Re: etags-regen-mode: handling extensionless files

[Eli Zaretskii <eliz@gnu.org>]

> From: Francesco Potortì <pot@gnu.org>
> Date: Wed, 25 Sep 2024 23:19:10 +0200
> Cc: emacs-devel@gnu.org,
> 	dgutov@yandex.ru,
> 	Sean Whitton <spwhitton@spwhitton.name>
> 
> Eli Zaretskii <eliz@gnu.org>
> >We could, but adding an option to disable the Fortran fallback is so
> >easy that I hope someone will just do it...
> 
> How about just going with the backward-incompatible change of disabling both fallbacks entirely?  In my opinion the whole fallback idea was already obsolete when I worked on it in 1993.

Since no one complained about it, and the only real use case is when
invoking 'etags' from a Lisp program, which can easily use a
non-standard option, I don't see a compelling reason for a
backward-incompatible change in behavior.  In some future version, we
can then flip the default and make the fallback disabled by default.

> Today, I can't imagine a situation where it can be useful, that is, where you work on Fortran or C sources without an extension.

My gray hair tells me that our ability to imagine such situations is
severely limited or biased, and we have enough evidence of this bias
to not trust our imagination in these matters anymore.

> On the other hand, if you are working on thirty-years old sources, I argue you should use thirty-years old tools, rather than assuming that today's tool do the right thing on them.

These arguments are usually not well taken, IME.  People want new
tools because they give them more functionality and performance, but
they do NOT want incompatibilities in the package.  IOW, everyone
likes to have the cake and eat it, too.