Re: XEmacs package code

[Kai Großjohann]

address@hidden (Michael Sperber [Mr.  Preprocessor]) writes:

> So we really need an infrastructure that deals with versioning and
> allows you to express requirements like "version x of package z" or
> "any version after x of package z" or "any version of package z
> between x and y" and so on.

There are Emacs developers who feel that this is not the right
answer.  Instead of requiring a specific version, one should look for
the features supported by that version and require those, instead.

My humble opinion is that one should look for the features whenever
feasible, but sometimes it might not be feasible to do that.  In those
cases, it is better to be able to require some version of a package.
(All of the operations suggested by Michael.)  Also, when we are
talking about packages that are external to the Emacs core, version
numbers become much more meaningful.  After all, if I require a
feature which was added in AUC-TeX 11.10, then I can just require
that version number and be sure that the feature has been added.
There is only one AUC-TeX package.  For the Emacs core, the situation
is different.  There, it makes sense to ask questions like "can Emacs
do faces now" instead of questions like "is Emacs running under X11".

So how about adding the features that Michael is looking for and how
about educating Lisp programmers about the problems of just checking
for versions?

kai
-- 
Silence is foo!