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  • Arrays not matching correctly

    - by Nick Gibson
    userAnswer[] holds the string of the answer the user types in and is comparing it to answers[] to see if they match up and then spits out correct or wrong. j is equal to the question number. So if j was question 6, answers[j] should refer to answers[6] right? Then userAnswer[6] should compare to answers[6] and match if its correct. But its giving me wrong answers and displaying the answer I typed as correct. int abc, loopCount = 100; int j = quesNum, overValue, forLoop = 100; for (int loop = 1; loop < loopCount; loop++) { aa = r.nextInt(10+1); abc = (int) aa; String[] userAnswer = new String[x]; JOptionPane.showMessageDialog(null,abc); if(abc < x) { userAnswer[j] = JOptionPane.showInputDialog(null,"Question "+quesNum+"\n"+questions[abc]+"\n\nA: "+a[abc]+"\nB: "+b[abc]+"\nC: "+c[abc]+"\nD: "+d[abc]); if(userAnswer[j].equals(answers[j])) { JOptionPane.showMessageDialog(null,"Correct. \nThe Correct Answer is "+answers[abc]); } else { JOptionPane.showMessageDialog(null,"Wrong. \n The Correct Answer is "+answers[abc]); }//else }//if }//for

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  • Is it poor design to create objects that only execute code during the constructor?

    - by Curtix
    In my design I am using objects that evaluate a data record. The constructor is called with the data record and type of evaluation as parameters and then the constructor calls all of the object's code necessary to evaluate the record. This includes using the type of evaluation to find additional parameter-like data in a text file. There are in the neighborhood of 250 unique evaluation types that use the same or similar code and unique parameters coming from the text file. Some of these evaluations use different code so I benefit a lot from this model because I can use inheritance and polymorphism. Once the object is created there isn't any need to execute additional code on the object (at least for now) and it is used more like a struct; its kept on a list and 3 properties are used later. I think this design is the easiest to understand, code, and read. A logical alternative I guess would be using functions that return score structs, but you can't inherit from methods so it would make it kind of sloppy imo. I am using vb.net and these classes will be used in an asp.net web app as well as in a distributed app. thanks for your input

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  • How do I create a simple Windows form to access a SQL Server database?

    - by NoCatharsis
    I believe this is a very novice question, and if I'm using the wrong forum to ask, please advise. I have a basic understanding of databasing with MS SQL Server, and programming with C++ and C#. I'm trying to teach myself more by setting up my own database with MS SQL Server Express 2008 R2 and accessing it via Windows forms created in C# Express 2010. At this point, I just want to keep it to free or Express dev tools (not necessarily Microsoft though). Anyway, I created a database using the instructions provided here and I set the data types appropriately for each column (no errors in setup at least). Now I'm designing the GUI in C# Express but I've kind of hit a wall as far as the database connection. Is there a simple way to access the database I created locally using C# Express? Can anyone suggest a guide that has all this spelled out already? I am a self-learner so I look forward to teaching myself how to use these applications, but any pointers to start me off in the right direction would be greatly appreciated.

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  • Keeping cached browser data inside ASP update panel textboxes/dropdowns for browser back click

    - by pmlevere
    I'm new in VB.net/asp and am running a VB web application in a visual database program called IronSpeed designer. I'm primarily using IronSpeed in this case for its login/role security features. I have a basic two page setup for this app. The user logs in then is taken to AccountEntry.aspx, they enter data into textboxes and select some dropdown values that are linked to a sql database, then they click "submit" to move to Results.aspx. On Results.aspx, the user can change data and then generate several types of reports (PDF, Excel, etc). I'm used to setting up ASP controls inside ASPContent areas, and in these areas if a user performs a browser back click the previously entered data will still be on the page for potential user modification. However in this web app, IronSpeed is setting up the page and asp controls inside an asp update panel. It appears inside an asp update panel, cached values can't be seen on a browser back click. In this case, it's important that the orginally entered values still be there for the user experience if the user advances to Results.aspx then clicks browser back to modify a value on AccountEntry.aspx. If I have to I'll setup Session Variables and disable browser clicking, but that is last resort. Is there any way to save cached data inside an asp update panel and have it there for a browser back click?

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  • Evaluating expressions using Visual Studio 2005 SDK rather than automation's Debugger::GetExpression

    - by brone
    I'm looking into writing an addin (or package, if necessary) for Visual Studio 2005 that needs watch window type functionality -- evaluation of expressions and examination of the types. The automation facilities provide Debugger::GetExpression, which is useful enough, but the information provided is a bit crude. From looking through the docs, it sounds like an IDebugExpressionContext2 would be more useful. With one of these it looks as if I can get more information from an expression -- detailed information about the type and any members and so on and so forth, without having everything come through as strings. I can't find any way of actually getting a IDebugExpressionContext2, though! IDebugProgramProvider2 sort of looks relevant, in that I could start with IDebugProgramProvider2::GetProviderProcessData and then slowly drill down until reaching something that can supply my expression context -- but I'll need to supply a port to this, and it's not clear how to retrieve the port corresponding to the current debug session. (Even if I tried every port, it's not obvious how to tell which port is the right one...) I'm becoming suspicious that this simply isn't a supported use case, but with any luck I've simply missed something crashingly obvious. Can anybody help?

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  • Surely a foolish error, but I can't see it

    - by dnagirl
    I have a form (greatly simplified): <form action='http://example.com/' method='post' name='event_form'> <input type='text' name='foo' value='3'/> <input type='submit' name='event_submit' value='Edit'/> </form> And I have a class "EventForm" to process the form. The main method, process() looks like this: public function process($submitname=false){ $success=false; if ($submitname && isset($_POST[$submitname])){ //PROBLEM: isset($_POST[$submitname] is always FALSE for some reason if($success=$this->ruler->validate()){//check that dependancies are honoured and data types are correct if($success=$this->map_fields()){//divide input data into Event, Schedule_Element and Temporal_Expression(s) $success=$this->eventholder->save(); } } } else {//get the record from the db based on event_id or schedule_element_id foreach($this->gets as $var){//list of acceptable $_GET keys if(isset($_GET[$var])){ if($success= $this->__set($var,$_GET[$var])) break; } } } $this->action=(empty($this->eventholder->event_id))? ADD : EDIT; return $success; } When the form is submitted, this happens: $form->process('event_submit'); For some reason though, isset($_POST['event_submit']) always evaluates to FALSE. Can anyone see why?

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  • What do I name classes whose only purpose is to act as a structure?

    - by Sergio Tapia
    For example, take my Actor class: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing; namespace FreeIMDB { class Actor { public string Name { get; set; } public Image Portrait { get; set; } public DateTime DateOfBirth { get; set; } public List<string> ActingRoles { get; set; } public List<string> WritingRoles { get; set; } public List<string> ProducingRoles { get; set; } public List<string> DirectingRoles { get; set; } } } This class will only be used to stuff information into it, and allow other developers to get their values. What are these types of classes officially called? What is the correct nomenclature?

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  • Drupal: allowing users to sign up to content using a form

    - by james6848
    My apologies if this is a little broad, but I'm struggling to know where to start here! OK, so I have a Drupal site and I need users to be able to sign up for certain content, here is the workflow in detail: I need a form within a block consisting of the following elements: First Name (required) Last Name (required) Organisation (optional) Email Address (required) Then there will be a choice of content to sign up to (using checkboxes): Policy Bulletin Action News eBulletin (which only members can sign up to) Then the usual submit button of course! Upon submission, users will: 1) Be taken to a confirmation page, or 2) Be informed about incorrectly filled in fields, and/or the need to become a user to be able to sign up for the eBulletin. Users will then receive an email when new content of the type(s) they signed up to is created, along with a link to the node. There should be details about how to unsubscribe within this email. I have used the Subscriptions module in the past, but I am not sure if it is possible to use a sign-up form with it. Plus, there is the added complexity that one of the content types, eBulletin, is only available for site members. Like I say, I'm struggling to know where to start, and any ideas would be gratefully received!

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  • deleting object with template for int and object

    - by Yokhen
    Alright so Say I have a class with all its definition, bla bla bla... template <class DT> class Foo{ private: DT* _data; //other stuff; public: Foo(DT* data){ _data = data } virtual ~Foo(){ delete _data } //other methods }; And then I have in the main method: int main(){ int number = 12; Foo<anyRandomClass>* noPrimitiveDataObject = new Foo<anyRandomClass>(new anyRandomClass()); Foo<int>* intObject = new Foo<int>(number); delete noPrimitiveDataObject; //Everything goes just fine. delete intObject; //It messes up here, I think because primitive data types such as int are allocated in a different way. return 0; } My question is: What could I do to have both delete statements in the main method work just fine? P.S.: Although I have not actually compiled/tested this specific code, I have reviewed it extensively (as well as indented. You're welcome.), so if you find a mistake, please be nice. Thank you.

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  • Solr : how do i index and search several fields?

    - by sbrattla
    Hi, I've set up my first 'installation' of Solr, where each index (document) represents a musical work (with properties like number (int), title (string), version (string), composers (string) and keywords (string)). I've set the field 'title' as the default search field. However, what do I do when I would like to do a query on all fields? I'd like to give users the opportunity to search in all fields, and as far as I've understood there is at least two options for this: (1) Specify which fields the query should be made against. (2) Set up the Solr configuration with copyfields, so that values added to each of the fields will be copied to a 'catch-all'-like field which can be used for searching. However, in this case, i am uncertain how things would turn out when i take into consideration that the data types are not all the same for the various fields (the various fields will to a lesser og greater degree go through filters, but as copyfield values are taken from their original fields before the values have been run through their original fields' filters, i would have to apply one single filter to all values on the copyfield. This, again, would result in integers being 'filtered' just as strings would). Is this a case where i should use copyfields? At first glance, it seems a bit more 'flexible' to rather just search on all fields. However, maybe there's a cost? All feedback appreciated! Thanks!

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  • GWT: creating a text widget for highly customized data entry

    - by Caffeine Coma
    I'm trying to implement a kind of "guided typing" widget for data entry, in which the user's text entry is highly controlled and filtered. When the user types a particular character I need to intercept and filter it before displaying it in the widget. Imagine if you will, a Unix shell embedded as a webapp; that's the kind of thing I'm trying to implement. I've tried two approaches. In the first, I extend a TextArea, and add a KeyPressHandler to filter the characters. This works, but the browser-provided spelling correction is totally inappropriate, and I don't see how to turn it off. I've tried: DOM.setElementProperty(textArea.getElement(), "spellcheck", "false"); But that seems to have no effect- I still get the red underlines over "typos". In the second approach I use a FocusWidget to get KeyPress events, and a separate Label or HTML widget to present the filtered characters back to the user. This avoids the spelling correction issue, but since the FocusWidget is not a TextArea, the browser tends to intercept certain typed characters for internal use; e.g. FireFox will use the "/" character to begin a "Quick Find" on the page, and hitting Backspace will load the previous web page. Is there a better way to accomplish what I'm trying to do?

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  • UIImagePickerController crashes on rapid scrolling, slower than photos app

    - by vvanhee
    Most of the time, my image picker works perfectly (iOS 4.2.1). However, if I scroll very rapidly up and down about 4-6 times through my camera roll of about 300 photos, I get a crash. This never happens with the "photos" app on the same iPhone 3Gs. Also, I'm noticing that the stock "photos" app scrolls much more smoothly than my image picker. Has anyone else noticed this behavior? I'd be interested if others could attempt this in their own apps and see if they crash. I don't think it's related to other objects hogging memory on my iPhone because it's a simple app, and this happens right after I start the app. It also doesn't seem to be related to messages sent to other released objects or overreleasing of other objects in viewdidunload, based on my crash logs and the fact that the simulator responds well to simulated memory warnings. I think it might be a bug in the internal implementation of the UIImagePickerController... This is how I start the picker. I've done this multiple ways (including setting a retain property for the UIImagePickerController in my header and releasing on dealloc). This seems to be the best way (crashes least): UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; picker.allowsEditing = YES; [self presentModalViewController:picker animated:YES]; [picker release]; This is the crashed thread (I get various exception types): Exception Type: SIGSEGV Exception Codes: SEGV_ACCERR at 0xfffffffff4faafa4 Crashed Thread: 8 ... Thread 8 Crashed: 0 CoreFoundation 0x000494ea -[__NSArrayM replaceObjectAtIndex:withObject:] + 98 1 PhotoLibrary 0x00008e0f -[PLImageTable _segmentAtIndex:] + 527 2 PhotoLibrary 0x00008a21 -[PLImageTable _mappedImageDataAtIndex:] + 221 3 PhotoLibrary 0x0000893f -[PLImageTable dataForEntryAtIndex:] + 15 4 PhotoLibrary 0x000087e7 PLThumbnailManagerImageDataAtIndex + 35 5 PhotoLibrary 0x00008413 -[PLThumbnailManager _dataForPhoto:format:width:height:bytesPerRow:dataWidth:dataHeight:imageDataOffset:imageDataFormat:preheat:] + 299 6 PhotoLibrary 0x000b6c13 __-[PLThumbnailManager preheatImageDataForImages:withFormat:]_block_invoke_1 + 159 7 libSystem.B.dylib 0x000d6680 _dispatch_call_block_and_release + 20 8 libSystem.B.dylib 0x000d6ba0 _dispatch_worker_thread2 + 128 9 libSystem.B.dylib 0x0007b251 _pthread_wqthread + 265

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  • Alternatives to static methods on interfaces for enforcing consistency

    - by jayshao
    In Java, I'd like to be able to define marker interfaces, that forced implementations to provide static methods. For example, for simple text-serialization/deserialization I'd like to be able to define an interface that looked something like this: public interface TextTransformable<T>{ public static T fromText(String text); public String toText(); Since interfaces in Java can't contain static methods though (as noted in a number of other posts/threads: here, here, and here this code doesn't work. What I'm looking for however is some reasonable paradigm to express the same intent, namely symmetric methods, one of which is static, and enforced by the compiler. Right now the best we can come up with is some kind of static factory object or generic factory, neither of which is really satisfactory. Note: in our case our primary use-case is we have many, many "value-object" types - enums, or other objects that have a limited number of values, typically carry no state beyond their value, and which we parse/de-parse thousands of time a second, so actually do care about reusing instances (like Float, Integer, etc.) and its impact on memory consumption/g.c. Any thoughts?

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  • Generic validate input data via regex. Input error when match.count == 0

    - by Valamas
    Hi, I have a number of types of data fields on an input form, for example, a web page. Some fields are like, must be an email address, must be a number, must be a number between, must have certain characters. Basically, the list is undefinable. I wish to come up with a generic way of validating the data inputed. I thought I would use regex to validate the data. The fields which need validation would be related to a "regex expression" and a "regex error message" stating what the field should contain. My current mock up has that when the match count is zero, that would signify an error and to display the message. While still a white belt regex designer I have come to understand that in certain situations that it is difficult to write a regex which results in a match count of zero for every case. A complex regex case I looked for help on was Link Here. The forum post was a disaster because I confused people helping me. But one of the statements said that it was difficult to make a regex with a match count of zero meaning the input data was invalid; that the regex was very difficult to write that for. Does anyone have comments or suggestions on this generic validation system I am trying to create? thanks

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  • Open closed prinicple, problem

    - by Marcus
    Hi, I'm trying to apply OCP to a code snippet I have that in it's current state is really smelly, but I feel I'm not getting all the way to the end. Current code: public abstract class SomeObject {} public class SpecificObject1 : SomeObject {} public class SpecificObject2 : SomeObject {} // Smelly code public class Model { public void Store(SomeObject someObject) { if (someObject is SpecificObject1) {} else if (someObject is SpecificObject2) {} } } That is really ugly, my new approach looks like this: // No so smelly code public class Model { public void Store(SomeObject someObject) { throw new Expception("Not allowed!"); } public void Store(SpecificObject1 someObject) {} public void Store(SpecificObject2 someObject) {} } When a new SomeObject type comes along I must implement how that specific object is stored, this will break OCP cause I need to alter the Model-class. To move the store logic to SomeObject also feels wrong cause then I will violate SRP (?), becuase in this case the SomeObject is almost like a DTO, it's resposibility it not how to know to store itself. If a new implementation to SomeObject comes along who's store implementation is missing I will get a runtime error due to exception in Store method in Model class, it also feels like a code smell. This is because calling code will in the form of IEnumerable<SomeObject> sequence; I will not know the specific types of the sequence objects. I can't seem to grasp the OCP-concept. Anyone has any concrete examples or links that is a bit more than just some Car/Fruit example?

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  • Need help tuning a SQL statement

    - by jeffself
    I've got a table that has two fields (custno and custno2) that need to be searched from a query. I didn't design this table, so don't scream at me. :-) I need to find all records where either the custno or custno2 matches the value returned from a query on the same table based on a titleno. In other words, the user types in 1234 for the titleno. My query searches the table to find the custno associated with the titleno. It also looks for the custno2 for that titleno. Then it needs to do a search on the same table for all other records that have either the custno or custno2 returned in the previous search in the custno or custno2 fields for those other records. Here is what I've come up with: SELECT BILLYR, BILLNO, TITLENO, VINID, TAXPAID, DUEDATE, DATEPIF, PROPDESC FROM TRCDBA.BILLSPAID WHERE CUSTNO IN (select custno from trcdba.billspaid where titleno = '1234' union select custno2 from trcdba.billspaid where titleno = '1234' and custno2 != '') OR CUSTNO2 IN (select custno from trcdba.billspaid where titleno = '1234' union select custno2 from trcdba.billspaid where titleno = '1234' and custno2 != '') The query takes about 5-10 seconds to return data. Can it be rewritten to work faster?

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  • Sync two SqlExpress using NHibernate

    - by Christian
    Hello, I am creating a simple project management system which uses NHibernate for object storage. The underlying database is SQL express (at least currently for development). The client runs on either the desktop or laptop. I know I could use web-services and store the DB only on the desktop, but this would force the desktop to be available all the time. I am currently thinking about duplicating the DB, having two instances with "different data". To clarify, we are not talking about a productive app here, its a prototype. One way to achieve this very simple would be the following process: Client: Check if desktop DB is available (through web service) Client: If yes, use desktop storage, no problem here Client: If not, use own DB as storage Client: Poll desktop regulary, as soon as it comes on, sync Client: Switch to desktop storage ... Desktop: Do not attempt any DB operation before checking for required sync Desktop: If sync needed, do it... My question is now, how would you sync? Assume 4 or 5 types of objects, all have GUID as identifiers. Would you always manually "lazy load" all objects of a certain type and feed them to the DB. Would you always drop the whole desktop DB in case the client DB may be newer and out of sync? Again, I want to stress out, I am not assuming any conflicts or stale data, I basically just want to "copy the whole DB from the client". Would you use NHibernate for this? Or would you separate the copy process? When I think about it, my questions comes down to this: Is there any function from NHibernate: SyncDBs_SourceWins_(SourceDB, TargetDB) Thanks for help, Chris

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  • Are there any code critique sites or similar resources?

    - by Ukko
    I have noticed when people post example code illustrating some issue that they are having often they will gather a number of comments addressing the quality of the code they presented and not the actual problem asked. This is very helpful--if not well directed. Often, this is wasted effort since the asker is often not receptive and the code is often chopped down to something small to post leaving lots of rough edges. In the old days you would see people asking questions like this on comp.lang.lisp and other parts of the comp.lang hierarchy. But that bit of the net kind of sank into the sewers of neglect. Is there a comparable one-stop-shop today? I am partially asking for selfish reasons, I know how to write good idiomatic C, Lisp, O'Caml, and Java code. But I learned C++ pre-template and STL, those rusty skills are not really applicable to today's C++. I have picked up languages like Scala in a vacuum and get by, but am I really doing it correctly? There are so many ways you can abuse a language, I am currently working against a codebase of Fortran written in C, and I recognize and loathe the "that guy" who wrote it. I don't want to be someone else's "that guy" if I can help it. Just because it works does not mean that one did not totally miss the boat on how it should have been done. Do you seek out this type of critique? If so how, where and why? What types of benefits do you derive from it? How about abuse and trolls?

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  • C# wrapper for objects

    - by Haggai
    I'm looking for a way to create a generic wrapper for any object. The wrapper object will behave just like the class it wraps, but will be able to have more properties, variable, methods etc., for e.g. object counting, caching etc. Say the wrapper class be called Wrapper, and the class to be wrapped be called Square and has the constructor Square(double edge_len) and the properties/methods EdgeLength and Area, I would like to use it as follows: Wrapper<Square> mySquare = new Wrapper<Square>(2.5); /* or */ new Square(2.5); Console.Write("Edge {0} -> Area {1}", mySquare.EdgeLength, mySquare.Area); Obviously I can create such a wrapper class for each class I want to wrap, but I'm looking for a general solution, i.e. Wrapper<T> which can handle both primitive and compound types (although in my current situation I would be happy with just wrapping my own classes). Suggestions? Thanks.

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  • Scala: Correcting type inference of representation type over if statement

    - by drhagen
    This is a follow-up to two questions on representation types, which are type parameters of a trait designed to represent the type underlying a bounded type member (or something like that). I've had success creating instances of classes, e.g ConcreteGarage, that have instances cars of bounded type members CarType. trait Garage { type CarType <: Car[CarType] def cars: Seq[CarType] def copy(cars: Seq[CarType]): Garage def refuel(car: CarType, fuel: CarType#FuelType): Garage = copy( cars.map { case `car` => car.refuel(fuel) case other => other }) } class ConcreteGarage[C <: Car[C]](val cars: Seq[C]) extends Garage { type CarType = C def copy(cars: Seq[C]) = new ConcreteGarage(cars) } trait Car[C <: Car[C]] { type FuelType <: Fuel def fuel: FuelType def copy(fuel: C#FuelType): C def refuel(fuel: C#FuelType): C = copy(fuel) } class Ferrari(val fuel: Benzin) extends Car[Ferrari] { type FuelType = Benzin def copy(fuel: Benzin) = new Ferrari(fuel) } class Mustang(val fuel: Benzin) extends Car[Mustang] { type FuelType = Benzin def copy(fuel: Benzin) = new Mustang(fuel) } trait Fuel case class Benzin() extends Fuel I can easily create instances of Cars like Ferraris and Mustangs and put them into a ConcreteGarage, as long as it's simple: val newFerrari = new Ferrari(Benzin()) val newMustang = new Mustang(Benzin()) val ferrariGarage = new ConcreteGarage(Seq(newFerrari)) val mustangGarage = new ConcreteGarage(Seq(newMustang)) However, if I merely return one or the other, based on a flag, and try to put the result into a garage, it fails: val likesFord = true val new_car = if (likesFord) newFerrari else newMustang val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here The switch alone works fine, it is the call to ConcreteGarage constructor that fails with the rather mystical error: error: inferred type arguments [this.Car[_ >: this.Ferrari with this.Mustang <: this.Car[_ >: this.Ferrari with this.Mustang <: ScalaObject]{def fuel: this.Benzin; type FuelType<: this.Benzin}]{def fuel: this.Benzin; type FuelType<: this.Benzin}] do not conform to class ConcreteGarage's type parameter bounds [C <: this.Car[C]] val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here ^ I have tried putting those magic [C <: Car[C]] representation type parameters everywhere, but without success in finding the magic spot.

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  • Appropriate uses of Monad `fail` vs. MonadPlus `mzero`

    - by jberryman
    This is a question that has come up several times for me in the design code, especially libraries. There seems to be some interest in it so I thought it might make a good community wiki. The fail method in Monad is considered by some to be a wart; a somewhat arbitrary addition to the class that does not come from the original category theory. But of course in the current state of things, many Monad types have logical and useful fail instances. The MonadPlus class is a sub-class of Monad that provides an mzero method which logically encapsulates the idea of failure in a monad. So a library designer who wants to write some monadic code that does some sort of failure handling can choose to make his code use the fail method in Monad or restrict his code to the MonadPlus class, just so that he can feel good about using mzero, even though he doesn't care about the monoidal combining mplus operation at all. Some discussions on this subject are in this wiki page about proposals to reform the MonadPlus class. So I guess I have one specific question: What monad instances, if any, have a natural fail method, but cannot be instances of MonadPlus because they have no logical implementation for mplus? But I'm mostly interested in a discussion about this subject. Thanks! EDIT: One final thought occured to me. I recently learned (even though it's right there in the docs for fail) that monadic "do" notation is desugared in such a way that pattern match failures, as in (x:xs) <- return [] call the monad's fail. It seems like the language designers must have been strongly influenced by the prospect of some automatic failure handling built in to haskell's syntax in their inclusion of fail in Monad.

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  • How do I implement a collection in Scala 2.8?

    - by Simon Reinhardt
    In trying to write an API I'm struggling with Scala's collections in 2.8(.0-beta1). Basically what I need is to write something that: adds functionality to immutable sets of a certain type where all methods like filter and map return a collection of the same type without having to override everything (which is why I went for 2.8 in the first place) where all collections you gain through those methods are constructed with the same parameters the original collection had (similar to how SortedSet hands through an ordering via implicits) which is still a trait in itself, independent of any set implementations. Additionally I want to define a default implementation, for example based on a HashSet. The companion object of the trait might use this default implementation. I'm not sure yet if I need the full power of builder factories to map my collection type to other collection types. I read the paper on the redesign of the collections API but it seems like things have changed a bit since then and I'm missing some details in there. I've also digged through the collections source code but I'm not sure it's very consistent yet. Ideally what I'd like to see is either a hands-on tutorial that tells me step-by-step just the bits that I need or an extensive description of all the details so I can judge myself which bits I need. I liked the chapter on object equality in "Programming in Scala". :-) But I appreciate any pointers to documentation or examples that help me understand the new collections design better.

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  • Remove this URL string when login fails and simply show div error

    - by Anagio
    My developer built our registration page to display a div when logins failed based on a string in the URL. When logins fail this is added to the URL /login?msg=invalid The PHP in my login.phtml which displays the error messages based on the msg= parameter is <?php $msg = ""; $msg = $_GET['msg']; if($msg==""){ $showMsg = ""; } elseif($msg=="invalid"){ $showMsg = ' <div class="alert alert-error"> <a class="close" data-dismiss="alert">×</a> <strong>Error!</strong> Login or password is incorrect! </div>'; } elseif($msg=="disabled"){ $showMsg = "Your account has been disabled."; } elseif($msg==2){ $showMsg = "Your account is not activated. Please check your email."; } ?> In the controller the redirect to that URL is else //email id does not exist in our database { //redirecting back with invalid email(invalid) msg=invalid. $this->_redirect($url."?msg=invalid"); } I know there are a few other validation types for disabled accounts etc. I'm in the process of redesigning the entire interface and would like to get rid of this kind of validation so that the div tags display when logins fail but not show the URL strings. If it matters the new div I want to display is <div class="alert alert-error alert-login"> Email or password incorrect </div> I'd like to replace the php my self in my login.phtml and controller but not a good programmer. What can I replace $this->_redirect($url."?msg=invalid"); with so that no strings are added to the URL and display the appropriate div tags? Thanks

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  • passing an "unknown enumeration" to a method

    - by firoso
    I'm currently trying to make a class that can register strings as identifiers and accociate them with different types of Enumerations, these enumerations are being evaluated only in so much that I am ensuring that when it's used, that the parameter passed to broadcast (messageType) is an instance of the associated Enum Type. This would work something like this: Diagnostics.RegisterIdentifier("logger", typeof(TestEnum)); Diagnostics.Broadcast("logger", TestEnum.Info, null, "Hello World", null); here's the code I currently have, I need to be able to verify that messageTypesEnum is contained in messageTypesFromIdentifier. private static Dictionary<string, Type> identifierMessageTypeMapping = new Dictionary<string, Type>(); private static List<IListener> listeners = new List<IListener>(); public static void RegisterIdentifier(string identifier, Type messageTypesEnum) { if (messageTypesEnum.BaseType.FullName == "System.Enum") { identifierMessageTypeMapping.Add(identifier, messageTypesEnum); } else { throw new ArgumentException("Expected type of messageTypesEnum to derive from System.Enum", "messageTypesEnum"); } } public static void Broadcast(string identifier, object messageType, string metaIdentifier, string message, Exception exception) { if (identifierMessageTypeMapping.ContainsKey(identifier)) { Type messageTypesFromIdentifier = identifierMessageTypeMapping[identifier]; foreach (var listener in listeners) { DiagnosticsEvent writableEvent = new DiagnosticsEvent(identifier, messageType, metaIdentifier, message, exception); listener.Write(writableEvent); } } }

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  • Setting Nullable Integer to String Containing Nothing yields 0

    - by Brian MacKay
    I've been pulling my hair out over some unexpected behavior from nullable integers. If I set an Integer to Nothing, it becomes Nothing as expected. If I set an Integer? to a String that is Nothing, it becomes 0! Of course I get this whether I explicitly cast the String to Integer? or not. I realize I could work around this pretty easily but I want to know what I'm missing. Dim NullString As String = Nothing Dim NullableInt As Integer? = CType(NullString, Integer?) 'Expected NullableInt to be Nothing, but it's 0! NullableInt = Nothing 'This works -- NullableInt now contains Nothing. How is this EDIT: Previously I had my code up here so without the explicit conversion to 'Integer?' and everyone seemed to be fixated on that. I want to be clear that this is not an issue that would have been caught by Option Strict On -- check out the accepted answer. This is a quirk of the string-to-integer conversion rules which predate nullable types, but still impact them.

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