Re: feature/integrated-elpa 4f6df43 15/23: README added

[Eli Zaretskii]

> From: address@hidden (Phillip Lord)
> Cc: address@hidden,  address@hidden
> Date: Tue, 18 Oct 2016 14:33:50 +0100
> 
> >> The point here is that load-path is *directory* based. As it stands, we
> >> cannot exclude some files in one directory.
> >
> > I don't see any need to exclude files.  If a newer version of a
> > package is installed outside of the Emacs lisp/ tree, the directory of
> > that package needs to be earlier in load-path than the main lisp/
> > directory and its subdirectories.  Again, not hard to arrange.
> 
> No, this doesn't work. The point is with the new exporter, org
> introduced new files. The new ox-html.el would not shadow the old
> org-html.el, however you organised the path. In otherwords, the org
> package changed the features that it provided over time.

Look, this discussion will go nowhere constructive if you change the
subject all the time.  You talked about load-path, and our inability
to exclude files in directories on load-path.  Clearly, this only
matters when Emacs wants to _load_ the file in question, and for that
the order of directories in load-path is all that counts.

Now you are evidently talking about a file that was already loaded,
and then the user upgraded the package from which that file comes, and
wants the new version to become effective without restarting Emacs,
which is where the old features already loaded get in the way because
the user wants their new versions.  Obviously, this has nothing to do
with load-path, right?

> More generally, you might also concieve of a situation where a new
> package replaces another.

If package.el already knows how to unload the old features and load
the new ones, it will continue doing this for any package, whether in
or out of core.  Right?