bug#60505: 29.0.60; Fido Mode and Tramp Completion

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: Gregory Heytings <gregory@heytings.org>,  60505@debbugs.gnu.org,
>   julien@jroy.ca
> Date: Thu, 02 Feb 2023 09:25:41 +0100
> 
> > From my POV, it is very reasonable to expect that completion
> > mechanisms know about Tramp syntax and support it.  Tramp became long
> > ago an integral part of the Emacs core, so its syntax is as important
> > to support as any other syntactical aspects of file names in Emacs,
> > such as the "/:" "quoting".
> 
> I could imagine that the completion machinery offers an API that a
> package could register its own idea of a file name syntax. Plus a hook,
> for parts of that file name the package is responsible itself. This
> would avoid the need to check in the completion machinery, which Tramp
> syntax is recent.

I won't object to developing such a mechanism.  Stefan, would that
make sense and/or be reasonably practical to implement?

> Other packages but Tramp would profit as well. For example, running
> "emacs -Q", typing "/: TAB", removes the colon and offers completions
> for "/". I don't know whether this is really right; there is a reason
> that a user has started with "/:".

That's true, but completing after typing just "/:" doesn't make a lot
of sense to me; maybe I'm missing something.  OTOH, I also don't
understand why remove the colon in this case.  If we know which code
does that, perhaps we could look into its VCS history and learn
something.