On 06-Oct-1999, John Atwood <[EMAIL PROTECTED]> wrote:
> Can't you trivially satisfy Eq:
>
> instance Eq b => Eq (a -> b) where
> f == g = False
Functions using the `Eq' class might rely on the property
that x == x is True for all x.
So
instance Eq b => Eq (a -> b) where
f == g = error "can't compute equality of functions"
might be safer, in the sense that at worst it would result
in a runtime error, rather than silently producing incorrect
output.
However, a `Show' instance that just printed "<<function>>"
for all functions would probably be OK.
--
Fergus Henderson <[EMAIL PROTECTED]> | "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh> | of excellence is a lethal habit"
PGP: finger [EMAIL PROTECTED] | -- the last words of T. S. Garp.
