Marcin 'Qrczak' Kowalczyk wrote:
> JK> Now, signum and abs seem to be quite distincts beasts. Signum seem
> JK> to require Ord (and a generic zero...).
>
> Signum doesn't require Ord.
> signum z = z / abs z
> for complex numbers.
Thank you, I know. And I ignore it. Calling "signum" the result of
a vector normalization (on the gauss plane in this case) is something
I don't really appreciate, and I wonder why this definition infiltrated
the prelude. Just because it conforms to the "normal" definition of
signum for reals?
Again, a violation of the orthogonality principle. Needing division
just to define signum. And of course a completely different approach
do define the signum of integers. Or of polynomials...
Jerzy Karczmarczuk
_______________________________________________
Haskell-Cafe mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/haskell-cafe
