unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
From: Eli Zaretskii <eliz@gnu.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: larsi@gnus.org, 52063@debbugs.gnu.org
Subject: bug#52063: 28.0.60; Confusing presentation of lambda
Date: Wed, 24 Nov 2021 21:53:33 +0200	[thread overview]
Message-ID: <83v90h72ki.fsf@gnu.org> (raw)
In-Reply-To: <jwvr1b5qsyh.fsf-monnier+emacs@gnu.org> (message from Stefan Monnier on Wed, 24 Nov 2021 14:06:37 -0500)

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: larsi@gnus.org,  52063@debbugs.gnu.org
> Date: Wed, 24 Nov 2021 14:06:37 -0500
> 
> > So this issue is specific to hooks?
> 
> No, but in 99% of the cases you won't actually *see* a function value
> (unless you specifically go looking for it, e.g. with `symbol-function`).

We also have gobs of variables that are not hooks, which accept
function values.  And we also have menu items and mode-line constructs
that sometimes use anonymous functions.  And timer functions.  And
process filter and sentinel functions.  And that's just 5 sec of
thinking where one could meet them.

> So you'll only get a value of the form (lambda ARGS . BODY) if you use
> the dynamically scoped dialect of ELisp (or if you manually create such
> a list, e.g. with '(lambda ...) or `(lambda ...) or (list 'lambda ...),
> etc...).

So I guess the warning about quoting lambdas with ' instead of #' is
actually misleading people into getting these closures instead of the
lambdas they might expect?  Because that is how this started for me:
during startup Emacs said:

 .emacs: Warning: (lambda nil \.\.\.) quoted with ' rather than with #'

So why do we emit those warnings for Lisp code evaluated from a file
that doesn't have lexical-binding setting in it?  If it were not for
this warning, I'd have never tried using #', and thus would have never
bumped into this curiosity.





  reply	other threads:[~2021-11-24 19:53 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-23 18:56 bug#52063: 28.0.60; Confusing presentation of lambda Eli Zaretskii
2021-11-24  7:35 ` Lars Ingebrigtsen
2021-11-24 12:48   ` Eli Zaretskii
2021-11-24 12:51     ` Lars Ingebrigtsen
2021-11-24 13:15       ` Eli Zaretskii
2021-11-24 13:31         ` Lars Ingebrigtsen
2021-11-24 14:38           ` Eli Zaretskii
2021-11-24 16:21             ` Lars Ingebrigtsen
2021-11-24 16:33               ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 16:54                 ` Eli Zaretskii
2021-11-24 17:19                   ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 17:44                     ` Eli Zaretskii
2021-11-24 19:06                       ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 19:53                         ` Eli Zaretskii [this message]
2021-11-24 20:08                           ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 20:14                             ` Eli Zaretskii
2021-11-24 22:02                               ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 22:33                               ` Jim Porter
2021-11-24 22:42                                 ` Jim Porter
2021-11-24 21:10                             ` Eduardo Ochs
2021-11-24 16:40             ` Filipp Gunbin
2021-11-24 16:54               ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 18:18                 ` Filipp Gunbin
2021-11-24 19:08                   ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 19:41                     ` Eli Zaretskii
2021-11-24 19:46                       ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 19:59                         ` Eli Zaretskii
2021-11-24 20:23                           ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-24 22:37                             ` Gregory Heytings
2021-11-25  0:09                               ` Filipp Gunbin
2021-11-25  8:57                               ` Michael Heerdegen
2021-11-25 13:09                                 ` Lars Ingebrigtsen
2021-11-25 14:08                                   ` Michael Heerdegen
2021-11-25 14:39                                   ` Gregory Heytings
2021-11-24 20:16                     ` Philipp Stephani
2021-11-24 21:44                       ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-25  0:13                       ` Filipp Gunbin
2021-11-25 13:15                         ` Lars Ingebrigtsen
2021-11-25 19:07                           ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-25 19:56                             ` Jim Porter
2021-11-26 12:28                               ` Lars Ingebrigtsen
2021-11-26 12:26                             ` Lars Ingebrigtsen
2021-11-26 13:13                               ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-26 13:22                                 ` Lars Ingebrigtsen
2021-11-26 13:26                                   ` Lars Ingebrigtsen
2021-11-26 14:57                                     ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-26 15:00                                       ` Lars Ingebrigtsen
2021-11-26 16:58                                         ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-27 14:17                                           ` Lars Ingebrigtsen
2021-11-27 15:28                                             ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-29 13:54                                               ` Lars Ingebrigtsen
2021-11-29 17:58                                                 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-11-30 14:07                                                 ` Michael Heerdegen
2021-11-30 14:20                                                   ` Lars Ingebrigtsen
2021-11-24 16:56               ` Eli Zaretskii

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=83v90h72ki.fsf@gnu.org \
    --to=eliz@gnu.org \
    --cc=52063@debbugs.gnu.org \
    --cc=larsi@gnus.org \
    --cc=monnier@iro.umontreal.ca \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).