19 Apr
2009
19 Apr
'09
4:56 p.m.
Bulat Ziganshin wrote:
Hello R.A.,
Sunday, April 19, 2009, 11:46:53 PM, you wrote:
Does anybody know if there are any plans to incorporate some of these extensions into GHC - specifically the existential typing ?
it is already here, but you should use "forall" keyword instead odf "exists"
More particularly, enable Rank2Types and then for any type lambda F and for any type Y which does not capture @a@: (x :: exists a. F a) ==> (x :: forall a. F a) (f :: exists a. (F a -> Y)) ==> (f :: (forall a. F a) -> Y) -- Live well, ~wren