bug#27646: Bug: Emacs Lisp Indentation

bug#27646: Bug: Emacs Lisp Indentation

[Alexander Shukaev]

Hi,

With latest Emacs, I see the following indentation quirk with the Emacs 
Lisp list:

(defconst init-font-lock-keywords
   `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
             (keywords         nil))
         (dolist (symbol '(init-a
                            init-b
                            init-c
                            init-d
                            init-e
                            init-f))
           (push `(,(format "(%s\\_>" symbol)
                   (,constant-pattern
                    (save-excursion
                      (search-forward-regexp ,constant-pattern))
                    nil
                    (0 font-lock-constant-face nil t)))
                 keywords))
         keywords)))

instead of the expected:

(defconst init-font-lock-keywords
   `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
             (keywords         nil))
         (dolist (symbol '(init-a
                           init-b
                           init-c
                           init-d
                           init-e
                           init-f))
           (push `(,(format "(%s\\_>" symbol)
                   (,constant-pattern
                    (save-excursion
                      (search-forward-regexp ,constant-pattern))
                    nil
                    (0 font-lock-constant-face nil t)))
                 keywords))
         keywords)))

Please, have a look as time permits.  Thank you in advance!

Kind regards,
Alexander

bug#27646: Bug: Emacs Lisp Indentation

[npostavs]

tags 27646 + unreproducible
quit

Alexander Shukaev <emacs@Alexander.Shukaev.name> writes:

> Hi,
>
> With latest Emacs, I see the following indentation quirk with the
> Emacs Lisp list:
>
> (defconst init-font-lock-keywords
>   `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
>             (keywords         nil))
>         (dolist (symbol '(init-a
>                            init-b

That would certainly be a bug, but I can't reproduce this, when I run
indent-region or indent-sexp on that code I get the correct indentation:

(defconst init-font-lock-keywords
  `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
            (keywords         nil))
        (dolist (symbol '(init-a
                          init-b

In GNU Emacs 26.0.50 (build 60, x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2017-07-10 built on zony
Repository revision: 689c5c20d1174e95be50e674d05632545eb4b9c5
Windowing system distributor 'The X.Org Foundation', version 11.0.11901000
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
You can run the command ‘emacs-lisp-mode’ with M-x e-li-mo RET
Mark set
Indenting region...done
Mark activated

Configured using:
 'configure --cache-file=../debug-config.cache 'CFLAGS=-O0 -g3
 -march=native' --enable-checking=yes,glyphs
 --enable-check-lisp-object-type MAKEINFO=makeinfo-4.13a
 --with-x-toolkit=lucid --with-toolkit-scroll-bars --with-gif=no
 --with-jpeg=no 'CFLAGS=-O2 -g3 -march=native'
 --cache-file=../opt-config.cache'

Configured features:
XPM TIFF PNG RSVG SOUND GPM DBUS GSETTINGS NOTIFY ACL GNUTLS LIBXML2
FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS LUCID X11 LIBSYSTEMD

bug#27646: Bug: Emacs Lisp Indentation

[Noam Postavsky]

close 27646
quit

npostavs@users.sourceforge.net writes:

> That would certainly be a bug, but I can't reproduce this, when I run
> indent-region or indent-sexp on that code I get the correct indentation:
>
> (defconst init-font-lock-keywords
>   `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
>             (keywords         nil))
>         (dolist (symbol '(init-a
>                           init-b

Closing, since there's been no followup.

bug#27646: Bug: Emacs Lisp Indentation

[Alexander Shukaev]

On 11/29/17 3:26 AM, Noam Postavsky wrote:
> close 27646
> quit
> 
> npostavs@users.sourceforge.net writes:
> 
>> That would certainly be a bug, but I can't reproduce this, when I run
>> indent-region or indent-sexp on that code I get the correct indentation:
>>
>> (defconst init-font-lock-keywords
>>    `(,@(let ((constant-pattern "\\(?:\\sw\\|\\s_\\)+")
>>              (keywords         nil))
>>          (dolist (symbol '(init-a
>>                            init-b
> 
> Closing, since there's been no followup.
> 

This time I realized what's happening.  Put

(dolist (symbol '(ignore-errors
                   xxx
                   yyy)))

to the "*scratch*" buffer and indent to observe the following result

(dolist (symbol '(ignore-errors
                    xxx
                    yyy)))

The reason why this happens is because `ignore-errors' is a macro that has

(declare (indent defun))

Any other macro with the same declaration whose innocent symbol is used 
as the first element in a list would reproduce the above indentation 
bug.  Backquote is also affected.

bug#27646: Bug: Emacs Lisp Indentation

[Noam Postavsky]

tags 27646 - moreinfo unreproducible
forcemerge 21922 27646
quit

Alexander Shukaev <emacs@Alexander.Shukaev.name> writes:

> to the "*scratch*" buffer and indent to observe the following result
>
> (dolist (symbol '(ignore-errors
>                    xxx
>                    yyy)))
>
> The reason why this happens is because `ignore-errors' is a macro that has
>
> (declare (indent defun))
>
> Any other macro with the same declaration whose innocent symbol is
> used as the first element in a list would reproduce the above
> indentation bug.  Backquote is also affected.

That's Bug#21922, although the backquoted case is intentional (e.g., for
writing code in macros).

bug#21922: bug#27646: Bug: Emacs Lisp Indentation

[Alexander Shukaev]

On 17/01/2020 18:58, Noam Postavsky wrote:
> tags 27646 - moreinfo unreproducible
> forcemerge 21922 27646
> quit
> 
> Alexander Shukaev <emacs@Alexander.Shukaev.name> writes:
> 
>> to the "*scratch*" buffer and indent to observe the following result
>>
>> (dolist (symbol '(ignore-errors
>>                     xxx
>>                     yyy)))
>>
>> The reason why this happens is because `ignore-errors' is a macro that has
>>
>> (declare (indent defun))
>>
>> Any other macro with the same declaration whose innocent symbol is
>> used as the first element in a list would reproduce the above
>> indentation bug.  Backquote is also affected.
> 
> That's Bug#21922, although the backquoted case is intentional (e.g., for
> writing code in macros).
> 

I use the following trick right now:

(dolist (symbol '(;
                   ignore-errors
                   xxx
                   yyy)))

Since it's impossible to resolve that issue reliably and for all cases 
including backquote, I propose to introduce some special comment (aka 
;###list) format to indicate that this is a list rather than code to be 
evaluated.  In different contexts the same code could be desired to be 
treated differently namely either as data or as to be evaluated.

bug#27646: Bug: Emacs Lisp Indentation

[Lars Ingebrigtsen]

Alexander Shukaev <emacs@Alexander.Shukaev.name> writes:

> I use the following trick right now:
>
> (dolist (symbol '(;
>                   ignore-errors
>                   xxx
>                   yyy)))
>
> Since it's impossible to resolve that issue reliably and for all cases
> including backquote, I propose to introduce some special comment (aka
> ;###list) format to indicate that this is a list rather than code to
> be evaluated.  In different contexts the same code could be desired to
> be treated differently namely either as data or as to be evaluated.

(I'm going through old bug reports that unfortunately weren't resolved
at the time.)

This is bee fixed in recent Emacs version by introducing the following
convention:

(dolist (symbol '( ignore-errors
                   xxx
                   yyy)))

That is, a space after the opening parenthesis to signal that it's a
list and not code.

I'm therefore closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no