[Moose-dev] Re: ideas for a new Famix

Hi Nicolas, hi Anne, I agree with the distinction of implementation reuse and sub-typing. When I said reuse, I did not refer to implementation reuse, but to typing reuse. When you say "Famix as implementation language", I presume you mean "the structure of FAMIX as implementation language". As soon as you will talk about "FAMIX as executable language" you will run into the little problem of having an executable language in the first place. In Moose, we want to have Smalltalk as the executable language. This is not just a matter of implementation. It is an important meta-modeling aspect. Fame is indeed a meta-meta-model, but Traits should be captured there as well. Obviously not the Smalltalk Traits, but the Fame Traits. As I said before, the important part of the reuse mechanism resides in its ability to deal with conflicts. Multiple-inheritance in its known language incarnations (e.g., C++) is a mechanism that comes with ambiguities. That is why I do not like this term. Traits comes with an explicit conflict resolution mechanism. That is why I like this one and I would like to see this mechanism in Fame. The most important part for me is that when we will come down from the paper discussion into the programming trenches, the mapping to the underlying implementation is decisive. Take PetitParser, for example. It also has a meta-model, but it also come with a neat mapping to Smalltalk classes. This helps us develop and debug with Smalltalk tools. Of course, if we get a dedicated tool, we can do even more cool things, like we do in the PPBrowser. As for generation, I completely agree that we are doing it all the time, but it only works when we do not get to see it.

But, we get to see FAMIX all the time, and as a consequence, FAMIX should be editable at plain Smalltalk level. Doing it otherwise would be shooting ourselves in the foot. So, I do not want to rely on generation in the Smalltalk incarnation of FAMIX. Anyway, it seems we are making progress and I think we are actually not disagreeing, only picking up on names. I think this is a really exciting direction that was long on the roadmap, but never really tackled. Cheers, Doru On Mon, Apr 15, 2013 at 11:12 AM, Anne Etien <anne.etien(a)univ-lille1.fr> wrote: Hi, Sorry for arriving after the battle. I just want to talk about my experiment in metamodel and model generation. It is clear for me that the concept of Trait should not appear in Fame. It can be use in its implementation, but can't be considered at the same level than Element, Class, Property or Package. I fully agree with Nicolas, when he says that Doru is talking programming and he is talking metamodelling. So Fame is a metametamodel. What is the concept that we want to implement with Traits (or something else) that does not exist currently in Fame? This concept is reuse. A class can reuse several properties from another or several other classes. Sometimes, we want to specify that the property is not reuse as such but using alias... There exist different way to implement this thing. Smalltalk calls it Traits, Eiffel calls it inheritance (there exist perhaps other). There are certainly some differences that are yet too subtle for me. Moreover, methods do not appear in Fame so according to me Traits should neither not appear. But it may happen that I do not understand how it should be introduced. Considering the generation. It is currently performed a lot. It makes sense only if we don't touch the intermediary nor the final level, otherwise the high level and the low level are no more align. I hope it can help in the discussion. Anne Le 13 avr. 2013 à 09:08, stephane ducasse a écrit : _______________________________________________ Moose-dev mailing list Moose-dev(a)iam.unibe.ch https://www.iam.unibe.ch/mailman/listinfo/moose-dev -- www.tudorgirba.com "Every thing has its own flow" On Mon, Apr 15, 2013 at 11:12 AM, Anne Etien <anne.etien(a)univ-lille1.fr> wrote: Hi, Sorry for arriving after the battle. I just want to talk about my experiment in metamodel and model generation. It is clear for me that the concept of Trait should not appear in Fame. It can be use in its implementation, but can't be considered at the same level than Element, Class, Property or Package. I fully agree with Nicolas, when he says that Doru is talking programming and he is talking metamodelling. So Fame is a metametamodel. What is the concept that we want to implement with Traits (or something else) that does not exist currently in Fame? This concept is reuse. A class can reuse several properties from another or several other classes. Sometimes, we want to specify that the property is not reuse as such but using alias... There exist different way to implement this thing. Smalltalk calls it Traits, Eiffel calls it inheritance (there exist perhaps other). There are certainly some differences that are yet too subtle for me. Moreover, methods do not appear in Fame so according to me Traits should neither not appear. But it may happen that I do not understand how it should be introduced. Considering the generation. It is currently performed a lot. It makes sense only if we don't touch the intermediary nor the final level, otherwise the high level and the low level are no more align. I hope it can help in the discussion. Anne Le 13 avr. 2013 à 09:08, stephane ducasse a écrit : _______________________________________________ Moose-dev mailing list Moose-dev(a)iam.unibe.ch https://www.iam.unibe.ch/mailman/listinfo/moose-dev -- www.tudorgirba.com "Every thing has its own flow" _______________________________________________ Moose-dev mailing list Moose-dev(a)iam.unibe.ch https://www.iam.unibe.ch/mailman/listinfo/moose-dev