GNU bug report logs - #40671
[DOC] modify literal objects

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Message #294 received at 40671 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Drew Adams <drew.adams <at> oracle.com>, Dmitry Gutov <dgutov <at> yandex.ru>
Cc: Michael Heerdegen <michael_heerdegen <at> web.de>,
 Mattias Engdegård <mattiase <at> acm.org>, 40671 <at> debbugs.gnu.org,
 Richard Stallman <rms <at> gnu.org>, ke.vigouroux <at> laposte.net
Subject: Re: bug#40671: [DOC] modify literal objects
Date: Tue, 28 Apr 2020 18:38:44 -0700

On 4/28/20 5:55 PM, Drew Adams wrote:
> You're _not_ using the language that's used for Common Lisp.

In what sense does the language differ? Here's a quote from CLtL2 (page 115):

"it is an error to destructively modify any object that appears as a constant
in executable code, whether within a 'quote' special form or as
a self-evaluating form."

This use of the word "constant" is consistent with what's in the emacs-27 doc.

> Elisp corresponds
> to the behavior of CLTL1 in this regard, not to any
> later update

Those older CLtL semantics were not well-defined, and to the extent that they
were defined were not followed by Common Lisp implementations. It's not clear
that the emacs-27 Elisp implementation corresponds to those older semantics, and
it's also not clear that documenting CLtL1 semantics would be a good idea for Elisp.

> A few mails ago, you wondered if the disagreement
> has been only about terminology.  And the response
> was mostly "Yes" - objections to your use of
> "mutable" and "constant"/"immutable", and your use
> of "cannot" instead of "should not" (aka "Don't").
> 
> You've since ignored that response, it seems.

I responded to those specific wording objections by removing the "immutable"s
and "cannots" that were objected to. At least, that was my intent; if I missed
something please let me know.

I admit I have not made changes in response to vaguer suggestions, but that's
partly because I don't really understand what's involved.

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