[Python-Dev] PEP239 (Rational Numbers) Reference Implementation and new issues
Eric S. Raymond
esr at thyrsus.com
Thu Oct 3 00:30:07 CEST 2002
Andrew Koenig <ark at research.att.com>:
> Eric> APL faced this problem twenty-five years ago. I like its
> Eric> solution; a `fuzz' variable defining the
> Eric> close-enough-for-equality range.
> I used to like APL's approach, but I've changed my mind.
> Part of the reason is that there are some places where unfuzzed
> comparison is essential, such as sorting. Another part is that
> fuzzy comparison destroys substitutability: If a==b, it is
> not always true that f(a)==f(b).
> Much as I like APL, I'd rather use Scheme's numeric model.
Good points...but the fuzz variable could default to zero. It didn't in APL,
which I always thought a mistake.
<a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a>
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