GNU bug report logs - #30426
division inconsistency?

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From: Mark H Weaver <mhw <at> netris.org>
To: bil <at> ccrma.Stanford.EDU
Cc: 30426 <at> debbugs.gnu.org
Subject: bug#30426: division inconsistency?
Date: Mon, 12 Feb 2018 16:15:51 -0500

Mark H Weaver <mhw <at> netris.org> writes:

> Our core '/' operator, as defined in numbers.c, raises an exception for
> (/ x 0), for any 'x'.  This does not conform to the R6RS, which
> specifies that (/ 0.0 0) => +inf.0.  I don't think that rule makes sense

Sorry, I meant to write (/ 1.0 0) => +inf.0, which is one of the
examples given in the R6RS.

> because the sign of the result cannot be justified.  (/ 1 0.0) => +inf.0
> and (/ 1 -0.0) => -inf.0 are more justifiable because of the signed
> inexact zeroes, but an exact zero is not signed.
>
> However, it may be that we should change this to conform to the R6RS,
> and certainly it would be good for our compiler and interpreter to agree
> on all of these edge cases.

        Mark

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