Re: Making project-files the "canonical" generic

[Dmitry Gutov]

On 17.01.2019 16:25, Stefan Monnier wrote:
> > But again, why allow it?
>
> For example because of backward compatibility.

We still consider project.el "experimental", and we should be allowed to 
roll back on bad ideas.

> Or because there is one example of its possible use.

The sole goal of that example is to change the UI of project-find-file 
for its backend, and for that backend only.

That doesn't seem like a worthy goal.

And right now project-find-file is incompatible with that completion 
table. The obvious move it to make it use project-files instead, and 
thus project-file-completion-table entirely unused.

Another fix could be to (try to?) move the common-parent-directory logic 
into the default completion table. Not sure if it's feasible, but you 
could prove me wrong.

In that case, though, different project backends will be able to show 
different UIs to the users.

> Why disallow it?

Per-backend, non-user-customizable UIs are bad. And we've seen no other 
use cases so far.