Class/Object

scalaz

ContravariantCoyoneda

Related Docs: object ContravariantCoyoneda | package scalaz

Permalink

sealed abstract class ContravariantCoyoneda[F[_], A] extends AnyRef

Decomposition of fi.contramap(k) into its components, as it is frequently convenient to apply k separately from sorting or whatever process with fi, even when B is unknown, which is very common.

This is isomorphic to F as long as F itself is a contravariant functor. The homomorphism from F[A] to ContravariantCoyoneda[F,A] exists even when F is not a contravariant functor.

See ContravariantCoyonedaUsage.scala in the scalaz source tree for an interesting usage demonstration.

As ContravariantCoyoneda(o)(identity).unlift = o, further factoring can occur as follows, for free:

ContravariantCoyoneda(o contramap g)(f).unlift =
  ContravariantCoyoneda(o)(g compose f).unlift
Source
ContravariantCoyoneda.scala
See also

https://hackage.haskell.org/package/kan-extensions-4.0.1/docs/Data-Functor-Contravariant-Coyoneda.html

Linear Supertypes
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. ContravariantCoyoneda
  2. AnyRef
  3. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Type Members

  1. abstract type I

    Permalink

    The pivot between fi and k, usually existential.

Abstract Value Members

  1. abstract val fi: F[I]

    Permalink

    The underlying value.

  2. abstract val k: (A) ⇒ I

    Permalink

    The transformer function, to be lifted into F by run.

Concrete Value Members

  1. final def !=(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0

    Permalink
    Definition Classes
    Any
  5. def clone(): AnyRef

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  6. final def contramap[B](f: (B) ⇒ A): Aux[F, B, I]

    Permalink

    Simple function composition.

    Simple function composition. Allows map fusion without touching the underlying F.

  7. final def eq(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  8. def equals(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  9. def finalize(): Unit

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  10. final def getClass(): Class[_]

    Permalink
    Definition Classes
    AnyRef → Any
  11. def hashCode(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  12. final def isInstanceOf[T0]: Boolean

    Permalink
    Definition Classes
    Any
  13. final def ne(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  14. final def notify(): Unit

    Permalink
    Definition Classes
    AnyRef
  15. final def notifyAll(): Unit

    Permalink
    Definition Classes
    AnyRef
  16. final def run(implicit F: Contravariant[F]): F[A]

    Permalink

    Converts to F[A] given that F is a contravariant.

  17. final def synchronized[T0](arg0: ⇒ T0): T0

    Permalink
    Definition Classes
    AnyRef
  18. def toString(): String

    Permalink
    Definition Classes
    AnyRef → Any
  19. final def trans[G[_]](f: ~>[F, G]): Aux[G, A, I]

    Permalink

    Natural transformation.

  20. final def unlift(implicit F: Contravariant[F]): F[A]

    Permalink

    Alias for run.

    Alias for run.

    Annotations
    @inline()
  21. final def wait(): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  22. final def wait(arg0: Long, arg1: Int): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  23. final def wait(arg0: Long): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped