On Wed, Mar 12, 2008 at 7:31 PM, Adrian Hey <
ahey@iee.org> wrote:
Remi Turk wrote:
> I wouldn't bet on it either:
>
> Prelude> 0.0 == -0.0
> True
> Prelude> isNegativeZero 0.0 == isNegativeZero (-0.0)
> False
>
> Although isNegativeZero might be considered a ``private,
> "internal" interface that exposes implementation details.''
Interesting example.
So is the correct conclusion from this that all (polymorphic) code
that assumes (x == y) = True implies x=y is inherently broken,
or is just this particular Eq instance that's broken?
Regards
--
Adrian Hey