Trait/Object

cats.arrow

Arrow

Related Docs: object Arrow | package arrow

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trait Arrow[F[_, _]] extends Category[F] with Strong[F] with Serializable

Must obey the laws defined in cats.laws.ArrowLaws.

Self Type
Arrow[F]
Linear Supertypes
Strong[F], Profunctor[F], Category[F], Compose[F], Serializable, Serializable, AnyRef, Any
Known Subclasses
Ordering
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  2. By Inheritance
Inherited
  1. Arrow
  2. Strong
  3. Profunctor
  4. Category
  5. Compose
  6. Serializable
  7. Serializable
  8. AnyRef
  9. Any
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Visibility
  1. Public
  2. All

Abstract Value Members

  1. abstract def compose[A, B, C](f: F[B, C], g: F[A, B]): F[A, C]

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    Definition Classes
    Compose
  2. abstract def first[A, B, C](fa: F[A, B]): F[(A, C), (B, C)]

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    Create a new F that takes two inputs, but only modifies the first input

    Create a new F that takes two inputs, but only modifies the first input

    Example:

    scala> import cats.implicits._
    scala> import cats.arrow.Strong
    scala> val f: Int => Int = _ * 2
    scala> val fab = Strong[Function1].first[Int,Int,Int](f)
    scala> fab((2,3))
    res0: (Int, Int) = (4,3)
    Definition Classes
    Strong
  3. abstract def lift[A, B](f: (A) ⇒ B): F[A, B]

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    Lift a function into the context of an Arrow.

    Lift a function into the context of an Arrow.

    In the reference articles "Arrows are Promiscuous...", and in the corresponding Haskell library Control.Arrow, this function is called arr.

Concrete Value Members

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

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

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

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    Definition Classes
    AnyRef → Any
  4. def algebra[A]: Monoid[F[A, A]]

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    Definition Classes
    CategoryCompose
  5. def algebraK: MonoidK[[α]F[α, α]]

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    Definition Classes
    CategoryCompose
  6. def andThen[A, B, C](f: F[A, B], g: F[B, C]): F[A, C]

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    Definition Classes
    Compose
  7. final def asInstanceOf[T0]: T0

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    Definition Classes
    Any
  8. def clone(): AnyRef

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  9. def dimap[A, B, C, D](fab: F[A, B])(f: (C) ⇒ A)(g: (B) ⇒ D): F[C, D]

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    Contramap on the first type parameter and map on the second type parameter

    Contramap on the first type parameter and map on the second type parameter

    Example:

    scala> import cats.implicits._
    scala> import cats.arrow.Profunctor
    scala> val fab: Double => Double = x => x + 0.3
    scala> val f: Int => Double = x => x.toDouble / 2
    scala> val g: Double => Double = x => x * 3
    scala> val h = Profunctor[Function1].dimap(fab)(f)(g)
    scala> h(3)
    res0: Double = 5.4
    Definition Classes
    ArrowProfunctor
  10. final def eq(arg0: AnyRef): Boolean

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

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

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

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

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    Definition Classes
    AnyRef → Any
  15. def id[A]: F[A, A]

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    Definition Classes
    ArrowCategory
  16. final def isInstanceOf[T0]: Boolean

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    Definition Classes
    Any
  17. def lmap[A, B, C](fab: F[A, B])(f: (C) ⇒ A): F[C, B]

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    contramap on the first type parameter

    contramap on the first type parameter

    Definition Classes
    Profunctor
  18. def merge[A, B, C](f: F[A, B], g: F[A, C]): F[A, (B, C)]

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    Create a new computation F that merge outputs of f and g both having the same input

    Create a new computation F that merge outputs of f and g both having the same input

    Example:

    scala> import cats.implicits._
    scala> val addEmpty: Int => Int = _ + 0
    scala> val multiplyEmpty: Int => Double= _ * 1d
    scala> val f: Int => (Int, Double) = addEmpty &&& multiplyEmpty
    scala> f(1)
    res0: (Int, Double) = (1,1.0)

    Note that the arrow laws do not guarantee the non-interference between the _effects_ of f and g in the context of F. This means that f &&& g may not be equivalent to g &&& f.

    Annotations
    @op( "&&&" , true )
  19. final def ne(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef
  20. final def notify(): Unit

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    Definition Classes
    AnyRef
  21. final def notifyAll(): Unit

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    Definition Classes
    AnyRef
  22. def rmap[A, B, C](fab: F[A, B])(f: (B) ⇒ C): F[A, C]

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    map on the second type parameter

    map on the second type parameter

    Definition Classes
    Profunctor
  23. def second[A, B, C](fa: F[A, B]): F[(C, A), (C, B)]

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    Create a new F that takes two inputs, but only modifies the second input

    Create a new F that takes two inputs, but only modifies the second input

    Example:

    scala> import cats.implicits._
    scala> import cats.arrow.Strong
    scala> val f: Int => Int = _ * 2
    scala> val fab = Strong[Function1].second[Int,Int,Int](f)
    scala> fab((2,3))
    res0: (Int, Int) = (2,6)
    Definition Classes
    ArrowStrong
  24. def split[A, B, C, D](f: F[A, B], g: F[C, D]): F[(A, C), (B, D)]

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    Create a new computation F that splits its input between f and g and combines the output of each.

    Create a new computation F that splits its input between f and g and combines the output of each.

    Example:

    scala> import cats.implicits._
    scala> import cats.arrow.Arrow
    scala> val toLong: Int => Long = _.toLong
    scala> val toDouble: Float => Double = _.toDouble
    scala> val f: ((Int, Float)) => (Long, Double) = Arrow[Function1].split(toLong, toDouble)
    scala> f((3, 4.0f))
    res0: (Long, Double) = (3,4.0)

    Note that the arrow laws do not guarantee the non-interference between the _effects_ of f and g in the context of F. This means that f *** g may not be equivalent to g *** f.

    Annotations
    @op( "***" , true )
  25. final def synchronized[T0](arg0: ⇒ T0): T0

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    Definition Classes
    AnyRef
  26. def toString(): String

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    Definition Classes
    AnyRef → Any
  27. final def wait(): Unit

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

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

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from Strong[F]

Inherited from Profunctor[F]

Inherited from Category[F]

Inherited from Compose[F]

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped