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

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Async properties in interfaces to cater for the possibility of expensive first-time evaluation: Is this a good idea?

First of all, sorry if this post is too long. I'll start with the… Short version: Is it generally advisable or a good idea to design an interface property as asynchronous simply because we cannot be ...
2
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4answers
213 views

Determining a class structure

I'm currently in the early stages of designing an e-commerce application. I'm working out some designs for my classes which have so far been fairly straightforward, but I've run into something of a ...
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3answers
169 views

Can a Java interface declaration enforce parameter properties?

As far as I know, declaring an interface is like so: public interface Roots_Squares { public double square_root( double value ); } Now... how do you enforce value to have non-negative values? ...
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0answers
31 views

Beginning Books for Understanding BIOS and UEFI [closed]

Is there a beginners book to understanding what BIOS and UEFI are, what they do, how they are coded, how do they make the interfaces, ect. Any help would be appreciated.
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4answers
551 views

Why 'List<E>' is an 'interface' but not 'abstract class'?

While defining the hierarchy, one can think to embed the abstract method(behaviour) in abstract class only because the derive concrete class posses that as core behaviour with it's specific ...
8
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4answers
405 views

Use cases for “private” interfaces?

I was wondering if there was a valid use case for being able to properly define the specific internal properties and functions of a class in a way similar to how an interface defines the public ...
14
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2answers
2k views

Illegal in PHP: Is there an OOP design reason?

The below interface inheritance is illegal in PHP, but I think it would be fairly useful in real life. Is there an actual antipattern or documented problem with the below design, that PHP is ...
4
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2answers
579 views

Code re-use in C++, via multiple inheritance or composition? Or…?

I originally asked this question on StackOverflow, but I was directed here, and I think my problem is perhaps as much conceptual as technical, so here goes. If you’re defining a hierarchy of abstract ...
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2answers
294 views

Programming against interfaces in Java

Supposing I have an interface Foo and a given implementation FooImpl. public class FooImpl implements Foo If I want to define a new operation on this class that depends on the particular ...
0
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1answer
68 views

Cleanest choice for symmetric operations

I have a need to do some processing from a format A to a format B and from B to A. The job in one direction is very similar to its counterpart. Both formats are represented with an interface Msg. In ...
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3answers
951 views

Why does C# allow properties in interfaces?

In C#, the following code is valid interface I{ int property{get;set;} } Which doesn't make any sense to me. This seems to break one of the most important principles of interfaces: lack of ...
2
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1answer
158 views

Interface hierarchy design for separate domains

There are businesses and people. People could be liked and businesses could be commented on: class Like class Comment class Person implements iLikeTarget class Business implements iCommentTarget ...
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3answers
142 views

Naming interfaces for persistent values

I have 2 distinct types of persistent values that I'm having trouble naming well. They're defined with the following Java-esque structure, borrowing Guava's Optional for the example and using generic ...
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1answer
85 views

Traits, Inheritance and Interfaces in Groovy, when to use them?

I'm learning groovy and I've just learned about the new feature added in 2.3, which is the addition of Traits. Now to me it seems like Traits allow you to do basically everything a super-class and an ...
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0answers
27 views

Restructuring similar interfaces to one unified design

In my project, I have several types of Web API controllers (and their corresponding services and repositories). When I started out, I made an interface of a generic type that would describe the basic ...
11
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4answers
2k views

Is it permissible to use explicit interface implementation to hide members in C#?

I understand how to work with interfaces and explicit interface implementation in C#, but I was wondering if it's considered bad form to hide away certain members that would not be used frequently. ...
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3answers
219 views

Implements > extends, but what about variables?

It's preferable to write programs that depend on interfaces rather than on superclasses, but what when you want a class to have certain variables? Sometimes you want a class to implement a certain ...
28
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9answers
4k views

Are abstract classes / methods obsolete?

I used to create a lot of abstract classes / methods. Then I started using interfaces. Now I am not sure if interfaces aren't making abstract classes obsolete. You need a fully abstract class? ...
0
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1answer
77 views

Android, using a Fragment to hold/edit complex object, accesible from any Activity

I'll do my best to describe the problem, but I'm still very new to several concepts that I think this problem requires to be solved (namely interfaces and threads). I should preface this by saying ...
0
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1answer
83 views

when would you wrap a service object with an interface? [duplicate]

I'm new to UT and some of the best practices and anti-patterns when writing testable code, made me think. I used to wrap any service object with interface. but I see many mocking frameworks can ...
2
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1answer
120 views

Trying to get a better understanding of Interfaces

Im working on a small program and I thought i would use it as a chance to get a better understanding of things I haven't really used before, mainly Interfaces and Inheritance from base classes. ...
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4answers
523 views

How to force “program to an interface” without using a java Interface in java 1.6

In java 1.8 they have wonderful new "default interface methods". In 1.6 how close can we come? The goal: keep clients (using code) from being able to tell that a class is not a java interface. If ...
4
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1answer
96 views

Handling interface segregation in C++

I'm designing a "view" handling system for a game. The goal is to be able to have different "views" that can be shown in sequence or stacked on-top of each other. For example, the initial splash ...
3
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3answers
198 views

Should I denote that a method satisfies an interface?

When writing a class which has ("satisfies") 1 or more interfaces, should I note somehow (e.g. in an XML comment, or with an attribute) that a particular method was added for one of the interfaces? ...
0
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1answer
115 views

Static methods vs Interface implementation

Here is my problem: I stared to create a e-commerce web sites info collector. So i created a parser for each site. The parser class is state less. got methods like: getItemPrice(WebElement page) ...
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2answers
134 views

How to organise and label methods, intended for debug?

I have a class System, which uses a bunch of other classes, to achieve a complex signal processing. In debugging System, one needs to observe the output signal for patterns. This is not achievable by ...
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3answers
218 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 ...
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0answers
111 views

How far to go when future proofing fluent-method-chained-DSL test code?

Is it worth implementing interfaces, or using the getThis() trick, or even static factory methods to future proof against the need to extend this DSL? The current design is a pair of thin ...
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4answers
6k views

Why were default and static methods added to interfaces in Java 8 when we already had abstract classes?

In Java 8, interfaces can contain implemented methods, static methods, and the so-called "default" methods (which the implementing classes do not need to override). In my (probably naive) view, there ...
3
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2answers
181 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
78 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 ...
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0answers
48 views

Pitfalls of combining dependant traits and exceptions in same file as interface in php

What are the potential pitfalls of combining related class like objects (interfaces, traits, custom exceptions) in the same source file? For code reuse and only loading what I need I always separate ...
72
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14answers
18k views

Do I need to use an interface when only one class will ever implement it?

Isn't the whole point of an interface to for multiple classes to adhere to a set of rules and implementations?
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9answers
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
81 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
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1answer
128 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; ...
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6answers
6k 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
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1answer
130 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 ...
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3answers
224 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 ...
33
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4answers
14k views

Why should I prefer composition over inheritance?

I always read that composition is to be preferred over inheritance. A blog post on unlike minds, for example, advocates using composition over inheritance, but I can't see how polymorphism is ...
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4answers
171 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
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1answer
101 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 ...
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4answers
475 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); } ...
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1answer
109 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
364 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(); ...
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2answers
124 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 ...
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3answers
495 views

Why not apply Interface Segregation Principle to “extreme”

Providing that clients would typically consume just one method, though methods would be conceptually related, why not always apply the Interface Segregation Principle to the extreme and have [many] ...
7
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2answers
277 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 ...
40
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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) ...
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2answers
255 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 { ...