Re: [Haskell-cafe] Re: instance Eq (a -> b)

On Wed, 2010-04-14 at 08:13 +0100, Thomas Davie wrote:

Your instances of Finite are not quite right:

bottom :: a bottom = doSomethingToLoopInfinitely.

instance Finite () where allValues = [(), bottom]

Bottom is not a value, it's failure to evaluate to a value. But if one did start considering bottom to be a value, one would have to distinguish different ones. For instance, (error "ABC") vs. (error "PQR"). Obviously this is not finite. -- Ashley Yakeley