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From: Drew Adams <drew.adams@oracle.com>
To: Paul Eggert <eggert@cs.ucla.edu>, Dmitry Gutov <dgutov@yandex.ru>
Cc: "Michael Heerdegen" <michael_heerdegen@web.de>,
	"Mattias Engdegård" <mattiase@acm.org>,
	ke.vigouroux@laposte.net, 40671@debbugs.gnu.org,
	"Richard Stallman" <rms@gnu.org>
Subject: bug#40671: [DOC] modify literal objects
Date: Fri, 1 May 2020 15:05:11 -0700 (PDT)	[thread overview]
Message-ID: <10f088bf-c5d7-4d20-a704-86e4d35b087b@default> (raw)
In-Reply-To: <e934c9e1-4915-6642-e253-137f65f7fb55@cs.ucla.edu>

> >> 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."
> >
> > As Drew pointed out (and if I understood this correctly), the above
> > specification leads to implementations that do raise an error when
> > someone tried to modify such a value.
> 
> Although those implementations conform to the Common Lisp spec, that's
> because the spec explicitly says such behavior is undefined - which means
> implementations can signal an error, dump core, or do whatever else
> they want.
> See
> <https://urldefense.com/v3/__https://www.cs.cmu.edu/Groups/AI/html/cltl
> /clm/node11.html__;!!GqivPVa7Brio!NeqWMrCFKgi8Ktwdz5aIkeBh_-TPzH-
> XiJbWDMeSRu1VKiI70b5LK6Sy2v5CMxaq$ >, which uses
> "should" in the same sense the emacs-27 elisp manual uses "should".

I stand corrected.  I was assuming that the "proposal"
I cited had actually been adopted for CLTL2.

So CLTL2 is in the same boat as CLTL(1), in the regard
relevant to this thread: There is NO systematic raising
of an error - no prevention of the gotcha.

So what I said about Elisp being like CLTL(1) applies
also to CLTL2:  We should NOT say that you _cannot_
do XYZ (because you might be able to, and the behavior
if you try is undefined).  We should instead say that
you _should not_.

We're still circling, though.  But thanks for clarifying
that "it's an error" meaning.  I misremembered that as
meaning that a conformant implementation is required to
raise an error.  I was thinking/assuming that the cited
proposal was in fact adopted as part of the CL definition.





  reply	other threads:[~2020-05-01 22:05 UTC|newest]

Thread overview: 170+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-16 19:28 bug#40671: [DOC] modify literal objects Kevin Vigouroux via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-04-17 16:09 ` Mattias Engdegård
2020-04-17 16:37   ` Mattias Engdegård
2020-04-17 17:27     ` Eli Zaretskii
2020-04-18 20:10 ` Paul Eggert
2020-04-18 21:54   ` Drew Adams
2020-04-19  2:39     ` Noam Postavsky
2020-04-19 20:39     ` Paul Eggert
2020-04-19 21:01       ` Drew Adams
2020-04-19 21:16         ` Paul Eggert
2020-04-19 22:24           ` Drew Adams
2020-04-19 22:51             ` Paul Eggert
2020-04-20  5:32               ` Drew Adams
2020-04-22 17:36                 ` Paul Eggert
2020-05-01  3:03     ` Dmitry Gutov
2020-05-01  5:16       ` Drew Adams
2020-05-01 21:46       ` Paul Eggert
2020-05-01 23:37         ` Dmitry Gutov
2020-04-19  2:26   ` Richard Stallman
2020-04-19 13:56   ` Eli Zaretskii
2020-04-19 16:59     ` Mattias Engdegård
2020-04-19 19:21       ` Eli Zaretskii
2020-04-19 21:02       ` Paul Eggert
2020-04-19 21:11         ` Drew Adams
2020-04-19 21:57         ` Michael Heerdegen
2020-04-19 22:41           ` Paul Eggert
2020-04-19 23:45             ` Michael Heerdegen
2020-04-20  0:24               ` Paul Eggert
2020-04-20  0:53                 ` Michael Heerdegen
2020-04-20  3:23                   ` Paul Eggert
2020-04-20  3:36                     ` Michael Heerdegen
2020-04-22  6:30                       ` Paul Eggert
2020-04-20  5:54                     ` Drew Adams
2020-04-22 17:21                       ` Paul Eggert
2020-04-23  0:49                         ` Michael Heerdegen
2020-04-24  2:36                           ` Richard Stallman
2020-04-24 15:08                             ` Drew Adams
2020-04-25  1:58                               ` Paul Eggert
2020-04-24 16:39                             ` Mattias Engdegård
2020-04-24 16:46                               ` Dmitry Gutov
2020-04-25  2:21                                 ` Paul Eggert
2020-04-25  2:40                                   ` Dmitry Gutov
2020-04-25  3:20                                     ` Paul Eggert
2020-04-25 19:30                                       ` Dmitry Gutov
2020-04-26  3:49                                         ` Paul Eggert
2020-04-26 14:03                                           ` Dmitry Gutov
2020-04-26 14:19                                             ` Eli Zaretskii
2020-04-26 14:34                                               ` Dmitry Gutov
2020-04-26 15:46                                                 ` Eli Zaretskii
2020-04-26 16:02                                                   ` Dmitry Gutov
2020-04-26 16:58                                                     ` Eli Zaretskii
2020-04-26 17:39                                                       ` Dmitry Gutov
2020-04-26 18:14                                                         ` Eli Zaretskii
2020-04-26 18:32                                                           ` Dmitry Gutov
2020-04-26 18:41                                                             ` Eli Zaretskii
2020-04-26 18:53                                                               ` Dmitry Gutov
2020-04-26 18:57                                             ` Paul Eggert
2020-04-26 19:22                                               ` Philipp Stephani
2020-04-26 20:14                                                 ` Paul Eggert
2020-04-26 21:23                                               ` Dmitry Gutov
2020-04-26 23:13                                                 ` Paul Eggert
2020-04-27  0:53                                                   ` Dmitry Gutov
2020-04-27  1:49                                                     ` Paul Eggert
2020-04-28  3:05                                                       ` Dmitry Gutov
2020-04-28  8:17                                                         ` Paul Eggert
2020-04-28 13:54                                                           ` Dmitry Gutov
2020-04-28 17:59                                                             ` Paul Eggert
2020-04-28 18:46                                                               ` Dmitry Gutov
2020-04-28 19:20                                                                 ` Paul Eggert
2020-04-28 19:33                                                                   ` Dmitry Gutov
2020-04-28 20:09                                                                     ` Paul Eggert
2020-04-28 21:10                                                                       ` Dmitry Gutov
2020-04-28 23:10                                                                         ` Paul Eggert
2020-04-28 23:36                                                                           ` Dmitry Gutov
2020-04-28 23:53                                                                             ` Paul Eggert
2020-04-28 23:57                                                                               ` Dmitry Gutov
2020-04-28 23:53                                                                           ` Dmitry Gutov
2020-04-29  0:04                                                                             ` Paul Eggert
2020-04-29  0:14                                                                               ` Dmitry Gutov
2020-04-29  0:55                                                                           ` Drew Adams
2020-04-29  1:03                                                                             ` Dmitry Gutov
2020-04-29  1:15                                                                               ` Drew Adams
2020-04-29  1:27                                                                                 ` Michael Heerdegen
2020-04-29  1:38                                                                             ` Paul Eggert
2020-04-29  4:36                                                                               ` Drew Adams
2020-04-29 16:18                                                                                 ` Paul Eggert
2020-05-01  2:47                                                                                   ` Richard Stallman
2020-05-01  6:23                                                                                     ` Eli Zaretskii
2020-05-01  3:13                                                                               ` Dmitry Gutov
2020-05-01  5:15                                                                                 ` Drew Adams
2020-05-01 21:40                                                                                 ` Paul Eggert
2020-05-01 22:05                                                                                   ` Drew Adams [this message]
2020-05-01 22:28                                                                                     ` Paul Eggert
2020-05-02  1:07                                                                                   ` Dmitry Gutov
2020-05-02  6:28                                                                                     ` Paul Eggert
2020-05-02 15:42                                                                                       ` Dmitry Gutov
2020-05-02 19:35                                                                                         ` Paul Eggert
2020-05-03  1:30                                                                                           ` Dmitry Gutov
2020-05-03  7:40                                                                                             ` Paul Eggert
2020-05-03 16:44                                                                                               ` Dmitry Gutov
2020-05-03 20:48                                                                                                 ` Paul Eggert
2020-05-03 22:17                                                                                                   ` Dmitry Gutov
2020-05-03 22:18                                                                                                   ` Dmitry Gutov
2020-05-03 22:39                                                                                                     ` Paul Eggert
2020-05-03 22:53                                                                                                       ` Dmitry Gutov
2020-05-03 23:10                                                                                                         ` Paul Eggert
2020-05-04 10:16                                                                                                           ` Dmitry Gutov
2020-05-04 17:52                                                                                                             ` Paul Eggert
2020-05-05  1:39                                                                                                               ` Dmitry Gutov
2020-05-05  6:09                                                                                                                 ` Paul Eggert
2020-05-05 12:38                                                                                                                   ` Dmitry Gutov
2020-05-09  6:10                                                                                                                     ` Paul Eggert
2020-05-10  3:13                                                                                                                       ` Dmitry Gutov
2020-05-10 13:34                                                                                                                         ` Dmitry Gutov
2020-05-10 17:29                                                                                                                         ` Paul Eggert
2020-05-11  0:00                                                                                                                           ` Michael Heerdegen
2020-05-11  0:26                                                                                                                             ` Dmitry Gutov
2020-05-11  1:47                                                                                                                             ` Drew Adams
2020-05-11  1:54                                                                                                                               ` Dmitry Gutov
2020-05-11  2:33                                                                                                                                 ` Drew Adams
2020-05-11  2:56                                                                                                                               ` Michael Heerdegen
2020-05-11  4:21                                                                                                                                 ` Drew Adams
2020-05-11  4:51                                                                                                                                   ` Michael Heerdegen
2020-05-11  6:28                                                                                                                                     ` Paul Eggert
2020-05-11 13:57                                                                                                                                       ` Noam Postavsky
2020-05-11 22:36                                                                                                                                         ` Michael Heerdegen
2020-05-11 22:30                                                                                                                                       ` Michael Heerdegen
2020-05-12  3:20                                                                                                                                       ` Richard Stallman
2020-05-12  4:24                                                                                                                                         ` Michael Heerdegen
2020-05-13  3:57                                                                                                                                           ` Richard Stallman
2020-05-13  5:05                                                                                                                                             ` Michael Heerdegen
2020-05-14  5:14                                                                                                                                               ` Richard Stallman
     [not found]                                                                                                                                       ` <05BEF593-F16A-4DEE-98BC-653221F1F9EE@acm.org>
2020-05-17  0:11                                                                                                                                         ` Paul Eggert
2020-05-17  9:43                                                                                                                                           ` Mattias Engdegård
2020-05-17 16:38                                                                                                                                             ` Paul Eggert
2020-05-11  1:53                                                                                                                             ` Paul Eggert
2020-05-11  3:18                                                                                                                               ` Michael Heerdegen
2020-05-11  0:44                                                                                                                           ` Dmitry Gutov
2020-05-11  1:57                                                                                                                             ` Paul Eggert
2020-05-12  1:59                                                                                                                               ` Dmitry Gutov
2020-05-17  1:28                                                                                                                                 ` Paul Eggert
2020-05-17  5:02                                                                                                                                   ` Michael Heerdegen
2020-05-17 16:34                                                                                                                                     ` Paul Eggert
2020-05-17 12:39                                                                                                                                   ` Dmitry Gutov
2020-05-17 16:21                                                                                                                                     ` Paul Eggert
2020-05-05 17:40                                                                                                                   ` Drew Adams
2020-05-05 18:49                                                                                                                     ` Dmitry Gutov
2020-05-05 19:26                                                                                                                       ` Drew Adams
2020-05-05 20:48                                                                                                               ` Kevin Vigouroux via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-05-09  5:57                                                                                                                 ` Paul Eggert
2020-04-28 21:18                                                                       ` Dmitry Gutov
2020-04-28 17:25                                                           ` Drew Adams
2020-04-28 17:47                                                             ` Paul Eggert
2020-04-29  0:32                                                               ` Michael Heerdegen
2020-04-29  1:40                                                                 ` Paul Eggert
2020-04-29  4:40                                                                   ` Michael Heerdegen
2020-04-29  8:01                                                                     ` Eli Zaretskii
2020-04-29 16:36                                                                 ` Paul Eggert
2020-04-24 17:18                               ` Drew Adams
2020-04-25  3:38                               ` Richard Stallman
2020-04-25 18:26                                 ` Paul Eggert
2020-04-25  2:22                           ` Paul Eggert
2020-04-25  6:00                             ` Andreas Schwab
2020-04-25 18:23                               ` Paul Eggert
2020-04-28 23:52                             ` Michael Heerdegen
2020-04-21  1:25               ` Michael Heerdegen
2020-04-21  2:20                 ` Paul Eggert
2020-04-20  6:02             ` Drew Adams
2020-04-19 20:45     ` Paul Eggert
2020-04-20 14:10       ` Eli Zaretskii

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