[r6rs-discuss] put-datum, get-datum, equal?, eqv?, and NaNs

From: Michael Sperber <sperber>
Date: Sat, 30 Jun 2007 09:56:42 +0200

Alan Watson <alan at alan-watson.org> writes:

> The description of eqv? in 11.5 leaves its behaviour partially
> unspecified when given two NaNs. It can return #t or #f.
>
> However, if I use put-datum and get-datum to write and read a NaN, the
> result has to be equal? to the original NaN. Since equal? and eqv? are
> identical for number objects, this means that the result has to be eqv?
> to the original NaN.
>
> Are the editors happy with this additional restriction on the behaviour
> of eqv? with NaNs?

Yes, but the tightening of the spec of `put-datum' was premature, I
believe, and needs to be suitably weakened.

Good catch!

-- 
Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla
Received on Sat Jun 30 2007 - 03:56:42 UTC

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