GNU bug report logs - #21922
Indentation of Emacs Lisp list constants is surprising

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Message #37 received at 21922 <at> debbugs.gnu.org (full text, mbox):

From: Alexander Shukaev <emacs <at> Alexander.Shukaev.name>
To: Noam Postavsky <npostavs <at> gmail.com>
Cc: 27646 <at> debbugs.gnu.org, 21922 <at> debbugs.gnu.org
Subject: Re: bug#27646: Bug: Emacs Lisp Indentation
Date: Fri, 17 Jan 2020 21:26:49 +0100

On 17/01/2020 18:58, Noam Postavsky wrote:
> tags 27646 - moreinfo unreproducible
> forcemerge 21922 27646
> quit
> 
> Alexander Shukaev <emacs <at> 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.

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