Naming Interfaces

[Mark Reyes]

Hi All,

Recently a colleague of mine shows me a sample of his program. I want to copy part of his module
so that I wont have to rewrite it myself..(lazy but effective I think)

But I was caught with how he names his interfaces, it always starts with IBladeTrans, IScrewTrans etc...

For once, it is easier to know which one is interface and which one is abstract.
I am not sure but I feel awkward with this. Do you think this will be OK?

Any thoughts?

[Bear Bibeault]

Ick.

That's a convention from C++.

I didn't like it then, and I like it even less for Java.

I just name them whatever makes sense.

[salvin francis]

you may want to refer this,
http://java.sun.com/docs/codeconv/html/CodeConventions.doc8.html
I have heard about the "IXXX" convention, but sun does not say so

[Maneesh Godbole]

Bear Bibeault wrote:Ick....I just name them whatever makes sense.

+1
Having an name which immediately tells you something about the class is always helpful. e.g. AbstractTableModel tells me the class is abstract and it implements the TableModel interface.

[salvin francis]

@Maneesh, ye "ick" kya hota hai ??

[salvin francis]

Bear Bibeault wrote:Ick.
...

What does 'ick' mean Bear ?

[Bear Bibeault]

salvin francis wrote:What does 'ick' mean Bear ?

Imagine that you've accidentally put your hand in something wet and gooey and gross. You say "Ick!"

[salvin francis]

hmm, and i went crazy searching for that acronym
so, I guess its a slang form of "yuck"

[Rob Spoor]

Maneesh Godbole wrote:

Bear Bibeault wrote:Ick....I just name them whatever makes sense.

+1
Having an name which immediately tells you something about the class is always helpful. e.g. AbstractTableModel tells me the class is abstract and it implements the TableModel interface.

+2

[Mike Simmons]

salvin francis wrote:hmm, and i went crazy searching for that acronym
so, I guess its a slang form of "yuck"

I would say that "yuck" and "ick" are both equally slang forms of each other. Neither is formal English; both are slang.

[Mike Simmons]

Maneesh Godbole wrote:

Bear Bibeault wrote:Ick....I just name them whatever makes sense.

+1
Having an name which immediately tells you something about the class is always helpful.

Well, names like IBladeTrans and IScrewTrans are useful in that respect - they immediately tell you that they are interfaces.

(Assuming you care.)

That seems to be antithetical to what Bear was saying. He doesn't want to worry about whether a given class or interface is a class, or abstact class, or interface. Most of the time at least. Not as part of the name. (And I agree with Bear on this point.)

So, Maneesh, when you say "+1", are you agreeing with Bear? (And me?) Or do you disagree? So far, I really can't tell.

Rob, when you say "+2", same question.

[Maneesh Godbole]

I agree on not liking the I... convention. I also agree about having sensible names.

[salvin francis]

Mike Simmons wrote:
That seems to be antithetical to what Bear was saying. He doesn't want to worry about whether a given class or interface is a class, or abstact class, or interface. Most of the time at least. Not as part of the name. (And I agree with Bear on this point.)

Quite frankly i never want to differentiate my interfaces from my classes in terms of naming conventions. I wonder whats the cause of doing so.
Putting it the other way around :

public void printFile(PrintableFile file)
{
   System.out.println("Print any file");
   file.print();
}

isnt it great to leave it to abstraction that the pfile is a class or an interface ? You dont care, it has a print method that's all you care

or would you rather prefer:

public void printFile(IPrintableFile file)
{
   System.out.println("Print any file");
   file.print();
}

or :

public void printFile(PrintableFileInterface file)
{
   System.out.println("Print any file");
   file.print();
}

[Seetharaman Venkatasamy]

Mike Simmons wrote:Well, names like IBladeTrans and IScrewTrans are useful in that respect - they immediately tell you that they are interfaces.

i Agree on this

[Seetharaman Venkatasamy]

salvin francis wrote:

public void printFile([b]IPrintableFile[/b] file)
{
   System.out.println("Print any file");
   file.print();
}

I prefere this. PrintableFile is a Class which implements IPrintableFile Interface . is it make sense ?

salvin francis wrote:

public void printFile(PrintableFile file)   
{   
   System.out.println("Print any file");   
   file.print();   
}  

Never do this [dont restrict the parameter type to a specific implementation]. and remember one thing that always prefere inteface type parameter to particular class type parameter

[salvin francis]

I would really really prefer to allow an interface there rather than a class.

[salvin francis]

btw what i did was a classic example of Using an Interface as a Type

[salvin francis]

Mike Simmons wrote:

Maneesh Godbole wrote:

Bear Bibeault wrote:Ick....I just name them whatever makes sense.

+1
Having an name which immediately tells you something about the class is always helpful.

Well, names like IBladeTrans and IScrewTrans are useful in that respect - they immediately tell you that they are interfaces.

(Assuming you care.)

That seems to be antithetical to what Bear was saying. He doesn't want to worry about whether a given class or interface is a class, or abstact class, or interface. Most of the time at least. Not as part of the name. (And I agree with Bear on this point.)

So, Maneesh, when you say "+1", are you agreeing with Bear? (And me?) Or do you disagree? So far, I really can't tell.

Rob, when you say "+2", same question.

on the lighter side :

how about IScrewedThis or LoveYou implements ILoveYou
The whole "I" thing sounds like iPod or iPhone

No offense to anyone please

[Rob Spoor]

Mike Simmons wrote:That seems to be antithetical to what Bear was saying. He doesn't want to worry about whether a given class or interface is a class, or abstact class, or interface. Most of the time at least. Not as part of the name. (And I agree with Bear on this point.)

So, Maneesh, when you say "+1", are you agreeing with Bear? (And me?) Or do you disagree? So far, I really can't tell.

Rob, when you say "+2", same question.

I agree with Bear, Maneesh and you that in general the name should not indicate what a class is. The only exception for me is the Abstract<Interface> names that are used for basic implementations of interfaces; abstract classes that can be used to help implement an interface, and have no other purpose. AbstractTableModel, AbstractCollection, AbstractList, AbstractMap, etc are examples of those. You can do without them, you just have to do all the hard work yourself.

The root of hierarchies should not have Abstract in the name. Calendar, Component, ClassLoader, Number are all examples of these. If Sun would decide that Calendar could become a basic calendar and no longer needed to be abstract all they would need to do is remove the abstract modifier and implement the abstract methods. No code would be broken, and the name would still be valid.

[salvin francis]

this statement :

seetharaman venkatasamy wrote:
I prefere this. PrintableFile is a Class which implements IPrintableFile Interface . is it make sense ?

contradicts this statement

seetharaman venkatasamy wrote:
Never do this [dont restrict the parameter type to a specific implementation].

for the example i provided
------------------------------------------------------------------------------------------------

In case of any misunderstandings:
I prefer public void printFile(PrintableFile file) where PrintableFile is an interface
over public void printFile(IPrintableFile file) or public void printFile(PrintableFileInterface file)

An IMHO,
An interface does not restrict the parameter type to a specific implementation, a class does.

[Seetharaman Venkatasamy]

@salvin : You are getting me wrong Completely .

[Seetharaman Venkatasamy]

salvin francis wrote:In case of any misunderstandings:
I prefer public void printFile(PrintableFile file) where PrintableFile is an interface

Hmm.. i thought of PrintableFile is a Class

[salvin francis]

[Mark Reyes]

Thanks for all your insights...

Fortunately, eclipse has the Refactor and Rename option. It made the whole work easy...