Re: Reverting eqv? behavior for signed zeros and nans to 1.6 semantics

[Kevin Ryde]

Per Bothner <address@hidden> writes:
>
>>  | From: Marius Vollmer <address@hidden>
>>  | Specifically, 'eqv?' would be changed to return '#t' when comparing
>>  | negative and positive zero:
>>  |
>>  |     (eqv? 0.0 -0.0) => #t
>
> I missed the explanation for why this might be desirable.

Primarily for compatibility.  In 1.6 you can cast out flonum zeros
with say "(delv 0.0 lst)", but if eqv is changed it depends whether
they're +0 or -0.

> I don't think it is the Right Thing.  Arguments from
> R5RS are irrelevant, since it doesn't consider NaNs
> and infinities.  Our goal should be to fix this.

R6RS looks like it's going to say something about such things,
including breaking the link between eqv and =.  I think it's best to
wait for that.