union package:unordered-containers

The union of two maps. If a key occurs in both maps, the mapping from the first will be the mapping in the result.

Examples

>>> union (fromList [(1,'a'),(2,'b')]) (fromList [(2,'c'),(3,'d')])
fromList [(1,'a'),(2,'b'),(3,'d')]
Construct a set containing all elements from both sets. To obtain good performance, the smaller set must be presented as the first argument.
>>> union (fromList [1,2]) (fromList [2,3])
fromList [1,2,3]
Strict in the result of f.
The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.
The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.
Construct a set containing all elements from a list of sets.
Construct a set containing all elements from a list of sets.