From: Michael Heerdegen <michael_heerdegen@web.de>
To: help-gnu-emacs@gnu.org
Subject: Re: Calling a function with undefined symbol
Date: Fri, 04 Nov 2022 13:16:33 +0100 [thread overview]
Message-ID: <87tu3egbj2.fsf@web.de> (raw)
In-Reply-To: 87o7toi68e.fsf@dataswamp.org
Emanuel Berg <incal@dataswamp.org> writes:
> >> Yes, but why do you need the "strange value" for that?
Let's call the strange `'''''''''...` values "quote-quine" for now so
that it's easier to talk about them (better than saying "the strange
value" all the time). I said value_s_ here because there is no unique
quote-quine in the `eq' sense.
> > I chose it because you get an `equal' value when you quote
> > the value (to suggest a wrong track to an answer), and
>
> You do?
>
> (setq print-circle t)
>
> (setq x #1=(quote #1#))
>
> (eq 'x x) ; nil
> (equal 'x x) ; nil
>
> ?
I don't see any place in your code where a quote-quine is quoted. You
correctly assign a quote-quine to a variable. But then you only quote
the symbol, not the value, and compare the quote-quine with the symbol
you had bound it to.
IOW: It's a trap!
So how could a correct `equal'ity test of a quote-quine and that
quote-quine quoted be achieved? This is exercise number 3.
> So the length is 2, but the depth is infinite. IOW: It's a trap!
Yes, this is the correct solution. Congratulations!
Michael.
next prev parent reply other threads:[~2022-11-04 12:16 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-31 8:15 Calling a function with undefined symbol Heime
2022-10-31 8:32 ` Jean Abou Samra
2022-10-31 8:42 ` tomas
2022-10-31 8:57 ` Heime
2022-10-31 9:07 ` tomas
2022-10-31 9:24 ` Jean Abou Samra
2022-10-31 9:43 ` Heime
2022-10-31 9:58 ` Jean Abou Samra
2022-10-31 10:57 ` Heime
2022-10-31 17:00 ` [External] : " Drew Adams
2022-10-31 17:10 ` Emanuel Berg
2022-11-01 4:11 ` Drew Adams
2022-11-01 5:24 ` tomas
2022-11-01 15:58 ` Drew Adams
2022-11-01 16:13 ` tomas
2022-11-01 19:22 ` Drew Adams
2022-10-31 12:29 ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-10-31 15:37 ` Emanuel Berg
2022-11-02 12:14 ` Michael Heerdegen
2022-11-02 14:25 ` Sam Steingold
2022-11-02 16:40 ` Michael Heerdegen
2022-11-02 17:28 ` Emanuel Berg
2022-11-02 23:04 ` Emanuel Berg
2022-11-03 11:09 ` Michael Heerdegen
2022-11-03 12:15 ` Emanuel Berg
2022-11-04 12:16 ` Michael Heerdegen [this message]
2022-11-05 14:32 ` Emanuel Berg
2022-11-05 23:22 ` Michael Heerdegen
2022-11-06 20:17 ` Emanuel Berg
2022-11-07 16:03 ` Michael Heerdegen
2022-11-07 16:50 ` [External] : " Drew Adams
2022-11-07 16:52 ` Emanuel Berg
2022-11-08 15:52 ` Michael Heerdegen
2022-11-08 19:15 ` tomas
2022-11-08 19:57 ` Michael Heerdegen
2022-11-08 20:47 ` tomas
2022-11-08 21:35 ` Sam Steingold
2022-11-08 23:53 ` Michael Heerdegen
2022-11-09 15:32 ` Sam Steingold
2022-11-09 15:59 ` Michael Heerdegen
2022-11-16 19:07 ` Emanuel Berg
2022-11-16 21:40 ` [External] : " Drew Adams
2022-11-16 21:55 ` Emanuel Berg
2022-11-04 14:33 ` Michael Heerdegen
2022-11-05 12:57 ` Emanuel Berg
2022-10-31 11:34 ` Emanuel Berg
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=87tu3egbj2.fsf@web.de \
--to=michael_heerdegen@web.de \
--cc=help-gnu-emacs@gnu.org \
/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.
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).