PEP 238 (revised)

James Logajan JamesL at Lugoj.Com
Fri Jul 27 20:50:12 CEST 2001


Andrei Kulakov wrote:
> 
> On Thu, 26 Jul 2001 22:09:06 GMT, Guido van Rossum <guido at python.org> wrote:
> >
> >     The correct work-around is subtle: casting an argument to float()
> >     is wrong if it could be a complex number; adding 0.0 to an
> >     argument doesn't preserve the sign of the argument if it was minus
> >     zero.
> 
> When is 0 different from -0?

When doing ones-complement arithmetic. Not too many machines use that
anymore, and the ones that did (or do) should have comparison logic to
consider -0 == 0. The CDC Cyber series used ones-complement.



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