
25 Jan
2010
25 Jan
'10
2:03 p.m.
Hi all, Just wondering if there could be a typo in section 7.7.2.1 of the GHC manual (type family declarations) http://www.haskell.org/ghc/docs/latest/html/users_guide/type-families.html Specifically, it says type family F a b :: * -> * -- F's arity is 2, -- although its overall kind is * -> * -> * -> * along with F Char [Int] -- OK! Kind: * -> * F Char [Int] Bool -- OK! Kind: * F IO Bool -- WRONG: kind mismatch in the first argument F Bool -- WRONG: unsaturated application and I'm wondering about the overall kind. Shouldn't that be * -> * -> *, or am I not understanding something? Thanks! -Tyson