When multiple modules define the same functions by name, the compiler will complain. In such cases (or to improve readability), we can use a qualified
import:
import qualified Data.Stream as D
Now we can prevent ambiguity compiler errors when we use map
, which is defined in Prelude
and Data.Stream
:
map (== 1) [1,2,3] -- will use Prelude.map
D.map (odd) (fromList [1..]) -- will use Data.Stream.map
It is also possible to import a module with only the clashing names being qualified via import Data.Text as T
, which allows one to have Text
instead of T.Text
etc.