresh (there would obviously be exceptions, I'm not looking for an arbitrary rule set, but some guidelines). I wanted an opinion on what would be your standard use cases (new projects) for Python, Ruby, and C# (Mono). At the moment, I have time like this:Languages: C#: Mid-Large Sized Projects (mainly server-side daemons) High Performance (I hardly ever need C's performance, but Python just doesn't cut it) Relatively Low Footprint (vs the JVM, for example) Ruby: Web Applications Python: General Use Scripts (automation, system config, etc) Small-Mid Sized Projects Prototyping Web Applications About Ruby, I have no idea what to use it for that I can't use Python for (specially considering Python is more easily found installed by default). And I like both languages (though I'm really new to Ruby), which makes things even worse. As for C#, I have not used a Windows powered computer in a few years, I don't make things for Windows computers, and I don't mind waiting for Mono to implement some new features. That being said, I haven't found many people on the internet using it for server-sided *nix programming (not web related). I would appreciate some insight on this too. Thanks for your time.

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  • How to have multiple instances of jQuery plugin on single page?

    - by James Skidmore
    I'm writing a simple jQuery plugin, but I'm having trouble being able to use multiple instances on a page. For instance, here is a sample plugin to illustrate my point: (function($) { $.fn.samplePlugin = function(options) { if (typeof foo != 'undefined') { alert('Already defined!'); } else { var foo = 'bar'; } }; })(jQuery); And then if I do this: $(document).ready(function(){ $('#myDiv').samplePlugin({}); // does nothing $('#myDiv2').samplePlugion({}); // alerts "Already defined!" }); This is obviously an over-simplified example to get across the point. So my question is, how do I have two separate instances of the plugin? I'd like to be able to use it across multiple instances on the same page. I'm guessing that part of the problem might be with defining the variables in a global scope. How can I define them unique to that instance of the plugin then? Thank you for your guidance!

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  • C# DLL Deployed in COM+. Error while accessing the methods.

    - by Dakshinamurthy
    I have the C# Dll (ABService) deployed in COM + and my os Is windows 2008. I have given the strong name for this dll and its dependent dll’s When I access the method of this dll through localhost or if I add the reference to the client project the method are executed successfully. Simply if I access the dll from the same machine with the reference it is working. So I think there is no problem with the way I deployed in the COM +. I have the doubt whether I have the problem in OS and Visual Studio 2008 combination. I have built all the dll with the Visual Studio 2008 with Target cpu as x86 and targert framework as 2.0. I have given in below the codes I have tried with and the errors. I need to create the object for the dll in server machine(64 bit) and access its method from the client(32 bit) Code : Type svr = Type.GetTypeFromProgID("ABService.Service", strserver1url[2],false); ABService.Service service1= (ABService.Service)Activator.CreateInstance(svr); strresult = service1.ExecuteService(orequest.xml); Error :{"Retrieving the COM class factory for remote component with CLSID {77BF00E0-41AC-3967-9E72-A4927CC0B880} from machine 10.105.138.64 failed due to the following error: 80040154."} Code Type svr = Type.GetTypeFromProgID("ABService.Service", strserver1url[2],true); object Service1 = null; Service1 = (ABService.Service)Activator.CreateInstance(svr, true); strresult = Convert.ToString(ReflectionHelper.Invoke(Service1, "ExecuteService", new object[] { orequest.xml })); Service1 = null; Error: Retrieving the COM class factory for remote component with CLSID {77BF00E0-41AC-3967-9E72-A4927CC0B880} from machine ftpsite failed due to the following error: 80040154. With the below code instead of C#.Net dll if i have the vb dll in Com + the method is executed successfully. Code ords = new RDS.DataSpace(); ords.InternetTimeout = 600000; object M_Service = null; ABService.Service oabservice = null; M_Service = ords.CreateObject("ABService.Service",url); strresult = Convert.ToString(ReflectionHelper.Invoke(M_Service, "ExecuteService", new object[] { orequest.xml })); Error : {"Object doesn't support this property or method 'ExecuteService'"} Code object obj=Interaction.CreateObject("ABService.Service", "10.105.138.64"); strresult = Convert.ToString(ReflectionHelper.Invoke(obj, "ExecuteService", new object[] { orequest.xml })); Error: {"Cannot create ActiveX component."} Code object obj = Activator.GetObject(typeof(ABService.Service), @"http://10.105.138.64:80/ABANET"); strresult = Convert.ToString(ReflectionHelper.Invoke(obj, "ExecuteService", new object[] { orequest.xml })); Error: InnerException {"The remote server returned an error: (405) Method Not Allowed."} System.Exception {System.Net.WebException} Message "Exception has been thrown by the target of an invocation.”

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  • jQuery Cycle - #next #prev, goto nextGallery after final slide of currentGallery

    - by FHP
    I am using jQuery cycle in several galleries with #next #prev navigation and a image counter output. Now I am trying to connect all these galleries together. If the user reaches the final slide of gallery A (galleryA.html), the #next anchor should point to gallery B (galleryB.html) / the #prev anchor should point to gallery C (galleryC.html). How can I combine my 2 functions to do that? // slideshow fx $(function() { $('#slideshow').cycle({ fx: 'fade', speed: 350, prev: '#prev', next: '#next', timeout: 0, after: onAfter }); }); //image counter output function onAfter(curr,next,opts) { var caption = (opts.currSlide + 1) + opts.slideCount; $('#counter').html(caption); } html: <div id="slideshow-container"> <div class="slideshow-nav"><a id="prev" href=""></a></div> <div class="slideshow-nav"><a id="next" href=""></a></div> <div id="slideshow" class="pics"> <img src="galleryA/01.jpg" /> <img src="galleryA/02.jpg" /> <img src="galleryA/03.jpg" /> <img src="galleryA/04.jpg" /> <img src="galleryA/05.jpg" /> <img src="galleryA/06.jpg" /> </div> </div>

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  • Possible Performance Considerations using Linq to SQL Repositories

    - by Robert Harvey
    I have an ASP.NET MVC application that uses Linq to SQL repositories for all interactions with the database. To deal with data security, I do trimming to filter data to only those items to which the user has access. This occurs in several places: Data in list views Links in a menu bar A treeview on the left hand side containing links to content Role-based security A special security attribute, inheriting from AuthorizeAttribute, that implements content-based authorization on every controller method. Each of these places instantiates a repository, which opens a Linq to Sql DataContext and accesses the database. So, by my count, each request for a page access opens at least six separate Linq to SQL DataContexts. Should I be concerned about this from a performance perspective, and if so, what can be done to mitigate it?

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  • Programmatically Binding to a Property

    - by M312V
    I know it's a generic title, but my question is specific. I think it will boil down to a question of practice. So, I have the following code: public class Component : UIElement { public Component() { this.InputBindings.Add(new MouseBinding(SomeCommandProperty, new MouseGesture(MouseAction.LeftClick))); } } I could easily aggregate the ViewModel that owns SomeCommandProperty into the Component class, but I'm currently waiving that option assuming there is another way. Component is a child of ComponentCollection which is child of a Grid which DataContext is the ViewModel. ComponentCollection as the name suggests contains a collection of Components. <Grid Name="myGrid"> <someNamespace:ComponentCollection x:Name="componentCollection"/> </Grid> It's the same scenario as the XAML below, but with TextBlock. I guess I'm trying to replicate what's being done in the XAML below programatically. Again, Component's top most ancestor's DataContext is set to ViewModel. <Grid Name="myGrid"> <TextBlock Text="SomeText"> <TextBlock.InputBindings> <MouseBinding Command="{Binding SomeCommandProperty}" MouseAction="LeftClick" /> </TextBlock.InputBindings> </TextBlock> </Grid> Update 1 Sorry, I'm unable to comment because I lack the reputation points. Basically, I have a custom control which inherit from a Panel which children are a collection of Component. It's not a hack, like I've mentioned, I could directly have access to SomeCommandProperty If I aggregate the ViewModel into Component. Doing so, however, feels icky. That is, having direct access to ViewModel from a Model. I guess the question I'm asking is. Given the situation that Component's parent UIElement's DataContext is set to ViewModel, is it possible to access SomeCommandProperty without Component owning a reference to the ViewModel that owns SomeCommandProperty? Programatically, that is. Using ItemsControl doesn't change the fact that I still need to bind SomeCommandProperty to each Items.

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  • How to find modal dialog opener from javascript?

    - by yapiskan
    I have a page that opens a modal dialog. After the operations done on dialog I want to refresh the opener page. But when I open the popup by using "openDialog" I cannot access to the opener by using window.opener on popup page. It appears "undefined" when I wanted to access. (I dont want to use "popup" method in this case. I want it to be a dialog by the way. using "popup" is my second plan.) What is the best practice to get rid off this issue?

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  • How to make an Asp.net MVC 2 website have a Private Beta Mode.

    - by Mark Kitz
    I am creating an ASP.Net MVC website that I am launching soon in private beta. What I am using. ASP.NET MVC 2 ASP.NET Sql Membership Provider Authorization Attributes on ActionMethods. ex. [EditorsOnly] What I am trying to accomplish: During the private Beta period of my website, I want no anonymous users to access my site. Only Beta Testers of my site should be able to login and use my site as normal. After the private beta period people can access it using the security structure I already have set up. I am hoping I do not have to recompile but can have a setting in the webconfig to switch between Private Beta mode to Normal mode. Thanks for your suggestions.

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  • Truly declarative language?

    - by gjvdkamp
    Hi all, Does anyone know of a truly declarative language? The behaviour I'm looking for is kind of what Excel does, where I can define variables and formulas, and have the formula's result change when the input changes (without having set the answer again myself) The behaviour I'm looking for is best shown with this pseudo code: X = 10 // define and assign two variables Y = 20; Z = X + Y // declare a formula that uses these two variables X = 50 // change one of the input variables ?Z // asking for Z should now give 70 (50 + 20) I've tried this in a lot of languages like F#, python, matlab etc, but every time i try this they come up with 30 instead of 70. Wich is correct from an imperative point of view, but i'm looking for a more declerative behaviour if you know what i mean. And this is just a very simple calculation. When things get more difficult it should handle stuff like recursion and memoization automagically. The code below would obviously work in C# but it's just so much code for the job, i'm looking for something a bit more to the point without all that 'technical noise' class BlaBla{ public int X {get;set;} // this used to be even worse before 3.0 public int Y {get;set;} public int Z {get{return X + Y;}} } static void main(){ BlaBla bla = new BlaBla(); bla.X = 10; bla.Y = 20; // can't define anything here bla.X = 50; // bit pointless here but I'll do it anyway. Console.Writeline(bla.Z);// 70, hurray! } This just seems like so much code, curly braces and semicolons that add nothing. Is there a language/ application (apart from Exel) that does this? Maybe I'm no doing it right in the mentioned langauges, or I've completely missed an app that does just this. I prototyped a language/ application that does this (along with some other stuff) and am thinking of productizing it. I just can't believe it's not there yet. Don't want to waste my time. Thanks in advance, Gert-Jan

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  • Thread-safe data structure design

    - by Inso Reiges
    Hello, I have to design a data structure that is to be used in a multi-threaded environment. The basic API is simple: insert element, remove element, retrieve element, check that element exists. The structure's implementation uses implicit locking to guarantee the atomicity of a single API call. After i implemented this it became apparent, that what i really need is atomicity across several API calls. For example if a caller needs to check the existence of an element before trying to insert it he can't do that atomically even if each single API call is atomic: if(!data_structure.exists(element)) { data_structure.insert(element); } The example is somewhat awkward, but the basic point is that we can't trust the result of "exists" call anymore after we return from atomic context (the generated assembly clearly shows a minor chance of context switch between the two calls). What i currently have in mind to solve this is exposing the lock through the data structure's public API. This way clients will have to explicitly lock things, but at least they won't have to create their own locks. Is there a better commonly-known solution to these kinds of problems? And as long as we're at it, can you advise some good literature on thread-safe design? EDIT: I have a better example. Suppose that element retrieval returns either a reference or a pointer to the stored element and not it's copy. How can a caller be protected to safely use this pointer\reference after the call returns? If you think that not returning copies is a problem, then think about deep copies, i.e. objects that should also copy another objects they point to internally. Thank you.

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  • How to disable back button in browser using javascript or any script

    - by user225269
    Im using wamp server for my php scripts. And Im having difficulties on the logout code. Every time I click on the logout link and then click on the back button on web browser it still shows the page which can only be access by the user who is logged in. I have this code at the beginning of the index.php which is called by the log out link to destroy the session: <?php session_start(); session_destroy(); ?> And I have this at the beginning of the user page: <? session_start(); if(!session_is_registered(myusername)){ header("location:login.php"); } ?> I don't know why the userpage can still be access after the user has logged out. So I'm thinking of disabling the back button when the user has logged out. Please help.

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