Ryan Ingram wrote:
module Prob where import qualified Data.Map as M ....
newtype Prob p a = Prob { runProb :: [(a,p)] }
combine :: (Num p, Ord a) => Prob p a -> Prob p a combine m = Prob $ M.assocs $ foldl' (flip $ uncurry $ M.insertWith (+)) M.empty $ runProb m
Do you see it? All those "M." just seem dirty to me, especially because the compiler should be able to deduce them from the types of the arguments.
May I humbly suggest a much simpler solution to your problem: if an identifier is ambiguous, the compiler will use the last import. So, in your example, the compiler will assume that any instance of empty is Data.Map.empty Some means of using an imported module as the default namespace, and requiring the Prelude to be qualified, may also help.