At 2002-06-06 00:40, Cagdas Ozgenc wrote:
From the previous discussion it has been brought to my attention that there is no much difference between
a -> b
and
data F a b = Blank a b -- "-> probably has a blank value constructor"
Well F and (->) may both be type-constructors of kind (* -> * -> *), but I think there the similarity ends. You may consider an F as holding an 'a' and a 'b', but a function holds a 'b' for every 'a'. It's quite different, and F does not implement functions. If you're wondering about the value constructor for a function, ask yourself, what would you pass to it? You could do this, though: newtype F' a b = MkF' (a -> b) ...or this: type F'' = (->) I think you'll find (->) is pretty much atomic. It's tempting to say a function is constructed from a piece of code, but for a lazy language pretty much any value might be represented by a piece of code... -- Ashley Yakeley, Seattle WA