GNU bug report logs - #64441
29.0.92; elisp arithmetic error at ielm prompt

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Package: emacs;

Reported by: Van Ly <van.ly <at> sdf.org>

Date: Mon, 3 Jul 2023 16:26:02 UTC

Severity: normal

Tags: notabug

Found in version 29.0.92

Done: Stefan Kangas <stefankangas <at> gmail.com>

Bug is archived. No further changes may be made.

Full log

Message #17 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Van Ly <van.ly <at> sdf.org>
To: Stephen Berman <stephen.berman <at> gmx.net>
Cc: bug-gnu-emacs <at> gnu.org, 64441 <at> debbugs.gnu.org
Subject: Re: bug#64441: 29.0.92; elisp arithmetic error at ielm prompt
Date: Tue, 4 Jul 2023 10:44:06 GMT

> From: Stephen Berman
>
> `/' in Elisp is different from `/' in Common Lisp.
> 
> (elisp) Arithmetic Operations:
> 
>   If all the arguments are integers, the result is an integer,
>   obtained by rounding the quotient towards zero after each division.
> 
> Hence (/ 3 4), (/ 7 13) and (/ 5 12) all evaluate to 0, and "If you
> divide an integer by the integer 0, Emacs signals an ‘arith-error’
> error".
> 
> But in Common Lisp
> (http://www.lispworks.com/documentation/HyperSpec/Body/f_sl.htm):
> 
>   If each argument is either an integer or a ratio, and the result is
>   not an integer, then it is a ratio.
> 
> Hence (/ 3 4) => 3/4,  (/ 7 13) => 7/13 and (/ 5 12) => 5/12
> 

Thank you Steve.
This bug report was last modified 1 year and 258 days ago.

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