Questions about interface related design considerations, such as programming to the interface.

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5
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3answers
322 views

Does it make sense to split up an existing multi-method interface into several single method interfaces just to take advantage of lambdas?

Say I have an existing callback interface that has multiple methods. To illustrate my point I use a callback the likes that you would see in code that performs some HTTP client operations: public ...
3
votes
2answers
267 views

Are there alternatives to using an optional type in a multithreaded environment?

I'm making an MPMC queue in C++, and I would like to find out what the best interface for a try_dequeue method would be (I'm not concerned about its implementation). I'd like to provide a method which ...
0
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2answers
115 views

Possible design patterns for base function with possible additions

I have various interfaces i have to implement. Let's assume ITypeA, ITypeB. They have following methods: ITypeA Connect Disconnect GetData SetData ClearData ITypeB Connect Disconnect ...
23
votes
8answers
2k views

Interface design where functions need to be called in a specific sequence

The task is to configure a piece of hardware within the device, according to some input specification. This should be achieved as follows: 1) Collect the configuration information. This can happen at ...
0
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1answer
182 views

Prepared statement alternatives for this middle-man program?

I have an program that is using a prepared statement to connect and write to a database working nicely, and now need to create a middle-man program to insert between this program and the database. ...
0
votes
1answer
294 views

How to generalize a classes that has identical function plus some additional function

I have some designing problems with my project. To illustrate my problem, I'll use the following two classes from my project. public class RAM_UserManagement{ private Map<int,User> userList; ...
11
votes
6answers
9k views

What are the differences between abstract classes, interfaces, and when to use them

Recently I have started to wrap my head around OOP, and I am now to the point where the more I read about the differences between abstract classes and interfaces the more confused I become. So far, ...
4
votes
1answer
154 views

Designing module interfaces

I'm studying software engineering and one thing I'm really trying to improve is my skill in software architecture. My question is quite broad, so I'll try to explain it with an example. Suppose you ...
1
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3answers
2k views

Make Return Type an Interface - Problem with Initialization

I would like to make the return type of my method an interface rather than a class for similar reasons stated in c# List or IList, however I am having trouble figuring out how to initialize the ...
3
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4answers
2k views

Should I put extension methods of an interface in the interface.cs file?

Imagine this set up: public interface IMass{ double Mass {get;} } public static class IMassExtension { public static double ToKg(this IMass massObject) { return massObject.Mass / ...
2
votes
1answer
123 views

How modularized should my interfaces be?

I stumbled upon a specific instance where it seems that modularity and simplicity are at conflict with each other. Usually that's not the case, so I was really unsure how to resolve it. Suppose I ...
7
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4answers
558 views

“Immutable” interfaces

I am confused about the notion of immutability. Consider the following structure of a simplistic calculator: Here are the interfaces: interface IOperationalInterface { int Sum(int a, int b); } ...
1
vote
1answer
160 views

Domain-specific Interfaces

Are there any real benefits of using interfaces over abstract classes in a domain model? Does anyone have any experience using interfaces in a domain model in a real project? From a technical ...
0
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1answer
399 views

Does it make sense to break fluid interface if a bad argument is passed?

If I chain some setters together and one of them does not return $this, then I will get a fatal error. But maybe that is a good thing. $object = new object(); $object->set('name','foo')->set('...
1
vote
2answers
181 views

Should an abstract class always abstract its methods to an interface?

I had learned sometime ago that abstract classes should always abstract their functions to an interface. So instead of having something like this - abstract class a{ public int i; public int ...
7
votes
2answers
379 views

How to hide AOP implementation dependency without breaking encapsulation?

I have the concept of a SlowLoading thing: public interface SlowLoading { boolean hasLoaded(); } I also have a component MyComponent: public interface myComponent{ void doSomething(); } My ...
41
votes
9answers
4k views

Programming for future use of interfaces

I have a colleague sitting next to me who designed an interface like this: public interface IEventGetter { public List<FooType> getFooList(String fooName, Date start, Date end) ...
2
votes
2answers
305 views

Does it make sense to use interfaces if you don't have polymorphism?

Suppose I have distinct classes that have the same behavior, which can be represented like this: public interface Behavior { void operationA(); } public class ImplementerA implements Behavior { ...
2
votes
2answers
116 views

How specific should be an interface about its implementation details?

Perhaps I should have picked a better title, but anyway... Basically what to do with two or more implementations that have the same public interface, but they are meant for slightly different ...
2
votes
0answers
217 views

The inheritance argument of zope.interface (providedby vs isinstance)

What limitations does inheritance of an interface through an abstract base class present that are addressed by zope.interface? In the following talk given in 2010 by Jeff Rush about interfaces, at 11:...
7
votes
4answers
794 views

Split up large interfaces

I'm using a large interface with about 50 methods to access a database. The interface has been written by a colleague of mine. We discussed this: Me: 50 methods is too much. It's a code smell. ...
0
votes
3answers
464 views

Why do APIs generally consist of interfaces? [duplicate]

I am starting out in Java API design and in reading existing code bases, I have found that most APIs consist of interfaces only with their implementations bundled in a different package. Having read ...
1
vote
2answers
331 views

Go-like interfaces + multi-methods make sense?

Thinking about the design of a potential new language, I wonder how related are the concepts of built a OO similar to GO interfaces and multi-methods (I get this from http://docs.julialang.org/en/...
1
vote
4answers
508 views

Combinatorial explosion of interfaces: How many is too many?

I'm a relative newcomer to OOP, and I'm having a bit of trouble creating good designs when it comes to interfaces. Consider a class A with N public methods. There are a number of other classes, B, C, ...
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2answers
86 views

Creating an Interface To a Language's Standard Library?

In the process of learning test-driven development, I've been introduced to dependency injection and the use of interfaces, and have started using these concepts in my own PHP code in order to make it ...
5
votes
1answer
77 views

Designing communications for extensibility

I am working on the design stages of an application that will a) collect data from various sources (in my case that's scientific data from serial ports), keeping track of the age of the data, b) ...
0
votes
2answers
446 views

Java best practice Interface - subclasses and constants

In the case where a couple of classes implements an interface, and those classes have a couple of constants in common (but no functions), were should I put this constant ? I've had this problem a ...
3
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2answers
169 views

Design for an interface implementation that provides additional functionality

There is a design problem that I came upon while implementing an interface: Let's say there is a Device interface that promises to provide functionalities PerformA() and GetB(). This interface will ...
0
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2answers
309 views

UML Class Diagram: Abstract or Interface?

I am modeling a class diagram and have spotted an opportunity to simplify it slightly. What I want to know is, would this it be better to implement an abstract class or an interface? The scenario is ...
0
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1answer
119 views

Should interface only be used for behavior and not to show logical data grouped together? [duplicate]

Should an interface only be used to specify certain behavior? Would it be wrong to use interface to group logically related data? To me it looks like we should not use interface to group logically ...
4
votes
4answers
1k views

Which methods should be put in an interface and which in abstract classes?

I have seen many frameworks and modules and their standard they follow is like this UserInterface which have some predefined methods AbstractUserClass which implements userInterface Then ...
1
vote
2answers
336 views

c# naming - What are common conventions for a suffix to distinguish between read-only and writable interfaces [closed]

Assume an interface that allows queries on a spatial tree public ISpatialTree { int FindChildIndex(Vector point); bool IsLeaf { get; } ICollection<ISpatialTree> Children { get; } } ...
0
votes
2answers
195 views

Is using interfaces on internal code a good idea? [duplicate]

I'm working on a set of automated tests that we use internally at work. Lately, we've been designing classes that implement interfaces in addition to inheritance. As I understand it, interfaces in ...
2
votes
2answers
147 views

Segregating interfaces/concerns to a tree

When working with a single object there are a number of ways to segregate interfaces to it. Breaking it into smaller components that can be treated independently. Breaking it into simpler interfaces....
5
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5answers
2k views

How to enforce implementation of interface to behave a certain way

Suppose you had the following interface public interface IUserRepository { User GetByID(int userID); } How would you enforce implementers of this interface to throw an exception if a user is ...
0
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2answers
246 views

Interface method signature not restrictive enough

I wrote a piece of code at my job sometime ago. While writting the code I wrote few interfaces who would allow me to add more flexibility and at that time I was also trying to understand OOP concept ...
14
votes
3answers
3k views

Why are interfaces more helpful than superclasses in achieving loose coupling?

(For the purpose of this question, when I say 'interface' I mean the language construct interface, and not an 'interface' in the other sense of the word, i.e. the public methods a class offers the ...
3
votes
1answer
288 views

Different scoring algorithms for different competition elements

I am creating a scoring system for a competition that is somewhat obscure, but it resembles the Olympics in terms of its high-level structure. Therefore, I will ask my question in terms of an ...
3
votes
2answers
475 views

How to manage memory in C interface for C++ implementation considering c++11?

I have a library implemented in C++ which has a C interface. This C interface is, for all intents and purposes, the only way to use this library. C++11 seems to discourage the use of raw pointers but ...
1
vote
1answer
283 views

Should I use inheritance or an interface?

So in a nutshell I have an abstract class : public abstract class Member { public string PCode { get; set; } public string Reference { get; set; } public DateTime? ElectedDate { get; set; } } And ...
1
vote
3answers
581 views

Empty superclass for Collection of derived classes

Basically, what I would like to obtain is a way to iterate through ONE list, and call methods specific to the interface the objects in the collection implement. In my Java project, it would result in ...
0
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2answers
263 views

Using interfaces as part of encapsulation

I'm creating interfaces for a number of our existing classes for mocking reasons. Many of these classes also have package scope methods as an attempt to give some level of encapsulation by ensuring ...
0
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1answer
151 views

When is it suitable to use inheritance [duplicate]

I recently had a small "argument" about inheritance with a friend. I think people overuse it a lot. Intuition tells me that that the only good reason for class inheritance is polymorphism - when there ...
1
vote
3answers
258 views

Necessity of Interfaces for Small Projects

Is it necessary to use interfaces for small projects? I work at a shop writing small custom applications for clients, primarily data manipulation. I'm mostly self-taught but also took some programming ...
2
votes
3answers
400 views

Why are inheritance and interfaces restricted to instance members?

Disclaimer: I think the rules are almost the same in most OO languages, but since I'm most familiar with C# I'll be relating to this specific language. I think that the use of attributes and ...
0
votes
3answers
194 views

Is declaring STL variables in a class definition too revealing?

If you are trying to hide implementation, would declaring STL variables be too revealing? // in Word_Bucket.h class Word_Bucket { private: std::vector<std::string> contents; ...etc } ...
0
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1answer
1k views

How to use namespaces to separate interface from implementation, in c++?

As far as I can tell, you can make your interface known to others by providing your .h file. Your .cpp is the implementation. Then they can see the function names, the parameter types, the return ...
3
votes
2answers
897 views

Implementing the Interface Segregation Principle

Does this IConvertible interface satisfy the Interface Segregation Principle (ie. the "I" in SOLID)? Here is the definition: public interface IConvertible { TypeCode GetTypeCode(); bool ...
52
votes
10answers
17k views

Is better Show() + Hide() or SetVisible(bool visible)?

What is better and why? (From interface-design point of view) : a) To have two Show() and Hide() functions b) To have one SetVisible(bool visible) function EDIT: For example some object have ...
0
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1answer
114 views

Inverse of Extract Interface refactoring

I'm working with a Java project that has several interfaces, many of which have only one implementation. (See related question) For a given revision of the software, one could think this acceptable ...