Data.Profunctor.Product.Internal.Adaptor

Generic adaptor.

genericAdaptor :: ProductProfunctor p =>
                  Adaptor p (Foo (p a a') (p b b') (p c c'))
genericAdaptor :: ProductProfunctor p =>
                  Foo (p a a') (p b b') (p c c') -> p (Foo a b c) (Foo a' b' c')

A type synonym to shorten the signature of an adaptor.

Adaptor p (Foo (p a a') (p b b') (p c c'))
~
Foo (p a a') (p b b') (p c c') -> p (Foo a b c) (Foo a' b' c')

A constraint synonym on generic types for which an adaptor can be defined generically.

A flag denoting a type-level field accessor.

A type like

T = Foo (p a a') (p b b') (p c c')

can be unzipped to

Unzip 'Fst T = Foo a  b  c
Unzip 'Snd T = Foo a' b' c'

This defines the type family Unzip with versions of GHC older than 8.0.1. For 8.0.1 and newer versions, Unzip is an independent type family and Unzippable is just an empty class for backwards compatibility.

A hack to enable kind-polymorphic recursion.

A type p a b can be seen as a type-level pair '(a, b).

Unzips the types of fields of a record.

            T = (M1 _ _ (K1 _ (p c1 c2))) :*: (M1 _ _ (K1 _ (p d1 d2)))
GUnzip 'Fst T = (M1 _ _ (K1 _    c1    )) :*: (M1 _ _ (K1 _    d1    ))
GUnzip 'Snd T = (M1 _ _ (K1 _       c2 )) :*: (M1 _ _ (K1 _       d2 ))

Adaptors over generic representations of types.