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Re: [Scheme-reports] EQV? on numbers should be based on operational equivalence



On Tue, May 8, 2012 at 8:42 AM, Mark H Weaver <mhw@x> wrote:
> John Cowan <cowan@x> writes:
>> Mark H Weaver scripsit:
>>
>>> In particular, on platforms with signed zeroes, the R7RS should mandate
>>> that (eqv? 0.0 -0.0) => #false.
>>
>> R6RS mandates that, but R7RS currently leaves it unspecified.
>
> How would you suggest implementing memoization in a portable R7RS
> program?

It must be unspecified in R7RS because R7RS
does not require that implementations distinguish
between 0.0 and -0.0, nor that they provide +inf.0
or -inf.0.

-- 
Alex

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