Search Results

Search found 14532 results on 582 pages for 'dynamic types'.

Page 420/582 | < Previous Page | 416 417 418 419 420 421 422 423 424 425 426 427  | Next Page >

• C# Bug or Brain Teaser? Cast working only with Coalesce (??) Operator

  - by Alex

  This is very strange, maybe someone can explain what's happening, or this is a bug (though I tend to think that this is probably just something intricate about C#). The following code throws the error "Cannot implicitly convert type 'uint?' to 'uint'.": public void Test(UInt32? p) { UInt32 x = p; } However, this code works without error: public void Test(UInt32? p) { UInt32 x = p ?? 1; } Huh? Why does this work? Why would the coalesce operator cause implicit conversion of UInt32? (nullable) to UInt32 (non-nullable), while the first error message says that there is no implicit conversion between those types?

  Read the article

• How do you make your Java application memory efficient?

  - by Boune

  How do you optimize the heap size usage of an application that has a lot (millions) of long-lived objects? (big cache, loading lots of records from a db) Use the right data type Avoid java.lang.String to represent other data types Avoid duplicated objects Use enums if the values are known in advance Use object pools String.intern() (good idea?) Load/keep only the objects you need I am looking for general programming or Java specific answers. No funky compiler switch. Edit: Optimize the memory representation of a POJO that can appear millions of times in the heap. Use cases Load a huge csv file in memory (converted into POJOs) Use hibernate to retrieve million of records from a database Resume of answers: Use flyweight pattern Copy on write Instead of loading 10M objects with 3 properties, is it more efficient to have 3 arrays (or other data structure) of size 10M? (Could be a pain to manipulate data but if you are really short on memory...)

  Read the article

• Inheritance in tables - structure problem

  - by Naor

  I have 3 types of users in my system. each type has different information I created the following tables: BaseUser(base_user_id, username, password, additional common data) base_user_id is PK and Identity UserType1(user_id, data related to type1 only) user_id is PK and FK to base_user_id UserType2(user_id, data related to type2 only) user_id is PK and FK to base_user_id UserType3(user_id, data related to type3 only) user_id is PK and FK to base_user_id Now I have relation from each type of user to warehouses table. Users from type1 and type2 should have only warehouse_id and users from type3 should have warehouse_id and customer_id. I thought about this structure: WarehouseOfUser(base_user_id,warehouse_id) base_user_id is FK to base_user_id in BaseUser WarehouseOfTyp3User(base_user_id,warehouse_id, customer_id) base_user_id is FK to base_user_id in BaseUser The problem is that such structure allows 2 things I want to prevent: 1. add to WarehouseOfTyp3User data of user from type2 or type1. 2. add to WarehouseOfUser data of user from type3. what is the best structure for such case?

  Read the article

• Is Classic ADO still viable for a mixed managed/unmanaged App?

  - by Andy Dent

  We have a complex architecture with much logic in unmanaged code that needs database access. Currently this is via ODBC drivers and MFC classes and we're considering the issues of migrating our abstraction layer to use ADO or ADO.Net. In the latter case we'd have to be pushing database logic back up into the .Net layer. I'm trying to decide if the pain of invoking the database via .Net callbacks is offset by the improvements in ADO.Net. The Wikipedia comparison was interesting although I'm not sure I believe all the points in the comparison table (eg: does ADO.Net always use XML to pass data?). A 2005 comparison shows ADO.Net performing dramatically faster. Microsoft's guide to ADO.Net for ADO programmers suggests we will gain much from going to ADO.Net especially the way that data is available in native (.Net) types rather than solely through OLEAutomation's Variant.

  Read the article

• Design pattern: polymorphisim for list of objects

  - by ziang

  Suppose I have a class A, and A1, A2 inherits from A. There are 2 functions: List<A1> getListA1(){...} List<A2> getListA2(){...} Now I want to do something similar to both A1 and A2 in another function public void process(List<A>){...} If I want to pass the instance of either ListA1 or ListA2, of course the types doesn't match because the compiler doesn't allow the coercion from List< A1 to List< A. I can't do something like this: List<A1> listA1 = getListA1(); List<A> newList = (List<A>)listA1; //this is not allowed. So what is the best approach to the process()? Is there any way to do it in a universal way rather than write the similar code to both List and List?

  Read the article

• CSS "and" and "or"

  - by Misiur

  Hi there. I've got quite big trouble, because i need to anathematise from styling some input types. I had something like: .registration_form_right input:not([type="radio") { //Nah. } But i don't want to style checkboxes too. I've tried: .registration_form_right input:not([type="radio" && type="checkbox"]) .registration_form_right input:not([type="radio" && "checkbox"]) .registration_form_right input:not([type="radio") && .registration_form_right input:not(type="checkbox"]) How to use &&? And I'll need to use || soon, and I think that usage will be same. Thanks.

  Read the article

• TDD Example for Business Apps

  - by Jimmo

  I understand the general idea about unit testing and have used it in scenarios where complex interactions were happening in a system, but I still have a question about all of those principles coming together. We are cautioned about not testing the framework, or the database. Good UI design does not lend itself to non-human testing. UI interaction in general is excluded in MVC frameworks. In many apps what is left?. 37signals talks about extensive unit testing, but in an app like Basecamp or Backpack, what exactly are the types of things being tested through appropriate unit tests? What would 100% code coverage mean in that scenario?

  Read the article

• MySQL: Efficient Blobbing?

  - by feklee

  I'm dealing with blobs of up to - I estimate - about 100 kilo bytes in size. The data is compressed already. Storage engine: InnoDB on MySQL 5.1 Frontend: PHP (Symfony with Propel ORM) Some questions: I've read somewhere that it's not good to update blobs, because it leads to reallocation, fragmentation, and thus bad performance. Is that true? Any reference on this? Initially the blobs get constructed by appending data chunks. Each chunk is up to 16 kilo bytes in size. Is it more efficient to use a separate chunk table instead, for example with fields as below? parent_id, position, chunk Then, to get the entire blob, one would do something like: SELECT GROUP_CONCAT(chunk ORDER BY position) FROM chunks WHERE parent_id = 187 The result would be used in a PHP script. Is there any difference between the types of blobs, aside from the size needed for meta data, which should be negligible.

  Read the article

• How do I use Declarations (type, inline, optimize) in Scheme?

  - by kunjaan

  How do I declare the types of the parameters in order to circumvent type checking? How do I optimize the speed to tell the compiler to run the function as fast as possible like (optimize speed (safety 0))? How do I make an inline function in Scheme? How do I use an unboxed representation of a data object? And finally are any of these important or necessary? Can I depend on my compiler to make these optimizations? thanks, kunjaan.

  Read the article

• Best way to test instance methods without running __init__

  - by KenFar

  I've got a simple class that gets most of its arguments via init, which also runs a variety of private methods that do most of the work. Output is available either through access to object variables or public methods. Here's the problem - I'd like my unittest framework to directly call the private methods called by init with different data - without going through init. What's the best way to do this? So far, I've been refactoring these classes so that init does less and data is passed in separately. This makes testing easy, but I think the usability of the class suffers a little. EDIT: Example solution based on Ignacio's answer: import types class C(object): def __init__(self, number): new_number = self._foo(number) self._bar(new_number) def _foo(self, number): return number * 2 def _bar(self, number): print number * 10 #--- normal execution - should print 160: ------- MyC = C(8) #--- testing execution - should print 80 -------- MyC = object.__new__(C) MyC._bar(8)

  Read the article

• What is the flag to show the nesting of views in a Mac app?

  - by theMikeSwan

  I have just spet the last few hours trying to find the flag to use in Terminal to launch an app with the colored outlines around the various view elements to show how they are nested. I know that Matt Gemmell covered it during the Cocoa Face Off session of NSConference 2009 (at about the 13minute mark in the video). Unfortunately I can't actually read what he types and he doesn't speak the exact command. I know it has to be in the Apple docs somewhere but the search system is currently not being of any use. It looks like her just adds -showAllViews YES to the end of the command to open TextEdit but that command has no effect in 10.6.6. I have also tried every other capitalization I can think of as well as using view instead of views. Every command opens TextEdit just fine but doesn't show the colored outlines.

  Read the article

• Jquery check array perform function

  - by mtwallet

  Hello. I am creating a site that requires a very small postcode checker. I have approx 8 postcode prefix's, HX, HD, BD, LS etc in an array. I also have a simple input field and submit btn. When the user types in a postcode for example HX5 9DU I want Jquery to check the array, if there is match for the first 2/3 letters I want a div to fade in displaying a message. How would I do this? Many thanks in advance.

  Read the article

• What structure of data use to communicate via tcp/ip in java?

  - by rmaster

  Let's assume I want to send many messages between 2 programs made in java that use TCP sockets. I think the most convienient way is to send objects like: PrintStream ps = new PrintStream(s.getOutputStream()); ObjectOutputStream oos = new ObjectOutputStream(ps); some_kind_of_object_here; oos.writeObject(some_kind_of_object_here); ps.print(oos); I want to send, strings, numbers, HashMaps, boolean values How can I do this using fx 1 object that can store all that properties? I though about ArrayList that is serializable and we can put there everything but is not elegant way. I want to send different types of data because user can choose from a variety of options that server can do for it. Any advices?

  Read the article

• Retrieving values from Env in mod_esi or webtools

  - by williamstw

  A complete noob question, but how exactly do I get values (e.g. path_info) from inside the callback? From the docs, I thought it was a list of tuples, which I thought would make it accessible via lists:keyfind, but I've had no luck. So far, all the examples I've found only show how to print everything with io_lib but not how to access the values by key... Thanks, --tim The docs: Module:Function(SessionID, Env, Input)- _ Types SessionID = term() Env = [EnvironmentDirectives] ++ ParsedHeader EnvironmentDirectives = {Key, Value} Key = query_string | content_length | server_software | gateway_interface | server_protocol | server_port | request_method | remote_addr | script_name. <v>Input = string()

  Read the article

• Definition of variables/fields type within a constructor, how is it done?

  - by elementz

  I just had a look at Suns Java tutorial, and found something that totally confused me: Given the following example: public Bicycle(int startCadence, int startSpeed, int startGear) { gear = startGear; cadence = startCadence; speed = startSpeed; } Why is it, that the types of the variables (fields?) gear, cadence and speed do not need to be defined? I would have written it as follows: public Bicycle(int startCadence, int startSpeed, int startGear) { int gear = startGear; int cadence = startCadence; int speed = startSpeed; } What would be the actual differnce?

  Read the article

• How to pass or display mySQL data based on subscription or billing

  - by spm

  I want to build a PHP based site where, the user can view data based on the types of data they've paid for. Allow me to use something simple for an example. Let's say historical data for basketball was not readily available but could be purchased. Simple information such as the Winner, Loser, Final score and date are all stored in a mySQL table. What would be involved so that, when the user logs in, they can only see the historical data they have paid for. My theories so far about the architecture: I imagined a mySQL table storing True or False values for all historical game data they have paid for. Based on this, a 'data chart' object enables the user to view all data within their mySQL row which has a value of 'true.' Follow ups: Assuming I am correct, what methods are popular or practical for this type of service.

  Read the article

• Getting .NET schema for a stored procedure result

  - by PHeiberg

  I have a couple of stored procedures in T-SQL where each stored procedure has a fixed schema for the result set. I need to map the result sets for each procedure to a POCO object and need the column name and type for each column in the result set. Is there a quick way of accessing the information? The best way I have found so far is accessing each stored procedure from .NET and writing my own extension method on a IDataReader/IDataRecord for dumping the information (column names and types) out. Example, a stored procedure executing the following query: SELECT Id, IntField, NullableIntField, VarcharField, DateField FROM SomeTable would require me to have the mapping information: Id - Guid IntField - System.Int32 NullableIntField - Nullable<System.Int32> VarcharField - String DateField - DateTime

  Read the article

• slow record deletion with large ntext values

  - by asking

  I'm having trouble deleting some records via a stored procedure from a table in SQLServer 2008R2 that has ntext columns. The stored proc is timing out and running the query directly takes a very long time. The initial query was a straight "delete from y where x = z" and I've also tried running it in batches of 1000 with transactions but it is still slow and timing out in a stored proc. The majority of the records in the table will not be deleted each time (it's not just a once-off query but will be run other times). The ntext columns are not used in the where clause and I can't change the column types. Any suggestions on the quickest way to delete records with large ntext values? Thanks

  Read the article

• Li with float in IE6/7. It disappears?

  - by Ricardo H.Bin

  Hi guys. Try test this code in IE 6/7: <html> <head> <title>Title</title> </head> <body> <ul> <li style="float:left">huisashaiuhs iuhuiahsiuhsaiu</li> </ul> </body> </html> Where is the circle of LI? I already do ALL types of workaround, in UL and LI. Nothing, NOTHING works. Do you have any idea? (BTW already tried hasLayout,padding-left,margin-left,display:inline, etc etc etc)

  Read the article

• Generic TypeIdenitifier convertion.How?

  - by John

  How do I convert the TypeIdenitifier to a class type? I need to use implicit convertion. type TMyChildArray<T>=class(TMyArray<T>) private FData:Array of T; procedure AddEnd(); end; TTypeIdenitifierParentClass=class(TAnotherParentClass) protected TestField:Cardinal; end; procedure TMyChildArray<T>.AddEnd(); var elem:T; begin for elem in Fdata do TTypeIdenitifierParentClass(elem).TestField:=0; end; I get "Invalid typecast" on the implicit convertion "TTypeIdenitifierParentClass(elem).TestField:=0;". The principle I want to use is that the TypeIdenitifier will represent a class that descends from TTypeIdenitifierParentClass.There are many class types,but all of them descend that class. How do I do this?

  Read the article

• Is my code really not unit-testable?

  - by John

  A lot of code in a current project is directly related to displaying things using a 3rd-party 3D rendering engine. As such, it's easy to say "this is a special case, you can't unit test it". But I wonder if this is a valid excuse... it's easy to think "I am special" but rarely actually the case. Are there types of code which are genuinely not suited for unit-testing? By suitable, I mean "without it taking longer to figure out how to write the test than is worth the effort"... dealing with a ton of 3D math/rendering it could take a lot of work to prove the output of a function is correct compared with just looking at the rendered graphics.

  Read the article

• Scala loop returns as Unit and compiler points to "for" syntax?

  - by DeLongey

  Seems like Unit is the theme of my troubles today. I'm porting a JSON deserializer that uses Gson and when it comes to this for loop: def deserialize(json:JsonElement, typeOfT:Type, context:JsonDeserializationContext) = { var eventData = new EventData(null, null) var jsonObject = json.getAsJsonObject for(entry <- jsonObject.entrySet()) { var key = entry.getKey() var element = entry.getValue() element if("previous_attributes".equals(key)) { var previousAttributes = new scala.collection.mutable.HashMap[String, Object]() populateMapFromJSONObject(previousAttributes, element.getAsJsonObject()) eventData.setPreviousAttributes(previousAttributes) eventData } else if ("object".equals(key)) { val `type` = element.getAsJsonObject().get("object").getAsString() var cl = objectMap.get(`type`).asInstanceOf[StripeObject] var `object` = abstractObject.retrieve(cl, key) eventData.setObject(`object`) eventData } } } The compiler spits out the error type mismatch; found : Unit required: com.stripe.EventData and it points to this line here: for(entry <- jsonObject.entrySet()) Questions Confirm that it is indeed the Gson method entrySet() appearing as unit? If not, what part of the code is creating the issue? I've set return types/values for eventData class methods Is there a workaround for the Gson Unit issue? Thanks!

  Read the article

• gwt - Using List<Serializable> in a RPC call?

  - by Garagos

  I have a RPC service with the following method: public List<Serializable> myMethod(TransactionCall call) {...} But I get a warning when this method is analyzed, and then the rpc call fails Analyzing 'my.project.package.myService' for serializable types Analyzing methods: public abstract java.util.List<java.io.Serializable> myMethod(my.project.package.TransactionCall call) Return type: java.util.List<java.io.Serializable> [...] java.io.Serializable Verifying instantiability (!) Checking all subtypes of Object wich qualify for serialization It seems I can't use Serializable for my List... I could use my own interface instead (something like AsyncDataInterface, wich implements the Serializable interface) but the fact is that my method will return a list custom objects AND basic objects (such as Strings, int....). So my questions are: Is it a standart behaviour? (I can't figure out why I can't use this interface in that case) Does anyone have a workaround for that kind of situation?

  Read the article

• Is there a way to reference a certain class/interface/... by enclosing it with its namespace rather than a using directive "using namespace_name" ?!

  - by Ahmed

  Is there a way to reference a certain class/interface/... by enclosing it with its namespace rather than a using directive "using namespace_name" ?! As, I'm working on a website, which uses SAP .NET connector. I already added a reference for connector ddl, and while referencing its namespace "using namespace_name", or set class namespace to another one rather than connector namespace, I got error regarding connector classes with that error message "The type or namespace couldn't be found, are you missing a using directive or an assembly reference?". But while changing namespace name to connector namespace, everything is going well?! // Set namespace to be IDestinationConfiguration interface namespace. namespace SAP.Middleware.Connector { public class ConnectorConfiguration : IDestinationConfiguration { } } So, connector types forced me to set namespace of class to their namespace! Is this possible? If so, how?

  Read the article

• Is both approach same ?

  - by Harikrishna

  I have one datatable which is not bindided and records are coming from the file by parsing it in the datatable dynamically every time. Now there is three columns in the datatable Marks1,Marks2 and FinalMarks. And their types is decimal. Now for making addition of columns Marks1 and Marks2 's records and store it into FinalMarks column,For that what I do is : datatableResult.Columns["FinalMarks"].Expression="Marks1+Marks2"; It's works properly. It can be done in other way also is foreach (DataRow r in datatableResult.Rows) { r["FinalMarks"]=Convert.ToDecimal(r["Marks1"])+Convert.ToDecimal(r["Marks2"]); } Now I don't know that which is the best way to do this means performance wise. Is first approach same as second approach in background means is both approach same or what?

  Read the article

< Previous Page | 416 417 418 419 420 421 422 423 424 425 426 427  | Next Page >