lens-1.1: Families of Lenses, Folds and Traversals

Data.Set.Lens

Description

Synopsis

contains :: Ord k => k -> Simple Lens (Set k) BoolSource

This Lens can be used to read, write or delete a member of a Set

Lens

Set

ghci> contains 3 +~ False $ Set.fromList [1,2,3,4] fromList [1,2,4]

contains :: Ord k => k -> (Bool -> f Bool) -> Set k -> f (Set k)