Re: project--completing-read-strict breaks ada-mode project completion table

[Dmitry Gutov]

On 17.01.2019 16:55, Stefan Monnier wrote:

> I actually think his approach is interesting and maybe we should think
> how our completion system could provide support for these kinds of
> "styles".

Sure, but in some different way. Having some wrapper middleware could 
work, but I'm afraid it might stumble against the same problem the 
current project-find-file does: completion tables are too flexible.

So it's hard to make a universal wrapper which would modify them all the 
same.

> Indeed, an important design constraint I followed for the completion
> styles is that the user should be able to choose the style (hence the
> indirection through completion-category-overrides).

Yup.

> I think part of Stephen's argument is that the same comment applies to
> the new completion behavior of M-x project-find-file you installed
> in 8f9d93f3054.

Like already said, nobody's stopping you or him or anyone else from 
adding a new command that shows file names in a different way (e.g. 
uniquified/abbreviated).

As long as both project-find-file and the new command work the same 
across all project backends, I'm happy.

And again, it doesn't have to be a separate command, the behavior could 
be customizable and dispatched inside the one command's implementation.

We can't do that if the said behavior already lives inside the 
completion table, however.

> > Far be it from me to criticize the exact "uniquified" look for the entries,
> > but I don't think it's a good place to produce them. If it's not possible to
> > implement them via a completion style or something like that, that would
> > apply to all project backends and their completion tables if the user so
> > chooses, maybe it should just be a different command.
>
> I'm not sure if it currently can work for any project backend, but its
> design definitely aims for it to be backend-agnostic

By "it", do you mean uniquify-files.el?

> so it can be used
> for any (flat) completion table (I don't think it'll work well with
> completion-file-name-table).

Would you agree that a "flat completion table" is basically always a 
list of files?