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  • Generate unique ID from multiple values with fault tolerance

    - by ojreadmore
    Given some values, I'd like to make a (pretty darn) unique result. $unique1 = generate(array('ab034', '981kja7261', '381jkfa0', 'vzcvqdx2993883i3ifja8', '0plnmjfys')); //now $unique1 == "sqef3452y"; I also need something that's pretty close to return the same result. In this case, 20% of the values is missing. $unique2 = generate(array('ab034', '981kja7261', '381jkfa0', 'vzcvqdx2993883i3ifja8')); //also $unique2 == "sqef3452y"; I'm not sure where to begin with such an algorithm but I have some assumptions. I assume that the more values given, the more accurate the resulting ID – in other words, using 20 values is better than 5. I also assume that a confidence factor can be calculated and adjusted. What would be nice to have is a weight factor where one can say 'value 1 is more important than value 3'. This would require a multidimensional array for input instead of one dimension. I just mashed on the keyboard for these values, but in practice they may be short or long alpha numeric values.

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  • Combine Arbitrary number of polygons together

    - by Jakobud
    I have an arbitrary number of polygons (hexes in this case) that are arranged randomly, but they are all touching another hex. Each individual hex has 6 x,y vertices. The vertex's are known for all the hexes. Can anyone point me in the direction of an algorithm that will combine all the hexes into a single polygon? Essentially I'm just looking for a function that spits out an array of vertex locations that are ordered in a way that when drawing lines from one to the next, it forms the polygon. This is my method so far: Create array of all the vertices for all the hexes. Determine the number of times a vertex occurs in the array If vertex is in the array 3+ times, delete the vertices from the array. If vertex is in the array 2 times, delete one of them. The next step is tricky though. I'm using canvas to draw out these polygons, which essentially involves drawing a line from one vertex to the next. So the order of the vertices in the final array is important. It can't be sorted arbitrarily. Also, I'm not looking for a "convex hull" algorithm, as that would not draw the polygon correctly. Are there any functions out there that do something like this? Am I on the right track or is there a better more efficient way?

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  • Why does the Maven goal "package" include the resources in the jar, but the goal "jar:jar" doesnt?

    - by Bernhard V
    Hi, when I package my project with the Maven goal "package", the resources are included as well. They are originally located in the directory "src/main/resources". Because I want to create an executable jar and add the classpath to the manifest, I'm using maven-jar-plugin. I've configured it as the following likes: <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <version>2.2</version> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <mainClass>at.sozvers.stp.zpv.ekvkumsetzer.Main</mainClass> </manifest> </archive> </configuration> </plugin> Why won't the jar file created with "jar:jar" include my resources as well. As far as I'm concerned it should use the same directories as the "package" goal (which are in my case inherited from the Maven Super POM).

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  • trouble with custom 'Text Bubble' component (examples included)

    - by gmoniey
    I'm trying to use a custom Text component to show a series of comments. I got the original idea from: http://www.eonflex.com/?p=40 I've got the base case working but I am stuck with 2 problems I cant seem to figure out: Since I am drawing around the text, the actual height of each bubble is greater than that of the Text field, as a result, the last bubble is always chopped off. I have tried explicitly overriding the height getter, and adding some padding, but I cant seem to get it right. You can see an example here: http://test.lambandtunafish.com/bubbles/CommentTest.swf In my layout, I have 2 VBoxes (one nested inside the other). The first vbox shows a form where the user can enter a comment, and the second box has all the comments. In order to ensure that the scrollbars only show up on the second box, I set minHeight="0" on the nested VBox, but then for some reason, some comments' text is shifted to the right. You can see an example here (look at the first comment): http://test.lambandtunafish.com/bubbles/CommentTest-minHeight.swf Rather than posting the code here, I've provided some links: Container: http://test.lambandtunafish.com/bubbles/CommentTest.mxml Bubble: http://test.lambandtunafish.com/bubbles/CommentBubble.as If anyone has any ideas, I would appreciate it. Thanks!

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  • Java convert time format to integer or long

    - by behrk2
    Hello, I'm wondering what the best method is to convert a time string in the format of 00:00:00 to an integer or a long? My ultimate goal is to be able to convert a bunch of string times to integers/longs, add them to an array, and find the most recent time in the array... I'd appreciate any help, thanks! Ok, based on the answers, I have decided to go ahead and compare the strings directly. However, I am having some trouble. It is possible to have more than one "most recent" time, that is, if two times are equal. If that is the case, I want to add the index of both of those times to an ArrayList. Here is my current code: days[0] = "15:00:00"; days[1] = "17:00:00"; days[2] = "18:00:00"; days[3] = "19:00:00"; days[4] = "19:00:00"; days[5] = "15:00:00"; days[6] = "13:00:00"; ArrayList<Integer> indexes = new ArrayList<Integer>(); String curMax = days[0]; for (int x = 1; x < days.length1; x++) { if (days[x].compareTo(curMax) > 0) { curMax = days[x]; indexes.add(x); System.out.println("INDEX OF THE LARGEST VALUE: " + x); } } However, this is adding index 1, 2, and 3 to the ArrayList... Can anyone help me?

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  • Java Class<T> static method forName() IncompatibleClassChangeError

    - by matt
    Hi, i have this code: private static Importable getRightInstance(String s) throws Exception { Class<? extends Importable> c = Class.forName(s).asSubclass(Importable.class); Importable i = c.newInstance(); return i; } which i can also write private static Importable getRightInstance(String s) throws Exception { Class<? extends Importable> c = (Class<? extends Importable>)Class.forName(s); Importable i = c.newInstance(); return i; } or private static Importable getRightInstance(String s) throws Exception { Class<?> c = Class.forName(s); Importable i = (Importable)c.newInstance(); return i; } where Importable is an interface and s is a string representing an implementing class. Well, in any case it gives the following: Exception in thread "main" java.lang.IncompatibleClassChangeError: class C1 has interface Importable as super class Here is the last snippet of the stack trace: at java.lang.Class.forName(Class.java:169) at Importer.getRightImportable(Importer.java:33) at Importer.importAll(Importer.java:44) at Test.main(Test.java:16) Now, class C1 actually implemens Importable and i totally don't understand why it complaints. Thanks in advance.

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  • Multiple leaf methods problem in composite pattern

    - by Ondrej Slinták
    At work, we are developing an PHP application that would be later re-programmed into Java. With some basic knowledge of Java, we are trying to design everything to be easily re-written, without any headaches. Interesting problem came out when we tried to implement composite pattern with huge number of methods in leafs. What are we trying to achieve (not using interfaces, it's just an example): class Composite { ... } class LeafOne { public function Foo( ); public function Moo( ); } class LeafTwo { public function Bar( ); public function Baz( ); } $c = new Composite( Array( new LeafOne( ), new LeafTwo( ) ) ); // will call method Foo in all classes in composite that contain this method $c->Foo( ); It seems like pretty much classic Composite pattern, but problem is that we will have quite many leaf classes and each of them might have ~5 methods (of which few might be different than others). One of our solutions, which seems to be the best one so far and might actually work, is using __call magic method to call methods in leafs. Unfortunately, we don't know if there is an equivalent of it in Java. So the actual question is: Is there a better solution for this, using code that would be eventually easily re-coded into Java? Or do you recommend any other solution? Perhaps there's some different, better pattern I could use here. In case there's something unclear, just ask and I'll edit this post.

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  • Want to add a functional language to my toolchest. Haskell or Erlang?

    - by sean.johnson
    I've been an OO/procedural guy my whole career except in school where I did a lot of logic programming (Prolog). I work on an amazing variety of projects (freelancer) and so I don't want the tools I know and understand to hold me back from using the right tool for the job. I've decided I should know a functional programming language. I've narrowed the field to Haskell and Erlang. What are the pros and cons, advantages and disadvantages, and major trade offs of Haskell and Erlang? How do I decide in a rational way, which is the better path? This is a big time investment, so I'd like to chose wisely. Is there a good case to be made for something else entirely? F#, Scala Ocaml? (BTW, I'm normally a Ruby/C/Obj.C guy, so I'm not terribly impressed or dependent on the JVM as a runtime. It's completely neutral to me. It's a fine runtime, I don't hold it for or against a language. I don't use Microsoft products though, so a .NET runtime would be a negative.)

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  • Reflection and Operator Overloads in C#

    - by TenshiNoK
    Here's the deal. I've got a program that will load a given assembly, parse through all Types and their Members and compile a TreeView (very similar to old MSDN site) and then build HTML pages for each node in the TreeView. It basically takes a given assembly and allows the user to create their own MSDN-like library for it for documentation purposes. Here's the problem I've run into: whenever an operator overload is encounted in a defined class, reflection returns that as a "MethodInfo" with the name set to something like "op_Assign" or "op_Equality". I want to be able to capture these and list them properly, but I can't find anything in the MethodInfo object that is returned to accurately identify that I'm looking at an operator. I definitely don't want to just capture everything that starts with "op_", since that will most certainly (at some point) will pick up a method it's not supposed to. I know that other methods and properties that are "special cases" like this one have the "IsSpecialName" property set, but appearantly that's not the case with operators. I've been scouring the 'net and wracking my brain to two days trying to figure this one out, so any help will be greatly appreciated.

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  • How to build a dynamic resize-able Flash player

    - by Leon
    Morning stackers! So my question today isn't dealing with any code, but how to go about this the correct way from the start. I have a video player built to a static size (max: 800x600) which I'll have to re-code every time I need it to be a different size. What I need it to do in the near future is dynamically resize itself and all the elements inside of it based on 1 width variable that it will received either from HTML or XML. Now to me there are 2 ways to go about this: Start with the smallest size possible and resize upwards, but I'm unsure of how the Flash movie will actually expand upwards as of right now. Or 2, start with the largest size possible (in this case 800x600) and size everything down. Step 1, I think seems to be the better way to go about this (ala YouTube style), but Step 2 also seems like it could be the easier way? A friend of mine mentioned that I should go with the larger size and have elements resize in each class, then fix to the upper left hand corner. However for the player to fit inside of certain div columns on sites, blogs whatever he said that there will have to be an HTML/CSS side of this... meaning that the div containing the resized flash player will have to cover up the areas of the Flash movie that are not to be shown? Is that possible to put a 800x600 flash movie into a div that smaller then 800 pixels wide? And cover it up with another div? Anyways, my mission is to be able to have a dynamically sized player like this: Thoughts? Recommendations? Best practices for this before I start?

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  • Commited memory goes to physical RAM or reserves space in the paging file?

    - by Sil
    When I do VirtualAlloc with MEM_COMMIT this "Allocates physical storage in memory or in the paging file on disk for the specified reserved memory pages" (quote from MSDN article http://msdn.microsoft.com/en-us/library/aa366887%28VS.85%29.aspx). All is fine up until now BUT: the description of Commited Bytes Counter says that "Committed memory is the physical memory which has space reserved on the disk paging file(s)." I also read "Windows via C/C++ 5th edition" and this book says that commiting memory means reserving space in the page file.... The last two cases don't make sense to me... If you commit memory, doesn't that mean that you commit to physical storage (RAM)? The page file being there for swaping out currently unused pages of memory in case memory gets low. The book says that when you commit memory you actually reserve space in the paging file. If this were true than that would mean that for a committed page there is space reserved in the paging file and a page frame in physical in memory... So twice as much space is needed ?! Isn't the page file's purpose to make the total physical memory larger than it actually is? If I have a 1G of RAM with a 1G page file = 2G of usable "physical memory"(the book also states this but right after that it says what I discribed at point 2). What am I missing? Thanks.

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  • Managing My Database in Source Control

    - by Jason
    As I am working with a new database project (within VS2008), and as I have never developed a database from scratch, I immediately began looking into how to manage a database within source control (in this case, Subversion). I found some information on SO, including this post: Keeping development databases in multiple environments in sync. One of the answers in particular pointed to a number of a links, all of which had good, useful information. I was reading a series of posts by K. Scott Allen which describe how he manages database change. From my reading (and please pardon the noobishness of my question), it seems as though the database itself is never checked into a repository. Rather, scripts that can build the database, along with test data (which is also populated from scripts) is checked into the repository. Ultimately, this means that, when a developer is testing his or her app, these scripts, which are part of the build process, are run. This ensures that the database is up-to-date, but is also run locally from every developer's machine. This makes sense to me (if I am indeed reading that correctly). However, if I am missing something, I would appreciate correction or additional guidance. In addition, another question I wanted to ask - does this also mean that I should NOT check in the mdf or ldf files that are created from Visual Studio? Thanks for any help and additional insight. Always appreciated.

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  • C++ variable to const expression

    - by user1344784
    template <typename Real> class A{ }; template <typename Real> class B{ }; //... a few dozen more similar template classes class Computer{ public slots: void setFrom(int from){ from_ = from; } void setTo(int to){ to_ = to; } private: template <int F, int T> void compute(){ using boost::fusion::vector; using boost::fusion::at_c; vector<A<float>, B<float>, ...> v; at_c<from_>(v).operator()(at_c<to_>(v)); //error; needs to be const-expression. }; This question isn't about Qt, but there is a line of Qt code in my example. The setFrom() and setTo() are functions that are called based on user selection via the GUI widget. The root of my problem is that 'from' and 'to' are variables. In my compute member function I need to pick a type (A, B, etc.) based on the values of 'from' and 'to'. The only way I know how to do what I need to do is to use switch statements, but that's extremely tedious in my case and I would like to avoid. Is there anyway to convert the error line to a constant-expression?

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  • Android: How to do this framing paint?

    - by iDroid Explorer
    I Have Some static images like below: Now, I want is, when i touch on the face or hand, then the selected color should be fill on that skin portion. See below image of result: So how to get the result like above ?? Redo and Undo Functionality Should be also there. I have try with the FloodFill color but doing that i can only able to do color in to the perticular portion. as FloodFill only fill the color till the same pixwl color comes. If the touch place pixel color get change the it will not fill color on it. So Usinf FloodFill i got the result like below image, If i press on the hand, then only hand portion will fill with color, instead of it i want to fill color to the other hand and face also. So Please help me in this case. EDITED After some reply i got the solution like this one. But still there is a memory issue. It consume lots of memory to draw the color. So please can anyone help me for it ?

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  • DefaultStyledDocument.styleChanged(Style style) may not run in a timely manner?

    - by Paul Reiners
    I'm experiencing an intermittent problem with a class that extends javax.swing.text.DefaultStyledDocument. This document is being sent to a printer. Most of the time the formatting of the document looks correct, but once in a while it doesn't. It looks like some of the changes in the formatting have not been applied. I took a look at the DefaultStyledDocument.styleChanged(Style style) code: /** * Called when any of this document's styles have changed. * Subclasses may wish to be intelligent about what gets damaged. * * @param style The Style that has changed. */ protected void styleChanged(Style style) { // Only propagate change updated if have content if (getLength() != 0) { // lazily create a ChangeUpdateRunnable if (updateRunnable == null) { updateRunnable = new ChangeUpdateRunnable(); } // We may get a whole batch of these at once, so only // queue the runnable if it is not already pending synchronized(updateRunnable) { if (!updateRunnable.isPending) { SwingUtilities.invokeLater(updateRunnable); updateRunnable.isPending = true; } } } } /** * When run this creates a change event for the complete document * and fires it. */ class ChangeUpdateRunnable implements Runnable { boolean isPending = false; public void run() { synchronized(this) { isPending = false; } try { writeLock(); DefaultDocumentEvent dde = new DefaultDocumentEvent(0, getLength(), DocumentEvent.EventType.CHANGE); dde.end(); fireChangedUpdate(dde); } finally { writeUnlock(); } } } Does the fact that SwingUtilities.invokeLater(updateRunnable) is called, rather than invokeAndWait(updateRunnable), mean that I can't count on my formatting changes appearing in the document before it is rendered? If that is the case, is there a way to ensure that I don't proceed with rendering until the updates have occurred?

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  • Speed comparison - Template specialization vs. Virtual Function vs. If-Statement

    - by Person
    Just to get it out of the way... Premature optimization is the root of all evil Make use of OOP etc. I understand. Just looking for some advice regarding the speed of certain operations that I can store in my grey matter for future reference. Say you have an Animation class. An animation can be looped (plays over and over) or not looped (plays once), it may have unique frame times or not, etc. Let's say there are 3 of these "either or" attributes. Note that any method of the Animation class will at most check for one of these (i.e. this isn't a case of a giant branch of if-elseif). Here are some options. 1) Give it boolean members for the attributes given above, and use an if statement to check against them when playing the animation to perform the appropriate action. Problem: Conditional checked every single time the animation is played. 2) Make a base animation class, and derive other animations classes such as LoopedAnimation and AnimationUniqueFrames, etc. Problem: Vtable check upon every call to play the animation given that you have something like a vector<Animation>. Also, making a separate class for all of the possible combinations seems code bloaty. 3) Use template specialization, and specialize those functions that depend on those attributes. Like template<bool looped, bool uniqueFrameTimes> class Animation. Problem: The problem with this is that you couldn't just have a vector<Animation> for something's animations. Could also be bloaty. I'm wondering what kind of speed each of these options offer? I'm particularly interested in the 1st and 2nd option because the 3rd doesn't allow one to iterate through a general container of Animations. In short, what is faster - a vtable fetch or a conditional?

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  • Which options do I have for Java process communication?

    - by Dmitriy Matveev
    We have a place in a code of such form: void processParam(Object param) { wrapperForComplexNativeObject result = jniCallWhichMayCrash(param); processResult(result); } processParam - method which is called with many different arguments. jniCallWhichMayCrash - a native method which is intended to do some complex processing of it's parameter and to create some complex object. It can crash in some cases. wrapperForComplexNativeObject - wrapper type generated by SWIG processResult - a method written in pure Java which processes it's parameter by creation of several kinds (by the kinds I'm not meaning classes, maybe some like hierarchies) of objects: 1 - Some non-unique objects which are referencing each other (from the same hierarchy), these objects can have duplicates created from the invocations of processParam() method with different parameter values. Since it's costly to keep all the duplicates it's necessary to cache them. 2 - Some unique objects which are referencing each other (from the same hierarchy) and some of the objects of 1st kind. After processParam is executed for each of the arguments from some set the data created in processResult will be processed together. The problem is in fact that jniCallWhichMayCrash method may crash the entire JVM and this will be very bad. The reason of crash may be such that it can happen for one argument value and not for the other. We've decided that it's better to ignore crashes inside of JVM and just skip some chunks of data when such crashes occur. In order to do this we should run processParam function inside of separate process and pass the result somehow (HOW? HOW?! This is a question) to the main process and in case of any crashes we will only lose some part of data (It's ok) without lose of everything else. So for now the main problem is implementation of transport between different processes. Which options do I have? I can think about serialization and transmitting of binary data by the streams, but serialization may be not very fast due to object complexity. Maybe I have some other options of implementing this?

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  • Split node list to parts.

    - by Kalinin
    xml: <mode>1</mode> <mode>2</mode> <mode>3</mode> <mode>4</mode> <mode>5</mode> <mode>6</mode> <mode>7</mode> <mode>8</mode> <mode>9</mode> <mode>10</mode> <mode>11</mode> <mode>12</mode> i need to separate it on parts (for ex. on 4): xslt: <xsl:variable name="vNodes" select="mode"/> <xsl:variable name="vNumParts" select="4"/> <xsl:variable name="vNumCols" select="ceiling(count($vNodes) div $vNumParts)"/> <xsl:for-each select="$vNodes[position() mod $vNumCols = 1]"> <xsl:variable name="vCurPos" select="(position()-1)*$vNumCols +1"/> <ul> <xsl:for-each select="$vNodes[position() >= $vCurPos and not(position() > $vCurPos + $vNumCols -1)]"> <li><xsl:value-of select="."/></li> </xsl:for-each> </ul> </xsl:for-each> this code is written by Dimitre Novatchev - great coder)) but for the number of nodes less then number of parts (for ex. i have 2 modes) this code does not work - it outputs nothing. How it upgrade for that case (without choose construction)?

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  • regexp to match string with (comma-separated) number at start and to split into number and rest?

    - by mix
    Given a string such as: 23,234,456 first second third How can I split string this into two parts, where part 1 contains the number at the beginning and part 2 contains the rest---but only if the string STARTS with a number, and the number can be comma-separated or not? In other words, I want two results: 23,234,456 and first second third. If there's a number in that string that isn't part of the first number then it should be in the second result. My best stab at this so far, to grab the number at the beginning, is something like this: ^[0-9]+(,[0-9]{3})* Which seems to grab a comma-separated or non-comma-separated number that starts the line. However, when I run this in the Javascript console I get not only the full number, but also a match on just the last 3 digits with their preceeding ,. (e.g. 23,234,456 and ,456). As for getting the rest into another var I'm having trouble. I tried working with \b, etc., but I think I must be missing something fundamental about grabbing the rest of the line. I'm doing this in Javascript in case it matters. More examples of what to match and what not to match. 2 one two three should return 2 and one two three 2345 one two three should return 2345 and one two three 2 one 2 three should return 2 and one 2 three 2,234 one two 3,000 should return 2,234 and one two 3,000 The space between parts 1 and two could be included in the beginning of part 2.

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  • system crash after declaring global object of the class

    - by coming out of void
    hi, i am very new to c++. i am getting system crash (not compilation error) in doing following: i am declaring global pointer of class. BGiftConfigFile *bgiftConfig; class BGiftConfigFile : public EftBarclaysGiftConfig { } in this class i am reading tags from xml file. it is crashing system when this pointer is used to retrieve value. i am doing coding for verifone terminal. int referenceSetting = bgiftConfig->getreferencesetting(); //system error getreferencesetting() is member fuction of class EftBarclaysGiftConfig i am confused about behavior of pointer in this case. i know i am doing something wrong but couldn't rectify it. When i declare one object of class locally it retrieves the value properly. BGiftConfigFile bgiftConfig1; int referenceSetting = bgiftConfig1->getreferencesetting(); //working But if i declare this object global it also crashes the system. i need to fetch values at different location in my code so i forced to use someting global. please suggest me how to rectify this problem.

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  • What are the best practices for unit testing properties with code in the setter?

    - by nportelli
    I'm fairly new to unit testing and we are actually attempting to use it on a project. There is a property like this. public TimeSpan CountDown { get { return _countDown; } set { long fraction = value.Ticks % 10000000; value -= TimeSpan.FromTicks(fraction); if(fraction > 5000000) value += TimeSpan.FromSeconds(1); if(_countDown != value) { _countDown = value; NotifyChanged("CountDown"); } } } My test looks like this. [TestMethod] public void CountDownTest_GetSet_PropChangedShouldFire() { ManualRafflePresenter target = new ManualRafflePresenter(); bool fired = false; string name = null; target.PropertyChanged += new PropertyChangedEventHandler((o, a) => { fired = true; name = a.PropertyName; }); TimeSpan expected = new TimeSpan(0, 1, 25); TimeSpan actual; target.CountDown = expected; actual = target.CountDown; Assert.AreEqual(expected, actual); Assert.IsTrue(fired); Assert.AreEqual("CountDown", name); } The question is how do I test the code in the setter? Do I break it out into a method? If I do it would probably be private since no one else needs to use this. But they say not to test private methods. Do make a class if this is the only case? would two uses of this code make a class worthwhile? What is wrong with this code from a design standpoint. What is correct?

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  • Is it true that in most Object Oriented Programming Languages, an "i" in an instance method always r

    - by Jian Lin
    In the following code: <script type="text/javascript"> var i = 10; function Circle(radius) { this.r = radius; this.i = radius; } Circle.i = 123; Circle.prototype.area = function() { alert(i); } var c = new Circle(1); var a = c.area(); </script> What is being alerted? The answer is at the end of this question. I found that the i in the alert call either refers to any local (if any), or the global variable. There is no way that it can be the instance variable or the class variable even when there is no local and no global defined. To refer to the instance variable i, we need this.i, and to the class variable i, we need Circle.i. Is this actually true for almost all Object oriented programming languages? Any exception? Are there cases that when there is no local and no global, it will look up the instance variable and then the class variable scope? (or in this case, are those called scope?) the answer is: 10 is being alerted.

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  • boost thread pool

    - by Dtag
    I need a threadpool for my application, and I'd like to rely on standard (C++11 or boost) stuff as much as possible. I realize there is an unofficial(!) boost thread pool class, which basically solves what I need, however I'd rather avoid it because it is not in the boost library itself -- why is it still not in the core library after so many years? In some posts on this page and elsewhere, people suggested using boost::asio to achieve a threadpool like behavior. At first sight, that looked like what I wanted to do, however I found out that all implementations I have seen have no means to join on the currently active tasks, which makes it useless for my application. To perform a join, they send stop signal to all the threads and subsequently join them. However, that completely nullifies the advantage of threadpools in my use case, because that makes new tasks require the creation of a new thread. What I want to do is: ThreadPool pool(4); for (...) { for (int i=0;i<something;i++) pool.pushTask(...); pool.join(); // do something with the results } Can anyone suggest a solution (except for using the existing unofficial thread pool on sourceforge)? Is there anything in C++11 or core boost that can help me here? Thanks a lot

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  • Performance of stored proc when updating columns selectively based on parameters?

    - by kprobst
    I'm trying to figure out if this is relatively well-performing T-SQL (this is SQL Server 2008). I need to create a stored procedure that updates a table. The proc accepts as many parameters as there are columns in the table, and with the exception of the PK column, they all default to NULL. The body of the procedure looks like this: CREATE PROCEDURE proc_repo_update @object_id bigint ,@object_name varchar(50) = NULL ,@object_type char(2) = NULL ,@object_weight int = NULL ,@owner_id int = NULL -- ...etc AS BEGIN update object_repo set object_name = ISNULL(@object_name, object_name) ,object_type = ISNULL(@object_type, object_type) ,object_weight = ISNULL(@object_weight, object_weight) ,owner_id = ISNULL(@owner_id, owner_id) -- ...etc where object_id = @object_id return @@ROWCOUNT END So basically: Update a column only if its corresponding parameter was provided, and leave the rest alone. This works well enough, but as the ISNULL call will return the value of the column if the received parameter was null, will SQL Server optimize this somehow? This might be a performance bottleneck on the application where the table might be updated heavily (insertion will be uncommon so the performance there is not a problem). So I'm trying to figure out what's the best way to do this. Is there a way to condition the column expressions with something like CASE WHEN or something? The table will be indexed up the wazoo as well for read performance. Is this the best approach? My alternative at this point is to create the UPDATE expression in code (e.g. inline SQL) and execute it against the server. This would solve my doubts about performance, but I'd rather leave this in a stored proc if possible.

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  • Best way to parse this particular string using awk / sed?

    - by Jack
    Hi, I need to get a particular version string from a file (call it version.lst) and use it to compare another in a shell script. For example sake, the file contains lines that look like this: V1.000 -- build date and other info here -- APP1 V1.000 -- build date and other info here -- APP2 V1.500 -- build date and other info here -- APP3 .. and so on. Let's say I am trying to grab the first version (in this case, V1.000) from APP1. Obviously, the versions can change and I want this to be dynamic. What I have right now works: var = `cat version.lst | grep " -- APP1" | grep -Eo V[0-9].[0-9]{3}` Pipe to grep will get the line containing APP1 and the second pipe to grep will get the version string. However, I hear grep is not the way to do this so I'd like to learn the best way using awk or sed. Any ideas? I am new to both and haven't found a tutorial easy enough to learn the syntax of it. Do they support egrep? Thanks!

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