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

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

[Sean Whitton]

Hello,

Can I install this simple change on the release branch, please?

-- >8 --
---
 lisp/progmodes/etags-regen.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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'.
-- 
Sean Whitton

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

[Eli Zaretskii]

> From: Sean Whitton <spwhitton@spwhitton.name>
> Date: Fri, 20 Sep 2024 10:15:50 +0100
> 
> Hello,
> 
> Can I install this simple change on the release branch, please?
> 
> -- >8 --
> ---
>  lisp/progmodes/etags-regen.el | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 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?

Dmitry, why do we need an explicit list instead of asking 'etags'
which extensions it supports?

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

[Sean Whitton]

Hello,

On Fri 20 Sep 2024 at 01:34pm +03, Eli Zaretskii wrote:

>> From: Sean Whitton <spwhitton@spwhitton.name>
>> Date: Fri, 20 Sep 2024 10:15:50 +0100
>>
>> Hello,
>>
>> Can I install this simple change on the release branch, please?
>>
>> -- >8 --
>> ---
>>  lisp/progmodes/etags-regen.el | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> 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?

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.

-- 
Sean Whitton

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

[Eli Zaretskii]

> From: Sean Whitton <spwhitton@spwhitton.name>
> Cc: Dmitry Gutov <dmitry@gutov.dev>,  emacs-devel@gnu.org
> Date: Fri, 20 Sep 2024 14:39:11 +0100
> 
> Hello,
> 
> On Fri 20 Sep 2024 at 01:34pm +03, Eli Zaretskii wrote:
> 
> >> From: Sean Whitton <spwhitton@spwhitton.name>
> >> Date: Fri, 20 Sep 2024 10:15:50 +0100
> >>
> >> Hello,
> >>
> >> Can I install this simple change on the release branch, please?
> >>
> >> -- >8 --
> >> ---
> >>  lisp/progmodes/etags-regen.el | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> 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?
> 
> 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.

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.

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

[Eli Zaretskii]

> Date: Fri, 20 Sep 2024 21:20:59 +0300
> Cc: emacs-devel@gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> >>> 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.

So I think we should add all of them on emacs-30.

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

Agreed.  But it sounds like the only such case is .m, which could be
Mercury, not just ObjC.

> >> 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.

Right.  These require to explicitly specify --language on the etags
command line.  So maybe etags-regen could learn to apply special
command-line options to files matching a regexp.  Or maybe we should
add an option to etags to disable the fallback to Fortran.

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

[Dmitry Gutov]

On 20/09/2024 22:11, Eli Zaretskii wrote:
>> Date: Fri, 20 Sep 2024 21:20:59 +0300
>> Cc: emacs-devel@gnu.org
>> From: Dmitry Gutov <dmitry@gutov.dev>
>>
>>>>> 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.
> 
> So I think we should add all of them on emacs-30.

I have no objections, if you're sure about misdetecion. Though note that 
the current logic only supports specifying extensions. So no 
Makefile/Rakefile/etc.

>> As long as the additions are not misdetected often - false positives
>> based on obscure languages might be a nuisance.
> 
> Agreed.  But it sounds like the only such case is .m, which could be
> Mercury, not just ObjC.

Even for .m we ultimately delegate to etags' internal detector, since 
etags-regen-mode just chooses which files to send to it.

If ObjC has priority, and the parser has some internal heuristics as 
well that would help it choose, it'll be fine.

.m could also be Matlab/Octave, though.

>>>> 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.
> 
> Right.  These require to explicitly specify --language on the etags
> command line.  So maybe etags-regen could learn to apply special
> command-line options to files matching a regexp.

I'm not sure which options or regexps it can add to the invocation. The 
problem is that the list would need to be exhaustive.

> Or maybe we should
> add an option to etags to disable the fallback to Fortran.

If someone were to implement that, it might solve two problems as once.

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

[Dmitry Gutov]

On 20/09/2024 22:35, Dmitry Gutov wrote:
>>> Adding "pm" sounds good.
>>>
>>> "All supported extensions" (or most) might be a good idea as well.
>>
>> So I think we should add all of them on emacs-30.
> 
> I have no objections, if you're sure about misdetecion. Though note that 
> the current logic only supports specifying extensions. So no Makefile/ 
> Rakefile/etc.

Maybe do that on master, though.

Scanning for tags in files that aren't considered code like .html or 
.texi, etc might create a lot more navigation locations, not all of them 
wanted in 'C-u M-.' completion.

I'm not actually sure it will be a problem, but it seems like a major 
enough change to allow for user feedback first.