Search Results

Search found 22900 results on 916 pages for 'pascal case'.

Page 190/916 | < Previous Page | 186 187 188 189 190 191 192 193 194 195 196 197  | Next Page >

  • C# naming convention for enum and matching property

    - by Serge - appTranslator
    Hi All, I often find myself implementing a class maintaining some kind of own status property as an enum: I have a Status enum and ONE Status property of Status type. How should I solve this name conflict? public class Car { public enum Status { Off, Starting, Moving }; Status status = Status.Off; public Status Status // <===== Won't compile ===== { get { return status; } set { status = value; DoSomething(); } } } If the Status enum were common to different types, I'd put it outside the class and the problem would be solved. But Status applies to Car only hence it doesn't make sense to declare the enum outside the class. What naming convention do you use in this case? NB: This question was partially debated in comments of an answer of this question. Since it wasn't the main question, it didn't get much visibility. EDIT: Filip Ekberg suggests an IMO excellent workaround for the specific case of 'Status'. Yet I'd be interesting to read about solutions where the name of the enum/property is different, as in Michael Prewecki's answer. EDIT2 (May 2010): My favorite solution is to pluralize the enum type name, as suggested by Chris S. According to MS guidelines, this should be used for flag enums only. But I've come to like it more and more. I now use it for regular enums as well.

    Read the article

  • Why does my IMultiBindingConverter get an array of strings when used to set TextBox.Text?

    - by mcohen75
    Hi- I'm trying to use a MultiBinding with a converter where the child elements also have a converter. The XAML looks like so: <TextBlock> <TextBlock.Text> <MultiBinding Converter="{StaticResource localizedMessageConverter}" ConverterParameter="{x:Static res:Resources.RecordsFound}" > <Binding Converter="{StaticResource localizedMessageParameterConverter}" ConverterParameter="ALIAS" Path="Alias" Mode="OneWay" /> <Binding Converter="{StaticResource localizedMessageParameterConverter}" ConverterParameter="COUNT" Path="Count" Mode="OneWay" /> </MultiBinding> </TextBlock.Text> The problem I'm facing here is, whenever this is used with a TextBlock to specify the Text property, my IMultiValueConverter implementation gets an object collection of strings instead of the class returned by the IValueConverter. It seems that the ToString() method is called on the result of the inner converter and passed to the IMultiValueConverter. If used to specify the Content property of Label, all is well. It seems to me that the framework is assuming that the return type will be string, but why? I can see this for the MultiBinding since it should yield a result that is compatible with TextBlock.Text, but why would this also be the case for the Bindings inside a MultiBinding? If I remove the converter from the inner Binding elements, the native types are returned. In my case string and int.

    Read the article

  • How can I work around the fact that in C++, sin(M_PI) is not 0?

    - by Adam Doyle
    In C++, const double Pi = 3.14159265; cout << sin(Pi); // displays: 3.58979e-009 it SHOULD display the number zero I understand this is because Pi is being approximated, but is there any way I can have a value of Pi hardcoded into my program that will return 0 for sin(Pi)? (a different constant maybe?) In case you're wondering what I'm trying to do: I'm converting polar to rectangular, and while there are some printf() tricks I can do to print it as "0.00", it still doesn't consistently return decent values (in some cases I get "-0.00") The lines that require sin and cosine are: x = r*sin(theta); y = r*cos(theta); BTW: My Rectangular - Polar is working fine... it's just the Polar - Rectangular Thanks! edit: I'm looking for a workaround so that I can print sin(some multiple of Pi) as a nice round number to the console (ideally without a thousand if-statements) edit: In case anyone's curious, this was what I landed on: double sin2(double theta) // in degrees { double s = sin(toRadians(theta)); if (fabs(s - (int)s) < 0.000001) { return floor(s + 0.5); } return s; } where toRadians() is a macro that converts to radians

    Read the article

  • Is a red-black tree my ideal data structure?

    - by Hugo van der Sanden
    I have a collection of items (big rationals) that I'll be processing. In each case, processing will consist of removing the smallest item in the collection, doing some work, and then adding 0-2 new items (which will always be larger than the removed item). The collection will be initialised with one item, and work will continue until it is empty. I'm not sure what size the collection is likely to reach, but I'd expect in the range 1M-100M items. I will not need to locate any item other than the smallest. I'm currently planning to use a red-black tree, possibly tweaked to keep a pointer to the smallest item. However I've never used one before, and I'm unsure whether my pattern of use fits its characteristics well. 1) Is there a danger the pattern of deletion from the left + random insertion will affect performance, eg by requiring a significantly higher number of rotations than random deletion would? Or will delete and insert operations still be O(log n) with this pattern of use? 2) Would some other data structure give me better performance, either because of the deletion pattern or taking advantage of the fact I only ever need to find the smallest item? Update: glad I asked, the binary heap is clearly a better solution for this case, and as promised turned out to be very easy to implement. Hugo

    Read the article

  • How to read spring-application-context.xml and AnnotationConfigWebApplicationContext both in spring mvc

    - by Suvasis
    In case I want to read bean definitions from spring-application-context.xml, I would do this in web.xml file. <context-param> <param-name>contextConfigLocation</param-name> <param-value> /WEB-INF/applicationContext.xml </param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> In case I want to read bean definitions through Java Configuration Class (AnnotationConfigWebApplicationContext), I would do this in web.xml <servlet> <servlet-name>appServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextClass</param-name> <param-value> org.springframework.web.context.support.AnnotationConfigWebApplicationContext </param-value> </init-param> <init-param> <param-name>contextConfigLocation</param-name> <param-value> org.package.MyConfigAnnotatedClass </param-value> </init-param> </servlet> How do I use both in my application. like reading beans from both configuration xml file and annotated class. Is there a way to load spring beans in xml file while we are using AppConfigAnnotatedClass to instantiate/use rest of the beans.

    Read the article

  • Test multiple domains using ASP.NET development server

    - by Pete Lunenfeld
    I am developing a single web application that will dynamically change its content depending on which domain name is used to reach the site. Multiple domains will point to the same application. I wish to use the following code (or something close) to detect the domain name and perform the customizations: string theDomainName = Request.Url.Host; switch (theDomainName) { case "www.clientone.com": // do stuff break; case "www.clienttwo.com": // do other stuff break; } I would like to test the functionality of the above using the ASP.NET development server. I created mappings in the local HOSTS file to map www.clientone.com to 127.0.0.1, and www.clienttwo.com to 127.0.0.1. I then browse to the application with the browser using www.clinetone.com (etc). When I try to test this code using the ASP.net development server the URL always says localhost. It does NOT capture the host entered in the browser, only localhost. Is there a way to test the URL detection functionality using the development server? Thanks.

    Read the article

  • Combine regular expressions for splitting camelCase string into words

    - by stou
    I managed to implement a function that converts camel case to words, by using the solution suggested by @ridgerunner in this question: Split camelCase word into words with php preg_match (Regular Expression) However, I want to also handle embedded abreviations like this: 'hasABREVIATIONEmbedded' translates to 'Has ABREVIATION Embedded' I came up with this solution: <?php function camelCaseToWords($camelCaseStr) { // Convert: "TestASAPTestMore" to "TestASAP TestMore" $abreviationsPattern = '/' . // Match position between UPPERCASE "words" '(?<=[A-Z])' . // Position is after group of uppercase, '(?=[A-Z][a-z])' . // and before group of lowercase letters, except the last upper case letter in the group. '/x'; $arr = preg_split($abreviationsPattern, $camelCaseStr); $str = implode(' ', $arr); // Convert "TestASAP TestMore" to "Test ASAP Test More" $camelCasePattern = '/' . // Match position between camelCase "words". '(?<=[a-z])' . // Position is after a lowercase, '(?=[A-Z])' . // and before an uppercase letter. '/x'; $arr = preg_split($camelCasePattern, $str); $str = implode(' ', $arr); $str = ucfirst(trim($str)); return $str; } $inputs = array( 'oneTwoThreeFour', 'StartsWithCap', 'hasConsecutiveCAPS', 'ALLCAPS', 'ALL_CAPS_AND_UNDERSCORES', 'hasABREVIATIONEmbedded', ); echo "INPUT"; foreach($inputs as $val) { echo "'" . $val . "' translates to '" . camelCaseToWords($val). "'\n"; } The output is: INPUT'oneTwoThreeFour' translates to 'One Two Three Four' 'StartsWithCap' translates to 'Starts With Cap' 'hasConsecutiveCAPS' translates to 'Has Consecutive CAPS' 'ALLCAPS' translates to 'ALLCAPS' 'ALL_CAPS_AND_UNDERSCORES' translates to 'ALL_CAPS_AND_UNDERSCORES' 'hasABREVIATIONEmbedded' translates to 'Has ABREVIATION Embedded' It works as intended. My question is: Can I combine the 2 regular expressions $abreviationsPattern and camelCasePattern so i can avoid running the preg_split() function twice?

    Read the article

  • Can Haskell's Parsec library be used to implement a recursive descent parser with backup?

    - by Thor Thurn
    I've been considering using Haskell's Parsec parsing library to parse a subset of Java as a recursive descent parser as an alternative to more traditional parser-generator solutions like Happy. Parsec seems very easy to use, and parse speed is definitely not a factor for me. I'm wondering, though, if it's possible to implement "backup" with Parsec, a technique which finds the correct production to use by trying each one in turn. For a simple example, consider the very start of the JLS Java grammar: Literal: IntegerLiteral FloatingPointLiteral I'd like a way to not have to figure out how I should order these two rules to get the parse to succeed. As it stands, a naive implementation like this: literal = do { x <- try (do { v <- integer; return (IntLiteral v)}) <|> (do { v <- float; return (FPLiteral v)}); return(Literal x) } Will not work... inputs like "15.2" will cause the integer parser to succeed first, and then the whole thing will choke on the "." symbol. In this case, of course, it's obvious that you can solve the problem by re-ordering the two productions. In the general case, though, finding things like this is going to be a nightmare, and it's very likely that I'll miss some cases. Ideally, I'd like a way to have Parsec figure out stuff like this for me. Is this possible, or am I simply trying to do too much with the library? The Parsec documentation claims that it can "parse context-sensitive, infinite look-ahead grammars", so it seems like something like I should be able to do something here.

    Read the article

  • SQL Server Index cost

    - by yellowstar
    I have read that one of the tradeoffs for adding table indexes in SQL Server is the increased cost of insert/update/delete queries to benefit the performance of select queries. I can conceptually understand what happens in the case of an insert because SQL Server has to write entries into each index matching the new rows, but update and delete are a little more murky to me because I can't quite wrap my head around what the database engine has to do. Let's take DELETE as an example and assume I have the following schema (pardon the pseudo-SQL) TABLE Foo col1 int ,col2 int ,col3 int ,col4 int PRIMARY KEY (col1,col2) INDEX IX_1 col3 INCLUDE col4 Now, if I issue the statement DELETE FROM Foo WHERE col1=12 AND col2 > 34 I understand what the engine must do to update the table (or clustered index if you prefer). The index is set up to make it easy to find the range of rows to be removed and do so. However, at this point it also needs to update IX_1 and the query that I gave it gives no obvious efficient way for the database engine to find the rows to update. Is it forced to do a full index scan at this point? Does the engine read the rows from the clustered index first and generate a smarter internal delete against the index? It might help me to wrap my head around this if I understood better what is going on under the hood, but I guess my real question is this. I have a database that is spending a significant amount of time in delete and I'm trying to figure out what I can do about it. When I display the execution plan for the deletion, it just shows an entry for "Clustered Index Delete" on table Foo which lists in the details section the other indices that need to be updated but I don't get any indication of the relative cost of these other indices. Are they all equal in this case? Is there some way that I can estimate the impact of removing one or more of these indices without having to actually try it?

    Read the article

  • What is faster- Java or C# (Or good old C)?

    - by Rexsung
    I'm currently deciding on a platform to build a scientific computational product on, and am deciding on either C#, Java, or plain C with Intels compiler on Core2 Quad CPU's. It's mostly integer arithmetic. My benchmarks so far show Java and C are about on par with each other, and dotNET/C# trails by about 5%- however a number of my coworkers are claiming that dotNET with the right optimizations will beat both of these given enough time for the JIT to do its work. I always assume that the JIT would have done it's job within a few minutes of the app starting (Probably a few seconds in my case, as it's mostly tight loops), so I'm not sure whether to believe them Can anyone shed any light on the situation? Would dotNET beat Java? (Or am I best just sticking with C at this point?). The code is highly multithreaded and data sets are several terabytes in size. Haskell/erlang etc are not options in this case as there is a significant quantity of existing legacy C code that will be ported to the new system, and porting C to Java/C# is a lot simpler than to Haskell or Erlang. (Unless of course these provide a significant speedup). Edit: We are considering moving to C# or Java because they may, in theory, be faster. Every percent we can shave off our processing time saves us tens of thousands of dollars per year. At this point we are just trying to evaluate whether C, Java, or c# would be faster.

    Read the article

  • Serializing a part of object graph

    - by Felix
    Hi all, I have a problem regarding Java custom serialization. I have a graph of objects and want to configure where to stop when I serialize a root object from client to server. Let's make it a bit concrete, clear by giving a sample scenario. I have Classes of type Company Employee (abstract) Manager extends Employee Secretary extends Employee Analyst extends Employee Project Here are the relations: Company(1)---(n)Employee Manager(1)---(n)Project Analyst(1)---(n)Project Imagine, I'm on the client side and I want to create a new company, assign it 10 employees (new or some existing) and send this new company to the server. What I expect in this scenario is to serialize the company and all bounding employees to the server side, because I'll save the relations on the database. So far no problem, since the default Java serialization mechanism serializes the whole object graph, excluding the field which are static or transient. My goal is about the following scenario. Imagine, I loaded a company and its 1000 employees from the server to the client side. Now I only want to rename the company's name (or some other field, that directly belongs to the company) and update this record. This time, I want to send only the company object to the server side and not the whole list of employees (I just update the name, the employees are in this use case irrelevant). My aim also includes the configurability of saying, transfer the company AND the employees but not the Project-Relations, you must stop there. Do you know any possibility of achieving this in a generic way, without implementing the writeObject, readObject for every single Entity-Object? What would be your suggestions? I would really appreciate your answers. I'm open to any ideas and am ready to answer your questions in case something is not clear.

    Read the article

  • Can't start the portable version of NetBeans 6.9.1 IDE

    - by Coder
    I downloaded the portable version of netbeans netbeans-6.9.1-201007282301-ml.zip from the netbeans site and changed the config file in etc/netbeans.conf as indicated on the netbeans site. The file contents are below. # ${HOME} will be replaced by JVM user.home system property #netbeans_default_userdir="${HOME}/.netbeans/6.9" netbeans_default_userdir=".netbeans/6.9" # Options used by NetBeans launcher by default, can be overridden by explicit # command line switches: netbeans_default_options="-J-client -J-Xss2m -J-Xms32m -J-XX:PermSize=32m -J-XX:MaxPermSize=200m -J-Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -J-Dsun.java2d.noddraw=true" # Note that a default -Xmx is selected for you automatically. # You can find this value in var/log/messages.log file in your userdir. # The automatically selected value can be overridden by specifying -J-Xmx here # or on the command line. # If you specify the heap size (-Xmx) explicitely, you may also want to enable # Concurrent Mark & Sweep garbage collector. In such case add the following # options to the netbeans_default_options: # -J-XX:+UseConcMarkSweepGC -J-XX:+CMSClassUnloadingEnabled -J-XX:+CMSPermGenSweepingEnabled # (see http://wiki.netbeans.org/wiki/view/FaqGCPauses) # Default location of JDK, can be overridden by using --jdkhome <dir>: #netbeans_jdkhome="/path/to/jdk" netbeans_jdkhome="C:\Program Files\Java\jdk1.6.0_24\" # Additional module clusters, using ${path.separator} (';' on Windows or ':' on Unix): #netbeans_extraclusters="/absolute/path/to/cluster1:/absolute/path/to/cluster2" # If you have some problems with detect of proxy settings, you may want to enable # detect the proxy settings provided by JDK5 or higher. # In such case add -J-Djava.net.useSystemProxies=true to the netbeans_default_options. But it refuses to start when i try to run it. If i change the JDK path to something incorrect it complains that it can't find the jdk so i think the jdk path is correct. It also creates a .netbeans directory when i try to start it. I don't see any errors and it just doesn't do anything else observable. Does anybody know how to set up this version of netbeans? Thanks.

    Read the article

  • NSPredicate as a constraint solver?

    - by Felixyz
    I'm working on a project which includes some slightly more complex dynamic layout of interface elements than what I'm used to. I always feel stupid writing complex code that checks if so-and-so is close to such-and-such and in that case move it x% in some direction, etc. That's just not how programming should be done. Programming should be as declarative as possible! Precisely because what I'm going to do is fairly simple, I thought it would be a good opportunity to try something new, and I thought of using NSPredicate as a simple constraints solver. I've only used NSPredicate for very simple tasks so far, but I know that it capable of much more. Are there any ideas, experiences, examples, warnings, insights that could be useful here? I'll give a very simple example so there will be something concrete to answer. How could I use NSPredicate to solve the following constraints: viewB.xmid = (viewB.leftEdge + viewB.width) / 2 viewB.xmid = max(300, viewA.rightEdge + 20 + viewB.width/2) ("viewB should be horizontally centered on coordinate 300, unless its left edge gets within 20 pixels of viewB's right edge, in which case viewA's left edge should stay fixed at 20 pixels to the right of viewB's right edge and viewA's horizontal center get pushed to the right.") viewA.rightEdge and viewB.width can vary, and those are the 'input variables'. EDIT: Any solution would probably have to use the NSExpression method -(id)expressionValueWithObject:(id)object context:(NSMutableDictionary *)context. This answer is relevant.

    Read the article

  • Changing CSS Rules using JavaScript or jQuery

    - by Praveen Kumar
    Initial Research I am aware of using .css() to get and set the CSS rules of a particular element. I have seen a website with this CSS: body, table td, select { font-family: Arial Unicode MS, Arial, sans-serif; font-size: small; } I never liked Arial Unicode as a font. Well, that was my personal feel. So, I would use Chrome's Style Inspector to edit the Arial Unicode MS to Segoe UI or something which I like. Is there anyway, other than using the following to achieve the same? Case I $("body, table td, select").css("font-family", "Segoe UI"); Recursive, performance intensive. Doesn't work when things are loaded on the fly. Case II $('<style>body, table td, select {font-famnily: "Segoe UI";}</style>') .appendTo("head"); Any other better method than this? Creates a lot of <style> tags!

    Read the article

  • Delphi 6 OleServer.pas Invoke memory leak

    - by Mike Davis
    There's a bug in delphi 6 which you can find some reference online for when you import a tlb the order of the parameters in an event invocation is reversed. It is reversed once in the imported header and once in TServerEventDIspatch.Invoke. you can find more information about it here: http://cc.embarcadero.com/Item/16496 somewhat related to this issue there appears to be a memory leak in TServerEventDispatch.Invoke with a parameter of a Variant of type Var_Array (maybe others, but this is the more obvious one i could see). The invoke code copies the args into a VarArray to be passed to the event handler and then copies the VarArray back to the args after the call, relevant code pasted below: // Set our array to appropriate length SetLength(VarArray, ParamCount); // Copy over data for I := Low(VarArray) to High(VarArray) do VarArray[I] := OleVariant(TDispParams(Params).rgvarg^[I]); // Invoke Server proxy class if FServer <> nil then FServer.InvokeEvent(DispID, VarArray); // Copy data back for I := Low(VarArray) to High(VarArray) do OleVariant(TDispParams(Params).rgvarg^[I]) := VarArray[I]; // Clean array SetLength(VarArray, 0); There are some obvious work-arounds in my case: if i skip the copying back in case of a VarArray parameter it fixes the leak. to not change the functionality i thought i should copy the data in the array instead of the variant back to the params but that can get complicated since it can hold other variants and seems to me that would need to be done recursively. Since a change in OleServer will have a ripple effect i want to make sure my change here is strictly correct. can anyone shed some light on exactly why memory is being leaked here? I can't seem to look up the callstack any lower than TServerEventDIspatch.Invoke (why is that?) I imagine that in the process of copying the Variant holding the VarArray back to the param list it added a reference to the array thus not allowing it to be release as normal but that's just a rough guess and i can't track down the code to back it up. Maybe someone with a better understanding of all this could shed some light?

    Read the article

  • Copying a directory that is version controlled

    - by ibz
    I am curious whether it is OK to copy a directory that is under version control and start working on both copies. I know it can be different from one VCS to another, but I intentionally don't specify any VCS since I am curious about different cases. I was talking to a coworker recently about doing it in SVN. I think it should be OK, but I am still not 100% sure, since I don't know what exactly SVN is storing in the working copy. However, if we talk about the DVCS world, things might be even more unclear, since every working copy is a repository by itself. Being faced with doing this in bzr now, I decided to ask the question. Later edit: Some people asked why I would want to do that. Here is the whole story: In the case of SVN it was because being out of the office, the connection to the SVN server was really slow, so me and my coworker decided to check out the sources only once and make a local copy. That's what we did and it worked OK, but I am still wondering whether it is guaranteed to work, or it just happened. In the bzr case, I am planning to move the "main" repo to another server. So I was thinking to just copy it there and start considering that the main repo. I guess the safest is to make a clone though.

    Read the article

  • xCode: iPhone Swipe Gesture crash

    - by David DelMonte
    I have an app that I'd like the swipe gesture to flip to a second view. The app is all set up with buttons that work. The swipe gesture though causes a crash ( “EXC_BAD_ACCESS”.). The gesture code is: - (void)handleSwipe:(UISwipeGestureRecognizer *)recognizer { NSLog(@"%s", __FUNCTION__); switch (recognizer.direction) { case (UISwipeGestureRecognizerDirectionRight): [self performSelector:@selector(flipper:)]; break; case (UISwipeGestureRecognizerDirectionLeft): [self performSelector:@selector(flipper:)]; break; default: break; } } and "flipper" looks like this: - (IBAction)flipper:(id)sender { FlashCardsAppDelegate *mainDelegate = (FlashCardsAppDelegate *)[[UIApplication sharedApplication] delegate]; [mainDelegate flipToFront]; } flipToBack (and flipToFront) look like this.. - (void)flipToBack { NSLog(@"%s", __FUNCTION__); BackViewController *theBackView = [[BackViewController alloc] initWithNibName:@"BackView" bundle:nil]; [self setBackViewController:theBackView]; [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:1.0]; [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:window cache:YES]; [frontViewController.view removeFromSuperview]; [self.window addSubview:[backViewController view]]; [UIView commitAnimations]; [frontViewController release]; frontViewController = nil; [theBackView release]; // NSLog (@" FINISHED "); } Maybe I'm going about this the wrong way... All ideas are welcome...

    Read the article

  • Does NULL and nil are equal?

    - by monish
    Hi Guys, Actually my question here is does Null and nil are equal or not? I had an Example but I am confused when they are equal when they are not. NSNull *nullValue = [NSNull null]; NSArray *arrayWithNull = [NSArray arrayWithObject:nullValue]; NSLog(@"arrayWithNull: %@", arrayWithNull); id aValue = [arrayWithNull objectAtIndex:0]; if (aValue == nil) { NSLog(@"equals nil"); } else if (aValue == [NSNull null]) { NSLog(@"equals NSNull instance"); if ([aValue isEqual:nil]) { NSLog(@"isEqual:nil"); } } Here in the above case it shows that both Null and nil are not equal and it displays "equals NSNull instance" NSString *str=NULL; id str1=nil; if(str1 == str) { printf("\n IS EQUAL........"); } else { printf("\n NOT EQUAL........"); } And in the second case it shows both are equal and it displays "IS EQUAL". Anyone's help will be much appreciated. Thank you, Monish.

    Read the article

  • C++ Returning a Reference

    - by Devil Jin
    Consider the following code where I am returning double& and a string&. The thing works fine in the case of a double but not in the case of a string. Why is this difference in the behavior? In both the cases compiler does not even throws the Warning: returning address of local variable or temporary as I am returning a reference. #include <iostream> #include <string> using namespace std; double &getDouble(){ double h = 46.5; double &hours = h; return hours; } string &getString(){ string str = "Devil Jin"; string &refStr = str; return refStr; } int main(){ double d = getDouble(); cout << "Double = " << d << endl; string str = getString(); cout << "String = " << str.c_str() << endl; return 0; } Output: $ ./a.exe Double = 46.5 String =

    Read the article

  • what exactly is the danger of an uninitialized pointer in C

    - by akh2103
    I am trying get a handle on C as I work my way thru Jim Trevor's "Cyclone: A safe dialect of C" for a PL class. Trevor and his co-authors are trying to make a safe version of C, so they eliminate uninitialized pointers in their language. Googling around a bit on uninitialized pointers, it seems like un-initialized pointers point to random locations in memory. It seems like this alone makes them unsafe. If you reference an un-itilialized pointer, you jump to an unsafe part of memory. Period. But the way Trevor talks about them seems to imply that it is more complex. He cites the following code, and explains that when the function FrmGetObjectIndex dereferences f, it isn’t accessing a valid pointer, but rather an unpredictable address — whatever was on the stack when the space for f was allocated. What does Trevor mean by "whatever was on the stack when the space for f was allocated"? Are "un-initialized" pointers initialized to random locations in memory by default? Or does their "random" behavior have to do with the memory allocated for these pointers getting filled with strange values (that are then referenced) because of unexpected behavior on the stack. Form *f; switch (event->eType) { case frmOpenEvent: f = FrmGetActiveForm(); ... case ctlSelectEvent: i = FrmGetObjectIndex(f, field); ... }

    Read the article

  • Will rel=canonical break site: queries ?

    - by Justin Grant
    Our company publishes our software product's documentation using a custom-built content management system using a dynamic URL namespace like this: http://ourproduct.com/documentation/version/pageid Where "version" is the version number to which the documentation applies, and "pageid" is a unique string which identifies that page in our back-end content management system. For example, if content (e.g. a page about configuration best practices) is unchanged from version 3.0 and 4.0 of our product, it'd be reachable by two different URLs: http://ourproduct.com/documentation/3.0/configuration-best-practices http://ourproduct.com/documentation/4.0/configuration-best-practices This URL scheme allows us to scope Google search results to see only documentaiton for a particular product version, like this: configuration site:ourproduct.com/documentation/4.0 But when the user is searching across all versions, we don't want Google to arbitrarily choose one of the URLs to show in results. Instead, we always want the latest version to show up. Hence our planned use of rel=canonical so we can proscriptively tell Google which URL we want to show up if multiple versions are being searched. (Users who do oddball things like searching 2 versions but not all of them are a corner case, so we don't care which version(s) show up in that case-- the primary use-cases we care about is searching one version or searching all versions) But what will happen to scoped searches if we do this? If my rel=canonical URL points to version 4.0, but my search is scoped to 3.0, will Google return a result? Even if you don't know the answer offhand, do you know a site which uses rel=canonical to redirect across folders in a URL namespace. If so, I could run a few Google searches and figure out the answer.

    Read the article

  • CoreData : store images to DB or not?

    - by Meko
    Hi.I am making an app that it takes photos from web site for some Username and shows it on UITable with username then when clicking user name it shows photos for this user and then clicking to name of photo it shows full screen photo. My question is I am using NSData to get photos from internet.Am I have to save also those data to CoreDAta? I am using like when pressing name of user it again creates NSData and downloads photos from internet and shows them on UTable. And it takes time. What is good approach? and How can save this images to CoreDAta? I am using this method NSData *imageData=[flickr dataForPhotoID:firstPhoto.id fromFarm:firstPhoto.farm onServer:firstPhoto.server withSecret:firstPhoto.secret inFormat: FlickrFetcherPhotoFormatSquare]; and here definition of dataForPtohoID method - (NSData *)dataForPhotoID:(NSString *)photoID fromFarm:(NSString *)farm onServer:(NSString *)server withSecret:(NSString *)secret inFormat:(FlickrFetcherPhotoFormat)format { #if TEST_HIGH_NETWORK_LATENCY sleep(1); #endif NSString *formatString; switch (format) { case FlickrFetcherPhotoFormatSquare: formatString = @"s"; break; case FlickrFetcherPhotoFormatLarge: formatString = @"b"; break; } NSString *photoURLString = [NSString stringWithFormat:@"http://farm%@.static.flickr.com/%@/%@_%@_%@.jpg", farm, server, photoID, secret, formatString]; NSURL *url = [NSURL URLWithString:photoURLString]; return [NSData dataWithContentsOfURL:url]; }

    Read the article

  • Poor execution plans when using a filter and CONTAINSTABLE in a query

    - by Paul McLoughlin
    We have an interesting problem that I was hoping someone could help to shed some light on. At a high level the problem is as below: The following query executes quickly (1 second): SELECT SA.* FROM cg.SEARCHSERVER_ACTYS AS SA JOIN CONTAINSTABLE(CG.SEARCHSERVER_ACTYS, NOTE, 'reports') AS T1 ON T1.[Key]=SA.UNIQUE_ID but if we add a filter to the query, then it takes approximately 2 minutes to return: SELECT SA.* FROM cg.SEARCHSERVER_ACTYS AS SA JOIN CONTAINSTABLE(CG.SEARCHSERVER_ACTYS, NOTE, 'reports') AS T1 ON T1.[Key]=SA.UNIQUE_ID WHERE SA.CHG_DATE'19 Feb 2010' Looking at the execution plan for the two queries, I can see that in the second case there are two places where there are huge differences between the actual and estimated number of rows, these being: 1) For the FulltextMatch table valued function where the estimate is approx 22,000 rows and the actual is 29 million rows (which are then filtered down to 1670 rows before the join) and 2) For the index seek on the full text index, where the estimate is 1 row and the actual is 13,000 rows As a result of the estimates, the optimiser is choosing to use a nested loops join (since it assumes a small number of rows) hence the plan is inefficient. We can work around the problem by either (a) parameterising the query and adding an OPTION (OPTIMIZE FOR UNKNOWN) to the query or (b) by forcing a HASH JOIN to be used. In both of these cases the query returns in sub 1 second and the estimates appear reasonable. My question really is 'why are the estimates being used in the poorly performing case so wildly inaccurate and what can be done to improve them'? Statistics are up to date on the indexes on the indexed view being used here. Any help greatly appreciated.

    Read the article

  • Getting a connection from a Sybase datasource in WAS 6.1 fails with message "User name property miss

    - by Abel Morelos
    I have a standalone application that needs to connect to a Sybase database via a datasource, I'm trying to connect using getConnection() and get the connection from this Sybase datasource which is hosted in WAS 6.1, sadly I'm getting an error JZ004 - Sybase(R) jConnect for JDBC(TM) Programmer's Reference: SQL Exception and Warning Messages JZ004 error message is: User name property missing in DriverManager.getConnection(..., Properties) Action: Provide the required user property. As you can see, this is not a connectivity (so we can discard JNDI or lookup problems), but rather a configuration problem. For my Sybase datasource in WAS 6.1 I have set up the proper authentication alias (Component-managed Authentication Alias), and I know the credentials are alright, "Test Connection" is successful for this datasource. Somebody had a similar problem and was because of the authentication alias- http://forum.springsource.org/showthread.php?t=39915 Next, I tried calling getConnection() but now I provided the credentials like getConnection(user, password)... and this time it worked!!! So I suspect that somehow WAS 6.1 is not picking or taking the authentication info I set in the datasource as mentioned before. If you think that maybe getConnection(user, password) should be OK for my case, well, that's not the case since I have a requirement to keep the credentials in the server, the standalone application only needs to know the JNDI information to lookup the datasource. Please let me know if have faced a similar problem, or what would you suggest me to do. Thanks.

    Read the article

  • backbone marionette - displaying a view in a layout region which has already been rendered

    - by Justin Wyllie
    I have something like this: //render the layout Layout.layout = new Layout.Screen(); MyApp.SomeRegion.show(Layout.layout); //render a view into it var mView = new CompositeView({collection: data}); Layout.layout.SomeRegion.show(mView); That all works fine. The layout has 3 regions. The above has rendered a view into one of them. Now, later, I want (in response to some user interaction) to render another view into one of the other regions. So I try: var mView2 = new CompositeView({collection: data}); Layout.layout.SomeOtherRegion.show(mView); But 'SomeOtherRegion' no longer exists on Layout.layout. I looked at this in Firebug. In the first case Layout.layout has my three regions defined on it. In the second case, not. Though they are still there in the regions object. This is the same layout instance. It looks like once a layout has been rendered you cannot render into it again? There must be a way. Nb. I don't want to re-render the layout. I hope that makes sense --Justin Wyllie

    Read the article

< Previous Page | 186 187 188 189 190 191 192 193 194 195 196 197  | Next Page >