Search Results

Search found 34176 results on 1368 pages for 'project types'.

Page 94/1368 | < Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >

  • Problem with MessageContract, Generic return types and clientside naming

    - by Soeteman
    I'm building a web service which uses MessageContracts, because I want to add custom fields to my SOAP header. In a previous topic, I learned that a composite response has to be wrapped. For this purpose, I devised a generic ResponseWrapper class. [MessageContract(WrapperNamespace = "http://mynamespace.com", WrapperName="WrapperOf{0}")] public class ResponseWrapper<T> { [MessageBodyMember(Namespace = "http://mynamespace.com")] public T Response { get; set; } } I made a ServiceResult base class, defined as follows: [MessageContract(WrapperNamespace = "http://mynamespace.com")] public class ServiceResult { [MessageBodyMember] public bool Status { get; set; } [MessageBodyMember] public string Message { get; set; } [MessageBodyMember] public string Description { get; set; } } To be able to include the request context in the response, I use a derived class of ServiceResult, which uses generics: [MessageContract(WrapperNamespace = "http://mynamespace.com", WrapperName = "ServiceResultOf{0}")] public class ServiceResult<TRequest> : ServiceResult { [MessageBodyMember] public TRequest Request { get; set; } } This is used in the following way [OperationContract()] ResponseWrapper<ServiceResult<HCCertificateRequest>> OrderHealthCertificate(RequestContext<HCCertificateRequest> context); I expected my client code to be generated as ServiceResultOfHCCertificateRequest OrderHealthCertificate(RequestContextOfHCCertificateRequest context); Instead, I get the following: ServiceResultOfHCCertificateRequestzSOTD_SSj OrderHealthCertificate(CompType1 c1, CompType2 c2, HCCertificateRequest context); CompType1 and CompType2 are properties of the RequestContext class. The problem is that a hash is added to the end of ServiceResultOfHCCertificateRequestzSOTD_SSj. How do I need define my generic return types in order for the client type to be generated as expected (without the hash)?

    Read the article

  • Extracting [] elements from form collection - mvc - should use icollection but have mix of types

    - by bergin
    hi there. have looked at Phil Haacks project on books at http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx which has been useful, but I have a mix of data types. I use a modelview so that i can have a mix of objects, in this case: Order (ie order.id, order.date etc), Customer, SoilSamplingOrder and a list of SoilSamplingSubJobs which is like this [0].id, [0].field, [1].id, [1].field etc Perhaps I should be using ICollection instead of List? I had problems getting UpdateModel to work so I used an extract from collection method. the first 4 method calls : orderRepository.FindOrder(id); etc give the model the original to be edited. but after this point i'm a little lost in how to update the subjobs. I hope i have delineated enough to make sense of the problem. [HttpPost] public ActionResult Edit(int id, FormCollection collection) { Order order = orderRepository.FindOrder(id); Customer cust = orderRepository.FindCustomer(order.customer_id); IList<SoilSamplingSubJob> sssj = orderRepository.FindSubOrders(id); SoilSamplingOrder sso = orderRepository.FindSoilSampleOrder(id); try { UpdateModel(order, collection.ToValueProvider()); UpdateModel(cust, collection.ToValueProvider()); UpdateModel(sso, collection.ToValueProvider()); IList<SoilSamplingSubJob> sssjs = orderRepository.extractSSSJ(collection); foreach (var sj in sssjs) UpdateModel(sso, collection.ToValueProvider()); orderRepository.Save(); return RedirectToAction("Details", new { id=order.order_id}); } catch { return View(); } }

    Read the article

  • Calling an Oracle PL/SQL procedure with Custom Object return types from 0jdbc6 JDBCthin drivers

    - by Andrew Harmel-Law
    I'm writing some JDBC code which calls a Oracle 11g PL/SQL procdedure which has a Custom Object return type. Whenever I try an register my return types, I get either ORA-03115 or PLS-00306 as an error when the statement is executed depending on the type I set. An example is below: PLSQL Code: Procedure GetDataSummary (p_my_key IN KEYS.MY_KEY%TYPE, p_recordset OUT data_summary_tab, p_status OUT VARCHAR2); Java Code: String query = "beginmanageroleviewdata.getdatasummary(?, ?, ?); end;"); CallableStatement stmt = conn.prepareCall(query); stmt.setInt(1, 83); stmt.registerOutParameter(2, OracleTypes.CURSOR); // Causes error: PLS-00306 stmt.registerOutParameter(3, OracleTypes.VARCHAR); stmt.execute(stmt); // Error mentioned above thrown here. Can anyone provide me with an example showing how I can do this? I guess it's possible. However I can't see a rowset OracleType. CURSOR, REF, DATALINK, and more fail. Apologies if this is a dumb question. I'm not a PL/SQL expert and may have used the wrong terminology in some areas of my question. (If so, please edit me). Thanks in advance. Regs, Andrew

    Read the article

  • Can Castle.Windsor do automatic resolution of concrete types

    - by Anthony
    We are evaluating IoC containers for C# projects, and both Unity and Castle.Windsor are standing out. One thing that I like about Unity (NInject and StructureMap also do this) is that types where it is obvious how to construct them do not have to be registered with the IoC Container. Is there way to do this in Castle.Windsor? Am I being fair to Castle.Windsor to say that it does not do this? Is there a design reason to deliberately not do this, or is it an oversight, or just not seen as important or useful? I am aware of container.Register(AllTypes... in Windsor but that's not quite the same thing. It's not entirely automatic, and it's very broad. To illustrate the point, here are two NUnit tests doing the same thing via Unity and Castle.Windsor. The Castle.Windsor one fails. : namespace SimpleIocDemo { using NUnit.Framework; using Castle.Windsor; using Microsoft.Practices.Unity; public interface ISomeService { string DoSomething(); } public class ServiceImplementation : ISomeService { public string DoSomething() { return "Hello"; } } public class RootObject { public ISomeService SomeService { get; private set; } public RootObject(ISomeService service) { SomeService = service; } } [TestFixture] public class IocTests { [Test] public void UnityResolveTest() { UnityContainer container = new UnityContainer(); container.RegisterType<ISomeService, ServiceImplementation>(); // Root object needs no registration in Unity RootObject rootObject = container.Resolve<RootObject>(); Assert.AreEqual("Hello", rootObject.SomeService.DoSomething()); } [Test] public void WindsorResolveTest() { WindsorContainer container = new WindsorContainer(); container.AddComponent<ISomeService, ServiceImplementation>(); // fails with exception "Castle.MicroKernel.ComponentNotFoundException: // No component for supporting the service SimpleIocDemo.RootObject was found" // I could add // container.AddComponent<RootObject>(); // but that approach does not scale RootObject rootObject = container.Resolve<RootObject>(); Assert.AreEqual("Hello", rootObject.SomeService.DoSomething()); } } }

    Read the article

  • Drupal: Template Files, Modules and Content Types for Advanced Theme

    - by theandym
    Intro I am in the process of trying to convert my first HTML/CSS design into a theme for Drupal. I have used ModX for quite a few designs and appreciate the ability to create different page templates and custom variables to be assigned to those templates. However I seem to be having some issues making the transition. The site I am working on theming in Drupal is for a real estate agent. Each page/section will have a different set of content associated with it and will need to display only that content. For example, there will be a page for current listings, each of which will be formatted by a custom content type. However, when I call the content on the home page (or on other pages) I do not want to see this listing data. Layout The layout of the site and the regions associated with each page/section is as follows: Home Spotlight Featured 1 Featured 2 About Spotlight Bios - Profiles of each agent (each will be a node with name, contact info, pic, etc) listed on the page; multiple nodes listed Sidebar Listings Spotlight Listings - Profiles of properties (each will be a node with locations, basic info, pic, etc) listed on the page; multiple nodes listed Sidebar Services Spotlight Content - general paragraph text area Sidebar News/Blog News/Blog Items - List of stories with summaries and links to full article Sidebar Each page/section will use the same header and footer. Issue I have done some reading on Drupal, custom content types (and CCK), Views, and Pathauto. However I have not been able to get a clear picture of how to put it all together to accomplish what I am attempting. What I really would like to know is which modules to use, how best to use them, which elements I need to use where, and what template files I should be using to theme the elements I need to use. Any help or reference to useful resources would be much appreciated.

    Read the article

  • jsprf.c:644: error: incompatible types in assignment

    - by giantKamote
    Hey guys, Can you help me with this error I encountered while building Spidermonkey in PPC? make -f Makefile.ref cat: ../../dist/Linux_All_DBG.OBJ/nspr/Version: No such file or directory cd editline; make -f Makefile.ref all make[1]: Entering directory `/units/ spidermonkey-1.8-next-wip/src/editline' make[1]: Nothing to be done for `all'. make[1]: Leaving directory `/units/ spidermonkey-1.8-next-wip/src/editline' make -f Makefile.ref Linux_All_DBG.OBJ/libjs.a Linux_All_DBG.OBJ/ libjs.so Linux_All_DBG.OBJ/js Linux_All_DBG.OBJ/jsautocfg.h Linux_All_DBG.OBJ/jscpucfg Linux_All_DBG.OBJ/jscpucfg.o cat: ../../dist/Linux_All_DBG.OBJ/nspr/Version: No such file or directory make[1]: Entering directory `/units/ spidermonkey-1.8-next-wip/src' make[1]: Circular jscpucfg.h <- Linux_All_DBG.OBJ/jsautocfg.h dependency dropped. make[1]: Circular Linux_All_DBG.OBJ/jsautocfg.h <- Linux_All_DBG.OBJ/ jsautocfg.h dependency dropped. /powerpc-750- linux-gnu_gcc-3.4.6/bin/powerpc-750-linux-gnu-gcc -o Linux_All_DBG.OBJ/ jsprf.o -c -Wall -Wno-format -MMD -DGCC_OPT_BUG -g3 -DXP_UNIX -DSVR4 - DSYSV -D_BSD_SOURCE -DPOSIX_SOURCE -DHAVE_LOCALTIME_R -DX86_LINUX - DDEBUG -DDEBUG_build -DEDITLINE -ILinux_All_DBG.OBJ jsprf.c jsprf.c: In function `BuildArgArray': jsprf.c:644: error: incompatible types in assignment make[1]: *** [Linux_All_DBG.OBJ/jsprf.o] Error 1 make[1]: Leaving directory `/units/ spidermonkey-1.8-next-wip/src' make: *** [all] Error 2 I'm using a Redhat-Linux machine. Do I need to have NSPR too to cross-compile spidermonkey? Thanks a lot!!

    Read the article

  • Evidence-Based-Scheduling - are estimations only as accurate as the work-plan they're based on?

    - by Assaf Lavie
    I've been using FogBugz's Evidence Based Scheduling (for the uninitiated, Joel explains) for a while now and there's an inherent problem I can't seem to work around. The system is good at telling me the probability that a given project will be delivered at some date, given the detailed list of tasks that comprise the project. However, it does not take into account the fact that during development additional tasks always pop up. Now, there's the garbage-can approach of creating a generic task/scheduled-item for "last minute hacks" or "integration tasks", or what have you, but that clearly goes against the idea of aggregating the estimates of many small cases. It's often the case that during the development stage of a project you realize that there's a whole area your planning didn't cover, because, well, that's the nature of developing stuff that hasn't been developed before. So now your ~3 month project may very well turn into a 6 month project, but not because your estimations were off (you could be the best estimator in the world, for those task the comprised your initial work plan); rather because you ended up adding a whole bunch of new tasks that weren't there to begin with. EBS doesn't help you with that. It could, theoretically (I guess). It could, perhaps, measure the amount of work you add to a project over time and take that into consideration when estimating the time remaining on a given project. Just a thought. In other words, EBS works on a task basis, but not on a project/release basis - but the latter is what's important. It's what your boss typically cares about - delivery date, not the time it takes to finish each task along the way, and not the time it would have taken, if your planning was perfect. So the question is (yes, there's a question here, don't close it): What's your methodology when it comes to using EBS in FogBugz and how do you solve the problem above, which seems to be a main cause of schedule delays and mispredictions? Edit Some more thoughts after reading a few answers: If it comes down to having to choose which delivery date you're comfortable presenting to your higher-ups by squinting at the delivery-probability graph and choosing 80%, or 95%, or 60% (based on what, exactly?) then we've resorted to plain old buffering/factoring of our estimates. In which case, couldn't we have skipped the meticulous case by case hour-sized estimation effort step? By forcing ourselves to break down tasks that take more than a day into smaller chunks of work haven't we just deluded ourselves into thinking our planning is as tight and thorough as it could be? People may be consistently bad estimators that do not even learn from their past mistakes. In that respect, having an EBS system is certainly better than not having one. But what can we do about the fact that we're not that good in planning as well? I'm not sure it's a problem that can be solved by a similar system. Our estimates are wrong because of tendencies to be overly optimistic/pessimistic about certain tasks, and because of neglect to account for systematic delays (e.g. sick days, major bug crisis) - and usually not because we lack knowledge about the work that needs to be done. Our planning, on the other hand, is often incomplete because we simply don't have enough knowledge in this early stage; and I don't see how an EBS-like system could fill that gap. So we're back to methodology. We need to find a way to accommodate bad or incomplete work plans that's better than voodoo-multiplication.

    Read the article

  • Using Sub-Types And Return Types in Scala to Process a Generic Object Into a Specific One

    - by pr1001
    I think this is about covariance but I'm weak on the topic... I have a generic Event class used for things like database persistance, let's say like this: class Event( subject: Long, verb: String, directobject: Option[Long], indirectobject: Option[Long], timestamp: Long) { def getSubject = subject def getVerb = verb def getDirectObject = directobject def getIndirectObject = indirectobject def getTimestamp = timestamp } However, I have lots of different event verbs and I want to use pattern matching and such with these different event types, so I will create some corresponding case classes: trait EventCC case class Login(user: Long, timestamp: Long) extends EventCC case class Follow( follower: Long, followee: Long, timestamp: Long ) extends EventCC Now, the question is, how can I easily convert generic Events to the specific case classes. This is my first stab at it: def event2CC[T <: EventCC](event: Event): T = event.getVerb match { case "login" => Login(event.getSubject, event.getTimestamp) case "follow" => Follow( event.getSubject, event.getDirectObject.getOrElse(0), event.getTimestamp ) // ... } Unfortunately, this is wrong. <console>:11: error: type mismatch; found : Login required: T case "login" => Login(event.getSubject, event.getTimestamp) ^ <console>:12: error: type mismatch; found : Follow required: T case "follow" => Follow(event.getSubject, event.getDirectObject.getOrElse(0), event.getTimestamp) Could someone with greater type-fu than me explain if, 1) if what I want to do is possible (or reasonable, for that matter), and 2) if so, how to fix event2CC. Thanks!

    Read the article

  • .Net xsd.exe tool doesn't generate all types

    - by Mrchief
    For some reason, MS .Net (v3.5) tool - xsd.exe doesn't generate types when they are not used inside any element. e.g. XSD File (I threw in the complex element to avoid this warning - "Warning: cannot generate classes because no top-level elements with complex type were found."): <?xml version="1.0" encoding="utf-8"?> <xs:schema targetNamespace="http://tempuri.org/XMLSchema.xsd" elementFormDefault="qualified" xmlns="http://tempuri.org/XMLSchema.xsd" xmlns:mstns="http://tempuri.org/XMLSchema.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema" > <xs:simpleType name="EnumTest"> <xs:restriction base="xs:string"> <xs:enumeration value="item1" /> <xs:enumeration value="item2" /> <xs:enumeration value="item3" /> </xs:restriction> </xs:simpleType> <xs:complexType name="myComplexType"> <xs:attribute name="Name" use="required" type="xs:string"/> </xs:complexType> <xs:element name="myElem" type="myComplexType"></xs:element> </xs:schema> When i run this thru xsd.exe using xsd /c xsdfile.xsd I don't see EnumTest in the generated cs file. Note; Even though I don't use the enum here, but in my actual project, I have cases like this where we send enum's string value as output. How can I force the xsd tool to include these? Or should I switch to some other tool? I work in Visual Studio 2008.

    Read the article

  • Types of Nested Loops in JAVA

    - by dominoos
    Hi guys. I have a simple question. I have to find out many nested loops as possible in java. I have something like for loop and if statement inside. i know that we can do like if{if{if{if{ something like that too. just need some more idea of more types of nested loops. if you can write down some examples. I'll be very glad. thank you. public class Test { public static void main (String []args) { int i = 0; for(int j = 1; j <= 5; j++) { if(j == 1 || j == 5) { i = 4; } else { i = 1; } for(int x = 0; x < i; x++) { System.out.print("**"); } System.out.println(); } } }

    Read the article

  • Intellisense on custom types in Iron Python

    - by Anish Patel
    Hi everybody, I'm just starting to play around with IronPython and am having a hard time using it with custom types created in C#. I can get IronPython to load in assemblies from C# classes, but I'm struggling without the help of intellisense. If I have a class in C# as defined below, how can I make it so that IronPython will be able to see the methods/properties that are available in it? public class Person { public string Name { get; set; } public int Age{ get; set; } public double Weight{ get; set; } public double Height { get; set; } public double CalculateBMI() { return Weight/Math.Pow(Height, 2); } } In Iron python I'd instance a Person object as follows: newPerson = Person() newPerson.Name = 'John' newPerson.Age = 25 newPerson.Weight = 75 newPerson.Height = 1.70 newPerson.CalculateBMI() The thing that is annoying me is that I want to be able to say newPerson = Person() And then be able to see all the methods and properties associated with the person object whenever I type: newPerson. Anyone have any ideas if this can be done?

    Read the article

  • What happens when value types are created?

    - by Bob
    I'm developing a game using XNA and C# and was attempting to avoid calling new struct() type code each frame as I thought it would freak the GC out. "But wait," I said to myself, "struct is a value type. The GC shouldn't get called then, right?" Well, that's why I'm asking here. I only have a very vague idea of what happens to value types. If I create a new struct within a function call, is the struct being created on the stack? Will it simply get pushed and popped and performance not take a hit? Further, would there be some memory limit or performance implications if, say, I need to create many instances in a single call? Take, for instance, this code: spriteBatch.Draw(tex, new Rectangle(x, y, width, height), Color.White); Rectangle in this case is a struct. What happens when that new Rectangle is created? What are the implications of having to repeat that line many times (say, thousands of times)? Is this Rectangle created, a copy sent to the Draw method, and then discarded (meaning no memory getting eaten up the more Draw is called in that manner in the same function)? P.S. I know this may be pre-mature optimization, but I'm mostly curious and wish to have a better understanding of what is happening.

    Read the article

  • Game architecture: modeling different steps/types of UI

    - by Sander
    I have not done any large game development projects, only messed around with little toy projects. However, I never found an intuitive answer to a specific design question. Namely, how are different types/states of UI modeled in games? E.g. how is a menu represented? How is it different from a "game world" state (let's use an FPS as an example). How is an overlaid menu on top of a "game world" modeled? Let's imagine the main loop of a game. Where do the game states come into play? It it a simple case-by-case approach? if (menu.IsEnabled) menu.Process(elapsedTime); if (world.IsEnabled) world.Process(elapsedTime); if (menu.IsVisible) menu.Draw(); if (world.IsVisible) world.Draw(); Or are menu and world represented somewhere in a different logic layer and not represented at this level? (E.g. a menu is just another high-level entity like e.g. player input or enemy manager, equal to all others) foreach (var entity in game.HighLevelEntities) entity.Process(elapsedTime); foreach (var entity in game.HighLevelEntities) entity.Draw(elapsedTime); Are there well-known design patterns for this? Come to think of it, I don't know any game-specific design patterns - I assume there are others, as well? Please tell me about them.

    Read the article

  • "The data types text and nvarchar are incompatible in the equal to operator" in SQL Query

    - by kenom
    Why i get this error: The data types text and nvarchar are incompatible in the equal to operator. The field of "username" in database is text type... This is my soruce: <%@ Control Language="C#" AutoEventWireup="true" CodeFile="my_answers.ascx.cs" Inherits="kontrole_login_my_answers" %> <div style=" margin-top:-1280px; float:left;"> <p></p> <div id="question"> Add question </div> </div> <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1" > </asp:GridView> <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:estudent_piooConnectionString %>" SelectCommand="SELECT * FROM [question] WHERE ([username] = @fafa)"> <SelectParameters> <asp:QueryStringParameter Name="fafa" QueryStringField="user" Type="String"/> </SelectParameters> </asp:SqlDataSource>

    Read the article

  • Unity 1.2 Dependency injection of internal types

    - by qvin
    I have a facade in a library that exposes some complex functionality through a simple interface. My question is how do I do dependency injection for the internal types used in the facade. Let's say my C# library code looks like - public class XYZfacade:IFacade { [Dependency] internal IType1 type1 { get; set; } [Dependency] internal IType2 type2 { get; set; } public string SomeFunction() { return type1.someString(); } } internal class TypeA { .... } internal class TypeB { .... } And my website code is like - IUnityContainer container = new UnityContainer(); container.RegisterType<IType1, TypeA>(); container.RegisterType<IType2, TypeB>(); container.RegisterType<IFacade, XYZFacade>(); ... ... IFacade facade = container.Resolve<IFacade>(); Here facade.SomeFunction() throws an exception because facade.type1 and facade.type2 are null. Any help is appreciated.

    Read the article

  • Extend and Overload MS and Point Types

    - by dr d b karron
    Do I have make my own Point and Vector types to overload them ? Why does this not work ? namespace System . windows { public partial struct Point : IFormattable { public static Point operator * ( Point P , double D ) { Point Po = new Point ( ); return Po; } } } namespace SilverlightApplication36 { public partial class MainPage : UserControl { public static void ShrinkingRectangle ( WriteableBitmap wBM , int x1 , int y1 , int x2 , int y2 , Color C ) { wBM . DrawRectangle ( x1 , y1 , x2 , y2 , Colors . Red ); Point Center = Mean ( x1 , y1 , x2 , y2 ); wBM . SetPixel ( Center , Colors.Blue , 3 ); Point P1 = new Point ( x1 , y1 ); Point P2 = new Point ( x1 , y2 ); Point P3 = new Point ( x1 , y2 ); Point P4 = new Point ( x2 , y1 ); const int Steps = 10; for ( int i = 0 ; i < Steps ; i++ ) { double iF = (double)(i+1) / (double)Steps; double jF = ( 1.0 - iF ); Point P11 = **P1 * jF;** } }

    Read the article

  • Hibernate collection multiple types

    - by CaptainAwesomePants
    I have a class Player that contains a list of Accessory objects. There are two kinds of Accessories. SocketedAccessories have a list of SocketJewels, and MagicAccessories have a list of MagicEnchantments. At the database level, there is a players table that represents the player, and an accessories table that contains a list of accessories. Accessories have a type field that indicates whether they are socketed or magical, and the columns that are only used by one type are just left blank by entries of the other type. There are socket_jewels and magic_enchantments tables, representing the socket jewels or the magic enchantments on each accessory. I am trying to figure out the correct way to map this with Hibernate. One way would be for the player to have two lists of accessories, one for SocketedAccessories and one for MagicAccessories. That seems undesirable, though. What I want is a way to specify that player should have a field List<Accessory> accessories that contains both types of thing. Is there a way to tell Hibernate, in either hbm.xml or annotations, to do this?

    Read the article

  • confusion about using types instead of gtts in oracle

    - by Omnipresent
    I am trying to convert queries like below to types so that I won't have to use GTT: insert into my_gtt_table_1 (house, lname, fname, MI, fullname, dob) (select house, lname, fname, MI, fullname, dob from (select 'REG' house, mbr_last_name lname, mbr_first_name fname, mbr_mi MI, mbr_first_name || mbr_mi || mbr_last_name fullname, mbr_dob dob from table_1 a, table_b where a.head = b.head and mbr_number = '01' and mbr_last_name = v_last_name) c above is just a sample but complex queries are bigger than this. the above is inside a stored procedure. So to avoid the gtt (my_gtt_table_1). I did the following: create or replace type lname_row as object ( house varchar2(30) lname varchar2(30), fname varchar2(30), MI char(1), fullname VARCHAR2(63), dob DATE ) create or replace type lname_exact as table of lname_row Now in the SP: type lname_exact is table of <what_table_should_i_put_here>%rowtype; tab_a_recs lname_exact; In the above I am not sure what table to put as my query has nested subqueries. query in the SP: (I am trying this for sample purpose to see if it works) select lname_row('', '', '', '', '', '', sysdate) bulk collect into tab_a_recs from table_1; I am getting errors like : ORA-00913: too many values I am really confused and stuck with this :(

    Read the article

  • Types in Haskell

    - by Linda Cohen
    I'm kind of new in Haskell and I have difficulty understanding how inferred types and such works. map :: (a -> b) -> [a] -> [b] (.) :: (a -> b) -> (c -> a) -> c -> b What EXACTLY does that mean? foldr :: (a -> b -> b) -> b -> [a] -> b foldl :: (a -> b -> a) -> a -> [b] -> a foldl1 :: (a -> a -> a) -> [a] -> a What are the differences between these? And how would I define the inferred type of something like foldr map THANKS!

    Read the article

  • Using different numeric variable types

    - by DataPimp
    Im still pretty new so bear with me on this one, my question(s) are not meant to be argumentative or petty but during some reading something struck me as odd. Im under the assumption that when computers were slow and memory was expensive using the correct variable type was much more of a necessity than it is today. Now that memory is a bit easier to come by people seem to have relaxed a bit. For example, you see this sample code everywhere: for (int i = 0; i < length; i++) int? (-2,147,483,648 to 2,147,483,648) for length? Isnt byte (0-255) a better choice? So Im curious of your opinion and what you believe to be best practice, I hate to think this would be used only because the acronym "int" is more intuitive for a beginner...or has memory just become so cheap that we really dont need to concern ourselves with such petty things and therefore we should just use long so we can be sure any other numbers/types(within reason) used can be cast automagically? ...or am Im just being silly by concerning myself with such things?

    Read the article

  • Generics in return types of static methods and inheritance

    - by Axel
    Generics in return types of static methods do not seem to get along well with inheritance. Please take a look at the following code: class ClassInfo<C> { public ClassInfo(Class<C> clazz) { this(clazz,null); } public ClassInfo(Class<C> clazz, ClassInfo<? super C> superClassInfo) { } } class A { public static ClassInfo<A> getClassInfo() { return new ClassInfo<A>(A.class); } } class B extends A { // Error: The return type is incompatible with A.getClassInfo() public static ClassInfo<B> getClassInfo() { return new ClassInfo<B>(B.class, A.getClassInfo()); } } I tried to circumvent this by changing the return type for A.getClassInfo(), and now the error pops up at another location: class ClassInfo<C> { public ClassInfo(Class<C> clazz) { this(clazz,null); } public ClassInfo(Class<C> clazz, ClassInfo<? super C> superClassInfo) { } } class A { public static ClassInfo<? extends A> getClassInfo() { return new ClassInfo<A>(A.class); } } class B extends A { public static ClassInfo<? extends B> getClassInfo() { // Error: The constructor ClassInfo<B>(Class<B>, ClassInfo<capture#1-of ? extends A>) is undefined return new ClassInfo<B>(B.class, A.getClassInfo()); } } What is the reason for this strict checking on static methods? And how can I get along? Changing the method name seems awkward.

    Read the article

  • Handling Apache Thrift list/map Return Types in C++

    - by initzero
    First off, I'll say I'm not the most competent C++ programmer, but I'm learning, and enjoying the power of Thrift. I've implemented a Thrift Service with some basic functions that return void, i32, and list. I'm using a Python client controlled by a Django web app to make RPC calls and it works pretty well. The generated code is pretty straight forward, except for list returns: namespace cpp Remote enum N_PROTO { N_TCP, N_UDP, N_ANY } service Rcon { i32 ping() i32 KillFlows() i32 RestartDispatch() i32 PrintActiveFlows() i32 PrintActiveListeners(1:i32 proto) list<string> ListAllFlows() } The generated signatures from Rcon.h: int32_t ping(); int32_t KillFlows(); int32_t RestartDispatch(); int32_t PrintActiveFlows(); int32_t PrintActiveListeners(const int32_t proto); int64_t ListenerBytesReceived(const int32_t id); void ListAllFlows(std::vector<std::string> & _return); As you see, the ListAllFlows() function generated takes a reference to a vector of strings. I guess I expect it to return a vector of strings as laid out in the .thrift description. I'm wondering if I am meant to provide the function a vector of strings to modify and then Thrift will handle returning it to my client despite the function returning void. I can find absolutely no resources or example usages of Thrift list< types in C++. Any guidance would be appreciated.

    Read the article

  • Multiple generic types in one container

    - by Lirik
    I was looking at the answer of this question regarding multiple generic types in one container and I can't really get it to work: the properties of the Metadata class are not visible, since the abstract class doesn't have them. Here is a slightly modified version of the code in the original question: public abstract class Metadata { } public class Metadata<T> : Metadata { // ... some other meta data public T Function{ get; set; } } List<Metadata> metadataObjects; metadataObjects.Add(new Metadata<Func<double,double>>()); metadataObjects.Add(new Metadata<Func<int,double>>()); metadataObjects.Add(new Metadata<Func<double,int>>()); foreach( Metadata md in metadataObjects) { var tmp = md.Function; // <-- Error: does not contain a definition for Function } The exact error is: error CS1061: 'Metadata' does not contain a definition for 'Function' and no extension method 'Function' accepting a first argument of type 'Metadata' could be found (are you missing a using directive or an assembly reference?) I believe it's because the abstract class does not define the property Function, thus the whole effort is completely useless. Is there a way that we can get the properties?

    Read the article

  • How to store and locate multiple interface types within a Delphi TInterfaceList

    - by Brian Frost
    Hi, I'm storing small interfaces from a range of objects into a single TInterfaceList 'store' with the intention of offering list of specific interface types to the end user, so each interface will expose a 'GetName' function but all other methods are unique to that interface type. For example here are two interfaces: IBase = interface //---------------------------------------- function GetName : string; //---------------------------------------- end; IMeasureTemperature = interface(IBase) //------------------------------------ function MeasureTemperature : double; //---------------------------------------- end; IMeasureHumidity = interface(IBase) //---------------------------------------- function MeasureHumidity: double; //---------------------------------------- end; I put several of these interfaces into a single TInterfaceList and then I'd like to scan the list for a specific interface type (e.g. 'IMeasureTemperature') building another list of pointers to the objects exporting those interfaces. I wish to make no assumptions about the locations of those objects, some may export more than one type of interface. I know I could do this with a class hierarchy using something like: If FList[I] is TMeasureTemperature then .. but I'd like to do something simliar with an interface type, Is this possible?

    Read the article

  • Java constructor using generic types

    - by Beer Me
    I'm having a hard time wrapping my head around Java generic types. Here's a simple piece of code that in my mind should work, but I'm obviously doing something wrong. Eclipse reports this error in BreweryList.java: The method breweryMethod() is undefined for the type <T> The idea is to fill a Vector with instances of objects that are a subclass of the Brewery class, so the invocation would be something like: BreweryList breweryList = new BreweryList(BrewerySubClass.class, list); BreweryList.java package com.beerme.test; import java.util.Vector; public class BreweryList<T extends Brewery> extends Vector<T> { public BreweryList(Class<T> c, Object[] j) { super(); for (int i = 0; i < j.length; i++) { T item = c.newInstance(); // breweryMethod() is an instance method // of Brewery, of which <T> is a subclass (right?) c.breweryMethod(); // "The method breweryMethod() is undefined // for the type <T>" } } } Brewery.java package com.beerme.test; public class Brewery { public Brewery() { super(); } protected void breweryMethod() { } } BrewerySubClass.java package com.beerme.test; public class BrewerySubClass extends Brewery { public BrewerySubClass() { super(); } public void brewerySubClassMethod() { } } I'm sure this is a complete-generics-noob question, but I'm stuck. Thanks for any tips!

    Read the article

< Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >