Meta technique, that allows to pospone the setting of the dependable type to the runtime.

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4answers
586 views

How to figure out design pattern for this particular solution?

While working on a project I've come up with some design solution. I am having a hard time relating it to any general design pattern or analyzing this situation in details. This is also prohibiting me ...
2
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1answer
5k views

Adding base-class (inherited) functionality to classes that you don't control

I have a set of classes from a 3rd party library. These classes use an inheritance structure to share logic. I would like to add a layer of abstraction in the middle of their inheritance tree to add ...
1
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1answer
176 views

How do I create a mutually-incompatible type library in Java?

Folks, this seems like it should be straightforward, but I'm drawing a blank here. As a simplified example, consider an abstract class called Number with an abstract method add(). I want to create ...
0
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2answers
167 views

Similar references to themselves in two classes

How can I make 1 class (base, generic or something else) from these two classes? class A { A Link { get; set; } } class B { B Link { get; set; } } UPD: This is what I have now: class BSTree { ...
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1answer
2k views

Why it is not possible to Instantiating Types with Wildcards in Java

I am trying to instantiate LinkedList<?> op = new LinkedList<?>(); But I get error Cannot instantiate the type LinkedList<?> Why is it that this cannot be instantiated in Java? ...
3
votes
5answers
7k views

What problems can be solved using Generics?

I haven't used Generics in C# for a long while. Every time I think I need to use them I either go in the wrong direction and give up or find that I don't really need them. I feel that I'm missing out ...
6
votes
2answers
527 views

Java Generics - how to strike a balance between expressiveness and simplicity

I'm developing some code that utilizes generics, and one of my guiding principles was to make it usable for future scenarios, and not just today's. However, several coworkers have expressed that I may ...
4
votes
3answers
509 views

Why is it so difficult to know where to use interfaces,generics in program design?

I am attempting to learn c# from the head first series, in addition i also consult other books such as Pro C# by Andrew Tolson. Now the thing is that i perfectly understand the interface,generics ...
6
votes
1answer
683 views

Why can't java generics be in arrays?

Why is it that when I try to make an array of ArrayLists: ArrayList<Integer>[] arr=new ArrayList<Integer>[40]; there is an error and java does not allow this? Is there a reason related to ...
13
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1answer
1k views

Scala as a language for Generic Programming

In the paper “An Extended Comparative Study of Language Support for Generic Programming” by Garcia et al. an interesting comparison of programming languages features for generic programming is given: ...
6
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1answer
490 views

Why do generics in Scala have erased types, and are not reifiable?

Why do generics in Scala have erased types, and are not reifiable? Is it due to lack of support from the JVM or for compatibility with Java libraries? What are the advantages in general of having ...
6
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4answers
270 views

Do functional generics exist and what is the correct name for them if they do?

Consider the following generic class: public class EntityChangeInfo<EntityType,TEntityKey> { ChangeTypeEnum ChangeType {get;} TEntityKeyType EntityKey {get;} } Here EntityType ...
3
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2answers
842 views

Need advice on framework design: how to make extending easy

I'm creating a framework/library for a rather specific use-case (data type). It uses diverse spring components, including spring-data. The library has a set of entity classes properly set up and ...
6
votes
1answer
641 views

Constraints while designing the Java generics

Java generics look quite different from those available in Scala, although both were designed by Martin Odersky. From my point of view, the design of generics in Java is worse, for instance: there ...
37
votes
1answer
10k views

Java: “Heap pollution”

A "Heap Pollution" as in Non-Reifiable Types (The Java™ Tutorials > Learning the Java Language > Generics (Updated)) Why is it called that way?
7
votes
3answers
566 views

Why don’t UI frameworks use generics?

One way of looking at type safety is that it adds automatic tests all over your code that stop some things breaking in some ways. One of the tools that helps this in .NET is generics. However, both ...
5
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1answer
3k views

Why can't I implement an interface which has a bounded generic type in this code in java?

I have the following interfaces: public interface Successorable<E> extends Comparable<E> E suc(); } and interface IInterval <E extends Successorable<E>> { E min(); ...
12
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3answers
2k views

Why should we preferably use first class collections?

As per rule number 4 of Object Calisthenics by Jeff Bay (RTF) in The ThoughtWorks Anthology, it is recommended that one should "Use first-class collections". Rule 4: First class collections ...
10
votes
4answers
13k views

Who extends interfaces? And why?

AFAIK, my class extends parent classes and implements interfaces. But I run across a situation, where I can't use implements SomeInterface. It is the declaration of a generic types. For example: ...
19
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8answers
2k views

How to spread awareness for generic programming among team members?

I am staying in an environment, where people believe: Java generics are the feature exclusively used for library writing and not for the real coding. C++ is an OO programming language; template is ...
3
votes
7answers
730 views

Protecting the uninitiated (developer) from generics

Is it acceptable to have a dummy generic parameter in the parameters list in order to save method consumers from the need to specify type arguments? For example - public T Generate<T>(int ...
4
votes
3answers
337 views

generic programming- where did it originate?

Im trying to work out if generic programming was a functional programming feature which was then introduced into Java, C++ and C# or did the latter copy it from the functional programming languages ...
9
votes
3answers
10k views

Difference between various Collection Generic Interfaces in C#

I have been playing around with C# for Windows and ASP.net MVC development for some time now. But I am still unclear on a few areas. I am trying to understand the basic difference between and ...
7
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1answer
555 views

Why prefer a wildcard to a type discriminator in a Java API (Re: Effective Java)

In the generics section of Bloch's Effective Java (which handily is the "free" chapter available to all: http://java.sun.com/docs/books/effective/generics.pdf), he says: If a type parameter ...
11
votes
3answers
2k views

generic programming, how often is it used in industry

I do programming in an academic setting at the moment, so I can use whatever I want. I'm using the boost graph library for a few things, and I'm wondering whether investing effort in understanding GP ...
12
votes
5answers
5k views

What's a good naming convention for generic types in C#? [closed]

I decided to ask this question here instead of on stack overflow because it is rather subjective. In C#, typically I see generic types with very poor names. Specifically, "T" is commonly used but is ...
1
vote
4answers
703 views

Is absence of generic OrderedDictionary class in .NET framework really a design flaw?

I was absolutly sure that I need one (and some SO users too), but it turns out that my case was easily refactored with simple List<object>, and more I think about it I am no so sure anymore that ...
39
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7answers
11k views

What is wrong with Java's generics? [closed]

I have seen several times on this site posts that decry Java's implementation of generics. Now, I can honestly say that I have not had any issues with using them. However, I have not attempted to make ...