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  • JUnit confusion: use 'extend Testcase' or '@Test' ?

    - by Rabarberski
    I've found the proper use (or at least the documentation) of JUnit very confusing. This question serves both as a future reference and as a real question. If I've understood correctly, there are two main approaches to create and run a JUnit test: Approach A: create a class that extends TestCase, and start test methods with the word test. When running the class as a JUnit Test (in Eclipse), all methods starting with the word test are automatically run. import junit.framework.TestCase; public class DummyTestA extends TestCase { public void testSum() { int a = 5; int b = 10; int result = a + b; assertEquals(15, result); } } Approach B: create a 'normal' class and prepend a @Test annotation to the method. Note that you do NOT have to start the method with the word test. import org.junit.*; import static org.junit.Assert.*; public class DummyTestB { @Test public void Sum() { int a = 5; int b = 10; int result = a + b; assertEquals(15, result); } } Mixing the two seems not to be a good idea, see e.g. this stackoverflow question: Now, my questions(s): What is the preferred approach, or when would you use one instead of the other? Approach B allows for testing for exceptions by extending the @Test annotation like in @Test(expected = ArithmeticException.class). But how do you test for exceptions when using approach A? When using approach A, you can group a number of test classes in a test suite. TestSuite suite = new TestSuite("All tests");<br/> suite.addTestSuite(DummyTestA.class); suite.addTestSuite(DummyTestAbis.class);` But this can't be used with approach B (since each testclass should subclass TestCase). What is the proper way to group tests for approach B?

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  • using compareTo in Binary Search Tree program

    - by Scott Rogener
    I've been working on this program for a few days now and I've implemented a few of the primary methods in my BinarySearchTree class such as insert and delete. Insert seemed to be working fine, but once I try to delete I kept getting errors. So after playing around with the code I wanted to test my compareTo methods. I created two new nodes and tried to compare them and I get this error: Exception in thread "main" java.lang.ClassCastException: TreeNode cannot be cast to java.lang.Integer at java.lang.Integer.compareTo(Unknown Source) at TreeNode.compareTo(TreeNode.java:16) at BinarySearchTree.myComparision(BinarySearchTree.java:177) at main.main(main.java:14) Here is my class for creating the nodes: public class TreeNode<T> implements Comparable { protected TreeNode<T> left, right; protected Object element; public TreeNode(Object obj) { element=obj; left=null; right=null; } public int compareTo(Object node) { return ((Comparable) this.element).compareTo(node); } } Am I doing the compareTo method all wrong? I would like to create trees that can handle integers and strings (seperatly of course)

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  • Returning true or error message in Ruby

    - by seaneshbaugh
    I'm wondering if writing functions like this is considered good or bad form. def test(x) if x == 1 return true else return "Error: x is not equal to one." end end And then to use it we do something like this: result = test(1) if result != true puts result end result = test(2) if result != true puts result end Which just displays the error message for the second call to test. I'm considering doing this because in a rails project I'm working on inside my controller code I make calls to a model's instance methods and if something goes wrong I want the model to return the error message to the controller and the controller takes that error message and puts it in the flash and redirects. Kinda like this def create @item = Item.new(params[:item]) if [email protected]? result = @item.save_image(params[:attachment][:file]) if result != true flash[:notice] = result redirect_to(new_item_url) and return end #and so on... That way I'm not constructing the error messages in the controller, merely passing them along, because I really don't want the controller to be concerned with what the save_image method itself does just whether or not it worked. It makes sense to me, but I'm curious as to whether or not this is considered a good or bad way of writing methods. Keep in mind I'm asking this in the most general sense pertaining mostly to ruby, it just happens that I'm doing this in a rails project, the actual logic of the controller really isn't my concern.

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  • Is there a safe / standard way to manage unstructured memory in C++?

    - by andand
    I'm building a toy VM that requires a block of memory for storing and accessing data elements of different types and of different sizes. I've done this by writing a wrapper class around a uint8_t[] data block of the needed size. That class has some template methods to write / read typed data elements to / from arbitrary locations in the memory block, both of which check to make certain the bounds aren't violated. These methods use memmove in what I hope is a more or less safe manner. That said, while I am willing to press on in this direction, I've got to believe that other with more expertise have been here before and might be willing to share their wisdom. In particular: 1) Is there a class in one of the C++ standards (past, present, future) that has been defined to perform a function similar to what I have outlined above? 2) If not, is there a (preferably free as in beer) library out there that does? 3) Short of that, besides bounds checking and the inevitable issue of writing one type to a memory location and reading a different from that location, are there other issues I should be aware of? Thanks.-&&

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  • Why does adding Crossover to my Genetic Algorithm give me worse results?

    - by MahlerFive
    I have implemented a Genetic Algorithm to solve the Traveling Salesman Problem (TSP). When I use only mutation, I find better solutions than when I add in crossover. I know that normal crossover methods do not work for TSP, so I implemented both the Ordered Crossover and the PMX Crossover methods, and both suffer from bad results. Here are the other parameters I'm using: Mutation: Single Swap Mutation or Inverted Subsequence Mutation (as described by Tiendil here) with mutation rates tested between 1% and 25%. Selection: Roulette Wheel Selection Fitness function: 1 / distance of tour Population size: Tested 100, 200, 500, I also run the GA 5 times so that I have a variety of starting populations. Stop Condition: 2500 generations With the same dataset of 26 points, I usually get results of about 500-600 distance using purely mutation with high mutation rates. When adding crossover my results are usually in the 800 distance range. The other confusing thing is that I have also implemented a very simple Hill-Climbing algorithm to solve the problem and when I run that 1000 times (faster than running the GA 5 times) I get results around 410-450 distance, and I would expect to get better results using a GA. Any ideas as to why my GA performing worse when I add crossover? And why is it performing much worse than a simple Hill-Climb algorithm which should get stuck on local maxima as it has no way of exploring once it finds a local max?

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  • general learning methodology

    - by momo
    just wanted to hear on the different general learning paths people embark on when learning a new language/framework. the one i currently use, which is how i learned bash and am currently learning python, is: instant hacking tutorial (very short tutorial introducing the basic syntax, variable declaration, loops, data types, etc. and how they are generally used) in depth tutorial with good programming style and slightly topic-specific (e.g. Mark Pilgrim's Dive into Python), important topics for me personally are regex methods, file IO, and ways the different data types are utilized best (i wrote a very primitive bayesian spam filter using python's dictionaries to keep track of word occurrences) spaced-repition of syntax or short recipes (i use anki, with questions like 'create dictionary with filename and filesize metadata, human-readable' or simpler ones like 'match 0 - 3 occurences of the letter M in a string', or 'return/create an iterator from two sequences') the use of spaced-repitition has been invaluable, and i credit it with the ease that i can recall/create python algorithms. however, i've recently started looking into django, and i've found that spaced-repitition, at least in my case, doesn't work very well for learning a framework, it works best with short code recipes (either that or i should start looking into more basic django framework tutorials). the problem i'm encountering is that since framework programming is not only algorithms, but actually learning the API, which can be quite complex since you have to learn all the methods, modules, the places where they are stored, and the sequence of which things have to be done. for ex. in django to start a project that deals with polls (from the django tutorial), one has to create the project, edit the settings.py file, create the polls app, edit the models.py file (which requires knowing the classes that are present in the module models), edit the urls.py file, etc. i found that my spaced-repition method didn't work very well for this type of learning, so i wanted to ask you guys what method(s) you use for learning the different frameworks/APIs.

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  • How to perform a binary search on IList<T>?

    - by Daniel Brückner
    Simple question - given an IList<T> how do you perform a binary search without writing the method yourself and without copying the data to a type with build-in binary search support. My current status is the following. List<T>.BinarySearch() is not a member of IList<T> There is no equivalent of the ArrayList.Adapter() method for List<T> IList<T> does not inherit from IList, hence using ArrayList.Adapter() is not possible I tend to believe that is not possible with build-in methods, but I cannot believe that such a basic method is missing from the BCL/FCL. If it is not possible, who can give the shortest, fastest, smartest, or most beatiful binary search implementation for IList<T>? UPDATE We all know that a list must be sorted before using binary search, hence you can assume that it is. But I assume (but did not verify) it is the same problem with sort - how do you sort IList<T>? CONCLUSION There seems to be no build-in binary search for IList<T>. One can use First() and OrderBy() LINQ methods to search and sort, but it will likly have a performance hit. Implementing it yourself (as an extension method) seems the best you can do.

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  • Refactor throwing not null exception if using a method that has a dependency on a certain contructor

    - by N00b
    In the method below the second constructor accepts a ForumThread object which the IncrementViewCount() method uses. There is a dependency between the method and that particular constructor. Without extracting into a new private method the null check in IncrementViewCount() and LockForumThread() (plus other methods not shown) is there some simpler re-factoring I can do or the implementation of a better design practice for this method to guard against the use of the wrong constructor with these dependent methods? Thank you for any suggestions in advance. private readonly IThread _forumLogic; private readonly ForumThread _ft; public ThreadLogic(IThread forumLogic) : this(forumLogic, null) { } public ThreadLogic(IThread forumLogic, ForumThread ft) { _forumLogic = forumLogic; _ft = ft; } public void Create(ForumThread ft) { _forumLogic.SaveThread(ft); } public void IncrementViewCount() { if (_ft == null) throw new NoNullAllowedException("_ft ForumThread is null; this must be set in the constructor"); lock (_ft) { _ft.ViewCount = _ft.ViewCount + 1; _forumLogic.SaveThread(_ft); } } public void LockForumThread() { if (_ft == null) throw new NoNullAllowedException("_ft ForumThread is null; this must be set in the constructor"); _ft.ThreadLocked = true; _forumLogic.SaveThread(_ft); }

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  • UITouch Events and Table Views

    - by Andy
    I'm working on a navigation-based iPhone-only app that serves two main purposes: One, to present data in a hierarchical view, allowing users to drill down and eventually edit said data, and, two, to all users to perform a default action when the table view cell is tapped. I now need to offer a small set of options tied to the same data; however, both the didSelectRowAtIndexPath: and accessoryButtonTappedForRowAtIndexPath: methods are obviously taken. So, my options seem to be to implement a double-tap method, wherein the small list of additional options would be presented after (you guessed it) a double-tap on said table row; or, preferably, a tap-and-hold method. From what I can tell, tap-and-hold seems like the way to go in SDK 4.0 - which does me no good right this red-hot minute. I decided to go with the double-tap option, but I'm having a little trouble. First and foremost, the touchesBegan:withEvent: method does not seem to be getting called at all; a breakpoint placed within the method is never called while the application runs, and the table view responds exactly as it did before I inserted the method (which is to say, it performs the default action): - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *aTouch = [touches anyObject]; if (aTouch.tapCount == 2) { [NSObject cancelPreviousPerformRequestsWithTarget:self]; } } Second, I don't really need to handle a single-tap - the didSelectRowAtIndexPath: method can handle the single-tap just fine. The double-tap is the funky one I want to handle. I suspect the answer is going to contain the phrase, "You can't have the table view handle the single-tap and the touchesBegan: method handle the double-tap. The touch handling methods have to handle all of them." I would really appreciate some guidance from some of you who've dealt with this issue. Thanks in advance.

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  • Accessing running task scheduled with java.util.Timer

    - by jbatista
    I'm working on a Java project where I have created a class that looks like this (abridged version): public class Daemon { private static Timer[] timerarray=null; private static Daemon instance=null; protected Daemon() { ArrayList<Timer> timers = new ArrayList<Timer>(); Timer t = new Timer("My application"); t.schedule(new Worker(), 10000,30000); timers.add(t); //... timerarray = timers.toArray(new Timer[]{}); } public static Daemon getInstance() { if(instance==null) instance=new Daemon(); return instance; } public SomeClass getSomeValueFromWorker() { return theValue; } ///////////////////////////////////////////// private class Worker extends TimerTask { public Worker() {} public void run() { // do some work } public SomeReturnClass someMethod(SomeType someParameter) { // return something; } } ///////////////////////////////////////////// } I start this class, e.g. by invoking daemon.getInstance();. However, I'd like to have some way to access the running task objects' methods (for example, for monitoring the objects' state). The Java class java.util.Timer does not seem to provide the means to access the running object, it just schedules the object instance extending TimerTask. Are there ways to access the "running" object instanciated within a Timer? Do I have to subclass the Timer class with the appropriate methods to somehow access the instance (this "feels" strange, somehow)? I suppose someone might have done this before ... where can I find examples of this "procedure"? Thank you in advance for your feedback.

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  • Different EF Property DataType than Storage Layer Possible?

    - by dj_kyron
    Hi, I am putting together a WCF Data Service for PatientEntities using Entity Framework. My solution needs to address these requirements: Property DateOfBirth of entity Patient is stored in SQL Server as string. It would be ideal if the entity class did not also use the "string" type but rather a DateTime type. (I would expect this to be possible since we're abstracting away from the storage layer). Where could a conversion mechanism be put in place that would convert to and from DateTime/string so that the entity and SQL Server are in sync?. I cannot change the storage layer's structure, so I have to work around it. WCF Data Services (Read-only, so no need for saving changes) need to be used since clients will be able to use LINQ expressions to consume the service. They can generate results based on any given query scenario they need and not be constrained by a single method such as GetPatient(int ID). I've tried to use DTOs, but run into problem of mapping the ObjectContext to a DTO, I don't think that is theoretically possible...or too complicated if it is. I've tried to use Self Tracking Entities but they require the metadata from the .edmx file if I'm correct, and this isn't allowing a different property data type. I also want to add customizations to my Entity getter methods so that a property "MRN" of type "string" needs to have .Replace("MR~", string.Empty) performed before it is returned. I can add this to the getter methods but the problem with that is Entity Framework will overwrite that next time it refreshes the entity classes. Is there a permanent place I can put these? Should I use POCO instead? How would that work with WCF Data Services? Where would the service grab the metadata?

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  • How to get a Class literal from a generically specific Class

    - by h2g2java
    There are methods like these which require Class literals as argument. Collection<EmpInfo> emps = SomeSqlUtil.select( EmpInfo.class, "select * from emps"); or GWT.create(Razmataz.class); The problem presents itself when I need to supply generic specific classes like EmpInfo<String> Razmataz<Integer> The following would be wrong syntax Collection<EmpInfo<String>> emps = SomeSqlUtil.select( EmpInfo<String>.class, "select * from emps"); or GWT.create(Razmataz<Integer>.class); Because you cannot do syntax like Razmataz<Integer>.class So, how would I be able to squeeze a class literal out of EmpInfo<String> Razmataz<Integer> so that I could feed them as arguments to methods requiring Class literals? Further info Okay, I confess that I am asking this primarily for GWT. I have a pair of GWT RPC interface Razmataz. (FYI, GWT RPC interface has to be defined in server-client pairs). I plan to use the same interface pair for communicating whether it be String, Integer, Boolean, etc. GWT.create(Razmataz) for Razmataz<T> complains that, since I did not specify T, GWT compiler treated it as Object. Then GWT compiler would not accept Object class. It needs to be more specific than being an Object. So, it seems there is no way for me to tell GWT.create what T is because a Class literal is a runtime concept while generics is a compile time concept, Right?

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  • Encapsulate update method inside of object or have method which accepts an object to update

    - by Tom
    Hi, I actually have 2 questions related to each other: I have an object (class) called, say MyClass which holds data from my database. Currently I have a list of these objects ( List < MyClass ) that resides in a singleton in a "communal area". I feel it's easier to manage the data this way and I fail to see how passing a class around from object to object is beneficial over a singleton (I would be happy if someone can tell me why). Anyway, the data may change in the database from outside my program and so I have to update the data every so often. To update the list of the MyClass I have a method called say, Update, written in another class which accepts a list of MyClass. This updates all the instances of MyClass in the list. However would it be better instead to encapulate the Update() method inside the MyClass object, so instead I would say foreach(MyClass obj in MyClassList) { obj.update(); } What is a better implementation and why? The update method requires a XML reader. I have written an XML reader class which is basically a wrapper over the standard XML reader the language natively provides which provides application specific data collection. Should the XML reader class be in anyway in the "inheritance path" of the MyClass object - the MyClass objects inherits from the XML reader because it uses a few methods. I can't see why it should. I don't like the idea of declaring an instance of the XML Reader class inside of MyClass and an MyClass object is meant to be a simple "record" from the database and I feel giving it loads of methods, other object instances is a bit messy. Perhaps my XML reader class should be static but C#'s native XMLReader isn't static.? Any comments would be greatly appreciated Thanks Thomas

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  • Independent name of a class

    - by tobi
    We have class lua. In lua class there is a method registerFunc() which is defined: void lua::registerFun() { lua_register( luaState, "asd", luaApi::asd); lua_register( luaState, "zxc", luaApi::zxc); } lua_register is a built-in function from lua library: http://pgl.yoyo.org/luai/i/lua_register it takes static methods from luaApi class as an 3rd argument. Now some programmer wants to use the lua class, so he is forced to create his own class with definitions of the static methods, like: class luaApi { public: static int asd(); static int zxc(); }; and now is the point. I don't want (as a programmer) to create class named exactly "luaApi", but e.g. myClassForLuaApi. But for now it's not possible because it is explicitly written in the code - in lua class: lua_register( luaState, "asd", luaApi::asd); I would have to change it to: lua_register( luaState, "asd", myClassForLuaApi::asd); but I don't want to (let's assume that the programmer has no access there). If it's still not understandable, I give up. :) Thanks.

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  • OO vs Simplicity when it comes to user interaction

    - by Oetzi
    Firstly, sorry if this question is rather vague but it's something I'd really like an answer to. As a project over summer while I have some downtime from Uni I am going to build a monopoly game. This question is more about the general idea of the problem however, rather than the specific task I'm trying to carry out. I decided to build this with a bottom up approach, creating just movement around a forty space board and then moving on to interaction with spaces. I realised that I was quite unsure of the best way of proceeding with this and I am torn between two design ideas: Giving every space its own object, all sub-classes of a Space object so the interaction can be defined by the space object itself. I could do this by implementing different land() methods for each type of space. Only giving the Properties and Utilities (as each property has unique features) objects and creating methods for dealing with the buying/renting etc in the main class of the program (or Board as I'm calling it). Spaces like go and super tax could be implemented by a small set of conditionals checking to see if player is on a special space. Option 1 is obviously the OO (and I feel the correct) way of doing things but I'd like to only have to handle user interaction from the programs main class. In other words, I don't want the space objects to be interacting with the player. Why? Errr. A lot of the coding I've done thus far has had this simplicity but I'm not sure if this is a pipe dream or not for larger projects. Should I really be handling user interaction in an entirely separate class? As you can see I am quite confused about this situation. Is there some way round this? And, does anyone have any advice on practical OO design that could help in general?

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  • c# delegate and abstract class

    - by BeraCim
    Hi all: I currently have 2 concrete methods in 2 abstract classes. One class contains the current method, while the other contains the legacy method. E.g. // Class #1 public abstract class ClassCurrent<T> : BaseClass<T> where T : BaseNode, new() { public List<T> GetAllRootNodes(int i) { //some code } } // Class #2 public abstract class MyClassLegacy<T> : BaseClass<T> where T : BaseNode, new() { public List<T> GetAllLeafNodes(int j) { //some code } } I want the corresponding method to run in their relative scenarios in the app. I'm planning to write a delegate to handle this. The idea is that I can just call the delegate and write logic in it to handle which method to call depending on which class/project it is called from (at least thats what I think delegates are for and how they are used). However, I have some questions on that topic (after some googling): 1) Is it possible to have a delegate that knows the 2 (or more) methods that reside in different classes? 2) Is it possible to make a delegate that spawns off abstract classes (like from the above code)? (My guess is a no, since delegates create concrete implementation of the passed-in classes) 3) I tried to write a delegate for the above code. But I'm being technically challenged: public delegate List GetAllNodesDelegate(int k); GetAllNodesDelegate del = new GetAllNodesDelegate(ClassCurrent.GetAllRootNodes); I got the following error: An object reference is required for the non-static field, method, property ClassCurrent<BaseNode>.GetAllRootNodes(int) I might have misunderstood something... but if I have to manually declare a delegate at the calling class, AND to pass in the function manually as above, then I'm starting to question whether delegate is a good way to handle my problem. Thanks.

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  • Importing data from third party datasource (open architecture design )

    - by mare
    How would you design an application (classes, interfaces in class library) in .NET when we have a fixed database design on our side and we need to support imports of data from third party data sources, which will most likely be in XML? For instance, let us say we have a Products table in our DB which has columns Id Title Description TaxLevel Price and on the other side we have for instance Products: ProductId ProdTitle Text BasicPrice Quantity. Currently I do it like this: Have the third party XML convert to classes and XSD's and then deserialize its contents into strong typed objects (what we get as a result of this process is classes like ThirdPartyProduct, ThirdPartyClassification, etc.). Then I have methods like this: InsertProduct(ThirdPartyProduct newproduct) I do not use interfaces at the moment but I would like them to. What I would like is implement something like public class Contoso_ProductSynchronization : ProductSynchronization InsertProduct(ContosoProduct p) where ProductSynchronization will be an interface or abstract class. There will most likely be many implementations of ProductSynchronization. I cannot hardcode the types - classes like ContosoProduct, NorthwindProduct might be created from the third party XML's (so preferably I would continue to use deserialization). Hopefully someone will understand what I'm trying to explain here. Just imagine you are the seller and you have numerous providers and each one uses their own proprietary XML format. I don't mind the development, which will of course be needed everytime new format appears, because it will only require 10-20 methods to be implemented, I just want the architecture to be open and support that.

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  • Should java try blocks be scoped as tightly as possible?

    - by isme
    I've been told that there is some overhead in using the Java try-catch mechanism. So, while it is necessary to put methods that throw checked exception within a try block to handle the possible exception, it is good practice performance-wise to limit the size of the try block to contain only those operations that could throw exceptions. I'm not so sure that this is a sensible conclusion. Consider the two implementations below of a function that processes a specified text file. Even if it is true that the first one incurs some unnecessary overhead, I find it much easier to follow. It is less clear where exactly the exceptions come from just from looking at statements, but the comments clearly show which statements are responsible. The second one is much longer and complicated than the first. In particular, the nice line-reading idiom of the first has to be mangled to fit the readLine call into a try block. What is the best practice for handling exceptions in a funcion where multiple exceptions could be thrown in its definition? This one contains all the processing code within the try block: void processFile(File f) { try { // construction of FileReader can throw FileNotFoundException BufferedReader in = new BufferedReader(new FileReader(f)); // call of readLine can throw IOException String line; while ((line = in.readLine()) != null) { process(line); } } catch (FileNotFoundException ex) { handle(ex); } catch (IOException ex) { handle(ex); } } This one contains only the methods that throw exceptions within try blocks: void processFile(File f) { FileReader reader; try { reader = new FileReader(f); } catch (FileNotFoundException ex) { handle(ex); return; } BufferedReader in = new BufferedReader(reader); String line; while (true) { try { line = in.readLine(); } catch (IOException ex) { handle(ex); break; } if (line == null) { break; } process(line); } }

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  • Pattern for UI configuration

    - by TERACytE
    I have a Win32 C++ program that validates user input and updates the UI with status information and options. Currently it is written like this: void ShowError() { SetIcon(kError); SetMessageString("There was an error"); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } void ShowSuccess() { SetIcon(kError); std::String statusText (GetStatusText()); SetMessageString(statusText); HideButton(kButton1); HideButton(kButton2); ShowButton(kButton3); } // plus several more methods to update the UI using similar mechanisms I do not likes this because it duplicates code and causes me to update several methods if something changes in the UI. I am wondering if there is a design pattern or best practice to remove the duplication and make the functionality easier to understand and update. I could consolidate the code inside a config function and pass in flags to enable/disable UI items, but I am not convinced this is the best approach. Any suggestions and ideas?

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  • How can i get rid of 'ORA-01489: result of string concatenation is too long' in this query?

    - by core_pro
    this query gets the dominating sets in a network. so for example given a network A<----->B B<----->C B<----->D C<----->E D<----->C D<----->E F<----->E it returns B,E B,F A,E but it doesn't work for large data because i'm using string methods in my result. i have been trying to remove the string methods and return a view or something but to no avail With t as (select 'A' as per1, 'B' as per2 from dual union all select 'B','C' from dual union all select 'B','D' from dual union all select 'C','B' from dual union all select 'C','E' from dual union all select 'D','C' from dual union all select 'D','E' from dual union all select 'E','C' from dual union all select 'E','D' from dual union all select 'F','E' from dual) ,t2 as (select distinct least(per1, per2) as per1, greatest(per1, per2) as per2 from t union select distinct greatest(per1, per2) as per1, least(per1, per2) as per1 from t) ,t3 as (select per1, per2, row_number() over (partition by per1 order by per2) as rn from t2) ,people as (select per, row_number() over (order by per) rn from (select distinct per1 as per from t union select distinct per2 from t) ) ,comb as (select sys_connect_by_path(per,',')||',' as p from people connect by rn > prior rn ) ,find as (select p, per2, count(*) over (partition by p) as cnt from ( select distinct comb.p, t3.per2 from comb, t3 where instr(comb.p, ','||t3.per1||',') > 0 or instr(comb.p, ','||t3.per2||',') > 0 ) ) ,rnk as (select p, rank() over (order by length(p)) as rnk from find where cnt = (select count(*) from people) order by rnk ) select distinct trim(',' from p) as p from rnk where rnk.rnk = 1`

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  • How do I create efficient instance variable mutators in Matlab?

    - by Trent B
    Previously, I implemented mutators as follows, however it ran spectacularly slowly on a recursive OO algorithm I'm working on, and I suspected it may have been because I was duplicating objects on every function call... is this correct? %% Example Only obj2 = tripleAllPoints(obj1) obj.pts = obj.pts * 3; obj2 = obj1 end I then tried implementing mutators without using the output object... however, it appears that in MATLAB i can't do this - the changes won't "stick" because of a scope issue? %% Example Only tripleAllPoints(obj1) obj1.pts = obj1.pts * 3; end For application purposes, an extremely simplified version of my code (which uses OO and recursion) is below. classdef myslice properties pts % array of pts nROW % number of rows nDIM % number of dimensions subs % sub-slices end % end properties methods function calcSubs(obj) obj.subs = cell(1,obj.nROW); for i=1:obj.nROW obj.subs{i} = myslice; obj.subs{i}.pts = obj.pts(1:i,2:end); end end function vol = calcVol(obj) if obj.nROW == 1 obj.volume = prod(obj.pts); else obj.volume = 0; calcSubs(obj); for i=1:obj.nROW obj.volume = obj.volume + calcVol(obj.subs{i}); end end end end % end methods end % end classdef

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  • ASP.NET MVC 2 - How do I use an Interface as the Type for a Strongly Typed View

    - by Rake36
    I'd like to keep my concrete classes separate from my views. Without using strongly typed views, I'm fine. I just use a big parameter list in the controller method signatures and then use my service layer factory methods to create my concrete objects. This is actually just fine with me, but it got me thinking and after a little playing, I realized it was literally impossible for a controller method to accept an interface as a method parameter - because it has no way of instantiating it. Can't create a strongly-typed view using an interface through the IDE either (which makes sense actually). So my question. Is there some way to tell the controller how to instantiate the interface parameter using my service layer factory methods? I'd like to convert from: [Authorize] [AcceptVerbs(HttpVerbs.Post)] [UrlRoute(Path = "Application/Edit/{id}")] public ActionResult Edit(String id, String TypeCode, String TimeCode, String[] SelectedSchoolSystems, String PositionChoice1, String PositionChoice2, String PositionChoice3, String Reason, String LocationPreference, String AvailableDate, String RecipientsNotSelected, String RecipientsSelected) { //New blank app IApplication _application = ApplicationService.GetById(id); to something like [Authorize] [AcceptVerbs(HttpVerbs.Post)] [UrlRoute(Path = "Application/Edit/{id}")] public ActionResult Edit(String id, IApplication app) { //Don't need to do this anymore //IApplication _application = ApplicationService.GetById(id);

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  • Is a call to the following method considered late binding?

    - by AspOnMyNet
    1) Assume: • B1 defines methods virtualM() and nonvirtualM(), where former method is virtual while the latter is non-virtual • B2 derives from B1 • B2 overrides virtualM() • B2 is defined inside assembly A • Application app doesn’t have a reference to assembly A In the following code application app dynamically loads an assembly A, creates an instance of a type B2 and calls methods virtualM() and nonvirtualM(): Assembly a=Assembly.Load(“A”); Type t= a.GetType(“B2”); B1 a = ( B1 ) Activator.CreateInstance ( “t” ); a.virtualM(); a.nonvirtualM(); a) Is call to a.virtualM() considered early binding or late binding? b) I assume a call to a.nonvirtualM() is resolved during compilation time? 2) Does the term late binding refer only to looking up the target method at run time or does it also refer to creating an instance of given type at runtime? thanx EDIT: 1) A a=new A(); a.M(); As far as I know, it is not known at compile time where on the heap (thus at which memory address ) will instance a be created during runtime. Now, with early binding the function calls are replaced with memory addresses during compilation process. But how can compiler replace function call with memory address, if it doesn’t know where on the heap will object a be created during runtime ( here I’m assuming the address of method a.M will also be at same memory location as a )? 2) The method slot is determined at compile time I assume that by method slot you’re referring to the entry point in V-table?

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  • Choosing a method for a webservice

    - by Wrikken
    I'm asked to set up a new webservice which should be easily usable in whatever language (php, .NET, Java, etc.) possible. Of course rolling my own can be done, accepting different content-types (xml / x-www-form-urlencoded (normal post) / json / etc.), but an existing method or mechanism would of course be prefered, cutting down time spent on development for the consumers of the service. The webservice does accept modifications / sets (it is not only simply data retrieval), but those will most likely be quite a lot less then gets (we estimate about 2.5% sets, 97.5 gets). The term webservice here indicates the protocol should go over HTTP, not being able to implement it totally client sided (javascript in the end-users browser etc.), as it needs specific user authentication. Both gets and sets are pretty light on the parameter count (usually 1 to 4). Methods like REST (which I'd prefer for only gets), XML-RPC & SOAP (might be a bit overkill, but has the advantage of explicitly defined methods and returns) are the usual suspects. What in your opinion / experience is the most widely 'spoken' and most easily implementable protocol in different languages (seen from the consumers' viewpoint) which could fullfill this need?

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  • MSBuild / PowerShell: Copy SQL Server 2012 database to SQL Azure via BACPAC (for Continuous Integration)

    - by giveme5minutes
    I'm creating a continuous integration MSBuild script which copies a database in on-premise SQL Server 2012 to SQL Azure. Easy right? Methods After a fair bit of research I've come across the following methods: Use PowerShell to access the DAC library directly, then use the MSBuild PowerShell extension to wrap the script. This would require installing PowerShell 3 and working out how to make the MSBuild PowerShell extension work with it, as apparently MS moved the DAC API to a different namespace in the latest version of the library. PowerShell would give direct access to the API, but may require quite a bit of boilerplate. Use the sample DAC Framework Client Side Tools, which requires compiling them myself, as the downloads available from Codeplex only include the Hosted version. It would also require fixing them to use DAC 3.0 classes as they appear to currently use an earlier version of DAC. I could then call these tools from an <Exec Command="" /> in the MSBuild script. Less boilerplate and if I hit any bumps in the road I can just make changes to the source. Processes Using whichever method, the process could be either: Export from on-premise SQL Server 2012 to local BACPAC Upload BACPAC to blog storage Import BACPAC to SQL Azure via Hosted DAC Or: Export from on-premise SQL Server 2012 to local BACPAC Import BACPAC to SQL Azure via Client DAC Question All of the above seems to be quite a lot of effort for something that seems to be a standard feature... so before I start reinventing the wheel and documenting the results for all to see, is there something really obvious that I've missed here? Is there pre-written script that MS has released that I have not yet uncovered? There's an command in the GUI of SQL Server Management Studio 2012 that does EXACTLY what I'm trying to do (right click on local database, click "Tasks", click "Deploy Database to SQL Azure"). Surely if it's a few clicks in the GUI it must be a single command on the command line somewhere??

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