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  • How to extract part of the path and the ending file name with Regex?

    - by brasofilo
    I need to build an associative array with the plugin name and the language file it uses in the following sequence: /whatever/path/length/public_html/wp-content/plugins/adminimize/languages/adminimize-en_US.mo /whatever/path/length/public_html/wp-content/plugins/audio-tube/lang/atp-en_US.mo /whatever/path/length/public_html/wp-content/languages/en_US.mo /whatever/path/length/public_html/wp-content/themes/twentyeleven/languages/en_US.mo Those are the language files WordPress is loading. They are all inside /wp-content/, but with variable server paths. I'm looking only for those inside the plugins folder, grab the plugin folder name and the filename. Hipothetical case in PHP, where reg_extract_* functions are the parts I'm missing: $plugins = array(); foreach( $big_array as $item ) { $folder = reg_extract_folder( $item ); if( 'plugin' == $folder ) { // "folder-name-after-plugins-folder" $plugin_name = reg_extract_pname( $item ); // "ending-mo-file.mo" $file_name = reg_extract_fname( $item ); $plugins[] = array( 'name' => $plugin_name, 'file' => $file_name ); } } [update] Ok, so I was missing quite a basic function, pathinfo... :/ No problem to detect if /plugins/ is contained in the array. But what about the plugin folder name?

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  • stealing inside the move constructor

    - by FredOverflow
    During the implementation of the move constructor of a toy class, I noticed a pattern: array2D(array2D&& that) { data_ = that.data_; that.data_ = 0; height_ = that.height_; that.height_ = 0; width_ = that.width_; that.width_ = 0; size_ = that.size_; that.size_ = 0; } The pattern obviously being: member = that.member; that.member = 0; So I wrote a preprocessor macro to make stealing less verbose and error-prone: #define STEAL(member) member = that.member; that.member = 0; Now the implementation looks as following: array2D(array2D&& that) { STEAL(data_); STEAL(height_); STEAL(width_); STEAL(size_); } Are there any downsides to this? Is there a cleaner solution that does not require the preprocessor?

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  • How to store unlimited characters in Oracle 11g?

    - by vicky21
    We have a table in Oracle 11g with a varchar2 column. We use a proprietary programming language where this column is defined as string. Maximum we can store 2000 characters (4000 bytes) in this column. Now the requirement is such that the column needs to store more than 2000 characters (in fact unlimited characters). The DBAs don't like BLOB or LONG datatypes for maintenance reasons. The solution that I can think of is to remove this column from the original table and have a separate table for this column and then store each character in a row, in order to get unlimited characters. This tble will be joined with the original table for queries. Is there any better solution to this problem? UPDATE: The proprietary programming language allows to define variables of type string and blob, there is no option of CLOB. I understand the responses given, but I cannot take on the DBAs. I understand that deviating from BLOB or LONG will be developers' nightmare, but still cannot help it.

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  • Android - Basic CRUD (REST/RPC client) to remote server

    - by bsreekanth
    There are lot of discussion about REST client implementation in android, based on the talk at GoogleIO 2010, by Virgil Dobjanschi. My requirement may not necessarily involved, as I have some freedom to choose the configuration. I only target tablets configuration changes can be prevented if no other easy way (fix at Landscape mode etc) I am trying to achieve. Basic CRUD operation to my server (JSON RPC/ REST). Basically mimic an ajax request from android app (no webview, need native app) Based on the above mentioned talk, and some reading I see these options. Implement any of the 3 mentioned in the Google IO talk Especially, the last pattern may be more suitable as I don't care much of caching. But not sure how "real time" is sync implementation. Use HTTP request in AsyncTask. Simplest, but need to avoid re-sending request during change in device configuration (orientation change etc). Even if I fix at one orientation, recreation of activity still happens. So need to handle it elegantly. Use service to handle http request. So far, it say use service for long ruiing request. Not sure whether it is a good approach for simple GET/POST/PUt requests. Please share your experience on what could be the best way.

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  • Indices instead of pointers in STL containers?

    - by zvrba
    Due to specific requirements [*], I need a singly-linked list implementation that uses integer indices instead of pointers to link nodes. The indices are always interpreted with respect to a vector containing the list nodes. I thought I might achieve this by defining my own allocator, but looking into the gcc's implementation of , they explicitly use pointers for the link fields in the list nodes (i.e., they do not use the pointer type provided by the allocator): struct _List_node_base { _List_node_base* _M_next; ///< Self-explanatory _List_node_base* _M_prev; ///< Self-explanatory ... } (For this purpose, the allocator interface is also deficient in that it does not define a dereference function; "dereferencing" an integer index always needs a pointer to the underlying storage.) Do you know a library of STL-like data structures (i am mostly in need of singly- and doubly-linked list) that use indices (wrt. a base vector) instead of pointers to link nodes? [*] Saving space: the lists will contain many 32-bit integers. With two pointers per node (STL list is doubly-linked), the overhead is 200%, or 400% on 64-bit platform, not counting the overhead of the default allocator.

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  • Writing an audio player in C#

    - by Malki
    Hi, I have a pretty cool idea for a very special media player. I like to think about this project as a mini-startup, since I don't yet know if my idea is practical. Anyways, before implementing my idea, I first need to be able to implement a simple audio player. My preferred language for this project is C#, simply because it's so easy to use, but any other object oriented language would be fine too I guess. I started out with no knowledge whatsoever about audio. My main goals right now are: Being able to play audio files - as many formats as possible (sort of a VLC type player, but only audio for now). Being able to analyze audio files - as in, reading frequency, amplitude, volume, and other information about the audio. I think maybe a good idea here is to be able to analyze one file format (PCM?), and then temporarily converting any file I want to analyze to that format. This is in order to later implement a mechanism that compares songs and identifies similar songs to recommend to the user (this feature isn't part of my idea, but I figured since it exists in many players nowadays, I need to have it too if I want be able to compete with them). BTW - I currently don't have any knowledge about audio/wavelengths/frequencies and such, so I'd appreciate it if someone could point me in the right direction about this analyzation feature. Maybe in the future I'd expand to playing video files as well, but for now I'm concentrating on audio. After searching the Internet for a while, I've come across LAME. Problem is, it's not C#, and I'm not sure how to use it. I know there is something called "Interoperability", that is supposed to let me work with native DLL files through C#. Any information about that would be helpful as well. Any help would be much appreciated. Thanks, Malki :)

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  • How can someone with no experience learn how to program?

    - by Mugatu
    A friend and I have been coming up with website ideas for a couple years, mostly just jotting them down whenever we come up with a good, useful idea when browsing the web. For the past 6 months we've hired a couple different programmers to make a couple of the sites for us, but have been disappointed with how it's gone. Been too slow and too many miscommunications for our liking. So like the saying goes if you want something done right do it yourself, we're going to do it ourselves. I know nothing about programming, I've never written a line of code in my life. I consider myself very good with math and about as logical as you can get, but I have zero real-life programming knowledge. The sites we want to make are all pretty 'Web 2.0'ish', meaning user-generated content, commenting on posts, pages that change on the fly, etc. So here are some of my questions for anyone who's been there before: Is there a language you'd recommend learning first? Something that is a good indicator how most other languages work? What web programming languages do you recommend learning first based on popularity both now and the future. I don't want to learn a language that's going to be outdated by the time I'm an expert at it. Any specific books you'd recommend? Any general advice you'd give to someone literally starting at square zero for coding who plans on being in it for the long haul?

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  • Can't add to NSMutableArray from SecondaryView

    - by Antonio
    Hi guys, I've searched and read and still haven't found a concrete answer. Brief: I have an application where I declare an NSMutableArray in my AppDelegate to synthesize when the application loads. (code below). I have a SecondaryViewController call this function, and I have it output a string to let me know what the array size is. Every time I run it, it executes but it does not add any objects to the array. How do I fix this? AppDelegate.h file #import <UIKit/UIKit.h> @class arrayTestViewController; @interface arrayTestAppDelegate : NSObject <UIApplicationDelegate> { UIWindow *window; arrayTestViewController *viewController; NSMutableArray *myArray3; } @property (nonatomic, retain) NSMutableArray *myArray3; @property (nonatomic, retain) IBOutlet UIWindow *window; @property (nonatomic, retain) IBOutlet arrayTestViewController *viewController; -(void)addToArray3; @end AppDelegate.m file #import "arrayTestAppDelegate.h" #import "arrayTestViewController.h" @implementation arrayTestAppDelegate @synthesize window; @synthesize viewController; @synthesize myArray3; #pragma mark - #pragma mark Application lifecycle - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { myArray3 = [[NSMutableArray alloc] init]; // Override point for customization after application launch. // Add the view controller's view to the window and display. [window addSubview:viewController.view]; [window makeKeyAndVisible]; return YES; } -(void)addToArray3{ NSLog(@"Array Count: %d", [myArray3 count]); [myArray3 addObject:@"Test"]; NSLog(@"Array triggered from SecondViewController"); NSLog(@"Array Count: %d", [myArray3 count]); } SecondViewController.m file #import "SecondViewController.h" #import "arrayTestAppDelegate.h" @implementation SecondViewController -(IBAction)addToArray{ arrayTestAppDelegate *object = [[arrayTestAppDelegate alloc] init]; [object addToArray3]; }

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  • Server returns 500 error only when called by Java client using urlConnection/httpUrlConnection

    - by user455889
    Hi - I'm having a very strange problem. I'm trying to call a servlet (JSP) with an HTTP GET and a few parameters (http://mydomain.com/method?param1=test&param2=123). If I call it from the browser or via WGET in a bash session, it works fine. However, when I make the exact same call in a Java client using urlConnection or httpURLConnection, the server returns a 500 error. I've tried everything I have found online including: urlConn.setRequestProperty("Accept-Language", "en-us,en;q=0.5"); Nothing I've tried, however, has worked. Unfortunately, I don't have access to the server I'm calling so I can't see the logs. Here's the latest code: private String testURLConnection() { String ret = ""; String url = "http://localhost:8080/TestService/test"; String query = "param1=value1&param2=value2"; try { URLConnection connection = new URL(url + "?" + query).openConnection(); connection.setRequestProperty("Accept-Charset", "UTF-8"); connection.setRequestProperty("Accept-Language", "en-us,en;q=0.5"); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream())); String line; StringBuilder content = new StringBuilder(); while ((line = bufferedReader.readLine()) != null) { content.append(line + "\n"); } bufferedReader.close(); metaRet = content.toString(); log.debug(methodName + " return = " + metaRet); } catch (Exception ex) { log.error("Exception: " + ex); log.error("stack trace: " + getStackTrace(ex)); } return metaRet; } Any help would be greatly appreciated!

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  • Some languages don't work when using Word 2007 Spellcheck from Interop

    - by Tridus
    I'm using the Word 2007 spellchecker via Interop in a VB.net desktop app. When using the default language (English), it works fine. If I set the language to French via LanguageId, it also works. But if I set it to French (Canadian) (Word.WdLanguageID.wdFrenchCanadian), it doesn't work. There's no error message, it simply runs and says the document contains no errors. I know it does, if I paste the exact same text into Word itself and run it with the French (Canadian) dictionary, it finds errors. Just why that dictionary doesn't work is kind of a mystery to me. Full code below: Public Shared Function SpellCheck(ByVal text As String, ByVal checkGrammar As Boolean) As String ' If there is no data to spell check, then exit sub here. If text.Length = 0 Then Return text End If Dim objWord As Word.Application Dim objTempDoc As Word.Document ' Declare an IDataObject to hold the data returned from the ' clipboard. Dim iData As IDataObject objWord = New Word.Application() objTempDoc = objWord.Documents.Add objWord.Visible = False ' Position Word off the screen...this keeps Word invisible ' throughout. objWord.WindowState = 0 objWord.Top = -3000 ' Copy the contents of the textbox to the clipboard Clipboard.SetDataObject(text) ' With the temporary document, perform either a spell check or a ' complete ' grammar check, based on user selection. With objTempDoc .Content.Paste() .Activate() .Content.LanguageID = Word.WdLanguageID.wdFrenchCanadian If checkGrammar Then .CheckGrammar() Else .CheckSpelling() End If ' After user has made changes, use the clipboard to ' transfer the contents back to the text box .Content.Copy() iData = Clipboard.GetDataObject If iData.GetDataPresent(DataFormats.Text) Then text = CType(iData.GetData(DataFormats.Text), _ String) End If .Saved = True .Close() End With objWord.Quit() Return text End Function

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  • What technology should I use to write my game?

    - by Alon
    I have a great idea for a 3D network game, and I've concluded that it is possible to write it in Java as an applet which will live under the web browser, just like a full software in C++. And it will look and feel the same. The main advantage of Java on C++ is that with Java you can play without downloading any software. I have already thought about the download of the graphics, sound, etc but I found a solution for it. RuneScape just proves that it is possible. So my first question is, should my game live on a web browser or on the operating system? I think that in a web browser it is much more portable, although you need install Java and stuff. But the fact is, that most MMO games are currently not in the web. If you suggest in a software so please suggest a language either - C++ or something more productive like Python or C#? So after choosing a language, I need a graphics solution. Should I write directly with OpenGL/DirectX or use a game engine? What game engine should I use? Ogre? jMonkeyEngine? What's your opinion? Thank you! P.S: Please don't use answers like "Use what you know".

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  • Silverlight, Flash, or JavaScript for web app that runs client-side, or just stick with C#?

    - by Sootah
    Silverlight, Flash, and JavaScript, oh my.. I have a couple of applications that I need to develop for one of my business partners that will be distributed to dozens of people. These applications will need to be able to query information from the internet (query via Google, grab feeds from our other sites, just general web access) and save files to their computer. The reason I want to host the application is so that it all can be centrally managed, and any updates would be instantly deployed to everyone that uses the service. There always seems to be headaches with developing a pure desktop app in a language like C# with regards to making sure people use the latest version, don't have some odd problem with the installer, etc. Since we don't want to tie up our server's CPU I want effectively all of the processing done client-side. Meaning that they would log into their account, access the app, and then all the work done within the app is all handled by their machine. Only specific data would be sent back to the server. So - which language is best for this? Microsoft's Silverlight, Adobe's Flash, or Sun's JavaScript? I've heard a lot of good things about Silverlight and have wanted to try it for some time. I've only done extremely limited JavaScript programming, and absolutely none with Flash. Or, with my main requirement being that the client does all of its own processing should I just stick with C#? Also, is there any way to integrate a C# app into a webpage? I've never even considered it (or have any idea if it's even possible) until just now. Thanks in advance! -Sootah

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  • LINQ to objects: Is there

    - by Charles
    I cannot seem to find a way to have LINQ return the value from a specified accessor. I know the name of the accessors for each object, but am unsure if it is possible to pass the requested accessor as a variable or otherwise achieve the desired refactoring. Consider the following code snippet: // "value" is some object with accessors like: format, channels, language row = new List<String> { String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.format).ToArray()), String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.channels).ToArray()), String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.language).ToArray()), // ... } I'd like to refactor this into a method that uses the specified accessor, or perhaps pass a delegate, though I don't see how that could work. string niceRefactor(myObj myObject, string /* or whatever type */ ____ACCESSOR) { return String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.____ACCESSOR).ToArray()); } I have written a decent amount of C#, but am still new to the magic of LINQ. Is this the right approach? How would you refactor this?

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  • Is learning C++ a good idea?

    - by chang
    The more I hear and read about C++ (e.g. this: http://lwn.net/Articles/249460/), I get the impression, that I'd waste my time learning C++. I some wrote network routing algorithm in C++ for a simulator, and it was a pain (as expected, especially coming from a perl/python/Java background ...). I'm never happy about giving up on some technology, but I would be happy, if I could limit my knowledge of C-family languages to just C, C# and Objective-C (even OS Xs Cocoa, which is huge and takes a lot of time to learn looks like joy compared to C++ ...). Do I need to consider myself dumb or unwilling, just because I'm not partial to the pain involved learning this stuff? Technologies advance and there will be options other than C++, when deciding on implementation languages, or not? And for speed: If speed were that critical, I'd go for a plain C implementation instead, or write C extensions for much more productive languages like ruby or python ... The one-line version of the above: Will C++ stay such a relevant language that every committed programmer should be familiar with it? [ edit / thank you very much for your interesting and useful answers so far .. ] [ edit / .. i am accepting the top-rated answer; thanks again for all answers! ]

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  • Boost multi_index_container crash in release mode

    - by Zan Lynx
    I have a program that I just changed to using a boost::multi_index_container collection. After I did that and tested my code in debug mode, I was feeling pretty good about myself. However, then I compiled a release build with NDEBUG set, and the code crashed. Not immediately, but sometimes in single-threaded tests and often in multi-threaded tests. The segmentation faults happen deep inside boost insert and rotate functions related to the index updates and they are happening because a node has NULL left and right pointers. My code looks a bit like this: struct Implementation { typedef std::pair<uint32_t, uint32_t> update_pair_type; struct watch {}; struct update {}; typedef boost::multi_index_container< update_pair_type, boost::multi_index::indexed_by< boost::multi_index::ordered_unique< boost::multi_index::tag<watch>, boost::multi_index::member<update_pair_type, uint32_t, &update_pair_type::first> >, boost::multi_index::ordered_non_unique< boost::multi_index::tag<update>, boost::multi_index::member<update_pair_type, uint32_t, &update_pair_type::second> > > > update_map_type; typedef std::vector< update_pair_type > update_list_type; update_map_type update_map; update_map_type::iterator update_hint; void register_update(uint32_t watch, uint32_t update); void do_updates(uint32_t start, uint32_t end); }; void Implementation::register_update(uint32_t watch, uint32_t update) { update_pair_type new_pair( watch_offset, update_offset ); update_hint = update_map.insert(update_hint, new_pair); if( update_hint->second != update_offset ) { bool replaced _unused_ = update_map.replace(update_hint, new_pair); assert(replaced); } }

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  • Rails - any fancy ways to handle 404s?

    - by jyoseph
    I have a rails app I built for an old site I converted from another cms (in a non-rails language, hehe). Most of the old pages are mapped to the new pages using routes.rb. But there are still a few 404s. I am a rails newb so I'm asking if there are any advanced ways to handle 404s. For example, if I was programming in my old language I'd do this: Get the URL (script_name) that was being accessed and parse it. Do a lookup in the database for any keywords, ids, etc found in the new URL. If found, redirect to the page (or if multiple records are found, show them all on a results page and let user choose). With rails I'd probably want to do :status = :moved_permanently I'm guessing? If not found, show a 404. Are there any gems/plugins or tutorials you know of that would handle such a thing, if it's even possible. Or can you explain on a high level how that can be done? I don't need a full code sample, just a push in the right direction. PS. It's a simple rails 3 app that uses a single Content model.

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  • Open source real life license examples: yours or others

    - by donpal
    I'm aware of the usual list of open source licenses, so I'm not even going to list it here. What I'd like to ask is about your open source projects (whether out or planned for the future), and why you're planning to choose a certain license over the other. Basically say I went for X license because I wanted Y and that other license didn't provide it for me. I understand that the language itself can make a difference in the choice of license: interpreted languages like PHP vs. compiled languages like Java. I'm mostly interested in hearing about PHP projects, but of course additional insights are welcome. You may even have chosen that particular language for a licensing reason. Ideally I want to hear answers from people who were involved in the actual project (i.e. your own project), because that usually means you've put some thought into the license yourself and understand the implications of that license. But examples of existing projects that aren't your own are OK. Please just say why you think that license was good/bad for them. But first-hand experience is preferred. Looking forward to hearing some informative input.

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  • Quality of TFS 2008 merged code

    - by paologios
    Does the quality of code merged by TFS 2008 depend on the used programming language? I know merging in Java / Subversion, and merging a branch to its trunk usually does not create much conflicts. Now in my company, we use VB.NET. When I merge two files TFS does not always get code blocks right, e.g. does not find the right If..then / end if lines. To give you an example, I mean: File 2 is created as a branch of File 1. Both files were changed later, now I'm going to merge those files and am recieving conficts: The marked end-if lines (1) are detected as corresponding, meaning the added event handler Button1_Click is being deleted. Now I wonder if this behavior is by language (C# vs. VB.NET) or are other source control solutions just better than TFS? (And I really liked TFS up to now :) ) File 1: Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not Page.IsPostBack Then Label1.Text = "Hello" Label2.Text = "World" End If End Sub Protected Sub Button2_Click(ByVal sender, ByVal e as System.EventArgs) Handles Button2.Click // .... If Page.IsValid Then Label3.Text = "Hello Button 2" End If // .... End Sub File 2 (Branch of File 1): Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not Page.IsPostBack Then fillTableFromDatabase() End If // (1) End Sub Protected Sub Button1_Click(ByVal sender, ByVal e as System.EventArgs) Handles Button1.Click // do something here End Sub Protected Sub Button2_Click(ByVal sender, ByVal e as System.EventArgs) Handles Button2.Click // .... If Page.IsValid Then End If // (1) // .... End Sub

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  • Is there an equivalent for ActiveRecord#find_by equivalent for C#?

    - by Benjamin Manns
    I'm originally a C# developer (as a hobby), but as of late I have been digging into Ruby on Rails and I am really enjoying it. Right now I am building an application in C# and I was wondering if there is any collection implementation for C# that could match (or "semi-match") the find_by method of ActiveRecord. What I am essentially looking for is a list that would hold Rectangles: class Rectangle { public int Width { get; set; } public int Height { get; set; } public String Name { get; set; } } Where I could query this list and find all entries with Height = 10, Width = 20, or name = "Block". This was done with ActiveRecord by doing a call similar to Rectangle.find_by_name('Block'). The only way I can think of doing this in C# is to create my own list implementation and iterate through each item manually checking each item against the criteria. I fear I would be reinventing the wheel (and one of poorer quality). Any input or suggestions is much appreciated.

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  • Why is my user control not instanciated on a postback?

    - by Antoine
    Hi, I'd like to set the trigger of an UpdatePanel to a user control outside the UpdatePanel on the same page . The user control is added at design time, not at runtime. If I statically declare the trigger, I get an error "A control with ID 'xx' cannot be found for the trigger in UpdatePanel". I tried to add the trigger at runtime in Page_Init or Page_Load, but it fails with the user control being null, although it has ViewState enabled. Has someone an idea on how to solve this? Here is the code of the user control: <%@ Control Language="C#" AutoEventWireup="true" CodeFile="ComponentDropDownControl.ascx.cs" Inherits="ComponentDropDownControl" EnableViewState="true" %> <asp:DropDownList ID="ComponentDropDown" runat="server" DataSourceID="ComponentFile" DataTextField="name" DataValueField="name" OnSelectedIndexChanged="ComponentDropDown_SelectedIndexChanged" AutoPostBack="True" EnableTheming="True"> </asp:DropDownList><asp:XmlDataSource ID="ComponentFile" runat="server" DataFile="~/App_Data/Components.xml" XPath="//component"></asp:XmlDataSource> And here it is in the aspx page: <%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="create.aspx.cs" Inherits="create" Title="Create task" %> <%@ Register Src="ComponentDropDownControl.ascx" TagName="ComponentDropDownControl" TagPrefix="uc1" %> ... <uc1:ComponentDropDownControl ID="CustomComponentDropDown" runat="server" EnableViewState="true" /> In the Page_Load function of the aspx page, the following lines work at first time, but fail on the first PostBack (line 2, CustomComponentDropDown is null). AsyncPostBackTrigger trigger = new AsyncPostBackTrigger(); trigger.ControlID = CustomComponentDropDown.UniqueID.ToString(); UpdatePanel1.Triggers.Add(trigger);

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  • Are .NET's regular expressions Turing complete?

    - by Robert
    Regular expressions are often pointed to as the classical example of a language that is not Turning complete. For example "regular expressions" is given in as the answer to this SO question looking for languages that are not Turing complete. In my, perhaps somewhat basic, understanding of the notion of Turning completeness, this means that regular expressions cannot be used check for patterns that are "balanced". Balanced meaning have an equal number of opening characters as closing characters. This is because to do this would require you to have some kind of state, to allow you to match the opening and closing characters. However the .NET implementation of regular expressions introduces the notion of a balanced group. This construct is designed to let you backtrack and see if a previous group was matched. This means that a .NET regular expressions: ^(?<p>a)*(?<-p>b)*(?(p)(?!))$ Could match a pattern that: ab aabb aaabbb aaaabbbb ... etc. ... Does this means .NET's regular expressions are Turing complete? Or are there other things that are missing that would be required for the language to be Turing complete?

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  • Groovy as a substitute for Java when using BigDecimal?

    - by geejay
    I have just completed an evaluation of Java, Groovy and Scala. The factors I considered were: readability, precision The factors I would like to know: performance, ease of integration I needed a BigDecimal level of precision. Here are my results: Java void someOp() { BigDecimal del_theta_1 = toDec(6); BigDecimal del_theta_2 = toDec(2); BigDecimal del_theta_m = toDec(0); del_theta_m = abs(del_theta_1.subtract(del_theta_2)) .divide(log(del_theta_1.divide(del_theta_2))); } Groovy void someOp() { def del_theta_1 = 6.0 def del_theta_2 = 2.0 def del_theta_m = 0.0 del_theta_m = Math.abs(del_theta_1 - del_theta_2) / Math.log(del_theta_1 / del_theta_2); } Scala def other(){ var del_theta_1 = toDec(6); var del_theta_2 = toDec(2); var del_theta_m = toDec(0); del_theta_m = ( abs(del_theta_1 - del_theta_2) / log(del_theta_1 / del_theta_2) ) } Note that in Java and Scala I used static imports. Java: Pros: it is Java Cons: no operator overloading (lots o methods), barely readable/codeable Groovy: Pros: default BigDecimal means no visible typing, least surprising BigDecimal support for all operations (division included) Cons: another language to learn Scala: Pros: has operator overloading for BigDecimal Cons: some surprising behaviour with division (fixed with Decimal128), another language to learn

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  • Does it ever make sense to make a fundamental (non-pointer) parameter const?

    - by Scott Smith
    I recently had an exchange with another C++ developer about the following use of const: void Foo(const int bar); He felt that using const in this way was good practice. I argued that it does nothing for the caller of the function (since a copy of the argument was going to be passed, there is no additional guarantee of safety with regard to overwrite). In addition, doing this prevents the implementer of Foo from modifying their private copy of the argument. So, it both mandates and advertises an implementation detail. Not the end of the world, but certainly not something to be recommended as good practice. I'm curious as to what others think on this issue. Edit: OK, I didn't realize that const-ness of the arguments didn't factor into the signature of the function. So, it is possible to mark the arguments as const in the implementation (.cpp), and not in the header (.h) - and the compiler is fine with that. That being the case, I guess the policy should be the same for making local variables const. One could make the argument that having different looking signatures in the header and source file would confuse others (as it would have confused me). While I try to follow the Principle of Least Astonishment with whatever I write, I guess it's reasonable to expect developers to recognize this as legal and useful.

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  • Why doesn't java.lang.Number implement Comparable?

    - by Julien Chastang
    Does anyone know why java.lang.Number does not implement Comparable? This means that you cannot sort Numbers with Collections.sort which seems to me a little strange. Post discussion update: Thanks for all the helpful responses. I ended up doing some more research about this topic. The simplest explanation for why java.lang.Number does not implement Comparable is rooted in mutability concerns. For a bit of review, java.lang.Number is the abstract super-type of AtomicInteger, AtomicLong, BigDecimal, BigInteger, Byte, Double, Float, Integer, Long and Short. On that list, AtomicInteger and AtomicLong to do not implement Comparable. Digging around, I discovered that it is not a good practice to implement Comparable on mutable types because the objects can change during or after comparison rendering the result of the comparison useless. Both AtomicLong and AtomicInteger are mutable. The API designers had the forethought to not have Number implement Comparable because it would have constrained implementation of future subtypes. Indeed, AtomicLong and AtomicInteger were added in Java 1.5 long after java.lang.Number was initially implemented. Apart from mutability, there are probably other considerations here too. A compareTo implementation in Number would have to promote all numeric values to BigDecimal because it is capable of accommodating all the Number sub-types. The implication of that promotion in terms of mathematics and performance is a bit unclear to me, but my intuition finds that solution kludgy.

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  • iOS: click counter for row in tableview

    - by roger.arliner21
    I am developing and tableView in which in each row I have to display the click counter and row number.Each cell must have an initial click counter value of 0 when application is initialized. Then increment the click counter value within a cell whenever a user clicks on the cell. I have take 26 fixed rows. I have taken tableData.plist file as in the attached image. I am initializing the self.dataArray with the plist . Now I want to do implementation in the didSelectRowAtIndexPath delegate method,if any row is tapped that row's click counter should increment. - (void)viewDidLoad { [super viewDidLoad]; NSString *path = [[NSBundle mainBundle] pathForResource:@"tableData" ofType:@"plist"]; self.dataArray = [NSMutableArray arrayWithContentsOfFile:path];//array initialized with plist } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return [self.dataArray count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *kCustomCellID = @"MyCellID"; UILabel *label1 = [[UILabel alloc] initWithFrame:CGRectMake(160.0f, 2.0f, 30.0f, 20.0f)]; UILabel *label2 = [[UILabel alloc] initWithFrame:CGRectMake(160.0f, 24.0f, 30.0f, 30.0f)]; label2.textColor = [UIColor grayColor]; UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:kCustomCellID]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kCustomCellID] autorelease]; cell.selectionStyle = UITableViewCellSelectionStyleNone; } if([self.dataArray count]>indexPath.row) { label1.text = [[self.dataArray objectAtIndex:indexPath.row] objectForKey:@"Lable1"]; label2.text =[[self.dataArray objectAtIndex:indexPath.row] objectForKey:@"Lable2"]; } else { label1.text = @""; label2.text =@""; } [cell.contentView addSubview:label1]; [cell.contentView addSubview:label2]; [label1 release]; [label2 release]; return cell; } #pragma mark - #pragma mark Table view delegate - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { //implementation for row counter incrementer. }

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