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Re: Making 'eq' == 'eql' in bignum branch

From: Eli Zaretskii
Subject: Re: Making 'eq' == 'eql' in bignum branch
Date: Fri, 10 Aug 2018 22:45:12 +0300

> From: John Yates <address@hidden>
> Date: Fri, 10 Aug 2018 12:52:53 -0400
> Cc: Eli Zaretskii <address@hidden>, Paul Eggert <address@hidden>,
>       Stefan Monnier <address@hidden>,
>       Emacs developers <address@hidden>
> More importantly the standard says that two NaN values (even if fetched
> from the same container within a single expression) _always_ compare
> not equal.
> Were I that "occasional user who wants" IEEE compliance in my elisp
> code I would expect comparisons of NaNs (whether via either eq or eql)
> to return nil.  My sense is that to achieve that effect one must _always_
> compare floating point objects, even if they reside at the same address.

We decided to follow IEEE for numerical comparisons ('='), but not for
object comparisons.  I'm using IEEE fp calculations all the time on my
daytime job, and it still makes no sense to me to compare NaN
_objects_ not equal.  IEEE only talks about comparing numerical

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