Ralf Lammel wrote:
What you can do is define a dedicated *type code* for composition.
comp = hFoldr (undefined::Comp) (id::Int - Int) test
data Comp
instance Apply Comp (x - y,y - z) (x - z)
where
apply _ (f,g) = g . f
That does it!
Thanks,
Greg Buchholz
Hi Greg,
Since hfoldr is right-associative, I prefer to reorder your list of
functions as follows:
test = HCons (length::String - Int) (HCons ((+1)::(Int-Int)) (HCons
((*2)::(Int-Int)) HNil))
Note that I also annotated length with its specific type.
(If you really wanted to leave things more
