From: Paul Eggert <eggert@cs.ucla.edu>
To: Noam Postavsky <npostavs@users.sourceforge.net>,
Emacs developers <emacs-devel@gnu.org>
Cc: Drew Adams <drew.adams@oracle.com>
Subject: Re: Change of Lisp syntax for "fancy" quotes in Emacs 27?
Date: Thu, 4 Oct 2018 18:01:26 -0700 [thread overview]
Message-ID: <a86b63c9-16e6-5d4a-94f7-de943886130a@cs.ucla.edu> (raw)
In-Reply-To: <CAM-tV-_i_K7_MRvHmuaaDJ2QSyn7wSrV_MFwu2L1+w=H1Ybf6A@mail.gmail.com>
I'm afraid this patch is heading in the wrong direction, as we should be
more vigilant about confusables, not less.
Consider this example, abstracted from the auth-source-secrets-create
source code:
(if (eq r 'secret)
(let ((data data))
(lambda () data))
data)
The intent of the (let ((data data)) ...) code is to create a thunk
which, when evaluated, yields the current value of 'data' (not the value
of 'data' when the thunk is called), and that is what any human reading
the code will see. However, that is not what the code actually does. In
the (let ((data data)) ...), the space between the two instances of
'data' is really an EN SPACE (U+2002) so the 'let' is declaring an
identifier 'data data' whose name contains an EN SPACE and whose value
is nil, an identifier that is never used; so the thunk yields the later
value of 'data', not the earlier one.
Because humans cannot reliably review source code containing characters
that are easily confusable with the ASCII symbols that are a basic part
of Elisp syntax, we should not be relaxing the reader to encourage
developers to use these characters in their identifiers. On the
contrary, we should be discouraging their use even more than we do now.
next prev parent reply other threads:[~2018-10-05 1:01 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-02 22:24 Change of Lisp syntax for "fancy" quotes in Emacs 27? Noam Postavsky
2018-02-02 22:52 ` Paul Eggert
2018-02-03 0:00 ` Drew Adams
2018-02-03 0:09 ` Paul Eggert
2018-02-03 0:39 ` Drew Adams
2018-02-03 8:33 ` Eli Zaretskii
2018-02-03 16:16 ` Drew Adams
2018-02-03 17:05 ` Eli Zaretskii
2018-02-04 1:16 ` Michael Heerdegen
2018-02-04 1:25 ` Clément Pit-Claudel
2018-02-04 2:05 ` Drew Adams
2018-02-04 2:06 ` Michael Heerdegen
2018-02-04 10:34 ` Alan Third
2018-02-04 15:36 ` Clément Pit-Claudel
2018-02-04 17:37 ` Eli Zaretskii
2018-02-04 21:31 ` Noam Postavsky
2018-02-04 11:15 ` Alan Mackenzie
2018-02-04 15:54 ` Drew Adams
2018-02-04 14:47 ` Noam Postavsky
2018-02-04 1:55 ` Drew Adams
2018-02-04 2:10 ` Noam Postavsky
2018-02-05 1:06 ` Why "symbol's value" error about a list? Richard Stallman
2018-02-05 20:35 ` Alan Mackenzie
2018-02-05 21:46 ` Drew Adams
2018-02-06 4:13 ` Eli Zaretskii
2018-02-06 7:32 ` Tim Cross
2018-02-06 7:40 ` Eli Zaretskii
2018-02-06 15:45 ` Drew Adams
2018-02-06 15:45 ` Drew Adams
2018-02-06 19:17 ` Eli Zaretskii
2018-02-06 14:51 ` Richard Stallman
2018-02-06 11:27 ` Noam Postavsky
2018-02-06 14:53 ` Richard Stallman
2018-02-06 18:59 ` Eli Zaretskii
2018-02-07 2:40 ` Richard Stallman
2018-02-07 3:42 ` Eli Zaretskii
2018-02-06 18:52 ` Eli Zaretskii
2018-02-05 1:06 ` Change of Lisp syntax for "fancy" quotes in Emacs 27? Richard Stallman
2018-02-03 18:13 ` Aaron Ecay
2018-02-04 2:05 ` Drew Adams
2018-02-04 4:51 ` Paul Eggert
2018-02-04 9:47 ` Andreas Schwab
2018-02-04 15:04 ` Noam Postavsky
2018-02-04 17:33 ` Eli Zaretskii
2018-02-04 19:36 ` Paul Eggert
2018-02-04 19:55 ` Philipp Stephani
2018-02-04 20:10 ` Eli Zaretskii
2018-02-04 20:36 ` Eli Zaretskii
2018-02-04 20:48 ` Paul Eggert
2018-02-04 20:59 ` Clément Pit-Claudel
2018-10-05 0:03 ` Noam Postavsky
2018-10-05 1:01 ` Paul Eggert [this message]
2018-10-05 8:43 ` Eli Zaretskii
2018-10-05 23:02 ` Paul Eggert
2018-10-06 0:20 ` Drew Adams
2018-10-06 9:14 ` Alan Mackenzie
2018-10-06 14:34 ` Stefan Monnier
2018-10-06 14:57 ` Drew Adams
2018-10-06 15:42 ` Garreau, Alexandre
2018-10-06 16:10 ` Paul Eggert
2018-10-06 16:17 ` Paul Eggert
2018-10-07 1:13 ` Drew Adams
2018-10-08 3:51 ` Richard Stallman
2018-10-06 10:11 ` Eli Zaretskii
2018-10-06 15:51 ` Paul Eggert
2018-10-06 16:45 ` Eli Zaretskii
2018-10-06 18:03 ` Paul Eggert
2018-10-06 18:29 ` Eli Zaretskii
2018-10-06 19:18 ` Paul Eggert
2018-10-06 19:30 ` Paul Eggert
2018-10-06 19:32 ` Garreau, Alexandre
2018-10-06 11:22 ` Garreau, Alexandre
2018-10-06 11:50 ` Eli Zaretskii
2018-10-06 12:10 ` Garreau, Alexandre
2018-10-06 14:00 ` Eli Zaretskii
2018-10-24 22:25 ` Noam Postavsky
2018-10-06 13:15 ` Unicode security-issues workarounds elsewhere [Was: Re: Change of Lisp syntax for "fancy" quotes in Emacs 27?] Garreau, Alexandre
2018-10-06 14:01 ` Eli Zaretskii
2018-10-06 16:24 ` Change of Lisp syntax for "fancy" quotes in Emacs 27? Paul Eggert
2018-10-06 16:40 ` Stefan Monnier
2018-10-09 14:43 ` Noam Postavsky
2018-10-09 15:30 ` Paul Eggert
2018-10-09 16:13 ` Eli Zaretskii
2018-10-09 17:07 ` Paul Eggert
2018-10-09 19:18 ` Andreas Schwab
2018-10-10 9:39 ` Aaron Ecay
2018-10-10 11:18 ` Garreau, Alexandre
2018-10-10 14:31 ` Eli Zaretskii
2018-10-10 15:18 ` Eli Zaretskii
2018-10-10 15:43 ` Drew Adams
2018-10-10 16:08 ` Yuri Khan
2018-10-15 20:30 ` Juri Linkov
2018-10-10 3:58 ` Richard Stallman
2018-10-10 3:57 ` Richard Stallman
2018-10-10 14:41 ` Eli Zaretskii
2018-10-11 5:01 ` Richard Stallman
2018-10-06 15:40 ` eval-last-sexp / C-x C-e, and punctuation like `?’' [Was: Re: Change of Lisp syntax for "fancy" quotes in Emacs 27?)] Garreau, Alexandre
2018-10-16 12:48 ` Change of Lisp syntax for "fancy" quotes in Emacs 27? Garreau, Alexandre
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