I think a better design for namespacing might be:
import Data.Map as M implicit (Map) import Data.Map as M explicit (lookup)
Why 'implicit' and 'explicit'? Do you mean something like 'include' and 'exclude'?
To me at least, implicit and explicit make more sense. I don't want to exclude importing lookup, I want to make it so I have to explicitly tag lookup as being M.lookup. Similarly, I don't want to include Map (as opposed to all the other things I'm getting from Data.Map), I just want to make it so that when I say Map, I implicitly mean M.Map. Personally I'd extend this syntax (something Neil may have had in mind), so that import Data.Map as M (lookup, union) implicit (Map) gives me M.lookup, M.union and Map while import Data.Map as M hiding (union) explicit (lookup) gives me everything in Data.Map with no qualification except for union and lookup, plus it gives me M.lookup. Bob