--Testing for proper name printing in complex error messages (a previous bug)
:set -XTypeFamilies
:set -XFlexibleInstances
class Listable t where ; type ListableElem t :: * ; asList :: t -> [ListableElem t]
instance Listable (a,a) where ; asList (a,b) = [a,b]
instance Listable (a,a) where ; type ListableElem (a,a) = a ; asList (a,b) = [a,b]
asList ("as","df")