Re: perhaps

ajb@spamcop.net wrote:

Slightly contradicting myself, here's one that I use:

class TestableProperty prop a | prop -> a where is :: prop -> a -> Bool

data Prime = Prime

instance TestableProperty Prime Integer where is Prime x = {- detail omitted -}

The only problem with this is that with the fundep, you can't do this:

instance (Integral i) => TestableProperty Prime i where is Prime x = {- same detail -}

Maybe I'm dense but couldn't you just drop the fundep? Cheers, Ben