From: Paul Eggert <eggert@cs.ucla.edu>
To: Eli Zaretskii <eliz@gnu.org>
Cc: schwab@linux-m68k.org, Emacs-devel@gnu.org
Subject: Re: (0 <= i && i < N) is not "backwards"
Date: Mon, 25 Mar 2013 09:49:28 -0700 [thread overview]
Message-ID: <51508018.7090609@cs.ucla.edu> (raw)
In-Reply-To: <83obe71qew.fsf@gnu.org>
On 03/25/13 07:53, Eli Zaretskii wrote:
> the problem with relying on 0 < foo is that most people won't even
> consider the subtle difference between that and !(foo >= 0)
There must be dozens of places in the Emacs source code that
use floating-point comparisons and rely on NaNs behaving the
way that they do. It'd be unnecessary clutter to add comments
and/or isnan() calls to them all. Sure, we could modify our
compilers (and this would include the Emacs Lisp compiler)
to recognize and optimize-away the isnan calls, but that would
be even more make-work. Programmers who deal with
floating-point should be cognizant of NaNs; that's just
life in the floating-point big city these days.
next prev parent reply other threads:[~2013-03-25 16:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-24 23:14 (0 <= i && i < N) is not "backwards" Paul Eggert
2013-03-24 23:53 ` Pascal J. Bourguignon
2013-03-25 14:23 ` Stefan Monnier
2013-03-25 14:59 ` Andreas Schwab
2013-03-25 8:20 ` Eli Zaretskii
2013-03-25 14:35 ` Paul Eggert
2013-03-25 14:53 ` Eli Zaretskii
2013-03-25 14:58 ` Noah Lavine
2013-03-25 15:09 ` Eli Zaretskii
2013-03-25 15:28 ` Noah Lavine
2013-03-25 16:49 ` Paul Eggert [this message]
2013-03-25 16:59 ` Eli Zaretskii
2013-03-30 21:45 ` Jim Meyering
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