27 Jul
2007
27 Jul
'07
5:22 a.m.
On Jul26, Stefan O'Rear wrote:
So, this syntax affects a lot of code, existing or otherwise, that doesn't use view patterns, which is something we're trying to avoid.
Eh? I *think* the typing rules are the same for the no-view case. If the auto-deriving hack isn't implemented, you only need a deriving(View), otherwise there should be no change at all...
Assuming you don't have the functional dependency: "affects" in the sense that any code you write has a generalized type, so you have to explain view patterns to beginners right out of the gate, etc. If you write length [] = [] length (h : t) = 1 + length t we don't want to have to explain to beginners why it has type length :: forall a,b,c. View a [b] -> a -> Num c -Dan