From: Andreas Schwab <schwab@suse.de>
To: David Kastrup <dak@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: Unary /
Date: Thu, 15 Oct 2015 14:09:52 +0200 [thread overview]
Message-ID: <mvm7fmos57z.fsf@hawking.suse.de> (raw)
In-Reply-To: <87pp0gweri.fsf@fencepost.gnu.org> (David Kastrup's message of "Thu, 15 Oct 2015 13:30:09 +0200")
David Kastrup <dak@gnu.org> writes:
> I was surprised to discover that unary / does not work analogously to
> unary -, namely creating the multiplicative inverse.
>
> In Elisp, (/ 2.0) returns 2.0. In Common Lisp
> <URL:http://www.lispworks.com/documentation/lw50/CLHS/Body/f_sl.htm>
> (and in Scheme), this returns 0.5.
>
> Any reason for that? The Elisp behavior does not appear overly useful.
Probably because before Emacs supported floats this wasn't such a useful
operation.
Andreas.
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."
prev parent reply other threads:[~2015-10-15 12:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-15 11:30 Unary / David Kastrup
2015-10-15 11:48 ` Stephen J. Turnbull
2015-10-15 11:54 ` David Kastrup
2015-10-15 12:00 ` Tassilo Horn
2015-10-15 12:17 ` David Kastrup
2015-10-15 13:31 ` Stefan Monnier
2015-10-15 14:02 ` David Kastrup
2015-10-15 18:45 ` Stefan Monnier
2015-10-15 19:20 ` Paul Eggert
2015-10-15 12:09 ` Andreas Schwab [this message]
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=mvm7fmos57z.fsf@hawking.suse.de \
--to=schwab@suse.de \
--cc=dak@gnu.org \
--cc=emacs-devel@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.
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).