Generics.Pointless.Lenses.Examples.MapExamples

Pointless Lenses: bidirectional lenses with point-free programming

More example involving composed maps.

map ! . filter_left . map (map f -|- map g)

mapbang_hand :: Lens [Either [(Int, Char)] [(Bool, Char)]] [One]

mapbang_pf :: Lens [Either [(Int, Char)] [(Bool, Char)]] [One]

mapbang_opt :: Lens [Either [(Int, Char)] [(Bool, Char)]] [One]

Persons (count the number of women)

type Person = (Name, Gender)

type Name = String

data Gender

Constructors

M

F

Instances

Eq Gender

Read Gender

Show Gender

Mu Gender

innGender :: Either One One -> Gender

outGender :: Gender -> Either One One

outGender_lns :: Lens Gender (Either One One)

women_hand :: Lens [Person] Nat

women_pf :: Lens [Person] Nat

women_opt :: Lens [Person] Nat