[Haskell-cafe] Re: Why purely in haskell?
g9ks157k at acme.softbase.org
Fri Jan 11 06:29:35 EST 2008
Am Freitag, 11. Januar 2008 10:54 schrieb Wilhelm B. Kloke:
> Wolfgang Jeltsch <g9ks157k at acme.softbase.org> schrieb:
> > However, the fact that (0 / 0) == (0 / 0) yields False is quite shocking.
> > It doesn?t adhere to any meaningful axiom set for Eq. So I think that
> > this behavior should be changed. Think of a set implementation which
> > uses (==) to compare set elements for equality. The NaN behavior would
> > break this implementation since it would allow for sets which contain NaN
> > multiple times.
> You forget, that the intention of NaN is denial of membership of any set of
This doesn’t matter. The Set data type I’m talking about would not know about
NaN and would therefore allow multiple NaNs in a set.
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