Search Results

Search found 89926 results on 3598 pages for 'abstract data type'.

Page 6/3598 | < Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >

  • Reference Data Management and Master Data: Are Relation ?

    - by Mala Narasimharajan
    Submitted By:  Rahul Kamath  Oracle Data Relationship Management (DRM) has always been extremely powerful as an Enterprise Master Data Management (MDM) solution that can help manage changes to master data in a way that influences enterprise structure, whether it be mastering chart of accounts to enable financial transformation, or revamping organization structures to drive business transformation and operational efficiencies, or restructuring sales territories to enable equitable distribution of leads to sales teams following the acquisition of new products, or adding additional cost centers to enable fine grain control over expenses. Increasingly, DRM is also being utilized by Oracle customers for reference data management, an emerging solution space that deserves some explanation. What is reference data? How does it relate to Master Data? Reference data is a close cousin of master data. While master data is challenged with problems of unique identification, may be more rapidly changing, requires consensus building across stakeholders and lends structure to business transactions, reference data is simpler, more slowly changing, but has semantic content that is used to categorize or group other information assets – including master data – and gives them contextual value. In fact, the creation of a new master data element may require new reference data to be created. For example, when a European company acquires a US business, chances are that they will now need to adapt their product line taxonomy to include a new category to describe the newly acquired US product line. Further, the cross-border transaction will also result in a revised geo hierarchy. The addition of new products represents changes to master data while changes to product categories and geo hierarchy are examples of reference data changes.1 The following table contains an illustrative list of examples of reference data by type. Reference data types may include types and codes, business taxonomies, complex relationships & cross-domain mappings or standards. Types & Codes Taxonomies Relationships / Mappings Standards Transaction Codes Industry Classification Categories and Codes, e.g., North America Industry Classification System (NAICS) Product / Segment; Product / Geo Calendars (e.g., Gregorian, Fiscal, Manufacturing, Retail, ISO8601) Lookup Tables (e.g., Gender, Marital Status, etc.) Product Categories City à State à Postal Codes Currency Codes (e.g., ISO) Status Codes Sales Territories (e.g., Geo, Industry Verticals, Named Accounts, Federal/State/Local/Defense) Customer / Market Segment; Business Unit / Channel Country Codes (e.g., ISO 3166, UN) Role Codes Market Segments Country Codes / Currency Codes / Financial Accounts Date/Time, Time Zones (e.g., ISO 8601) Domain Values Universal Standard Products and Services Classification (UNSPSC), eCl@ss International Classification of Diseases (ICD) e.g., ICD9 à IC10 mappings Tax Rates Why manage reference data? Reference data carries contextual value and meaning and therefore its use can drive business logic that helps execute a business process, create a desired application behavior or provide meaningful segmentation to analyze transaction data. Further, mapping reference data often requires human judgment. Sample Use Cases of Reference Data Management Healthcare: Diagnostic Codes The reference data challenges in the healthcare industry offer a case in point. Part of being HIPAA compliant requires medical practitioners to transition diagnosis codes from ICD-9 to ICD-10, a medical coding scheme used to classify diseases, signs and symptoms, causes, etc. The transition to ICD-10 has a significant impact on business processes, procedures, contracts, and IT systems. Since both code sets ICD-9 and ICD-10 offer diagnosis codes of very different levels of granularity, human judgment is required to map ICD-9 codes to ICD-10. The process requires collaboration and consensus building among stakeholders much in the same way as does master data management. Moreover, to build reports to understand utilization, frequency and quality of diagnoses, medical practitioners may need to “cross-walk” mappings -- either forward to ICD-10 or backwards to ICD-9 depending upon the reporting time horizon. Spend Management: Product, Service & Supplier Codes Similarly, as an enterprise looks to rationalize suppliers and leverage their spend, conforming supplier codes, as well as product and service codes requires supporting multiple classification schemes that may include industry standards (e.g., UNSPSC, eCl@ss) or enterprise taxonomies. Aberdeen Group estimates that 90% of companies rely on spreadsheets and manual reviews to aggregate, classify and analyze spend data, and that data management activities account for 12-15% of the sourcing cycle and consume 30-50% of a commodity manager’s time. Creating a common map across the extended enterprise to rationalize codes across procurement, accounts payable, general ledger, credit card, procurement card (P-card) as well as ACH and bank systems can cut sourcing costs, improve compliance, lower inventory stock, and free up talent to focus on value added tasks. Change Management: Point of Sales Transaction Codes and Product Codes In the specialty finance industry, enterprises are confronted with usury laws – governed at the state and local level – that regulate financial product innovation as it relates to consumer loans, check cashing and pawn lending. To comply, it is important to demonstrate that transactions booked at the point of sale are posted against valid product codes that were on offer at the time of booking the sale. Since new products are being released at a steady stream, it is important to ensure timely and accurate mapping of point-of-sale transaction codes with the appropriate product and GL codes to comply with the changing regulations. Multi-National Companies: Industry Classification Schemes As companies grow and expand across geographies, a typical challenge they encounter with reference data represents reconciling various versions of industry classification schemes in use across nations. While the United States, Mexico and Canada conform to the North American Industry Classification System (NAICS) standard, European Union countries choose different variants of the NACE industry classification scheme. Multi-national companies must manage the individual national NACE schemes and reconcile the differences across countries. Enterprises must invest in a reference data change management application to address the challenge of distributing reference data changes to downstream applications and assess which applications were impacted by a given change. References 1 Master Data versus Reference Data, Malcolm Chisholm, April 1, 2006.

    Read the article

  • Focus on Oracle Data Profiling and Data Quality 11g - 24/Fev/11

    - by Claudia Costa
    Thursday 24th February, 11am GMTOracle offers an integrated suite Data Quality software architected to discover and correct today's data quality problems and establish a platform prepared for tomorrow's yet unknown data challenges.Oracle Data Profiling provides data investigation, discovery, and profiling in support of quality, migration, integration, stewardship, and governance initiatives. It includes a broad range of features that expand upon basic profiling, including automated monitoring, business-rule validation, and trend analysis.Oracle Data Quality for Data Integrator provides cleansing, standardization, matching, address validation, location enrichment, and linking functions for global customer data and operational business data.It ensures that data adheres to established standards that are adaptable to fit each organization's specific needs. Both single - and double - byte data are processed in local languages to provide a unique and centralized view of customers, products and services.  During this in-person briefing, Data Integration Solution Specialists will be providing a technical overview and a walkthrough.Agenda Oracle Data Integration Strategy overview A focus on Oracle Data Profiling and Oracle Data Quality for Data Integrator: Oracle Data Profiling Oracle Data Quality for Data Integrator Live demo Q&A  This FREE online LIVE eSeminar will be delivered over the Web and Conference Call. Registrations received less than 24hours prior to start time may not receive confirmation to attend.To register click here.For any questions please contact [email protected]

    Read the article

  • Class Mapping Error: 'T' must be a non-abstract type with a public parameterless constructor

    - by Amit Ranjan
    Hi, While mapping class i am getting error 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. Below is my SqlReaderBase Class public abstract class SqlReaderBase<T> : ConnectionProvider { #region Abstract Methods protected abstract string commandText { get; } protected abstract CommandType commandType { get; } protected abstract Collection<IDataParameter> GetParameters(IDbCommand command); **protected abstract MapperBase<T> GetMapper();** #endregion #region Non Abstract Methods /// <summary> /// Method to Execute Select Queries for Retrieveing List of Result /// </summary> /// <returns></returns> public Collection<T> ExecuteReader() { //Collection of Type on which Template is applied Collection<T> collection = new Collection<T>(); // initializing connection using (IDbConnection connection = GetConnection()) { try { // creates command for sql operations IDbCommand command = connection.CreateCommand(); // assign connection to command command.Connection = connection; // assign query command.CommandText = commandText; //state what type of query is used, text, table or Sp command.CommandType = commandType; // retrieves parameter from IDataParameter Collection and assigns it to command object foreach (IDataParameter param in GetParameters(command)) command.Parameters.Add(param); // Establishes connection with database server connection.Open(); // Since it is designed for executing Select statements that will return a list of results // so we will call command's execute reader method that return a Forward Only reader with // list of results inside. using (IDataReader reader = command.ExecuteReader()) { try { // Call to Mapper Class of the template to map the data to its // respective fields MapperBase<T> mapper = GetMapper(); collection = mapper.MapAll(reader); } catch (Exception ex) // catch exception { throw ex; // log errr } finally { reader.Close(); reader.Dispose(); } } } catch (Exception ex) { throw ex; } finally { connection.Close(); connection.Dispose(); } } return collection; } #endregion } What I am trying to do is , I am executine some command and filling my class dynamically. The class is given below: namespace FooZo.Core { public class Restaurant { #region Private Member Variables private int _restaurantId = 0; private string _email = string.Empty; private string _website = string.Empty; private string _name = string.Empty; private string _address = string.Empty; private string _phone = string.Empty; private bool _hasMenu = false; private string _menuImagePath = string.Empty; private int _cuisine = 0; private bool _hasBar = false; private bool _hasHomeDelivery = false; private bool _hasDineIn = false; private int _type = 0; private string _restaurantImagePath = string.Empty; private string _serviceAvailableTill = string.Empty; private string _serviceAvailableFrom = string.Empty; public string Name { get { return _name; } set { _name = value; } } public string Address { get { return _address; } set { _address = value; } } public int RestaurantId { get { return _restaurantId; } set { _restaurantId = value; } } public string Website { get { return _website; } set { _website = value; } } public string Email { get { return _email; } set { _email = value; } } public string Phone { get { return _phone; } set { _phone = value; } } public bool HasMenu { get { return _hasMenu; } set { _hasMenu = value; } } public string MenuImagePath { get { return _menuImagePath; } set { _menuImagePath = value; } } public string RestaurantImagePath { get { return _restaurantImagePath; } set { _restaurantImagePath = value; } } public int Type { get { return _type; } set { _type = value; } } public int Cuisine { get { return _cuisine; } set { _cuisine = value; } } public bool HasBar { get { return _hasBar; } set { _hasBar = value; } } public bool HasHomeDelivery { get { return _hasHomeDelivery; } set { _hasHomeDelivery = value; } } public bool HasDineIn { get { return _hasDineIn; } set { _hasDineIn = value; } } public string ServiceAvailableFrom { get { return _serviceAvailableFrom; } set { _serviceAvailableFrom = value; } } public string ServiceAvailableTill { get { return _serviceAvailableTill; } set { _serviceAvailableTill = value; } } #endregion public Restaurant() { } } } For filling my class properties dynamically i have another class called MapperBase Class with following methods: public abstract class MapperBase<T> where T : new() { protected T Map(IDataRecord record) { T instance = new T(); string fieldName; PropertyInfo[] properties = typeof(T).GetProperties(); for (int i = 0; i < record.FieldCount; i++) { fieldName = record.GetName(i); foreach (PropertyInfo property in properties) { if (property.Name == fieldName) { property.SetValue(instance, record[i], null); } } } return instance; } public Collection<T> MapAll(IDataReader reader) { Collection<T> collection = new Collection<T>(); while (reader.Read()) { collection.Add(Map(reader)); } return collection; } } There is another class which inherits the SqlreaderBaseClass called DefaultSearch. Code is below public class DefaultSearch: SqlReaderBase<Restaurant> { protected override string commandText { get { return "Select Name from vw_Restaurants"; } } protected override CommandType commandType { get { return CommandType.Text; } } protected override Collection<IDataParameter> GetParameters(IDbCommand command) { Collection<IDataParameter> parameters = new Collection<IDataParameter>(); parameters.Clear(); return parameters; } protected override MapperBase<Restaurant> GetMapper() { MapperBase<Restaurant> mapper = new RMapper(); return mapper; } } But whenever I tried to build , I am getting error 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. Even T here is Restaurant has a Parameterless Public constructor.

    Read the article

  • Extending WCF Data Service to synthesize missing data on request

    - by Schneider
    I have got a WCF Data Service based on a LINQ to SQL data provider. I am making a query "get me all the records between two dates". The problem is that I want to synthesize two extra records such that I always get records that fall on the start and end dates, plus all the ones in between which come from the database. Is there a way to "intercept" the request so I can synthesize these records and return them to the client? Thanks

    Read the article

  • Scala type system : basic type mismatch

    - by SiM
    I have a basic type system type mismatch problem: I have a class with a method def Create(nodeItem : NodeItem) = {p_nodeStart.addEndNode(nodeItem)} where p_nodeStart is NodeCache class NodeCache[END_T<:BaseNode] private(node: Node) extends BaseNode { def addEndNode(endNode : END_T) = {this.CACHE_HAS_ENDNODES.Create(endNode)} and the error its giving me is: error: type mismatch; found : nodes.NodeItem required: Nothing def Create(nodeItem : NodeItem) = {p_nodeStart.addEndNode(nodeItem)} while the NodeCache is defined as object NodeTrigger { def Create() { val nodeTimeCache = NodeCache.Create[NodeItem](node) and in object NodeCache object NodeCache { def Create[END_T<:BaseNode]() { val nodeCache = new NodeCache[END_T](node); Any ideas, how to fix the error?

    Read the article

  • Tackling Big Data Analytics with Oracle Data Integrator

    - by Irem Radzik
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";}  By Mike Eisterer  The term big data draws a lot of attention, but behind the hype there's a simple story. For decades, companies have been making business decisions based on transactional data stored in relational databases. Beyond that critical data, however, is a potential treasure trove of less structured data: weblogs, social media, email, sensors, and documents that can be mined for useful information.  Companies are facing emerging technologies, increasing data volumes, numerous data varieties and the processing power needed to efficiently analyze data which changes with high velocity. Oracle offers the broadest and most integrated portfolio of products to help you acquire and organize these diverse data sources and analyze them alongside your existing data to find new insights and capitalize on hidden relationships Oracle Data Integrator Enterprise Edition(ODI) is critical to any enterprise big data strategy. ODI and the Oracle Data Connectors provide native access to Hadoop, leveraging such technologies as MapReduce, HDFS and Hive. Alongside with ODI’s metadata driven approach for extracting, loading and transforming data; companies may now integrate their existing data with big data technologies and deliver timely and trusted data to their analytic and decision support platforms. In this session, you’ll learn about ODI and Oracle Big Data Connectors and how, coupled together, they provide the critical integration with multiple big data platforms. Tackling Big Data Analytics with Oracle Data Integrator October 1, 2012 12:15 PM at MOSCONE WEST – 3005 For other data integration sessions at OpenWorld, please check our Focus-On document.  If you are not able to attend OpenWorld, please check out our latest resources for Data Integration.

    Read the article

  • A follow up on type coercion in C++, as it may be construed by type conversion

    - by David
    This is a follow up to my previous question. Consider that I write a function with the following prototype: int a_function(Foo val); Where foo is believed to be a type defined unsigned int. This is unfortunately not verifiable for lack of documentation. So, someone comes along and uses a_function, but calls it with an unsigned int as an argument. Here the story takes a turn. Foo turns out to actually be a class, which can take an unsigned int as a single argument of unsigned int in an explicit constructor. Is it a standard and reliable behavior for the compiler to render the function call by doing a type conversion on the argument. I.e. is the compiler supposed to recognize the mismatch and insert the constructor? Or should I get a compile time error reporting the type mismatch.

    Read the article

  • BCP???!????????????:Oracle Data Guard ????

    - by Shinobu FUJINAMI
    ??????????????????????????????????????????????????·????????????????? ??????DG???????????????????????Disk Group???Down Grade????????????????????????????????????????? Oracle ? DG ??Data Guard????????????Oracle Data Guard ???????????????????????????????·??????????????????·???????????????????????????????????????????????????????????????? BCP(??????)????????????????????????????????? Oracle Data Guard ??? Oracle Data Guard ????????KROWN??????·????(KDS) ? Data Guard ??????????????????????????????????????????????????????( KROWN??????·????(KDS) ???????? ) ????·???????????? - ???????? Data Guard Data Guard ?????????BCP ????????????????? Data Guard ???????????????????????????????????? - ???????????????????????????? Data Guard ???????·??????(????????)???????????·??????????·??????2?????????????????·?????????????????? ???????????????????????????????·????????????????????????? - Data Guard >> ??????????? ??????????? Data Guard ???????????ASM ? RAC ??????????????????????????? Data Guard ??? Oracle Database ?????????????????  - DataGuard ??????????????????? (11gR1/11gR2) ???????????????????????????????????????????????????  Data Guard ??? Oracle Database ????????????????? - [DataGuard 11g] ?????·?????????????·???? 11g ????????????·?????????????·????????????????? ??????·??????????????????????????????????? ??·???????????? -  Data Guard >> ??????????? ???????????(?????·?????)?????????(????·?????)?????????/??????·???????????????????????? ??????????????????????? ??????????????????????????????? ???·????????????  - Data Guard >> ???? ????????????????????????????????? Data Guard ???????????????????????????????????? ?????????????????????DataGuard??????????????????????????????? ?????DataGuard???????????????????????????????Data Guard ???????????????????????·????????????????????????????? ???????????????????????????????????????????????????????- Data Guard >> ???? ??????????????? ?????????????????????????????????????????????????????????????? ????????????????????????????????? - Data Guard >> ??????????? ??????????????? ?????README, PSR ???????????????????????????????????????????????????????????????????????????????????????????? Oracle Data Guard ? Oracle9i ???????????????????????????????????Oracle Database 10g ???????????·??????? Data Guard ?????????????????????????????????????????????????????????????????Oracle Database 11g ??????·?????·????????????????????????????????????Oracle Data Guard ????????????????????????????????????????

    Read the article

  • nHibernate, Automapping and Chained Abstract Classes

    - by Mr Snuffle
    I'm having some trouble using nHibernate, automapping and a class structure using multiple chains of abstract classes It's something akin to this public abstract class AbstractClassA {} public abstract class AbstractClassB : AbstractClassA {} public class ClassA : AbstractClassB {} When I attempt to build these mappings, I receive the following error "FluentNHibernate.Cfg.FluentConfigurationException was unhandled Message: An invalid or incomplete configuration was used while creating a SessionFactory. Check PotentialReasons collection, and InnerException for more detail. Database was not configured through Database method." However, if I remove the abstract keyword from AbstractClassB, everything works fine. The problem only occurs when I have more than one abstract class in the class hierarchy. I've manually configured the automapping to include both AbstractClassA and AbstractClassB using the following binding class public class BindItemBases : IManualBinding { public void Bind(FluentNHibernate.Automapping.AutoPersistenceModel model) { model.IncludeBase<AbstractClassA>(); model.IncludeBase<AbstractClassB>(); } } I've had to do a bit of hackery to get around this, but there must be a better way to get this working. Surely nHibernate supports something like this, I just haven't figured out how to configure it right. Cheers, James

    Read the article

  • Abstract class and constructor

    - by Amutha
    As abstract class can be instantiated ,still why constructor is allowed inside abstract class? public abstract class SomeClass { private string _label; public SomeClass(string label) { _label=label; } }

    Read the article

  • Inheritance of Custom Attributes on Abstract Properties

    - by Marty Trenouth
    I've got a custom attribute that I want to apply to my base abstract class so that I can skip elements that don't need to be viewed by the user when displaying the item in HTML. It seems that the properties overriding the base class are not inheriting the attributes. Does overriding base properties (abstract or virtual) blow away attributes placed on the original property? From Attribute class Defination [AttributeUsage(AttributeTargets.Property, Inherited = true, AllowMultiple = false)] public class NoHtmlOutput : Attribute { } From Abstract Class Defination [NoHtmlOutput] public abstract Guid UniqueID { get; set; } From Concrete Class Defination public override Guid UniqueID{ get{ return MasterId;} set{MasterId = value;}} From class checking for attribute Type t = o.GetType(); foreach (PropertyInfo pi in t.GetProperties()) { if (pi.GetCustomAttributes(typeof(NoHtmlOutput), true).Length == 1) continue; // processing logic goes here }

    Read the article

  • Static classes in PHP via abstract keyword?

    - by Boldewyn
    According to the PHP manual, a class like this: abstract class Example {} cannot be instantiated. If I need a class without instance, e.g. for a registry pattern: class Registry {} // and later: echo Registry::$someValue; would it be considered good style to simply declare the class as abstract? If not, what are the advantages of hiding the constructor as protected method compared to an abstract class? Rationale for asking: As far as I see it, it could a bit of feature abuse, since the manual refers to abstract classes more as like blueprints for later classes with instantiation possibility.

    Read the article

  • abstract method signature, inheritance, and "Do" naming convention

    - by T. Webster
    I'm learning about design patterns and in examples of code I've seen a convention where the abstract class declares a method, for example: public abstract class ServiceBase { ... public virtual object GetSomething(); and then protected abstract object DoGetSomething(); My question is on why these two methods exist, since they appear to serve the same purpose. Is this so that the base class GetSomething() method logic cannot be overridden by inherited classes? But then again, the method is marked virtual, so it can be overridden anyway. What is the usefulness here in requiring derived class implementers to implement the abstract method when the virtual method can be called anyway?

    Read the article

  • Abstract classes in shared library

    - by JTom
    Hi, I have an ordinary abstract class that has couple of pure virtual methods. The class itself is a part of the shared library. The compilation of the shared library itself is OK. But when the library is linked to another program that has another class deriving from the abstract one in the shared library and defining the pure virtual methods, I get the following linker error: I compile like this..: g++ -I../path/to/the/library main.cpp derived.cpp -L../path/to/the/library -lsomename -o shared ...and the linker error is: libsomename.so: undefined reference to `AbstractClass::method()' It's like the abstract class cannot access its pure virtual methods but I do not try to make any instance of the abstract class anywhere in the library. What could be the problem?

    Read the article

  • Python 2.6, 3 abstract base class misunderstanding

    - by Aaron
    I'm not seeing what I expect when I use ABCMeta and abstractmethod. This works fine in python3: from abc import ABCMeta, abstractmethod class Super(metaclass=ABCMeta): @abstractmethod def method(self): pass a = Super() TypeError: Can't instantiate abstract class Super ... And in 2.6: class Super(): __metaclass__ = ABCMeta @abstractmethod def method(self): pass a = Super() TypeError: Can't instantiate abstract class Super ... They both also work fine (I get the expected exception) if I derive Super from object, in addition to ABCMeta. They both "fail" (no exception raised) if I derive Super from list. I want an abstract base class to be a list but abstract, and concrete in sub classes. Am I doing it wrong, or should I not want this in python?

    Read the article

  • Size of abstract class

    - by webgenius
    How can I find the size of an abstract class? class A { virtual void PureVirtualFunction() = 0; }; Since this is an abstract class, I can't create objects of this class. How will I be able to find the size of the abstract class A using the 'sizeof' operator?

    Read the article

  • Create a new instance in a static function of an abstract class

    - by arno
    abstract class db_table { static function get_all_rows() { ... while(...) { $rows[] = new self(); ... } return $rows; } } class user extends db_table { } $rows = user::get_all_rows(); I want to create instances of a class from a static method defined in the abstract parent class but PHP tells me "Fatal error: Cannot instantiate abstract class ..." How should I implement it correctly?

    Read the article

  • Which statically typed languages support intersection types for function return values?

    - by stakx
    Initial note: This question got closed after several edits because I lacked the proper terminology to state accurately what I was looking for. Sam Tobin-Hochstadt then posted a comment which made me recognise exactly what that was: programming languages that support intersection types for function return values. Now that the question has been re-opened, I've decided to improve it by rewriting it in a (hopefully) more precise manner. Therefore, some answers and comments below might no longer make sense because they refer to previous edits. (Please see the question's edit history in such cases.) Are there any popular statically & strongly typed programming languages (such as Haskell, generic Java, C#, F#, etc.) that support intersection types for function return values? If so, which, and how? (If I'm honest, I would really love to see someone demonstrate a way how to express intersection types in a mainstream language such as C# or Java.) I'll give a quick example of what intersection types might look like, using some pseudocode similar to C#: interface IX { … } interface IY { … } interface IB { … } class A : IX, IY { … } class B : IX, IY, IB { … } T fn() where T : IX, IY { return … ? new A() : new B(); } That is, the function fn returns an instance of some type T, of which the caller knows only that it implements interfaces IX and IY. (That is, unlike with generics, the caller doesn't get to choose the concrete type of T — the function does. From this I would suppose that T is in fact not a universal type, but an existential type.) P.S.: I'm aware that one could simply define a interface IXY : IX, IY and change the return type of fn to IXY. However, that is not really the same thing, because often you cannot bolt on an additional interface IXY to a previously defined type A which only implements IX and IY separately. Footnote: Some resources about intersection types: Wikipedia article for "Type system" has a subsection about intersection types. Report by Benjamin C. Pierce (1991), "Programming With Intersection Types, Union Types, and Polymorphism" David P. Cunningham (2005), "Intersection types in practice", which contains a case study about the Forsythe language, which is mentioned in the Wikipedia article. A Stack Overflow question, "Union types and intersection types" which got several good answers, among them this one which gives a pseudocode example of intersection types similar to mine above.

    Read the article

  • Inventory is not abstract and does not override abstract method

    - by Dan
    OK so my applet is not compiling and I Googled some answers and none worked. (Such as taking public out of public class)... Here's my code: http://www.so.pastebin.com/MBjZGneg Heere is my error: C:\Users\Dan\Documents\DanJavaGen\Inventory.java:12: Inventory is not abstract and does not override abstract method keyReleased(java.awt.event.KeyEvent) in java.awt.event.KeyListener public class Inventory extends Applet implements KeyListener { ... help? :) please.

    Read the article

  • Core Data Model Design Question - Changing "Live" Objects also Changes Saved Objects

    - by mwt
    I'm working on my first Core Data project (on iPhone) and am really liking it. Core Data is cool stuff. I am, however, running into a design difficulty that I'm not sure how to solve, although I imagine it's a fairly common situation. It concerns the data model. For the sake of clarity, I'll use an imaginary football game app as an example to illustrate my question. Say that there are NSMO's called Downs and Plays. Plays function like templates to be used by Downs. The user creates Plays (for example, Bootleg, Button Hook, Slant Route, Sweep, etc.) and fills in the various properties. Plays have a to-many relationship with Downs. For each Down, the user decides which Play to use. When the Down is executed, it uses the Play as its template. After each down is run, it is stored in history. The program remembers all the Downs ever played. So far, so good. This is all working fine. The question I have concerns what happens when the user wants to change the details of a Play. Let's say it originally involved a pass to the left, but the user now wants it to be a pass to the right. Making that change, however, not only affects all the future executions of that Play, but also changes the details of the Plays stored in history. The record of Downs gets "polluted," in effect, because the Play template has been changed. I have been rolling around several possible fixes to this situation, but I imagine the geniuses of SO know much more about how to handle this than I do. Still, the potential fixes I've come up with are: 1) "Versioning" of Plays. Each change to a Play template actually creates a new, separate Play object with the same name (as far as the user can tell). Underneath the hood, however, it is actually a different Play. This would work, AFAICT, but seems like it could potentially lead to a wild proliferation of Play objects, esp. if the user keeps switching back and forth between several versions of the same Play (creating object after object each time the user switches). Yes, the app could check for pre-existing, identical Plays, but... it just seems like a mess. 2) Have Downs, upon saving, record the details of the Play they used, but not as a Play object. This just seems ridiculous, given that the Play object is there to hold those just those details. 3) Recognize that Play objects are actually fulfilling 2 functions: one to be a template for a Down, and the other to record what template was used. These 2 functions have a different relationship with a Down. The first (template) has a to-many relationship. But the second (record) has a one-to-one relationship. This would mean creating a second object, something like "Play-Template" which would retain the to-many relationship with Downs. Play objects would get reconfigured to have a one-to-one relationship with Downs. A Down would use a Play-Template object for execution, but use the new kind of Play object to store what template was used. It is this change from a to-many relationship to a one-to-one relationship that represents the crux of the problem. Even writing this question out has helped me get clearer. I think something like solution 3 is the answer. However if anyone has a better idea or even just a confirmation that I'm on the right track, that would be helpful. (Remember, I'm not really making a football game, it's just faster/easier to use a metaphor everyone understands.) Thanks.

    Read the article

< Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >