On 03/08/2013 08:10 AM, stephane ducasse wrote:

On Mar 7, 2013, at 5:08 PM, Tudor Girba <tudor@tudorgirba.com> wrote:

Yes, we do :).

A model without the appropriate behavior has little value. For example, we want to have traversals next to the model. It is for this reason that we should use Traits.

Yes


We do not want to use multiple inheritance as a design tool. We should use Traits instead, as we know it scales better.
do we?  :-)

We were discussing this over lunch with Damien Cassou (our trait expert)

It seems to me traits are a behaviour reuse mechanism, Famix is mostly about typing and structure.

I do not see why we could not use traits to make fame modular.
I did not say I don't want to use it
But I don't believe it covers all the needs.

For me a model and therefore Famix is inherently typed because it is about describing things.
For exmple I fighted with Usman and Guillaume because they were using FamixReference to represent an import between two programs when it should have been some other association.
It worked, but it was not the right semantic.
And models are essentially tools to describe semantics, not implementation.

This is why I don't think traits are the solution in this case.
They are a reuse mechanism, not a typing one.

I don't think models are just another kind of programming language, they were primarily intended to be conceptual tools that could be derived to programs.

A programming language must be implementable on a computer (or fail to present much interest).
A model must be mostly transformable into a program, but some manual tweaking seems acceptable.

It depends and I do not see the point.

The points is: we know that multiple inheritance is a pain in the back to implement in programming language.

Yet, we also know that everything everywhere uses something that in lack of better image I would call multiple inheritance.

So I would like to see if we can define some kind of multiple inheritance to describe things (fame/famix), and then some clever mechanism to translate this multiple inheritance into real program (pharo, java, whatever).

nicolas


Alain Plantec already did a prototype for having Traits in Fame, but it was not integrated. It would be great if someone would look into this. The only thing to keep in mind is that we would have to also update the Java version of Fame.

Cheers,
Doru

-- 
Nicolas Anquetil -- RMod research team (Inria)