Data.IntSet.Lens

Documentation

members :: Fold IntSet Int

IntSet isn't Foldable, but this Fold can be used to access the members of an IntSet.

>>> sumOf members $ setOf folded [1,2,3,4]
10

setmapped :: IndexPreservingSetter' IntSet Int

This Setter can be used to change the contents of an IntSet by mapping the elements to new values.

Sadly, you can't create a valid Traversal for a Set, because the number of elements might change 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 :: Getting IntSet s Int -> s -> IntSet

Construct an IntSet from a Getter, Fold, Traversal, Lens or Iso.

>>> setOf folded [1,2,3,4]
fromList [1,2,3,4]

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

 setOf :: Getter s Int     -> s -> IntSet
 setOf :: Fold s Int       -> s -> IntSet
 setOf :: Iso' s Int       -> s -> IntSet
 setOf :: Lens' s Int      -> s -> IntSet
 setOf :: Traversal' s Int -> s -> IntSet