Documentation

This Setter can be used to change the type of a HashSet by mapping the elements to new values.

Sadly, you can't create a valid Traversal for a HashSet, but you can manipulate it by reading using folded and reindexing it via setmapped.

>>> over setmapped (+1) (fromList [1,2,3,4])
fromList [2,3,4,5]

Construct a HashSet from a fold.

>>> setOf folded ["hello","world"]
fromList ["hello","world"]

>>> setOf (folded % _2) [("hello",1),("world",2),("!!!",3)]
fromList [1,2,3]