On Fri, Aug 19, 2011 at 11:49 AM, Didier Verna <didier@lrde.epita.fr> wrote:
Juan Jose Garcia-Ripoll <juanjose.garciaripoll@googlemail.com> wrote:

> I have been reading the CDR documents and none of them seems to
> mandate the inclusion of some feature to signal the presence of a CDR
> in an implementation. *features* right now is quite populated and I
> would not want to fill it with further names that may collide with
> other users's. Does anybody have a strong opinion or is better
> informed than me in this respect?

 We had a short discussion about this on the CDR mailing list when I
issued the "File Local Variables" CDR. See:
http://lists.common-lisp.net/pipermail/cdr-discuss/2011-April/thread.html

I see both things mentioned:

- Adding :CDRnn or :CDR-nn to *features*
- Making the symbols live in some package.

The first one is not agreed upon. Each one says a different name and a vague reference to CDR recommending this does not lead to any document. This is problematic.

The second thing solves a different problem: conflicts among extensions. But this is not our case. ECL's CDR symbols now live in EXT and do not conflict with anything. I see, however, a potential need for packages to solve clashes among versions, but this does not seem to be a problem with CDR right now.

So we still have two problems (determining the existence of a CDR extension or not, and using it through appropriate names) but no convention has been mandated. What do other implementations do?

Juanjo

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