Packages

trait Bitraverse[F[_, _]] extends Bifoldable[F] with Bifunctor[F]

A type class abstracting over types that give rise to two independent cats.Traverses.

Self Type
Bitraverse[F]
Annotations
@implicitNotFound( ... ) @typeclass( ... , ... )
Source
Bitraverse.scala
Linear Supertypes
Bifunctor[F], Bifoldable[F], Serializable, Serializable, AnyRef, Any
Known Subclasses
BinestedBitraverse
Ordering
  1. Alphabetic
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Inherited
  1. Bitraverse
  2. Bifunctor
  3. Bifoldable
  4. Serializable
  5. Serializable
  6. AnyRef
  7. Any
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Visibility
  1. Public
  2. All

Abstract Value Members

  1. abstract def bifoldLeft[A, B, C](fab: F[A, B], c: C)(f: (C, A) ⇒ C, g: (C, B) ⇒ C): C

    Collapse the structure with a left-associative function

    Collapse the structure with a left-associative function

    Example:

    scala> import cats.Bifoldable
scala> val fab = (List(1), 2)

Folding by addition to zero:
scala> Bifoldable[Tuple2].bifoldLeft(fab, Option(0))((c, a) => c.map(_ + a.head), (c, b) => c.map(_ + b))
res0: Option[Int] = Some(3)

    With syntax extensions, bifoldLeft can be used like:

    scala> import cats.implicits._
scala> fab.bifoldLeft(Option(0))((c, a) => c.map(_ + a.head), (c, b) => c.map(_ + b))
res1: Option[Int] = Some(3)
    Definition Classes
    Bifoldable
  2. abstract def bifoldRight[A, B, C](fab: F[A, B], c: Eval[C])(f: (A, Eval[C]) ⇒ Eval[C], g: (B, Eval[C]) ⇒ Eval[C]): Eval[C]

    Collapse the structure with a right-associative function Right associative lazy bifold on F using the folding function 'f' and 'g'.

    Collapse the structure with a right-associative function Right associative lazy bifold on F using the folding function 'f' and 'g'.

    This method evaluates c lazily (in some cases it will not be needed), and returns a lazy value. We are using (_, Eval[C]) => Eval[C] to support laziness in a stack-safe way. Chained computation should be performed via .map and .flatMap.

    For more detailed information about how this method works see the documentation for Eval[_].

    Example:

    scala> import cats.Bifoldable
scala> val fab = (List(1), 2)

Folding by addition to zero:
scala> val bifolded1 = Bifoldable[Tuple2].bifoldRight(fab, Eval.now(0))((a, c) => c.map(_ + a.head), (b, c) => c.map(_ + b))
scala> bifolded1.value
res0: Int = 3

    With syntax extensions, bifoldRight can be used like:

    scala> import cats.implicits._
scala> val bifolded2 = fab.bifoldRight(Eval.now(0))((a, c) => c.map(_ + a.head), (b, c) => c.map(_ + b))
scala> bifolded2.value
res1: Int = 3
    Definition Classes
    Bifoldable
  3. abstract def bitraverse[G[_], A, B, C, D](fab: F[A, B])(f: (A) ⇒ G[C], g: (B) ⇒ G[D])(implicit arg0: Applicative[G]): G[F[C, D]]

    Traverse each side of the structure with the given functions.

    Traverse each side of the structure with the given functions.

    Example:

    scala> import cats.implicits._

scala> def parseInt(s: String): Option[Int] = Either.catchOnly[NumberFormatException](s.toInt).toOption

scala> ("1", "2").bitraverse(parseInt, parseInt)
res0: Option[(Int, Int)] = Some((1,2))

scala> ("1", "two").bitraverse(parseInt, parseInt)
res1: Option[(Int, Int)] = None

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def bifold[A, B](fab: F[A, B])(implicit A: Monoid[A], B: Monoid[B]): (A, B)
    Definition Classes
    Bifoldable
  6. def bifoldMap[A, B, C](fab: F[A, B])(f: (A) ⇒ C, g: (B) ⇒ C)(implicit C: Monoid[C]): C

    Collapse the structure by mapping each element to an element of a type that has a cats.Monoid

    Collapse the structure by mapping each element to an element of a type that has a cats.Monoid

    Definition Classes
    Bifoldable
  7. def bimap[A, B, C, D](fab: F[A, B])(f: (A) ⇒ C, g: (B) ⇒ D): F[C, D]

    The quintessential method of the Bifunctor trait, it applies a function to each "side" of the bifunctor.

    The quintessential method of the Bifunctor trait, it applies a function to each "side" of the bifunctor.

    Example:

    scala> import cats.implicits._

scala> val x: (List[String], Int) = (List("foo", "bar"), 3)
scala> x.bimap(_.headOption, _.toLong + 1)
res0: (Option[String], Long) = (Some(foo),4)
    Definition Classes
    Bitraverse → Bifunctor
  8. def bisequence[G[_], A, B](fab: F[G[A], G[B]])(implicit arg0: Applicative[G]): G[F[A, B]]

    Invert the structure from F[G[A], G[B]] to G[F[A, B]].

    Invert the structure from F[G[A], G[B]] to G[F[A, B]].

    Example:

    scala> import cats.implicits._

scala> val rightSome: Either[Option[String], Option[Int]] = Either.right(Some(3))
scala> rightSome.bisequence
res0: Option[Either[String, Int]] = Some(Right(3))

scala> val rightNone: Either[Option[String], Option[Int]] = Either.right(None)
scala> rightNone.bisequence
res1: Option[Either[String, Int]] = None

scala> val leftSome: Either[Option[String], Option[Int]] = Either.left(Some("foo"))
scala> leftSome.bisequence
res2: Option[Either[String, Int]] = Some(Left(foo))

scala> val leftNone: Either[Option[String], Option[Int]] = Either.left(None)
scala> leftNone.bisequence
res3: Option[Either[String, Int]] = None
  9. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native() @IntrinsicCandidate()
  10. def compose[G[_, _]](implicit ev: Bitraverse[G]): Bitraverse[[α, β]F[G[α, β], G[α, β]]]

    If F and G are both cats.Bitraverse then so is their composition F[G[_, _], G[_, _]]

  11. def compose[G[_, _]](implicit G0: Bifunctor[G]): Bifunctor[[α, β]F[G[α, β], G[α, β]]]

    The composition of two Bifunctors is itself a Bifunctor

    The composition of two Bifunctors is itself a Bifunctor

    Definition Classes
    Bifunctor
  12. def compose[G[_, _]](implicit ev: Bifoldable[G]): Bifoldable[[α, β]F[G[α, β], G[α, β]]]
    Definition Classes
    Bifoldable
  13. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  14. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  15. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @IntrinsicCandidate()
  16. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @IntrinsicCandidate()
  17. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  18. def leftFunctor[X]: Functor[[α$1$]F[α$1$, X]]
    Definition Classes
    Bifunctor
  19. def leftMap[A, B, C](fab: F[A, B])(f: (A) ⇒ C): F[C, B]

    apply a function to the "left" functor

    apply a function to the "left" functor

    Definition Classes
    Bifunctor
  20. def leftSequence[G[_], A, B](fgab: F[G[A], B])(implicit G: Applicative[G]): G[F[A, B]]

    Sequence the left side of the structure.

    Sequence the left side of the structure. For the right side, use the standard sequence from cats.Traverse.

    Example:

    scala> import cats.implicits._

scala> val optionalErrorRight: Either[Option[String], Int] = Either.right(123)
scala> optionalErrorRight.leftSequence
res1: Option[Either[String, Int]] = Some(Right(123))

scala> val optionalErrorLeftSome: Either[Option[String], Int] = Either.left(Some("something went wrong"))
scala> optionalErrorLeftSome.leftSequence
res2: Option[Either[String, Int]] = Some(Left(something went wrong))

scala> val optionalErrorLeftNone: Either[Option[String], Int] = Either.left(None)
scala> optionalErrorLeftNone.leftSequence
res3: Option[Either[String,Int]] = None
    Annotations
    @noop()
  21. def leftTraverse[G[_], A, B, C](fab: F[A, B])(f: (A) ⇒ G[C])(implicit G: Applicative[G]): G[F[C, B]]

    Traverse over the left side of the structure.

    Traverse over the left side of the structure. For the right side, use the standard traverse from cats.Traverse.

    Example:

    scala> import cats.implicits._

scala> val intAndString: (Int, String) = (7, "test")

scala> Bitraverse[Tuple2].leftTraverse(intAndString)(i => Option(i).filter(_ > 5))
res1: Option[(Int, String)] = Some((7,test))

scala> Bitraverse[Tuple2].leftTraverse(intAndString)(i => Option(i).filter(_ < 5))
res2: Option[(Int, String)] = None
    Annotations
    @noop()
  22. def leftWiden[A, B, AA >: A](fab: F[A, B]): F[AA, B]

    Widens A into a supertype AA.

    Widens A into a supertype AA. Example:

    scala> import cats.implicits._
scala> sealed trait Foo
scala> case object Bar extends Foo
scala> val x1: Either[Bar.type, Int] = Either.left(Bar)
scala> val x2: Either[Foo, Int] = x1.leftWiden
    Definition Classes
    Bifunctor
  23. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  24. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  25. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  26. def rightFunctor[X]: Functor[[β$0$]F[X, β$0$]]
    Definition Classes
    Bifunctor
  27. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  28. def toString(): String
    Definition Classes
    AnyRef → Any
  29. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  30. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  31. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] ) @Deprecated
    Deprecated

Inherited from Bifunctor[F]

Inherited from Bifoldable[F]

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped