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Re: [Scheme-reports] Formal Comment: R7RS 'eqv?' cannot be used for reliable memoization

On Tue, Nov 13, 2012 at 1:26 AM, Mark H Weaver <mhw@x> wrote:
Alex Shinn <alexshinn@x> writes:

> Thank you for the well reasoned formal comment.  Note
> the formal comment period ended June 30,

For the record, lest anyone believe that I waited too long
to bring this up, I first raised this issue here on May 7:


> and we've
> published a draft which many people are now reviewing and
> will be used for the ratification vote.  I will discuss with the WG,
> but it is unlikely we would consider such a change at this late time.

What is the purpose of allowing people to review a draft if you are
unwilling to fix serious flaws such as this?

If a serious flaw turned up even at this late stage
we would address it.

I do not consider this a serious flaw.  I dislike it and
voted against it, but it's a reasonable specification of

First, the implementation strategy you suggest is only
hypothetical.  Although I agree MPFR is a worthwhile
target, no such implementations exist yet.  Actual
working code speaks much louder than ideas.

Second, the only potential difference between the
current draft and your proposal is with -0.0, which does
not mathematically exist.  One can argue that the MPRF
implementation of -0.0 is an implementation of the IEEE
754 value, and so you can treat this the same without
even a disclaimer.


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