From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Re: bignum branch
Date: Wed, 18 Jul 2018 16:41:14 -0400 [thread overview]
Message-ID: <jwvy3e82sf6.fsf-monnier+gmane.emacs.devel@gnu.org> (raw)
In-Reply-To: 87o9f45ot8.fsf@Rainer.invalid
> NaN (specifically of the IEEE754 variety) is supposed to compare
> non-equal even when compared to itself.
There's "compare" and there's "compare".
I think we always want (eql x x) to return t, so the above behavior
makes a lot of sense. The rule that NaN is not equal to itself should
only be applied when doing a numerical comparison (i.e. (= x x) may
return nil).
> I recognize that eql is used in the above, but that would probably
> still create two LISP objects that happen to have the same value, but
> the established FP math says these two values should not compare equal
> anyway. If you stray from that convention there should be a really
> good reason for that and it needs to be prominently documented.
NaNs are a minefield. I understand there are good reasons for this
minefield, but it's good practice to try and confine the pain to those
places where it is indispensable.
Stefan
next prev parent reply other threads:[~2018-07-18 20:41 UTC|newest]
Thread overview: 205+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-13 4:26 bignum branch Tom Tromey
2018-07-13 7:38 ` Eli Zaretskii
2018-07-13 8:45 ` Robert Pluim
2018-07-13 9:51 ` Robert Pluim
2018-07-13 11:59 ` Eli Zaretskii
2018-07-13 13:31 ` Robert Pluim
2018-07-13 18:06 ` Tom Tromey
2018-07-13 12:04 ` Eli Zaretskii
2018-07-13 12:14 ` Eli Zaretskii
2018-07-13 13:02 ` Robert Pluim
2018-07-13 13:50 ` Eli Zaretskii
2018-07-15 16:29 ` Andy Moreton
2018-07-17 18:10 ` Robert Pluim
2018-07-17 18:24 ` Eli Zaretskii
2018-07-17 19:06 ` Eli Zaretskii
2018-07-17 20:00 ` Robert Pluim
2018-07-17 21:17 ` Clément Pit-Claudel
2018-07-18 1:01 ` Stefan Monnier
2018-07-18 9:28 ` Andy Moreton
2018-07-18 13:21 ` Robert Pluim
2018-07-18 13:32 ` Stefan Monnier
2018-07-18 16:01 ` Eli Zaretskii
2018-07-18 16:21 ` Robert Pluim
2018-07-18 16:47 ` Eli Zaretskii
2018-07-13 12:34 ` Robert Pluim
2018-07-13 14:28 ` Andy Moreton
2018-07-13 14:42 ` Eli Zaretskii
2018-07-13 14:53 ` Andy Moreton
2018-07-13 15:03 ` Eli Zaretskii
2018-07-13 15:30 ` Andy Moreton
2018-07-13 19:35 ` Andy Moreton
2018-07-14 16:20 ` Eli Zaretskii
2018-07-14 20:04 ` Andy Moreton
2018-07-15 13:46 ` Tom Tromey
2018-07-15 15:01 ` Eli Zaretskii
2018-07-16 12:19 ` Stefan Monnier
2018-07-16 14:40 ` Eli Zaretskii
2018-07-16 16:09 ` Stefan Monnier
2018-07-16 18:06 ` Eli Zaretskii
2018-07-16 18:32 ` Stefan Monnier
2018-07-16 18:42 ` Eli Zaretskii
2018-07-16 14:35 ` Tom Tromey
2018-07-16 22:28 ` Andy Moreton
2018-07-21 15:35 ` Andy Moreton
2018-07-22 16:43 ` Tom Tromey
2018-07-22 17:41 ` Andy Moreton
2018-08-03 0:43 ` Andy Moreton
2018-08-03 6:23 ` Eli Zaretskii
2018-08-03 9:01 ` Andy Moreton
2018-08-03 9:47 ` Eli Zaretskii
2018-08-03 10:07 ` Andy Moreton
2018-08-03 13:16 ` Eli Zaretskii
2018-08-03 14:05 ` Andy Moreton
2018-08-03 17:44 ` Eli Zaretskii
2018-08-03 19:54 ` Andy Moreton
2018-08-04 6:11 ` Eli Zaretskii
2018-08-04 11:14 ` Andy Moreton
2018-08-04 11:29 ` Eli Zaretskii
2018-08-03 20:17 ` Tom Tromey
2018-08-03 21:02 ` Paul Eggert
2018-08-03 21:19 ` Tom Tromey
2018-08-04 1:22 ` Paul Eggert
2018-08-04 6:18 ` Eli Zaretskii
2018-08-04 10:49 ` Achim Gratz
2018-08-04 11:07 ` Eli Zaretskii
2018-08-04 10:43 ` Achim Gratz
2018-08-04 16:33 ` Tom Tromey
2018-08-04 18:28 ` Achim Gratz
2018-08-04 6:20 ` Eli Zaretskii
2018-08-04 11:17 ` Andy Moreton
2018-08-04 16:41 ` Tom Tromey
2018-08-06 10:18 ` Robert Pluim
2018-08-07 0:36 ` Tom Tromey
2018-08-07 8:38 ` Andy Moreton
2018-08-08 0:25 ` Tom Tromey
2018-08-04 17:10 ` Tom Tromey
2018-08-03 17:30 ` Tom Tromey
2018-08-03 19:16 ` Andy Moreton
2018-08-04 6:07 ` Eli Zaretskii
2018-08-05 11:36 ` Andy Moreton
2018-08-05 15:18 ` Eli Zaretskii
2018-08-06 18:12 ` Andy Moreton
2018-08-07 0:41 ` Tom Tromey
2018-08-07 2:03 ` Paul Eggert
2018-08-07 3:59 ` Tom Tromey
2018-08-07 4:02 ` Tom Tromey
2018-08-07 11:22 ` Andy Moreton
2018-08-07 16:53 ` Paul Eggert
2018-08-07 17:12 ` Eli Zaretskii
2018-08-07 17:52 ` Paul Eggert
2018-08-08 0:23 ` Tom Tromey
2018-08-07 11:17 ` Andy Moreton
2018-08-08 0:26 ` Tom Tromey
2018-08-08 14:24 ` Andy Moreton
2018-08-08 16:35 ` Andy Moreton
2018-08-08 23:14 ` Tom Tromey
2018-08-09 2:33 ` Eli Zaretskii
2018-08-09 7:59 ` Michael Albinus
2018-08-09 13:01 ` Eli Zaretskii
2018-08-09 17:31 ` Paul Eggert
2018-08-09 18:32 ` Eli Zaretskii
2018-08-09 19:22 ` Stefan Monnier
2018-08-09 16:34 ` Tom Tromey
2018-08-09 18:28 ` Eli Zaretskii
2018-08-09 19:30 ` Tom Tromey
2018-08-08 23:37 ` Tom Tromey
2018-08-09 0:07 ` Andy Moreton
2018-08-09 2:03 ` Tom Tromey
2018-08-09 9:19 ` Andy Moreton
2018-08-09 20:49 ` Andy Moreton
2018-08-10 5:45 ` Eli Zaretskii
2018-08-10 7:43 ` Andy Moreton
2018-08-10 7:59 ` Paul Eggert
2018-08-10 9:48 ` Eli Zaretskii
2018-08-10 20:58 ` Paul Eggert
2018-08-11 7:08 ` Eli Zaretskii
2018-08-11 8:02 ` Paul Eggert
2018-08-11 10:50 ` Eli Zaretskii
2018-08-11 12:57 ` Stefan Monnier
2018-08-11 19:38 ` Paul Eggert
2018-08-10 11:18 ` Andy Moreton
2018-08-10 11:56 ` Andreas Schwab
2018-08-10 12:25 ` Eli Zaretskii
2018-08-10 12:27 ` Andy Moreton
2018-08-10 18:37 ` Achim Gratz
2018-08-10 12:26 ` Eli Zaretskii
2018-08-10 12:46 ` Andy Moreton
2018-08-10 9:46 ` Eli Zaretskii
2018-08-10 11:39 ` Andy Moreton
2018-08-10 12:33 ` Eli Zaretskii
2018-08-10 14:05 ` Andy Moreton
2018-08-10 19:57 ` Eli Zaretskii
2018-08-11 15:21 ` Andy Moreton
2018-08-11 15:25 ` Tom Tromey
2018-08-11 16:04 ` Eli Zaretskii
2018-08-11 16:16 ` Eli Zaretskii
2018-08-11 16:54 ` Andy Moreton
2018-08-11 17:34 ` Eli Zaretskii
2018-08-11 17:56 ` Andy Moreton
2018-08-11 18:10 ` Eli Zaretskii
2018-08-11 18:15 ` Andy Moreton
2018-08-11 19:08 ` Eli Zaretskii
2018-08-11 22:15 ` Andy Moreton
2018-08-12 18:54 ` Eli Zaretskii
2018-08-12 19:44 ` Andy Moreton
2018-08-13 15:02 ` Eli Zaretskii
2018-08-13 23:13 ` Andy Moreton
2018-08-14 14:55 ` Eli Zaretskii
2018-08-14 15:11 ` Andy Moreton
2018-08-14 15:19 ` Eli Zaretskii
2018-08-14 16:16 ` Andy Moreton
2018-08-15 17:01 ` Eli Zaretskii
2018-08-11 17:00 ` Andy Moreton
2018-08-10 15:25 ` Stefan Monnier
2018-08-10 16:45 ` Andy Moreton
2018-08-10 19:34 ` Eli Zaretskii
2018-08-09 3:49 ` Stefan Monnier
2018-08-09 9:21 ` Andy Moreton
2018-08-09 2:37 ` Eli Zaretskii
2018-08-03 20:13 ` Tom Tromey
2018-08-04 16:39 ` Tom Tromey
2018-08-04 17:24 ` Tom Tromey
2018-08-05 10:46 ` Andy Moreton
2018-08-05 18:59 ` Tom Tromey
2018-08-06 18:17 ` Andy Moreton
2018-07-15 15:00 ` Eli Zaretskii
2018-07-15 17:31 ` Paul Eggert
2018-07-15 18:27 ` Eli Zaretskii
2018-07-16 19:02 ` Paul Eggert
2018-07-17 2:42 ` Eli Zaretskii
2018-07-17 15:53 ` Paul Eggert
2018-07-17 17:03 ` Eli Zaretskii
2018-07-17 17:24 ` Paul Eggert
2018-07-17 17:38 ` Eli Zaretskii
2018-07-17 17:41 ` Paul Eggert
2018-07-17 17:53 ` Eli Zaretskii
2018-07-17 18:55 ` Paul Eggert
2018-07-17 19:04 ` Eli Zaretskii
2018-07-17 22:39 ` Paul Eggert
2018-07-18 2:41 ` Eli Zaretskii
2018-07-18 7:39 ` Paul Eggert
2018-07-18 11:14 ` Andy Moreton
2018-07-18 11:57 ` Paul Eggert
2018-07-18 13:09 ` Clément Pit-Claudel
2018-07-18 13:18 ` Stefan Monnier
2018-07-18 13:43 ` Clément Pit-Claudel
2018-07-18 14:06 ` Andy Moreton
2018-07-18 19:25 ` Achim Gratz
2018-07-18 20:41 ` Stefan Monnier [this message]
2018-07-19 2:36 ` Eli Zaretskii
2018-07-19 20:32 ` Paul Eggert
2018-07-20 20:02 ` Achim Gratz
2018-07-20 20:58 ` Paul Eggert
2018-07-20 21:48 ` Stefan Monnier
2018-07-22 19:49 ` Achim Gratz
2018-07-18 18:29 ` Paul Eggert
2018-07-18 11:10 ` Andy Moreton
2018-07-18 18:34 ` Paul Eggert
2018-07-25 21:02 ` Andy Moreton
2018-08-09 14:26 ` Charles A. Roelli
2018-08-09 15:17 ` Andy Moreton
2018-08-09 16:23 ` Charles A. Roelli
2018-08-09 16:25 ` Tom Tromey
2018-08-09 17:08 ` Andy Moreton
2018-08-09 19:29 ` Tom Tromey
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