[Haskell-cafe] Re: NaN, Infinity literals

Ashley Yakeley ashley at semantic.org
Fri Sep 8 20:11:31 EDT 2006

Bertram Felgenhauer wrote:

> This is correct according to the IEEE 754 standard, which defines
> that NaN compares unequal to everything, including itself.

This is numerically useful, perhaps, but nonetheless disturbing. For it 
would be helpful to expect that any type that presumes to be an instance 
of Eq has a == a = True.

There really are two different notions of equality here. Perhaps they 
should be given two different names in the language?

Ashley Yakeley
Seattle, WA

More information about the Haskell-Cafe mailing list