Data.Mapping.Util

Documentation

insertIfAbsent :: Ord k => k -> v -> Map k v -> (v, Maybe (Map k v))

inserts key with value only if absent, returns map if changed

nonDefault :: Eq a => a -> a -> Maybe a

For use in maps where we don't want to store default values

equating :: Eq a => (b -> a) -> b -> b -> Bool

Helper function (not exported)