Data.Set.Optics

This module defines optics for constructing and manipulating finite Sets.

Documentation

setmapped :: Ord b => Setter (Set a) (Set b) a b

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

Sadly, you can't create a valid Traversal for a Set, 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]

setOf :: (Is k A_Fold, Ord a) => Optic' k is s a -> s -> Set a

Construct a set from a fold.

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

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