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• VS compiling Error 1256 ( integer overflow in internal computation ... ) during inheritance

  - by odbb

  Hi there, my problem occurs during compiling Irrlicht3D Engine in VS 2008. 1Error 1256: integer overflow in internal computation due to size or complexity of "irr::IReferenceCounted" I'm currently merging a very old Softwaredriver I have written with the rest of the engine which is much newer. The main Problme is that I have tried to resolve abstract inherince problems. But now I get this error and it is the only one. "irr::IReferenceCounted" is one of the base classes used by other classes which have been inherinced from. What does that mean? I know that an integer overflow can be a normal overflow, but why is this shown during compilation? Any help appreciated! -db

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• advantages of Zend_Db_Table vs raw (My)SQL?

  - by sunwukung

  Currently working on a new Zend application and developing the Model. Having worked with Zend_Db_Table before, I opted to replace references in the Model to the Table API with a custom SQL script to take care of data access duties. Now I'm looking at developing a new application/domain model, and I wanted to get some feedback from people re: their experiences with Zend_Db API vs raw SQL, and use cases where it would be preferable to use the API. From a project perspective, the DB platform is unlikely to change from MySQL - so it doesn't need to be particularly abstract - and I assume writing a custom SQL API will be more performant than the assorted classes the Zend DB API requires.

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• Java/JAXB: Unmarshall Xml to specific subclass based on an attribute

  - by Frothy

  Is it possible to use JAXB to unmarshall xml to a specific Java class based on an attribute of the xml? <shapes> <shape type="square" points="4" square-specific-attribute="foo" /> <shape type="triangle" points="3" triangle-specific-attribute="bar" /> </shapes> I would like to have a List of Shape objects containing a triangle and a square, each with their own shape-specific attribute. IE: abstract class Shape { int points; //...etc } class Square extends Shape { String square-specific-attribute; //...etc } class Triangle extends Shape { String triangle-specific-attribute; //...etc } I'm currently just putting all attributes in one big "Shape" class and it's less than ideal. I could get this to work if the shapes were properly named xml elements, but unfortunately I don't have control of the xml I'm retrieving. Thanks!

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• C# to Java: What is a [DefaultProperty("value")]?

  - by Shiftbit

  I do not understand how the DefaultProperty Metadata tag work or what it signifies. I've read the MSDN and went through the sample but I find it confusing. DefaultPropertyAttribute Class I've read a few blogs and they seem to refer to the indexers. I'm not sure why you would want metadata for your properties? I am coming from a Java background, perhaps a Java analogy would help. [DefaultProperty("Value")] public abstract class FOO<T> : ANY, IBAR<T> { public FOO() { } public FOO(T value) { this.Value = value; } public virtual T Value { get; set; } } Follow up: Property Grid

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• Comparison of collection datatypes in C#

  - by Joel in Gö

  Does anyone know of a good overview of the different C# collection types? I am looking for something showing which basic operations such as Add, Remove, RemoveLast etc. are supported, and giving the relative performance. It would be particularly interesting for the various generic classes - and even better if it showed eg. if there is a difference in performance between a List<T> where T is a class and one where T is a struct. A start would be a nice cheat-sheet for the abstract data structures, comparing Linked Lists, Hash Tables etc. etc. Thanks!

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• Can't instantiate javax.servlet.ServletException

  - by Denis

  Hello, experts! I am trying to create instance of class javax.servlet.ServletException with following code public class MyTroubleViewer { public static void main(String[] args) { javax.servlet.ServletException servletException = new javax.servlet.ServletException("Hello"); System.out.println(servletException.getMessage()); } } But I get exception on creating: Exception in thread "main" java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/servlet/ServletException ... Maven helps me with dependecies: <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>6.0</version> <type>jar</type> <scope>compile</scope> </dependency> What am I doing wrong?

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• Looking for a syntactic shortcut for accessing dictionaries

  - by Sisiutl

  I have an abstract base class that holds a Dictionary. I'd like inherited classes to be able to access the dictionary fields using a convenient syntax. Currently I have lots of code like this: string temp; int val; if (this.Fields.TryGetValue("Key", out temp)) { if (int.TryParse(temp, out val)) { // do something with val... } } Obviously I can wrap this in utility functions but I'd like to have a cool, convenient syntax for accessing the dictionary fields where I can simply say something like: int result = @Key; Is there any way to do something like this in C# (3.5)?

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• Create Java method from a string?

  - by drozzy

  Is it possible in Java, to declare a method with a string instead of an identifier? For example can I do something like the following: class Car{ new Method("getFoo", { return 1+1; }); } //Use it Car car = new Car(); car.getFoo(); EDIT: I am adding a Purpose WHY I need this. In order to not hardcode method names when using Jersey and it's UriBuilder, which requires a method name: https://jsr311.dev.java.net/nonav/releases/1.1/javax/ws/rs/core/UriBuilder.html See path() method with signature: public abstract UriBuilder path(java.lang.Class resource, java.lang.String method) throws java.lang.IllegalArgumentException I hope my question is clear, if not - let me know and I can clarify it.

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• how to translate Haskell into Scalaz?

  - by TOB

  One of my high school students and I are going to try to do a port of Haskell's Parsec parser combinator library into Scala. (It has the advantage over Scala's built-in parsing library that you can pass state around fairly easily because all the parsers are monads.) The first hitch I've come across is trying to figure out how Functor works in scalaz. Can someone explain how to convert this Haskell code: data Reply s u a = Ok a !(State s u) ParseError | Error ParseError instance Functor (Reply s u) where fmap f (Ok x s e) = Ok (f x) s e fmap _ (Error e) = Error e -- XXX into Scala (using Scalaz, I assume). I got as far as sealed abstract class Reply[S, U, A] case class Ok[S, U, A](a: A, state: State[S, U], error: ParseError) extends Reply[S, U, A] case class Error[S, U, A](error: ParseError) extends Reply[S, U, A] and know that I should make Reply extend the scalaz.Functor trait, but I can't figure out how to do that. (Mostly I'm having trouble figuring out what the F[_] parameter does.) Any help appreciated! Thanks, Todd

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• what is wrong: "value Parsers is not a member of package scala.util.parsing.combinator"?

  - by Nick Fortescue

  I've got the above odd error message that I don't understand "value Parsers is not a member of package scala.util.parsing.combinator". I'm trying to learn Parser combinators by writing a C parser step by step. I started at token, so I have the classes: import util.parsing.combinator.JavaTokenParsers object CeeParser extends JavaTokenParsers { def token: Parser[CeeExpr] = ident } abstract class CeeExpr case class Token(name: String) extends CeeExpr This is as simple as I could make it. The code below works fine, but if I uncomment the commented line I get the error message given above: object Play { def main(args: Array[String]) { //val parser: _root_.scala.util.parsing.combinator.Parsers.Parser[CeeExpr] CeeParser.token val x = CeeParser.token print(x) } } In case it is a problem with my setup, I'm using scala 2.7.6 via the scala-plugin for intellij. Can anyone shed any light on this? The message is wrong, Parsers is a member of scala.util.parsing.combinator.

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• How to send news letters in zend

  - by Sherif

  i am trying to send something like news letter Via Zend_Mail but after 12 mail i got this message Fatal error: Maximum execution time of 30 seconds exceeded in C:\Program Files\Zend\Apache2\htdocs\forga\library\Zend\Mail\Protocol\Abstract.php on line 321 my Code is like: $smtpHost = 'smtp.gmail.com'; $smtpConf = array( 'auth' = 'login', 'ssl' = 'tls', 'port' = '587', 'username' ='[email protected]', 'password' = 'xxxxxxxx' ); $transport = new Zend_Mail_Transport_Smtp($smtpHost, $smtpConf); foreach($users as $user) { $mail = new Zend_Mail(); $mail-setFrom("[email protected]", 'Forga'); $mail-setSubject($subject); if($html=='on') $mail-setBodyHtml($message); else $mail-setBodyText($message); $mail-addto($user); $transport-send($mail); }

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• C++ overloading virtual = operator

  - by taz

  Hello, here is the code for my question: class ICommon { public: virtual ICommon& operator=(const ICommon & p)const=0; }; class CSpecial : public ICommon { public: CSpecial& operator=(const CSpecial & cs) { //custom operations return *this; } }; CSpecial obj; Basically: I want the interface ICommon to force it's descendants to implement = operator but don't want to have any typecasts in the implementation. The compiler says "can't instantiate an abstract class. Any help/advice will be appreciated.

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• Need help mocking a ASP.NET Controller in Rhino Mocks

  - by Pure.Krome

  Hi folks, I'm trying to mock up a fake ASP.NET Controller. I don't have any concrete controllers, so I was hoping to just mock a Controller and it will work. This is what I currently have: _fakeRequestBase = MockRepository.GenerateMock<HttpRequestBase>(); _fakeRequestBase.Stub(x => x.HttpMethod).Return("GET"); _fakeContextBase = MockRepository.GenerateMock<HttpContextBase>(); _fakeContextBase.Stub(x => x.Request).Return(_fakeRequestBase); var controllerContext = new ControllerContext(_fakeContextBase, new RouteData(), MockRepository.GenerateMock<ControllerBase>()); _fakeController = MockRepository.GenerateMock<Controller>(); _fakeController.Stub(x => x.ControllerContext).Return(controllerContext); Everything works except the last line, which throws a runtime error and is asking me for some Rhino.Mocks source code or something (which I don't have). See how I'm trying to mock up an abstract Controller - is that allowed? Can someone help me?

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• What lessons can you learn from software maintanence?

  - by Vasil Remeniuk

  Hello everyone, In the perfect world, all the software developers would work with the cutting edge technologies, creating systems from the scratch. In the real life, almost all of us have to maintain software from time to time (unlucky ones do it on a regular basis). Personally I first 2 years of my career was fixing bugs in the company that no longer exists (it has been taken up by Oracle). And probably the biggest lesson I've learned that time - despite of the pressure, always try to get as much information about the domain as possible (even if it's irrelevant to fixing a specific bug or adding a feature) - abstract domain knowledge doesn't lose value as fast as knowledge about trendy frameworks or methodologies. What lessons have you learned from maintenance?

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• creative way for implementing Data object with its corresponding business logic class in java

  - by ekeren

  I have a class that need to be serialized (for both persistentcy and client-server communication) for simplicity's sake let's call the classes Business a BusinessData and I prefix for their Interfaces. All the getter and setter are delegated from Business class to BusinessData class. I thought about implementing IBusinessData interface that will contain all the getter and setters and IBusiness interface that will extend it. I can either make Business extend BuisnessData so I will not need to implement all getter and setter delegates, or make some abstract class ForwardingBusinessData that will only delegate getter and setters. Any of the above option I lose my hierarchy freedom, do any of you have any creative solutions for this problem... I also reviewed DAO pattern: http://java.sun.com/blueprints/patterns/DAO.html

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• VB to C# conversion incongruency with lambdas

  - by Jason

  I have a bit of code that I have been tasked with converting to C# from VB. A snippet of mine seems like it cannot be converted from one to the other, and if so, I just don't know how to do it and am getting a little frustrated. Here's some background: OrderForm is an abstract class, inherited by Invoice (and also PurchaseOrder). The following VB snippet works correctly: Dim Invs As List(Of OrderForm) = GetForms(theOrder.OrderID) .... Dim inv As Invoice = Invs.Find( Function(someInv As Invoice) thePO.SubPONumber = someInv.SubInvoiceNumber) In C#, the best I came to converting this is: List<OrderForm> Invs = GetForms(theOrder.OrderID); .... Invoice inv = Invs.Find( (Invoice someInv) => thePO.SubPONumber == someInv.SubInvoiceNumber); However, I get the following error when I do this: Cannot convert lambda expression to delegate type 'System.Predicate' because the parameter types do not match the delegate parameter types Is there any way to fix this without restructuring my whole codebase?

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• Hiding an internal interface in a "friend" assembly

  - by dmo

  I have two assemblies: A and B. A has InternalsVisibleTo set for B. I would like to make calls from A to get information that can only be known by a type defined in B in a way that keeps things internal. I can do this using an internal interface defined in A and implemented explicitly in B. Assembly A internal interface IHasData { Data GetData(); } class ClassA { DoSomething(IHasData); } Assembly B public abstract class ClassB : IHasData { Data IHasData.GetData() { /** do something internal **/ } } The trouble comes when someone references assembly B and derives from ClassB - they get the error: "The type 'AssemblyA.IHasData' is defined in an assembly that is not referenced" even though that type should be invisible to them. If I look at the public type definition I see what I expect - ClassB with no interfaces implemented. Why do I get this error? All of the implementation is in assembly B. I could use IHasData internally in ClassB and that wouldn't require assembly A to be referenced. Can someone help me understand what is going on?

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• WPF DataGrid Entity Framework: Is it possible to bind a datagrid column to a method/function?

  - by seddler

  Hi. I'm wondering if it's possible to bind a gridcolumn (field) to a method or function of an entity? For example I have two entities Person and Company that both inherit the abstract entity Addressee. In my grid I'm listing all Addressees (both persons and companies). I have a column, Name, in the datagrid that I whish to bind to a function GetName(). This function is part of the entity Addressee and based on what type of addressee it is it returns CompanyName (if company) or FirstName+' '+LastName (if person). I also have tried to add a partial class Addressee with a property Name that does the same thing as the function descried over, but this failes when I'm saving to database because the column Name does not exist in database. Can anybody please help me? :-)

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• In ASP.NET MVC (3.0/Razor), do you prefer multiple views, or conditionals within views? Why?

  - by Chad

  For my new web app, I'm debating on using multiple views, or conditionals within views. An example scenario would be showing different info to users who are authenticated vs non-authenticated. This could be handled a couple ways. In the controller, check IsAuthenticated and return a view based on that In the view, check IsAuthenticated and show blocks of info based on that Pros of multiple views: Smaller, less complicated view - next to no logic in the view Pros of single views: less view files to maintain The obvious cons are the opposites of the pros: more files to maintain or more complicated view files. Which do you prefer? Why? Any pros/cons I haven't outlined here? Update: Assume each view uses a layout page and partial views to abstract the obviously repetitive code.

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• FieldError when annotating over foreign keys

  - by X_9

  I have a models file that looks similar to the following: class WithDate(models.Model): adddedDate = models.DateTimeField(auto_now_add=True) modifiedDate = models.DateTimeField(auto_now=True) class Meta: abstract = True class Match(WithDate): ... class Notify(WithDate): matchId = models.ForeignKey(Match) headline = models.CharField(null=True, blank=True, max_length=10) For each Match I'm trying to get a count of notify records that have a headline. So my call looks like matchObjs = Match.objects.annotate(notifies_made=Count('notify__headline__isnull')) This keeps throwing a FieldError. I've simplified the query down to matchObjs = Match.objects.annotate(notifies_made=Count('notify')) And I still get the same FieldError... I've seen this work in other cases (other documentation, other SO questions like this one) but I can't figure out why I'm getting an error. The specific error that is returned is as follows: Cannot resolve keyword 'notify' into field. Choices are: (all fields from Match model) Does anyone have a clue as to why I can't get this annotation to work across tables? I'm baffled after looking at the other SO question and various Django docs where I've seen this done. Edit: I am using Django 1.1.1

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• Passing arguments to anonymous inner classes

  - by synic

  I'm trying to make an API library for our web services, and I'm wondering if it's possible to do something like this: abstract class UserRequest(val userId: Int) { def success(message: String) def error(error: ApiError) } api.invokeRequest(new UserRequest(121) { override def success(message: String) = { // handle success } override def error(error: ApiError) = { // handle the error } } I'm talking about passing parameters to the anonymous inner class, and also overriding the two methods. I'm extremely new to Scala, and I realize my syntax might be completely wrong. I'm just trying to come up with a good design for this library before I start coding it. I'm willing to take suggestions for this, if I'm doing it the completely wrong way, or if there's a better way. The idea is that the API will take some sort of request object, use it to make a request in a thread via http, and when the response has been made, somehow signal back to the caller if the request was a success or an error. The request/error functions have to be executed on the main thread.

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• How do I make this ASP.NET MVC controller more testable?

  - by Ragesh

  I have a controller that overrides OnActionExecuting and does something like this: protected override void OnActionExecuting(ActionExecutingContext filterContext) { base.OnActionExecuting(filterContext); string tenantDomain = filterContext.RouteData.Values["tenantDomain"] as string; if (!string.IsNullOrWhiteSpace(tenantDomain)) { using (var tx = BeginTransaction()) { this.Tenant = repo.FindOne(t => t.Domain == tenantDomain); } } } Tenant is a protected property with a private setter. The class itself is an abstract base controller that my real controllers derive from. I have code in other controllers that looks a lot like this: if (Tenant == null) { // Do something } else { // Do something else } How do I test this code? What I need to do is to somehow set the Tenant property, but I can't because: It's a protected property, and It has a private setter Changing the visibility of Tenant doesn't "feel" right. What are my alternatives to unit test my derived controllers?

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• If .net sha1 hash expects a byte array, and php sha1() wants a string, can I match the results?

  - by lynn

  I have a set of bytes I want to apply an sha1 hash to. One hash will be in .net, the other in PHP. Then I'll test to see if they match. In .net, you can create a byte array and use sha.ComputeHash(). byte[] data = new byte[DATA_SIZE]; byte[] result; SHA1 sha = new SHA1CryptoServiceProvider(); // This is one implementation of the abstract class SHA1. result = sha.ComputeHash(data); In PHP, you call sha1($string). I can't do anything about the .net side of the code, but how can I get the same hash out of PHP that .net will generate? Please note: I am ONLY able to work on the PHP side of this. The .net stuff is fixed and can't be modified. Thanks!

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• Choosing a design pattern for a class that might change it's internal attributes

  - by the_drow

  I have a class that holds arbitrary state and it's defined like this: class AbstractFoo { }; template <class StatePolicy> class Foo : public StatePolicy, public AbstractFoo { }; The state policy contains only protected attributes that represent the state. The state might be the same for multiple behaviors and they can be replaced at runtime. All Foo objects have the same interface to abstract the state itself and to enable storing Foo objects in containers. I would like to find the least verbose and the most maintainable way to express this.

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• c# Generic overloaded method dispatching ambiguous

  - by sebgod

  Hello, I just hit a situation where a method dispatch was ambiguous and wondered if anyone could explain on what basis the compiler (.NET 4.0.30319) chooses what overload to call interface IfaceA { } interface IfaceB<T> { void Add(IfaceA a); T Add(T t); } class ConcreteA : IfaceA { } class abstract BaseClassB<T> : IfaceB<T> { public virtual T Add(T t) { ... } public virtual void Add(IfaceA a) { ... } } class ConcreteB : BaseClassB<IfaceA> { // does not override one of the relevant methods } void code() { var concreteB = new ConcreteB(); // it will call void Add(IfaceA a) concreteB.Add(new ConcreteA()); } In any case, why does the compiler not warn me or even why does it compile? Thank you very much for any answers.

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