Re: Subprojects in project.el

[Dmitry Gutov <dgutov@yandex.ru>]

On 29/11/2022 11:56, João Távora wrote:
> Dmitry Gutov <dgutov@yandex.ru> writes:
> 
>> But I'd be happy to find out that 98% of our users' cases can be
>> handled with markers.
> 
> I think you'll begin to lose that bet right here in the Emacs repo.
> Take the doc/ directory where Emacs's manuals live.  It's pretty
> reasonable to consider a non-programmer (or non-Elisp) contributor
> working on that directory almost exclusively, perhaps as a proof-reader.

Setting aside the artificial nature of this example, they could add 
"lispintro" or "lispref" to project-vc-extra-root-markers and have that 
nested project recognized.

As long as the directory contains at least some unique (in the scope of 
the containing project) file or directory, the marker-based approach can 
work fine.

> That person would like C-x p f, C-x p g, etc to operate on the /doc
> hierarchy almost always.  For example to escape the enormous amount of
> grep matches in the Changelog files.  Occasionally, that person might
> want to grep the super-project (Emacs itself) or run a compilation
> command from there, but that would be infrequent.

Sounds fine to me.

> Now, using marker files to mark doc/ as a subproject is not only
> impossible (there are none) and also useless.
> 
> Marker files _are_ useful in e.g. large Javascript monorepos where a lot
> of NPM packages live.  These are frequently added, removed, reshuffled.
> There, looking for `package.json` to designate subprojects makes a lot
> of sense, this is beyond question IMO.  But that doesn't make the case I
> describe above an exotic exception in any way.

I don't know how many people actually intend to do what you described, 
though. But it seems workable just the same.