Coyoneda

 
public final class Coyoneda<F, A> : CoyonedaOf<F, A>

This type implements the dual version of the Yoneda lemma, stating that F is naturally isomorphic to Coyoneda.

Coyoneda can be viewed as the arguments that we need for the map function.

  • Initializes a Coyoneda value.

    Declaration

    Swift

    public convenience init<P>(pivot: Kind<F, P>, f: @escaping (P) -> A)

    Parameters

    pivot

    A value in the context of F.
    function

    A function transforming the type parameter into a new type.

  • Safe downcast.

    Declaration

    Swift

    public static func fix(_ fa: CoyonedaOf<F, A>) -> Coyoneda<F, A>

    Parameters

    fa

    Value in higher-kind form.

    Return Value

    Value cast to Coyoneda.

  • Lifts a value in the F context into a Coyoneda.

    Declaration

    Swift

    public static func liftCoyoneda(_ fa: Kind<F, A>) -> Coyoneda<F, A>

    Parameters

    fa

    Value in the F context.

    Return Value

    A Coyoneda value.

  • Reduces the Coyoneda value into the functorial context.

    Declaration

    Swift

    public func lower() -> Kind<F, A>

    Return Value

    A value in the functorial context.