Hi John,
In the class I wrote, c has kind * (e.g. [a]), but then I don't see how to write a suitable map function. For that, I would want c to have kind * -> *. Unfortunately then I don't know to write the others.
Would I have to do something with c having kind (* -> *) ?
class Chunkable2 c el where cLength :: c el -> Int cHead :: c el -> Maybe el cMap :: (el -> el') -> c el -> c el'
When c is (* -> *), why do you need el to be a parameter of the typeclass at all? I.e., would this work for your purposes:
class Chunkable3 c where
cLength :: c el -> Int
cHead :: c el -> Maybe el
cMap :: (a -> b) -> c a -> c b
instance Chunkable3 [] where
cLength = length
cMap = map cHead = ...
Using Functor as a superclass of Chunkable3 works too. Thanks, -Brian _________________________________________________________________ More than messages–check out the rest of the Windows Live™. http://www.microsoft.com/windows/windowslive/