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  • What happens when we combine RAII and GOTO ?

    - by Robert Gould
    I'm wondering, for no other purpose than pure curiosity (because no one SHOULD EVER write code like this!) about how the behavior of RAII meshes with the use of Goto (lovely idea isn't it). class Two { public: ~Two() { printf("2,"); } }; class Ghost { public: ~Ghost() { printf(" BOO! "); } }; void foo() { { Two t; printf("1,"); goto JUMP; } Ghost g; JUMP: printf("3"); } int main() { foo(); } When running the following code in VS2005 I get the following output: 1,2,3 BOO! However I imagined, guessed, hoped that 'BOO!' wouldn't actually appear as the Ghost should have never been instantiated (IMHO, because I don't know the actual expected behavior of this code). Any Guru out there knows what's up? Just realized that if I instantiate an explicit constructor for Ghost the code doesn't compile... class Ghost { public: Ghost() { printf(" HAHAHA! "); } ~Ghost() { printf(" BOO! "); } }; Ah, the mystery ...

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  • Is it possible to defer member initialization to the constructor body?

    - by Kjir
    I have a class with an object as a member which doesn't have a default constructor. I'd like to initialize this member in the constructor, but it seems that in C++ I can't do that. Here is the class: #include <boost/asio.hpp> #include <boost/array.hpp> using boost::asio::ip::udp; template<class T> class udp_sock { public: udp_sock(std::string host, unsigned short port); private: boost::asio::io_service _io_service; udp::socket _sock; boost::array<T,256> _buf; }; template<class T> udp_sock<T>::udp_sock(std::string host = "localhost", unsigned short port = 50000) { udp::resolver res(_io_service); udp::resolver::query query(udp::v4(), host, "spec"); udp::endpoint ep = *res.resolve(query); ep.port(port); _sock(_io_service, ep); } The compiler tells me basically that it can't find a default constructor for udp::socket and by my research I understood that C++ implicitly initializes every member before calling the constructor. Is there any way to do it the way I wanted to do it, or is it too "Java-oriented" and not feasible in C++? I worked around the problem by defining my constructor like this: template<class T> udp_sock<T>::udp_sock(std::string host = "localhost", unsigned short port = 50000) : _sock(_io_service) { udp::resolver res(_io_service); udp::resolver::query query(udp::v4(), host, "spec"); udp::endpoint ep = *res.resolve(query); ep.port(port); _sock.bind(ep); } So my question is more out of curiosity and to better understand OOP in C++

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  • Five unique, random numbers from a subset

    - by tau
    I know similar questions come up a lot and there's probably no definitive answer, but I want to generate five unique random numbers from a subset of numbers that is potentially infinite (maybe 0-20, or 0-1,000,000). The only catch is that I don't want to have to run while loops or fill an array. My current method is to simply generate five random numbers from a subset minus the last five numbers. If any of the numbers match each other, then they go to their respective place at the end of the subset. So if the fourth number matches any other number, it will bet set to the 4th from the last number. Does anyone have a method that is "random enough" and doesn't involve costly loops or arrays? Please keep in mind this a curiosity, not some mission-critical problem. I would appreciate it if everyone didn't post "why are you having this problem?" answers. I am just looking for ideas. Thanks a lot!

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  • Does .Net use Device Dependent or Device Independent Bitmaps?

    - by Brian
    When loading an image into memory, does .Net use DDB, DIB, or something else entirely? If possible, please cite your sources. I'm wondering because we currently have a classic ASP application that is using a 3rd party component to load images that is occasionally creating a “Not enough storage is available to process this command.” error. The error is very inconsistent but tends to happen on larger images (not always, but often). After resetting IIS, processing the same file again typically works just fine. After much research I have found that DDBs tend to have this problem when processing large images because they work out of video memory. Considering that we are running on a web server with an integrated video card and limited shared memory, this could certainly be our problem. We are in the early stages of converting our app to .Net and am wondering if using .Net for this might be a viable alternative to our current method which is why I am asking the question. Any advice is welcome :) but out of curiosity if nothing else, I am really hoping for an answer to the question; does .Net use DDB or DIB?

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  • Initial capacity of collection types, i.e. Dictionary, List

    - by Neil N
    Certain collection types in .Net have an optional "Initial Capacity" constructor param. i.e. Dictionary<string, string> something = new Dictionary<string,string>(20); List<string> anything = new List<string>(50); I can't seem to find what the default initial capacity is for these objects on MSDN. If I know I will only be storing 12 or so items in a dictionary, doesn't it make sense to set the initial capacity to something like 20? My reasoning is, assuming the capacity grows like it does for a StringBuiler, which doubles each time the capacity is hit, and each re-allocation is costly, why not pre-set the size to something you know will hold your data, with some extra room just in case? If the initial capacity is 100, and I know I will only need a dozen or so, it seems as though the rest of that allocated RAM is allocated for nothing. Please spare me the "premature optimization" speil for the O(n^n)th time. I know it won't make my apps any faster or save any meaningful amount of memory, this is mostly out of curiosity.

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  • are C functions declared in <c____> headers gauranteed to be in the global namespace as well as std?

    - by Evan Teran
    So this is something that I've always wondered but was never quite sure about. So it is strictly a matter of curiosity, not a real problem. As far as I understand, what you do something like #include <cstdlib> everything (except macros of course) are declared in the std:: namespace. Every implementation that I've ever seen does this by doing something like the following: #include <stdlib.h> namespace std { using ::abort; // etc.... } Which of course has the effect of things being in both the global namespace and std. Is this behavior guaranteed? Or is it possible that an implementation could put these things in std but not in the global namespace? The only way I can think of to do that would be to have your libstdc++ implement every c function itself placing them in std directly instead of just including the existing libc headers (because there is no mechanism to remove something from a namespace). Which is of course a lot of effort with little to no benefit. The essence of my question is, is the following program strictly conforming and guaranteed to work? #include <cstdio> int main() { ::printf("hello world\n"); }

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  • C#: Non-constructed generics as properties (eg. List<T>)

    - by Dav
    The Problem It's something I came across a while back and was able to work around it somehow. But now it came back, feeding on my curiosity - and I'd love to have a definite answer. Basically, I have a generic dgv BaseGridView<T> : DataGridView where T : class. Constructed types based on the BaseGridView (such as InvoiceGridView : BaseGridView<Invoice>) are later used in the application to display different business objects using the shared functionality provided by BaseGridView (like virtual mode, buttons, etc.). It now became necessary to create a user control that references those constructed types to control some of the shared functionality (eg. filtering) from BaseGridView. I was therefore hoping to create a public property on the user control that would enable me to attach it to any BaseGridView in Designer/code: public BaseGridView<T> MyGridView { get; set; }. The trouble is, it doesn't work :-) When compiled, I get the following message: The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?) Solutions? I realise I could extract the shared functionality to an interface, mark BaseGridView as implementing that interface, and then refer to the created interface in my uesr control. But I'm curious if there exists some arcane C# command/syntax that would help me achieve what I want - without polluting my solution with an interface I don't really need :-)

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  • My project is no longer used - how should I feel?

    - by flybywire
    For the last two years I have been developing and supporting an important project for a big customer. The project included mining data from the customer's existing systems, processing, and displaying and updating in the customer's public home page. The project was defined as crucial by the customer and I was payed good money and flown at the customer's expense to meet key employees. Some months ago, when the project was finished and in maintainance mode, I informed the customer that I am no longer interested in doing it as I had a new opportunity that would not be compatible with my existing customer. I was payed to train one of their employees, flown to meet him, make sure everything works and that he can be safely left in charge of the project. We finished in good terms after I complied with all my obligations and they payed me all they owed me. Some days ago, just out of curiosity, I entered to their website to see how the data continues to be updated and much to my dismay I discovered that the day after my contract was finished my system was "turned off" and it ceased to feed data to the public website. Let's put it clear, there is no issue of money or broken contract here. They are in they full right to do whatever they want with my software. But it is an issue of broken "programmer's ego". Should I feel bad about it (I do). Should I care and check out with my customer if they need some help? Or is it none of my matters?

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  • Efficient way to maintain a sorted list of access counts in Python

    - by David
    Let's say I have a list of objects. (All together now: "I have a list of objects.") In the web application I'm writing, each time a request comes in, I pick out up to one of these objects according to unspecified criteria and use it to handle the request. Basically like this: def handle_request(req): for h in handlers: if h.handles(req): return h return None Assuming the order of the objects in the list is unimportant, I can cut down on unnecessary iterations by keeping the list sorted such that the most frequently used (or perhaps most recently used) objects are at the front. I know this isn't something to be concerned about - it'll make only a miniscule, undetectable difference in the app's execution time - but debugging the rest of the code is driving me crazy and I need a distraction :) so I'm asking out of curiosity: what is the most efficient way to maintain the list in sorted order, descending, by the number of times each handler is chosen? The obvious solution is to make handlers a list of (count, handler) pairs, and each time a handler is chosen, increment the count and resort the list. def handle_request(req): for h in handlers[:]: if h[1].handles(req): h[0] += 1 handlers.sort(reverse=True) return h[1] return None But since there's only ever going to be at most one element out of order, and I know which one it is, it seems like some sort of optimization should be possible. Is there something in the standard library, perhaps, that is especially well-suited to this task? Or some other data structure? (Even if it's not implemented in Python) Or should/could I be doing something completely different?

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  • Preprocessor "macro function" vs. function pointer - best practice?

    - by Dustin
    I recently started a small personal project (RGB value to BGR value conversion program) in C, and I realised that a function that converts from RGB to BGR can not only perform the conversion but also the inversion. Obviously that means I don't really need two functions rgb2bgr and bgr2rgb. However, does it matter whether I use a function pointer instead of a macro? For example: int rgb2bgr (const int rgb); /* * Should I do this because it allows the compiler to issue * appropriate error messages using the proper function name, * not to mention possible debugging benefits? */ int (*bgr2rgb) (const int bgr) = rgb2bgr; /* * Or should I do this since it is merely a convenience * and they're really the same function anyway? */ #define bgr2rgb(bgr) (rgb2bgr (bgr)) I'm not necessarily looking for a change in execution efficiency as it's more of a subjective question out of curiosity. I am well aware of the fact that type safety is neither lost nor gained using either method. Would the function pointer merely be a convenience or are there more practical benefits to be gained of which I am unaware?

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  • Not getting key value from Identity column back after inserting new row with SubSonic ActiveRecord

    - by mikedevenney
    I'm sure I'm missing the obvious answer here, but could use a hand. I'm new to SubSonic and using version 3. I've got myself to the point of being able to query and insert, but I'm stuck with how I would get the value of the identity column back after my insert. I saw another post that mentioned Linq Templates. I'm not using those (at least I don't think I am...?) TIA ... UPDATE ... So I've been debugging through my code watching how the SubSonic code works and I found where the indentity column is being ignored. I use int as the datatype for my ID columns in the database and set them as identity. Since int is a non-nullable data type in c# the logical test in the Add method (public void Add(IDataProvider provider)) that checks if there is a value in the key column by doing a (key==null) could be the issue. The code that gets the new value for the identity field is in the 'true path', since an int can't be null and I use ints as my identity column data types this test will never pass. The ID field for my object has a 0 in it that I didn't put there. I assume it's set during the initialization of the object. Am I off base here? Is the answer to change my data types in the database? Another question (more a curiosity). I noticed that some of the properties in the generated classes are declared with a ? after the datatype. I'm not familiar with this declaration construct... what gives? There are some declared as an int (non key fields) and others that are declared as int? (key fields). Does this have something to do with how they're treated at initialization? Any help is appreciated! --BUMP--

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  • Best way to implement plugin framework - are DLLs the only way (C/C++ project)?

    - by Microkernel
    Introduction: I am currently developing a document classifier software in C/C++ and I will be using Naive-Bayesian model for classification. But I wanted the users to use any algorithm that they want(or I want in the future), hence I went to separate the algorithm part in the architecture as a plugin that will be attached to the main app @ app start-up. Hence any user can write his own algorithm as a plugin and use it with my app. Problem Statement: The way I am intending to develop this is to have each of the algorithms that user wants to use to be made into a DLL file and put into a specific directory. And at the start, my app will search for all the DLLs in that directory and load them. My Questions: (1) What if a malicious code is made as a DLL (and that will have same functions mandated by plugin framework) and put into my plugins directory? In that case, my app will think that its a plugin and picks it and calls its functions, so the malicious code can easily bring down my entire app down (In the worst case could make my app as a malicious code launcher!!!). (2) Is using DLLs the only way available to implement plugin design pattern? (Not only for the fear of malicious plugin, but its a generic question out of curiosity :) ) (3) I think a lot of softwares are written with plugin model for extendability, if so, how do they defend against such attacks? (4) In general what do you think about my decision to use plugin model for extendability (do you think I should look at any other alternatives?) Thank you -MicroKernel :)

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  • What's the difference between the [OptionalField] and [NonSerialized]

    - by IbrarMumtaz
    I came across this question on transcender: What should you apply to a field if its value is not required during deserialization? Me = [NonSerialized], ANSWER = [OptionalField] My gut reaction was NonSerialised, I have no idea why but in the space of 5 seconds thats what I thought but to my surprise, Transcender says I am wrong. OK fair enough .... but why? looking more closely at the question I have a good idea what to look out for as far as the [Nonseralized] attribute is concerned but still I would really like this clearing up. As far as I can tell the former has relationship with versioning conflicts between newer and older versions of the same assembly. The later is more concerned with not serializing a field FULLSTOP. Is there anything else that might pick these two apart? MSDN does not really say much about this as they both are used on the BinaryFormatters and SoapFormatter with the XMLFormatter using the XMLIgnoreAttribute. My second question is can you mix and match either one of the two attributes ... I am yet to use them as I have not had an excuse to mess about with them. So my curiosity can only go so far. Just throwing this one out there, but does my answer have something to do with the way [OnDeserialized] and the IdeserilizationCallback interface is implemented???? Am guessing here .... Thanks In Advance UPDATE: I know that optional field attribute does not serialize the value held by a data member but NonSerialized will not even serialise the data member or its value. That sounds about a right???? That's all I got on these two attributes.

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  • Using an embedded DB (SQLite / SQL Compact) for Message Passing within an app?

    - by wk1989
    Hello, Just out of curiosity, for applications that have a fairly complicated module tree, would something like sqlite/sql compact edition work well for message passing? So if I have modules containing data such as: \SubsystemA\SubSubSysB\ModuleB\ModuleDataC, \SubSystemB\SubSubSystemC\ModuleA\ModuleDataX Using traditional message passing/routing, you have to go through intermediate modules in order to pass a message to ModuleB to request say ModuleDataC. Instead of doing that, if we we simply store "\SubsystemA\SubSubSysB\ModuleB\ModuleDataC" in a sqlite database, getting that data is as simple as a sql query and needs no routing and passing stuff around. Has anyone done this before? Even if you haven't, do you foresee any issues & performance impact? The only concern I have right now would be the passing of custom types, e.g. if ModuleDataC is a custom data structure or a pointer, I'll need some way of storing the data structure into the DB or storing the pointer into the DB. Thanks, JW EDIT One usage case I haven't thought about is when you want to send a message from ModuleA to ModuleB to get ModuleB to do something rather than just getting/setting data. Is it possible to do this using an embedded DB? I believe callback from the DB would be needed, how feasible is this?

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  • Preprocessor #define vs. function pointer - best practice?

    - by Dustin
    I recently started a small personal project (RGB value to BGR value conversion program) in C, and I realised that a function that converts from RGB to BGR can not only perform the conversion but also the inversion. Obviously that means I don't really need two functions rgb2bgr and bgr2rgb. However, does it matter whether I use a function pointer instead of a macro? For example: int rgb2bgr (const int rgb); /* * Should I do this because it allows the compiler to issue * appropriate error messages using the proper function name, * not to mention possible debugging benefits? */ int (*bgr2rgb) (const int bgr) = rgb2bgr; /* * Or should I do this since it is merely a convenience * and they're really the same function anyway? */ #define bgr2rgb(bgr) (rgb2bgr (bgr)) I'm not necessarily looking for a change in execution efficiency as it's more of a subjective question out of curiosity. I am well aware of the fact that type safety is neither lost nor gained using either method. Would the function pointer merely be a convenience or are there more practical benefits to be gained of which I am unaware?

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  • C++, generic programming and virtual functions. How do I get what I want?

    - by carleeto
    This is what I would like to do using templates: struct op1 { virtual void Method1() = 0; } ... struct opN { virtual void MethodN() = 0; } struct test : op1, op2, op3, op4 { virtual void Method1(){/*do work1*/}; virtual void Method2(){/*do work2*/}; virtual void Method3(){/*do work3*/}; virtual void Method4(){/*do work4*/}; } I would like to have a class that simply derives from a template class that provides these method declarations while at the same time making them virtual. This is what I've managed to come up with: #include <iostream> template< size_t N > struct ops : ops< N - 1 > { protected: virtual void DoStuff(){ std::cout<<N<<std::endl; }; public: template< size_t i > void Method() { if( i < N ) ops<i>::DoStuff(); } //leaving out compile time asserts for brevity } struct test : ops<6> { }; int main( int argc, char ** argv ) { test obj; obj.Method<3>(); //prints 3 return 0; } However, as you've probably guessed, I am unable to override any of the 6 methods I have inherited. I'm obviously missing something here. What is my error? No, this isn't homework. This is curiosity.

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  • Using "margin: 0 auto;" in Internet Explorer 8

    - by stusmith
    I'm in the process of doing some advance IE8 testing, and it seems that the old technique of using "margin: 0 auto;" doesn't work in all cases in IE8. The following piece of HTML gives a centered button in FF3, Opera, Safari, Chrome, IE7, and IE8 compat, but NOT in IE8 standard: <div style="height: 500px; width: 500px; background-color: Yellow;"> <input type="submit" style="display: block; margin: 0 auto;" /> </div> (As a work-around I can add an explicit width to the button). So the question is: which browsers are correct? Or is this one of those cases where the behaviour is undefined? (My thinking is that all the browsers are incorrect - shouldn't the button be 100% width if it's "display: block"?) UPDATE: I'm being a dunce. Since input isn't a block-level element, I should have just contained it within a div with "text-align: center". Having said that, for curiosity's sake, I'd still like to know whether the button should or shouldn't be centered in the example above. FOR THE BOUNTY: I know I'm doing odd things in the example, and as I point out in the update, I should have just aligned it center. For the bounty, I'd like references to the specs that answer: If I set "display: block", should the button be width 100%? Or is this undefined? Since the display is block, should "margin: 0 auto;" center the button, or not, or undefined?

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  • How to defer execution of an Event on each item in a collection until iteration of collection is com

    - by Metro Smurf
    Of Note: This is more of a curiosity question than anything else. Given a List<Window> where each window has an event attached to the Close Event which removes the window from the collection, how could you use delegates / events to defer the execution of the Close Event until the collection has been iterated? For example: public class Foo { private List<Window> OpenedWindows { get; set; } public Foo() { OpenedWindows = new List<Window>(); } public void AddWindow( Window win ) { win.Closed += OnWindowClosed; OpenedWindows.Add( win ); } void OnWindowClosed( object sender, EventArgs e ) { var win = sender as Window; if( win != null ) { OpenedWindows.Remove( win ); } } void CloseAllWindows() { // obviously will not work because we can't // remove items as we iterate the collection // (the close event removes the window from the collection) OpenedWindows.ForEach( x => x.Close() ); // works fine, but would like to know how to do // this with delegates / events. while( OpenedWindows.Any() ) { OpenedWindows[0].Close(); } } } Specifically, within the CloseAllWindows() method, how could you iterate the collection to call the close event, but defer the event being raised until the collection has been completely iterated?

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  • Serialization for memcached

    - by Ram
    I have this huge domain object(say parent) which contains other domain objects. It takes a lot of time to "create" this parent object by querying a DB (OK we are optimizing the DB). So we decided to cache it using memcached (with northscale to be specific) So I have gone through my code and marked all the classes (I think) as [Serializable], but when I add it to the cache, I see a Serialization Exception getting thrown in my VS.net output window. var cache = new NorthScaleClient("MyBucket"); cache.Store(StoreMode.Set, key, value); This is the exception: A first chance exception of type 'System.Runtime.Serialization.SerializationException' occurred in mscorlib.dll SO my guess is, I have not marked all classes as [Serializable]. I am not using any third party libraries and can mark any class as [Serializable], but how do I find out which class is failing when the cache is trying to serialize the object ? Edit1: casperOne comments make me think. I was able to cache these domain object with Microsoft Cache Application Block without marking them [Serializable], but not with NorthScale memcached. It makes me think that there might be something to do with their implementation, but just out of curiosity, am still interested in finding where it fails when trying to add the object to memcached

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  • 20 lines of code you're working on right now [closed]

    - by Anton Gogolev
    Out of sheer curiosity. Hope none of you NDAs are violated or whatever. Here are mine. I'm currently refactoring a massively coupled webapp. As it usually is, no comments and no documentation whatsoever. if (paymentMethod == PaymentMethod.InAgency ) { EmailController.SendBookingCreateEmails(booking); this.DC.SubmitChanges(); return RedirectToAction("Result", new { id = booking.Id }); } else if (paymentMethod == PaymentMethod.CreditCard) { return RedirectToAction("Pay", new { id = booking.Id }); } else if(paymentMethod == PaymentMethod.MostravelBank || paymentMethod == PaymentMethod.MostravelCallback || paymentMethod == PaymentMethod.MostravelCardCredit || paymentMethod == PaymentMethod.MostravelCourierCash || paymentMethod == PaymentMethod.MostravelCourierPlasticCard) { isExclusive = true; Log.TraceInformation("Started booking for Mostravel. Payment method: {0}", paymentMethod); try { Log.TraceInformation("Sending emails"); EmailController.SendBookingCreateEmailsEx(booking); Log.TraceInformation("Sent emails. Started booking"); MakeRealBooking(booking, DC.MailRuAgencies.First(a => a.Id == MvcApplication.DefaultMailRuAgencyId)); Log.TraceInformation("Finished booking"); } catch(Exception ex) { Log.TraceEvent(TraceEventType.Error, 0, "Error while booking: {0}", ex.ToString()); } What are you working on right now?

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  • Vim: How do I tell where a function is defined? (

    - by sixtyfootersdude
    I just installed macvim yesterday and I installed vim latex today. One of the menu items is calling a broken fuction (TeX-Suite -> view). When I click on the menu-time it makes this call: :silent! call Tex_ViewLatex() Question: Where can I find that function? Is there some way to figure out where it is defined? Just for curiosity sake I removed the silent part and ran this: :call Tex_ViewLatex() Which produces: Error detected while processing function Tex_ViewLaTeX: line 34: E121: Undefined variable: s:viewer E116: Invalid arguments for function strlen(s:viewer) E15: Invalid expression: strlen(s:viewer) line 39: E121: Undefined variable: appOpt E15: Invalid expression: 'open '.appOpt.s:viewer.' $*.'.s:target line 79: E121: Undefined variable: execString E116: Invalid arguments for function substitute(execString, '\V$*', mainfname, 'g' ) E15: Invalid expression: substitute(execString, '\V$*', mainfname, 'g') line 80: E121: Undefined variable: execString E116: Invalid arguments for function Tex_Debug line 82: E121: Undefined variable: execString E15: Invalid expression: 'silent! !'.execString Press ENTER or type command to continue I suspect that if I could see the source function I could figure out what inputs are bad or what it is looking for. Thanks.

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  • What are the best websites/web applications for specific languages?

    - by JM4
    Browsing around Stackoverflow, I get overwhelmed with the number of "Why should I learn Python/Ruby/PHP/.Net/jQuery..." and the list goes on. Most answers, although good, are usually battles from language A programmer to language B programmer detailing why one piece sucks more than another. People can discuss the theoretical benefits of one over another but in the end, money/glitz talks and the rest walks. I am more interested in the potential opportunity that can come from one language or another over others. A little background, I am a project manager turned novice 'programmer' out of corporate necessity within the small company I currently work with so I have both relatively no set preference or experience, more out of curiosity. While I realize all are not created equal and for similar things, I think it would be interesting to start a list of the best websites / web applications built on specific languages/frameworks just to highlight the possibilities with each and give somebody like me motivation to say "How the heck was that done? Time to buy a book/take a class and learn." Tell me and I will forget, Show me and I will learn, Involve me and I will understand - Teton Lakota

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  • Retrieving an element by array index in jQuery vs the each() function.

    - by Alex Ciminian
    I was writing a "pluginable" function when I noticed the following behavior (tested in FF 3.5.9 with Firebug 1.5.3). $.fn.computerMove = function () { var board = $(this); var emptySquares = board.find('div.clickable'); var randPosition = Math.floor(Math.random() * emptySquares.length); emptySquares.each(function (index) { if (index === randPosition) { // logs a jQuery object console.log($(this)); } }); target = emptySquares[randPosition]; // logs a non-jQuery object console.log(target); // throws error: attr() not a function for target board.placeMark({'position' : target.attr('id')}); } I noticed the problem when the script threw an error at target.attr('id') (attr not a function). When I checked the log, I noticed that the output (in Firebug) for target was: <div style="width: 97px; height: 97px;" class="square clickable" id="8"></div> If I output $(target), or $(this) from the each() function, I get a nice jQuery object: [ div#8.square ] Now here comes my question: why does this happen, considering that find() seems to return an array of jQuery objects? Why do I have to do $() to target all over again? [div#0.square, div#1.square, div#2.square, div#3.square, div#4.square, div#5.square, div#6.square, div#7.square, div#8.square] Just a curiosity :).

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  • Change Default Winform Icon Across Entire App

    - by Kyle Gagnet
    Can I change the default icon used on a Winform? Most of my forms have their icon property set to a custom icon. For the few forms that slip through the cracks, I don't want the generic "hey look, he made this in visual studio" icon. One solution is to tediously check every one of my forms to make sure they either have a custom icon set or have ShowIcon set to False. Another solution is to have every one of my forms inherit from a base class that sets a custom icon in the constructor. Aside from those solutions, what other options do I have? EDIT: I was hoping there would be a way to replace the source of the stock icon with my own. Is it in a resource file somewhere? Or is it embedded in a .NET dll that I can't (or really, really shouldn't) modify? BOUNTY EDIT: Is there a way to accomplish this without editing or writing a single line of code? I don't care how impractical, complicated, waste-of-time the solution is... I just want to know if it's possible. I need to satisfy my curiosity.

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  • yet another logic.

    - by Sunil
    I'm working on a research problem out of curiosity and I don't know how to program the logic that I've in mind. Let me explain it to you : I've 4 vectors say for example, v1 = 1 1 1 1 v2 = 2 2 2 2 v3 = 3 3 3 3 v4 = 4 4 4 4 Now what I want to do is to add them combination-wise. i.e v12 = v1+v2 v13 = v1+v3 v14 = v1+v4 v23 = v2+v3 v24 = v2+v4 v34 = v3+v4 Till this step it is just fine. The problem/trick is now, at the end of each iteration I give the obtained vectors into a black box function and it returns only few of the vectors say v12, v13 and v34. Now, I want to add each of these vectors one vector from v1,v2,v3,v4 which it hasn't added before. For example v3 and v4 hasn't been added to v12 so I want to create v123 and v124. similarly for all the vectors like, v12 should become : v123 = v12+v3 v124 = v12+v4 v13 should become : v132 // this should not occur because I already have v123 v134 = v13+v4; v14,v23 and v24 cannot be considered because it was deleted in the black box function so all we have in our hands to work with is v12,v13 and v34. v34 should become : v341 // cannot occur because we have 134 v342 = v34+v2 It is important that I do not do all at one step at the start like for example I can do (4 choose 3) 4C3 and finish it off but I want to do it step by step at each iteration. I've asked a modified version of this question before (without including the black box function) and got answers here. Can anybody tell me how to do it when the black box function is included ? A modification of the previous answer would also be great. Thanks in advance.

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