Re: Missing entries for Perl in etags-regen-file-extensions -- okay for emacs-30?

[Dmitry Gutov]

Hi!

On 20/09/2024 16:41, Eli Zaretskii wrote:
> > > > diff --git a/lisp/progmodes/etags-regen.el b/lisp/progmodes/etags-regen.el
> > > > index 21ea9bfb8b3..e97b0cd7574 100644
> > > > --- a/lisp/progmodes/etags-regen.el
> > > > +++ b/lisp/progmodes/etags-regen.el
> > > > @@ -119,7 +119,7 @@ etags-regen-regexp-alist
> > > >   ;;http://lists.gnu.org/archive/html/emacs-devel/2018-01/msg00323.html
> > > >   (defcustom etags-regen-file-extensions
> > > >     '("rb" "js" "py" "pl" "el" "c" "cpp" "cc" "h" "hh" "hpp"
> > > > -    "java" "go" "cl" "lisp" "prolog" "php" "erl" "hrl"
> > > > +    "java" "go" "cl" "lisp" "prolog" "php" "erl" "hrl" "pl" "pm"
> > > >       "F" "f" "f90" "for" "cs" "a" "asm" "ads" "adb" "ada")
> > > >     "Code file extensions for `etags-regen-mode'.
> > > We already have "pl" in the list.  Adding "pm" is okay, but then why
> > > only it? why not add all the extensions that 'etags' supports?

Adding "pm" sounds good.

"All supported extensions" (or most) might be a good idea as well.

As long as the additions are not misdetected often - false positives 
based on obscure languages might be a nuisance.

> > Okay thanks, I'll add "pm" so we don't have just one Perl extension, and
> > hopefully we can figure out a better solution for master.
> My question about adding more extensions was for emacs-30.
>
> Let's wait for Dmitry to chime in, and take it from there.

The reason why is that etags parses files with unknown extensions as 
Fortran sources, and there is currently no opt-out. See this thread:

https://lists.gnu.org/archive/html/emacs-devel/2018-01/msg00323.html

The same issue stops us from benefiting from etags' hashbang detection.