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From Gilles Sadowski <>
Subject Re: [Math] Fraction parsing bug?
Date Thu, 01 Dec 2011 15:49:08 GMT
On Thu, Dec 01, 2011 at 04:28:12PM +0100, S├ębastien Brisard wrote:
> Hello,
> >
> > IMHO, no.
> > The fact 0 is signed for doubles is really a trick set up in the IEE754 standard
only for dealing with branch cuts (like the division you present). It is not available for
other types like int or longs where 0 is not signed and special numbers like infinity and
NaN and even subnormals do not exist. Our fractions are both closer to the mathematical Z
set and to the computer science int primitives pairs than to double. There is a conversion
method doubleValue, but it should rather be considered an extension than a core feature.
> >
> > Luc
> >
> I was initially going to answer along these lines, but refrained to do
> so, because I realized that Q is actually closer to R than Z. Indeed,
> you cannot define a limit in Z, but you probably can in Q, since Q is
> dense in R. So, defining a signed zero as being as signed fraction
> with absolute value smaller than 1/Integer.MAX_VALUE might be
> meaningful.
> I'm not saying we should do it, but I can see Gilles' point. Gilles,
> do you have any practical application in mind ?

Heu, no. I just thought that it would be, hmm... more consistent. ;-)


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