all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
From: Dave Goel <deego3@gmail.com>
To: "Gerd Möllmann" <gerd.moellmann@gmail.com>
Cc: 66940@debbugs.gnu.org
Subject: bug#66940: Dynamic scoping is all weird now?
Date: Sun, 5 Nov 2023 14:07:02 -0500	[thread overview]
Message-ID: <CAOCW0DiDypdSdpK38f94LS0rqGAC7LUtE5f9UqeUTzaRXFEbbQ@mail.gmail.com> (raw)
In-Reply-To: <m2cywopp9h.fsf@Pro.fritz.box>

[-- Attachment #1: Type: text/plain, Size: 1058 bytes --]

Gerd,

Ok.

I hope this bugreport is clearer -

Here's some code.

The variable ii is clearly set every time mac was defined OR called.

backquote should expand, and mac should have read its content as (list
'message "%S" ii).




(progn
  (setq lexical-binding nil)

  (dotimes (ii 10)
    (defmacro mac ()
      `(message "%S" ,ii)
      )
    (let
        ((old_ii ii))
      (setq ii 33)
      (mac)
      (setq ii old_ii)
      )))


You eval this code once. It works.
You eval this again. It works.
The third time, though, it lands you in the debugger. The very same code.
Why the third time? And, why the debugger?  ii is well set every time it is
used.

That was bug (b). That's clearly an emacs bug?


Here's (c) -

The third time, change every "ii" to "var" ,and change every "old_ii" to
"old_var".
And, evaluate it.
We still get the very same error, but the error involves ii, not var. The
code we are defining and eval'ing has no "ii" whatsoever. It should have
forgotten the old mac that involved ii. We defined a new mac involving
"var."


>
>

[-- Attachment #2: Type: text/html, Size: 1642 bytes --]

  reply	other threads:[~2023-11-05 19:07 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-05  4:06 bug#66940: Dynamic scoping is all weird now? Dave Goel
2023-11-05  4:09 ` Dave Goel
2023-11-05  6:04   ` Gerd Möllmann
2023-11-05  6:58     ` Dave Goel
2023-11-05  7:25       ` Gerd Möllmann
2023-11-05  8:12         ` Dave Goel
2023-11-05  8:39           ` Gerd Möllmann
2023-11-05 19:07             ` Dave Goel [this message]
2023-11-05 20:21               ` Dave Goel
2023-11-06  1:52               ` Michael Heerdegen
2023-11-06  6:25                 ` Gerd Möllmann
2023-11-06 16:49                   ` Drew Adams
2023-11-06  6:57                 ` Dave Goel
2023-11-07  5:59                   ` Michael Heerdegen
2023-11-08  2:49                     ` Dave Goel
2023-11-08  3:08                       ` Michael Heerdegen
2023-11-08  3:21                         ` Dave Goel

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

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

  git send-email \
    --in-reply-to=CAOCW0DiDypdSdpK38f94LS0rqGAC7LUtE5f9UqeUTzaRXFEbbQ@mail.gmail.com \
    --to=deego3@gmail.com \
    --cc=66940@debbugs.gnu.org \
    --cc=gerd.moellmann@gmail.com \
    /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 external index

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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.