Search Results

Search found 6682 results on 268 pages for 'edge cases'.

Page 215/268 | < Previous Page | 211 212 213 214 215 216 217 218 219 220 221 222  | Next Page >

• Regular expression for finding non-breaking string names in code and then breaking them up for SQL q

  - by Rob Segal

  I am trying to devlop a regex for finding camel case strings in several code files I am working with so I can break them up into separate words for use in a SQL query. I have strings of the form... EmailAddress FirstName MyNameIs And I want them like this... Email Address First Name My Name Is An example SQL query which I currently have is... select FirstName, MyNameIs from MyTables I need the queries in the form... select FirstName as 'First Name', MyNameIs as 'My Name Is' from MyTables Any time a new capital letter appears that should be a new grouping which I can pick out of the matched string. I currently have the following regex... ([A-Z][a-z]+)+ Which does match the cases I have shown above but when I want to perform a replace I need to define groups. Currently I have tried... (([A-Z])([a-z]+))+ Which sort of works. It will pick out "Address" as the first grouping from "EmailAddress" as opposed to "Email" which is what I was expecting. No doubt there is something I'm misunderstanding here so any help is greatly appreciated.

  Read the article

• Does SetFileBandwidthReservation affect memory-mapped file performance?

  - by Ghostrider

  Does this function affect Memory-mapped file performance? Here's the problem I need to solve: I have two applications competing for disk access: "reader" and "updater". Whole system runs on Windows Server 2008 R2 x64 "Updater" constantly accesses disk in a linear manner, updating data. They system is set up in such a way that updater always has infinite data to update. Consider that it is constantly approximating a solution of a huge set of equations that takes up entire 2TB disk drive. Updater uses ReadFile and WriteFile to process data in a linear fashion. "Reader" is occasionally invoked by user to get some pieces of data. Usually user would read several 4kb blocks from the drive and stop. Occasionally user needs to read up to 100mb sequentially. In exceptional cases up to several gigabytes. Reader maps files to memory to get data it needs. What I would like to achieve is for "reader" to have absolute priority so that "updater" would completely stop if needed so that "reader" could get the data user needs ASAP. Is this problem solvable by using SetPriorityClass and SetFileBandwidthReservation calls? I would really hate to put synchronization login in "reader" and "updater" and rather have the OS take care of priorities.

  Read the article

• Closing the gap between 2 inline elements

  - by insanepaul

  I have a simple div element that contains 2 inline tags. I've associated a onmouseout event to the div element. The problem is that the onmouseout event is fired when the user hovers their mouse between the two tags in the div and also after the end of the second tag. What I want to do is allow the user to hover their mouse across the whole of the div tag and only fire the onmouseout event when the mouse pointer is outside the div element (which is what I assumed from what I've done). I increased padding to close the gap between the 2 tags. This works but where they meet in IE7 at least the event is fired!!! I must be doing something wrong can someone please help. <div id="Div1" onmouseover="hideDiv()"> <a id="A1" href="HTMLNew.htm">ARTICLES</a> <a id="A2" href="HTMLNew.htm">COURSES & CASES</a> </div>

  Read the article

• Is extending a base class with non-virtual destructor dangerous in C++

  - by Akusete

  Take the following code class A { }; class B : public A { }; class C : public A { int x; }; int main (int argc, char** argv) { A* b = new B(); A* c = new C(); //in both cases, only ~A() is called, not ~B() or ~C() delete b; //is this ok? delete c; //does this line leak memory? return 0; } when calling delete on a class with a non-virtual destructor with member functions (like class C), can the memory allocator tell what the proper size of the object is? If not, is memory leaked? Secondly, if the class has no member functions, and no explicit destructor behaviour (like class B), is everything ok? I ask this because I wanted to create a class to extend std::string, (which I know is not recommended, but for the sake of the discussion just bear with it), and overload the +=,+ operator. -Weffc++ gives me a warning because std::string has a non virtual destructor, but does it matter if the sub-class has no members and does not need to do anything in its destructor? -- FYI the += overload was to do proper file path formatting, so the path class could be used like class path : public std::string { //... overload, +=, + //... add last_path_component, remove_path_component, ext, etc... }; path foo = "/some/file/path"; foo = foo + "filename.txt"; //and so on... I just wanted to make sure someone doing this path* foo = new path(); std::string* bar = foo; delete bar; would not cause any problems with memory allocation

  Read the article

• JQuery Hover does not work Mozilla

  - by josephj1989

  I have the following Snippet of code.The hover has a problem in Mozilla - It changes color on hover but some times it does not revert back when we go out.Mind you it only happens sometimes.Also in such cases if I examine the HTML using FireBug I can see that the Extra Class is assigned even after hover is out.It works OK on IE .This is a simplified version Also as you can see I am setting color on the TR.But this does not change the Color on TextBoxes inside TR. How can I make sure the background color of the Controls contained in the TR is also changed on hover. <style type="text/css"> .HighLight { background-color:Fuchsia; } .Select { border:soild 2px Blue; margin:3px; } </style> <script type="text/javascript" src="jquery-1.4.2.js"> </script> <script type="text/javascript"> $(function() { $(".Select").hover( function() { $(this).addClass("HighLight"); }, function() { $(this).removeClass("HighLight"); }); }); My Markup generated by ASP.NET Repeater Control is a table with TR assigned Class Select. <tr class="Select" > <td> <input type="checkbox" id="chkSelect" /> </td> <td> <input name="Repeater1$ctl11$tb" type="text" value="Sharp Bikes" id="Repeater1_ctl11_tb" /> </td> <td> <input name="Repeater1$ctl11$tb2" type="text" value="10/13/2004 11:15:07 AM" id="Repeater1_ctl11_tb2" /> </td> </tr>

  Read the article

• Detect TCP connection close when playing Flash video

  - by JoJo

  On the Flash client side, how do I detect when the server purposely closes the TCP connection to its video stream? I'll need to take action when this occurs - maybe attempt to restart the video or display an error message. Currently, the connection closing and the connection being slow look the same to me. The NetStream object ushers a NetStream.Play.Stop event in both cases. When the connection is slow, it usually recovers by itself within seconds. I wish to only take action when the connection is closed, not when it is slow. Here's how my general setup looks like. It's the basic NetConnection-NetStream-Video setup. this.vidConnection = new NetConnection(); this.vidConnection.addEventListener(AsyncErrorEvent.ASYNC_ERROR, this.connectionAsyncError); this.vidConnection.addEventListener(IOErrorEvent.IO_ERROR, this.connectionIoError); this.vidConnection.addEventListener(NetStatusEvent.NET_STATUS, this.connectionNetStatus); this.vidConnection.connect(null); this.vidStream = new NetStream(this.vidConnection); this.vidStream.addEventListener(AsyncErrorEvent.ASYNC_ERROR, this.streamAsyncError); this.vidStream.addEventListener(IOErrorEvent.IO_ERROR, this.streamIoError); this.vidStream.addEventListener(NetStatusEvent.NET_STATUS, this.streamNetStatus); this.vid.attachNetStream(this.vidStream); None of the error events fire when the server closes the TCP or when the connection freezes up. Only the NetStream.Play.Stop event fires. Here's a trace of what happens from initially playing the video to the TCP connection closing. connection net status = NetConnection.Connect.Success playStream(http://192.168.0.44/flv/4d29104a9aefa) NetStream.Play.Start NetStream.Buffer.Flush NetStream.Buffer.Full NetStream.Buffer.Empty checkDimensions 0 0 onMetaData NetStream.Buffer.Full NetStream.Buffer.Flush checkDimensions 960 544 NetStream.Buffer.Empty NetStream.Buffer.Flush NetStream.Play.Stop

  Read the article

• Inner join on 2 arrays?

  - by russ

  I'm trying to find a solution to the following (I'm thinking with Linq) to the following: I need to pull down certain files from a larger list of files on an ftp server that have a similar file name. For example, we send an order file to some company for processing then they return a response file that we can download. So, I could send them the files "order_123.txt" and "order_456.txt". After a certain amount of time I need to go look for and download the responses for those files that will be named "order_123.resp" and "order_456.resp". The kicker is that in some cases I can have multiple responses in which case they would create "order_123-1.resp" and "order_123-2.resp" and also the files don't get removed from the server. I know this can be accomplished by looping through the files I know I need responses to then loop through all the files on the server until I find files that match but I'm hoping that I don't have to loop through the files on the server more than once. This example may help clarify: I've sent "order_222.txt" and "order_333.txt" they processed them and the ftp server contains: "order_111-1.resp" "order_001.resp" "order_222-1.resp" "order_222-2.resp" "order_333.resp" I need to download the 3rd, 4th, and 5th file. Thanks.

  Read the article

• Web development: Haskell or Scheme

  - by Robert E. Lester

  I would like to to choose one of these languages for building web applications. I'm not interested in framework per say, but have the following needs: Rapid development. Easy to scale. Strong community for the web. Quick and easy to deploy. I'm very familiar with Haskell, and have some familiarity with scheme (in particular PLT). Scheme appeals to me as good candidate for web development due to it's simple syntax which is homogenous across libraries. I state this despite my subjective opinion that Haskell is a 'cleaner' language. Haskell web apps seem to require learning and building a patchwork of different combinator libraries. On the plus side, I realise this can be quite expressive, although I'd prefer to eliminate impedance mismatches where possible. While scheme-plt looks to be a good fit, I can find but one example of it being used in the "real world". Haskell doesn't seem to fair too much better here, but there seems to be a bigger community behind the web side. Please help me make up my mind. For the most part I'm interested in real-world use cases.

  Read the article

• How to correctly load dependent JavaScript files

  - by Vaibhav Garg

  I am trying to extent a website page that displays google maps with the LabeledMarker. Google Maps API defines a class called GMarker which is extended by the LabeledMarker. The problem is, I cant seem to load the LabeledMarker script properly, i.e. after the Google API loads and I get the 'GMarker not defined' error. What is the correct way to specify the scripts in such cases? I am using ASP.NET's ClientScript.RegisterClientScriptInclude() first for the google API url and then immediately after with the LabeledMarker script file. The initial google API loader writes further script links that load the actual GMarker class. Shouldnt all those scripts be executed before the next script block(LabeledMarker script) is processed. I have checked the generated HTML and the script blocks are emitted in the right order. <script src="google api url" type="text/javascript"></script> ... (the above scripts uses document.write() etc to append further script blocks/sources) ... <script src="Scripts/LabeledMarker.js" type="text/javascript"></script> Once again, the LabeledMarker.js seems to get executed before the google API finishes loading.

  Read the article

• When to choose which machine learning classifier?

  - by LM

  Suppose I'm working on some classification problem. (Fraud detection and comment spam are two problems I'm working on right now, but I'm curious about any classification task in general.) How do I know which classifier I should use? (Decision tree, SVM, Bayesian, logistic regression, etc.) In which cases is one of them the "natural" first choice, and what are the principles for choosing that one? Examples of the type of answers I'm looking for (from Manning et al.'s "Introduction to Information Retrieval book": http://nlp.stanford.edu/IR-book/html/htmledition/choosing-what-kind-of-classifier-to-use-1.html): a. If your data is labeled, but you only have a limited amount, you should use a classifier with high bias (for example, Naive Bayes). [I'm guessing this is because a higher-bias classifier will have lower variance, which is good because of the small amount of data.] b. If you have a ton of data, then the classifier doesn't really matter so much, so you should probably just choose a classifier with good scalability. What are other guidelines? Even answers like "if you'll have to explain your model to some upper management person, then maybe you should use a decision tree, since the decision rules are fairly transparent" are good. I care less about implementation/library issues, though. Also, for a somewhat separate question, besides standard Bayesian classifiers, are there 'standard state-of-the-art' methods for comment spam detection (as opposed to email spam)? [Not sure if stackoverflow is the best place to ask this question, since it's more machine learning than actual programming -- if not, any suggestions for where else?]

  Read the article

• Parsing and replacing Javascript identifiers with Rhino in Java

  - by Parhs

  Suppose I let the user to write a condition using Javascript, the user can write conditions to perform a test and return true or false. E.g.: INS>5 || ASTO.valueBetween(10,210) I want to find which variables are used in the script that the user wrote. I tried to find a way to get the identifier names in Java. The Rhino library didn't help a lot. However I found that via handling exceptions I could get all the identifiers. So this problem is solved. So everything is great, but there is one little problem. How can I replace these identifiers with a numeric identifier? E.g. INS should be _234 and ASTO should be _331. INS and ASTO etc are entities in my database. I want to replace them, because the name may change. I could do it using a replace but this isn't easy because: It should be reversible. E.g. ASTO to _234 and _234 to ASTO again. Replacing _23 with MPLAH may also replace _234. This could be fixed with regexp somehow. What if _23 is in a comment section? Rare to happen, but possible /* _23 fdsafd ktl */. It should also be replaced. What if it is a name of a function? E.g. _32() {}. Also rare, but it shouldn't be replaced. What if it is enclosed in "" or ''? I am sure that there are a lot more cases. Any ideas?

  Read the article

• How do I improve this design for dealing with intersecting date ranges and resolving date range conf

  - by derdo

  I am working on some code that deals with date ranges. I have pricing activities that have a starting-date and an end-date to set a certain price for that range. There are multiple pricing activities with intersecting date ranges. What I ultimately need is the ability to query valid prices for a date range. I pass in (jan1,jan31) and I get back a list that says jan1--jan10 $4 , jan11--jan19 $3 jan20--jan31 $4. There are priorities between pricing activities. Some type of pricing activities have high priority, so they override other pricing activities and for certain type of pricing activities lowest price wins etc. I currently have a class that holds these pricing activities and keeps a resolved pricing calendar. As I add new pricing activities I update the resolved calendar. As I write more tests/code, it started to get very complicated with all the different cases (pricing activities intersecting in different ways). I am ending up with very complicated code where I am resolving a newly added pricing activity. See AddPricingActivity() method below. Can anybody think of a simpler way to deal with this? Could there be similar code somewhere out there? Public class PricingActivity() { DateTime startDate; DateTime endDate; Double price; Public bool StartsBeforeEndsAfter (PricingActivity pAct) { // pAct covers this pricing activity } Public bool StartsMiddleEndsAfter (PricingActivity pAct){ // early part of pAct Itersects with later part of this pricing activity } //more similar methods to cover all the combinations of intersecting } Public Class PricingActivityList() { List<PricingActivity> activities; SortedDictionary<Date, PricingActivity> resolvedPricingCalendar; Public void AddPricingActivity(PricingActivity pAct) { //update the resolvedCalendar //go over each activity and find intersecting ones //update the resolved calendar correctly //depending on the type of the intersection //this part is getting out of hand….. } }

  Read the article

• The fastest way to iterate through a collection of objects

  - by Trev

  Hello all, First to give you some background: I have some research code which performs a Monte Carlo simulation, essential what happens is I iterate through a collection of objects, compute a number of vectors from their surface then for each vector I iterate through the collection of objects again to see if the vector hits another object (similar to ray tracing). The pseudo code would look something like this for each object { for a number of vectors { do some computations for each object { check if vector intersects } } } As the number of objects can be quite large and the amount of rays is even larger I thought it would be wise to optimise how I iterate through the collection of objects. I created some test code which tests arrays, lists and vectors and for my first test cases found that vectors iterators were around twice as fast as arrays however when I implemented a vector in my code in was somewhat slower than the array I was using before. So I went back to the test code and increased the complexity of the object function each loop was calling (a dummy function equivalent to 'check if vector intersects') and I found that when the complexity of the function increases the execution time gap between arrays and vectors reduces until eventually the array was quicker. Does anyone know why this occurs? It seems strange that execution time inside the loop should effect the outer loop run time.

  Read the article

• Question about WeakHashMap

  - by michael

  Hi, In the Javadoc of "http://java.sun.com/j2se/1.4.2/docs/api/java/util/WeakHashMap.html", it said "Each key object in a WeakHashMap is stored indirectly as the referent of a weak reference. Therefore a key will automatically be removed only after the weak references to it, both inside and outside of the map, have been cleared by the garbage collector." And then Note that a value object may refer indirectly to its key via the WeakHashMap itself; that is, a value object may strongly refer to some other key object whose associated value object, in turn, strongly refers to the key of the first value object. But should not both Key and Value should be used weak reference in WeakHashMap? i.e. if there is low on memory, GC will free the memory held by the value object (since the value object most likely take up more memory than key object in most cases)? And if GC free the Value object, the Key Object can be free as well? Basically, I am looking for a HashMap which will reduce memory usage when there is low memory (GC collects the value and key objects if necessary). Is it possible in Java? Thank you.

  Read the article

• Changing the direction of a Combo box dropdown in SWT

  - by Kris

  Hi, I'm building an Eclipse plugin in SWT, and I have the following problem: one of my fields is a combo box, and in some cases it may have fairly long items as selection options. My plugin runs on the right side of the screen, so when you go to use the combo-box, the right side of the combo box is cut off. So, my question is: is there any way to change the dropdown's alignment relative to the combo control? It seems to be permanently left-aligned... and I'm pretty sure you can change the direction in Swing (though the only place I've seen it done is in the Substance UI demo. The Combo Box tab has boxes with North, South East, and West flyout directions... for my application, I need something like the West flyout) Note: Setting actual text limits is a last-case-scenario option; it would be quite a bit of guesswork to set the text limit dynamically (since the widget's view can be resized). Here's a picture (sorry, I can only have one link and no images :( ... I need some more rep :p) Left side of the line: Proper width - the view is the wide enough for the combo dropdown to display all the text; you can see the scrollbars on the right side. Right side of the line: Too small - Here, the view has been resized, and the combo dropdown scrollbar (as well as some of the text) is cut off by the right side of the screen. I always have more screen space available to the left (since this is always on the right hand side of the screen), but the combo dropdown always appears to the lower right. Hopefully this is clear enough.

  Read the article

• Using ember-resource with couchdb - how can i save my documents?

  - by Thomas Herrmann

  I am implementing an application using ember.js and couchdb. I choose ember-resource as database access layer because it nicely supports nested JSON documents. Since couchdb uses the attribute _rev for optimistic locking in every document, this attribute has to be updated in my application after saving the data to the couchdb. My idea to implement this is to reload the data right after saving to the database and get the new _rev back with the rest of the document. Here is my code for this: // Since we use CouchDB, we have to make sure that we invalidate and re-fetch // every document right after saving it. CouchDB uses an optimistic locking // scheme based on the attribute "_rev" in the documents, so we reload it in // order to have the correct _rev value. didSave: function() { this._super.apply(this, arguments); this.forceReload(); }, // reload resource after save is done, expire to make reload really do something forceReload: function() { this.expire(); // Everything OK up to this location Ember.run.next(this, function() { this.fetch() // Sub-Document is reset here, and *not* refetched! .fail(function(error) { App.displayError(error); }) .done(function() { App.log("App.Resource.forceReload fetch done, got revision " + self.get('_rev')); }); }); } This works for most cases, but if i have a nested model, the sub-model is replaced with the old version of the data just before the fetch is executed! Interestingly enough, the correct (updated) data is stored in the database and the wrong (old) data is in the memory model after the fetch, although the _rev attribut is correct (as well as all attributes of the main object). Here is a part of my object definition: App.TaskDefinition = App.Resource.define({ url: App.dbPrefix + 'courseware', schema: { id: String, _rev: String, type: String, name: String, comment: String, task: { type: 'App.Task', nested: true } } }); App.Task = App.Resource.define({ schema: { id: String, title: String, description: String, startImmediate: Boolean, holdOnComment: Boolean, ..... // other attributes and sub-objects } }); Any ideas where the problem might be? Thank's a lot for any suggestion! Kind regards, Thomas

  Read the article

• What algorithm should i follow to retrieve data in the prescribed format?

  - by Prateek

  I have to retrieve data from a database in which tables are consisting of fields like "ttc, rm, atc and lta" namely. Actually these values are stored on daily basis with a 15 min interval like From_time to_time ttc rm atc lta 00:00 00:15 45 10 35 25, 00:15 00:30 35 10 25 25 and so on .. These values are stored for every day of every month and i want it to be previewed in the prescribed format then what algorithm should i follow. I am confused about how to do comparisons for a format like below mentioned. The format is at this link https://drive.google.com/a/itbhu.ac.in/file/d/0B_J0Ljq64i4Za2J1V0lvbDZ4eGc/edit?usp=sharing To be specific once again, my question is, I have to prepare a report from the retrieved data which is being stored in the databases as explained above. But the report which is going to be prepared will be of entire month. So, to say the least, there may be cases that for two particular days the value of "ttc" would be same for some time so i want it to be listed together (as shown in format). And the confusing part is any of the values "ttc", "rm", "atc", "lta" can be same for any particular interval. So what algorithm should i follow for such comparisons. And if still any query with question, u can ask your doubt. Thanks

  Read the article

• should the builder reset its build environment after delivering the product

  - by Sudhi

  I am implementing a builder where in the deliverable is retrieved by calling Builder::getProduct() . The director asks various parts to build Builder::buildPartA() , Builder::buildPartB() etc. in order to completely build the product. My question is, once the product is delivered by the Builder by calling Builder::getProduct(), should it reset its environment (Builder::partA = NULL;, Builder::partB = NULL;) so that it is ready to build another product? (with same or different configuration?) I ask this as I am using PHP wherein the objects are by default passed by reference (nope, I don't want to clone them, as one of their field is a Resource) . However, even if you think from a language agnostic point of view, should the Builder reset its build environment ? If your answer is 'it depends on the case' what use cases would justify reseting the environment (and other way round) ? For the sake of providing code sample here's my Builder::gerProcessor() which shows what I mean by reseting the environment /** * @see IBuilder::getProessor() */ public function getProcessor() { if($this->_processor == NULL) { throw new LogicException('Processor not yet built!'); } else { $retval = $this->_processor; $this->_product = NULL, $this->_processor = NULL; } return $retval; }

  Read the article

• Destructors not called when native (C++) exception propagates to CLR component

  - by Phil Nash

  We have a large body of native C++ code, compliled into DLLs. Then we have a couple of dlls containing C++/CLI proxy code to wrap the C++ interfaces. On top of that we have C# code calling into the C++/CLI wrappers. Standard stuff, so far. But we have a lot of cases where native C++ exceptions are allowed to propagate to the .Net world and we rely on .Net's ability to wrap these as System.Exception objects and for the most part this works fine. However we have been finding that destructors of objects in scope at the point of the throw are not being invoked when the exception propagates! After some research we found that this is a fairly well known issue. However the solutions/ workarounds seem less consistent. We did find that if the native code is compiled with /EHa instead of /EHsc the issue disappears (at least in our test case it did). However we would much prefer to use /EHsc as we translate SEH exceptions to C++ exceptions ourselves and we would rather allow the compiler more scope for optimisation. Are there any other workarounds for this issue - other than wrapping every call across the native-managed boundary in a (native) try-catch-throw (in addition to the C++/CLI layer)?

  Read the article

• When software problems reported are not really software problems

  - by AndyUK

  Hi Apologies if this has already been covered or you think it really belongs on wiki. I am a software developer at a company that manufactures microarray printing machines for the biosciences industry. I am primarily involved in interfacing with various bits of hardware (pneumatics, hydraulics, stepper motors, sensors etc) via GUI development in C++ to aspirate and print samples onto microarray slides. On joining the company I noticed that whenever there was a hardware-related problem this would cause the whole setup to freeze, with nobody being any the wiser as to what the specific problem was - hardware / software / misuse etc. Since then I have improved things somewhat by introducing software timeouts and exception handling to better identify and deal with any hardware-related problems that arise eg PLC commands not successfully completed, inappropriate FPGA response commands, and various other deadlock type conditions etc. In addition, the software will now log a summary of the specific problem, inform the user and exit the thread gracefully. This software is not embedded, just interfacing using serial ports. In spite of what has been achieved, non-software guys still do not fully appreciate that in these cases, the 'software' problem they are reporting to me is not really a software problem, rather the software is reporting a problem, but not causing it. Don't get me wrong, there is nothing I enjoy more than to come down on software bugs like a ton of bricks, and looking at ways of improving robustness in any way. I know the system well enough now that I almost have a sixth sense for these things. No matter how many times I try to explain this point to people, it does not really penetrate. They still report what are essentially hardware problems (which eventually get fixed) as software ones. I would like to hear from any others that have endured similar finger-pointing experiences and what methods they used to deal with them.

  Read the article

• C++ interpreter conceptual problem

  - by Jan Wilkins

  I've built an interpreter in C++ for a language created by me. One main problem in the design was that I had two different types in the language: number and string. So I have to pass around a struct like: class myInterpreterValue { myInterpreterType type; int intValue; string strValue; } Objects of this class are passed around million times a second during e.g.: a countdown loop in my language. Profiling pointed out: 85% of the performance is eaten by the allocation function of the string template. This is pretty clear to me: My interpreter has bad design and doesn't use pointers enough. Yet, I don't have an option: I can't use pointers in most cases as I just have to make copies. How to do something against this? Is a class like this a better idea? vector<string> strTable; vector<int> intTable; class myInterpreterValue { myInterpreterType type; int locationInTable; } So the class only knows what type it represents and the position in the table This however again has disadvantages: I'd have to add temporary values to the string/int vector table and then remove them again, this would eat a lot of performance again. Help, how do interpreters of languages like Python or Ruby do that? They somehow need a struct that represents a value in the language like something that can either be int or string.

  Read the article

• Why doesn't C# do "simple" type inference on generics?

  - by Ken Birman

  Just curious: sure, we all know that the general case of type inference for generics is undecidable. And so C# won't do any kind of subtyping at all: if Foo<T> is a generic, Foo<int> isn't a subtype of Foo<T>, or Foo<Object> or of anything else you might cook up. And sure, we all hack around this with ugly interface or abstract class definitions. But... if you can't beat the general problem, why not just limit the solution to cases that are easy. For example, in my list above, it is OBVIOUS that Foo<int> is a subtype of Foo<T> and it would be trivial to check. Same for checking against Foo<Object>. So is there some other deep horror that would creep forth from the abyss if they were to just say, aw shucks, we'll do what we can? Or is this just some sort of religious purity on the part of the language guys at Microsoft?

  Read the article

• Cant' cast a class with multiple inheritance

  - by Jay S.

  I am trying to refactor some code while leaving existing functionality in tact. I'm having trouble casting a pointer to an object into a base interface and then getting the derived class out later. The program uses a factory object to create instances of these objects in certain cases. Here are some examples of the classes I'm working with. // This is the one I'm working with now that is causing all the trouble. // Some, but not all methods in NewAbstract and OldAbstract overlap, so I // used virtual inheritance. class MyObject : virtual public NewAbstract, virtual public OldAbstract { ... } // This is what it looked like before class MyObject : public OldAbstract { ... } // This is an example of most other classes that use the base interface class NormalObject : public ISerializable // The two abstract classes. They inherit from the same object. class NewAbstract : public ISerializable { ... } class OldAbstract : public ISerializable { ... } // A factory object used to create instances of ISerializable objects. template<class T> class Factory { public: ... virtual ISerializable* createObject() const { return static_cast<ISerializable*>(new T()); // current factory code } ... } This question has good information on what the different types of casting do, but it's not helping me figure out this situation. Using static_cast and regular casting give me error C2594: 'static_cast': ambiguous conversions from 'MyObject *' to 'ISerializable *'. Using dynamic_cast causes createObject() to return NULL. The NormalObject style classes and the old version of MyObject work with the existing static_cast in the factory. Is there a way to make this cast work? It seems like it should be possible.

  Read the article

• JUnit Test method with randomized nature

  - by Peter

  Hey, I'm working on a small project for myself at the moment and I'm using it as an opportunity to get acquainted with unit testing and maintaining proper documentation. I have a Deck class with represents a deck of cards (it's very simple and, to be honest, I can be sure that it works without a unit test, but like I said I'm getting used to using unit tests) and it has a shuffle() method which changes the order of the cards in the deck. The implementation is very simple and will certainly work: public void shuffle() { Collections.shuffle(this.cards); } But, how could I implement a unit test for this method. My first thought was to check if the top card of the deck was different after calling shuffle() but there is of course the possibility that it would be the same. My second thought was to check if the entire order of cards has changed, but again they could possibly be in the same order. So, how could I write a test that ensures this method works in all cases? And, in general, how can you unit test methods for which the outcome depends on some randomness? Cheers, Pete

  Read the article

• Query notation for the sitecore 'source' field in template builder

  - by M.R.

  I am trying to set the the source field of a template using the query notation (or xpath - whichever works), but none of them seems to be working. My content tree is a multisite content tree: France --Page 1 ----Page1A -------Page1AA --Page 2 --Page 3 --METADATA ----Regions US --Page 1 ----Page1A -------Page1AA --Page 2 --Page 3 --METADATA ----Regions Each site has its own METADATA folder, and I want it so that when adding a page inside each of the main country nodes, I want the values to reflect whatever is in the METADATA of that site. I have two different fields for now - a droplink and a treelistex field. So I thought I can just get the parent item that is a country site, and get the metadata folder for that. When I put the following query in both the fields, I get different results: query:./ancestor::*[@@templatename='CountryHome']/METADATA/Regions/* For the droplink field, I get only the first Region (one item) For the treelistex field, I get the entire content tree I then tried to modify the query a little bit and took the 'query' notation out ./ancestor::*[@@templatename='CountryHome']/METADATA/Regions/* If I go to the developer center/xpath builder, and set the context node to any item underneath the main country site, it returns me exactly what I need, but when I put this in the source, I get the entire content tree in both the cases. Help!

  Read the article

< Previous Page | 211 212 213 214 215 216 217 218 219 220 221 222  | Next Page >