traverse package:unordered-containers

Perform an Applicative action for each key-value pair in a HashMap and produce a HashMap of all the results. Note: the order in which the actions occur is unspecified. In particular, when the map contains hash collisions, the order in which the actions associated with the keys involved will depend in an unspecified way on their insertion order.

Perform an Applicative action for each key-value pair in a HashMap and produce a HashMap of all the results. Each HashMap will be strict in all its values.

traverseWithKey f = fmap (map id) . Data.HashMap.Lazy.traverseWithKey f

Note: the order in which the actions occur is unspecified. In particular, when the map contains hash collisions, the order in which the actions associated with the keys involved will depend in an unspecified way on their insertion order.