HKD.Lens

Lens Wrappers

LensOf, PrismOf, and TraversalOf wrap lenses, prisms, and traversals. 'LensOf s t n', for instance, wrapps some 'lens s s' a b', with 's\'', a, and b, determined by s, t, and n.

newtype LensOf s t n

Constructors

LensOf

Fields

• getLensOf :: Lens s (SubSub s t n) (GetNProxyFrom s n) (GetNProxyFrom t n)

newtype PrismOf s t n

Constructors

PrismOf

Fields

• getPrismOf :: Prism s (SubSub s t n) (GetNProxyFrom s n) (GetNProxyFrom t n)

newtype TraversalOf s t n

Constructors

TraversalOf

Fields

• getTraversalOf :: Traversal s (SubSub s t n) (GetNProxyFrom s n) (GetNProxyFrom t n)

Type of Lens Kinded Data

LensesOf, PrismsOf, and TraversalsOf determine the appropriate "lens-kinded data" type.

type LensesOf (s :: Type) (t :: Type) (i :: Nat) = MakeNProxyHK (LensOf s t) s i

type PrismsOf (s :: Type) (t :: Type) (i :: Nat) = MakeNProxyHK (PrismOf s t) s i

type TraversalsOf (s :: Type) (t :: Type) (i :: Nat) = MakeNProxyHK (TraversalOf s t) s i

Making Lens Kinded Data

Lens Kinded Data, or higher kinded data parameterized such that data fields are populated with lenses, are made with makeLensesOf, makePrismsOf, and makeTraversalOf

makeTraversalsOf :: forall c o s t i. (MakeLowerKinded o s ~ i, GetSourceAndTarget o ~ (s, t), Generic o, Generic s, Generic t, Generic i, GLensLike End c (TraversalOf s t) (Rep i) (Rep o)) => o

makeLensesOf :: forall o s t i. (MakeLowerKinded o s ~ i, GetSourceAndTarget o ~ (s, t), Generic o, Generic s, Generic t, Generic i, GLensLike End "" (LensOf s t) (Rep i) (Rep o)) => o

makePrismsOf :: forall c o s t i. (MakeLowerKinded o s ~ i, GetSourceAndTarget o ~ (s, t), Generic o, Generic s, Generic t, Generic i, GLensLike End c (PrismOf s t) (Rep i) (Rep o)) => o

NProxyK

NProxyK is a multi-kinded data family that allows Nats to be used in place of types of any arity. They are used in this library to track data's parameters' occurences in their fields.

type family ToNProxyK (n :: Nat) (a :: k) :: k where ...

Equations

ToNProxyK n (a :: Type) = NProxyK n a

ToNProxyK n (a :: j -> k) = NProxyK n a

data family NProxyK (n :: Nat) (a :: j) :: k

Instances

data NProxyK n (a :: Type)

Defined in HKD.Lens

data NProxyK n (a :: Type) = NProxyK0

data NProxyK n (f :: j -> k)

Defined in HKD.Lens

data NProxyK n (f :: j -> k) = NProxyK1