Re: [Scheme-reports] ballot question #229: EQV? and NaN

[John Cowan <cowan@x>]

Alex Shinn scripsit:
> On Fri, Sep 30, 2011 at 9:44 AM, Alex Shinn <alexshinn@x> wrote:
> >
> > By all means, but the ballot item was unclear and
> > will require a re-vote.  In the meantime, the draft
> > we submit with the call for formal comments will
> > need to revert to either R5RS (unspecified) or R6RS.
> 
> Sorry, still catching up on this.  The R5RS description
> of `eqv?' is completely unambiguous in requiring the
> "different" semantics.

Well, presuming that (= +nan.0 x) is #f for all x.

> R6RS loosened the semantics slightly to make NaN
> `eqv?' comparisons unspecified.

(eqv? nan nan) and (eqv? nan nan2) are unspecified, but
(eqv? nan not-nan) is specified as #f.

-- 
He played King Lear as though           John Cowan <cowan@x>
someone had played the ace.             http://www.ccil.org/~cowan
        --Eugene Field

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