delete package:unordered-containers

Remove the mapping for the specified key from this map if present.
Delete an element at the given position in this array, decreasing its size by one.
Remove the specified value from this set if present.
>>> HashSet.delete 1 (HashSet.fromList [1,2,3])
fromList [2,3]

>>> HashSet.delete 1 (HashSet.fromList [4,5,6])
fromList [4,5,6]
Delete optimized for the case when we know the key is in the map. It is only valid to call this when the key exists in the map and you know the hash collision position if there was one. This information can be obtained from lookupRecordCollision. If there is no collision, pass (-1) as collPos.