Trait

cats

CompositeFoldable

Related Doc: package cats

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trait CompositeFoldable[F[_], G[_]] extends Foldable[[α]F[G[α]]]

Methods that apply to 2 nested Foldable instances

Linear Supertypes
Foldable[[α]F[G[α]]], Serializable, Serializable, AnyRef, Any
Known Subclasses
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Inherited
  1. CompositeFoldable
  2. Foldable
  3. Serializable
  4. Serializable
  5. AnyRef
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Abstract Value Members

  1. implicit abstract def F: Foldable[F]

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  2. implicit abstract def G: Foldable[G]

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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. final def asInstanceOf[T0]: T0

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    Definition Classes
    Any
  5. def clone(): AnyRef

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  6. def compose[G[_]](implicit ev: Foldable[G]): Foldable[[α]F[G[G[α]]]]

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    Compose this Foldable[F] with a Foldable[G] to create a Foldable[F[G]] instance.

    Compose this Foldable[F] with a Foldable[G] to create a Foldable[F[G]] instance.

    Definition Classes
    Foldable
  7. def dropWhile_[A](fa: F[G[A]])(p: (A) ⇒ Boolean): List[A]

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    Convert F[A] to a List[A], dropping all initial elements which match p.

    Convert F[A] to a List[A], dropping all initial elements which match p.

    Definition Classes
    Foldable
  8. final def eq(arg0: AnyRef): Boolean

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

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    Definition Classes
    AnyRef → Any
  10. def exists[A](fa: F[G[A]])(p: (A) ⇒ Boolean): Boolean

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    Check whether at least one element satisfies the predicate.

    Check whether at least one element satisfies the predicate.

    If there are no elements, the result is false.

    Definition Classes
    Foldable
  11. def filter_[A](fa: F[G[A]])(p: (A) ⇒ Boolean): List[A]

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    Convert F[A] to a List[A], only including elements which match p.

    Convert F[A] to a List[A], only including elements which match p.

    Definition Classes
    Foldable
  12. def finalize(): Unit

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  13. def find[A](fa: F[G[A]])(f: (A) ⇒ Boolean): Option[A]

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    Find the first element matching the predicate, if one exists.

    Find the first element matching the predicate, if one exists.

    Definition Classes
    Foldable
  14. def fold[A](fa: F[G[A]])(implicit A: Monoid[A]): A

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    Fold implemented using the given Monoid[A] instance.

    Fold implemented using the given Monoid[A] instance.

    Definition Classes
    Foldable
  15. def foldK[G[_], A](fga: F[G[G[A]]])(implicit G: MonoidK[G]): G[A]

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    Fold implemented using the given MonoidK[G] instance.

    Fold implemented using the given MonoidK[G] instance.

    This method is identical to fold, except that we use the universal monoid (MonoidK[G]) to get a Monoid[G[A]] instance.

    For example:

    val F = Foldable[List]
    F.foldK(List(1 :: 2 :: Nil, 3 :: 4 :: 5 :: Nil))
    // List(1, 2, 3, 4, 5)
    Definition Classes
    Foldable
  16. def foldLeft[A, B](fga: F[G[A]], b: B)(f: (B, A) ⇒ B): B

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    Left assocative fold on F[G[A]] using 'f'

    Left assocative fold on F[G[A]] using 'f'

    Definition Classes
    CompositeFoldableFoldable
  17. def foldMap[A, B](fa: F[G[A]])(f: (A) ⇒ B)(implicit B: Monoid[B]): B

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    Fold implemented by mapping A values into B and then combining them using the given Monoid[B] instance.

    Fold implemented by mapping A values into B and then combining them using the given Monoid[B] instance.

    Definition Classes
    Foldable
  18. def foldRight[A, B](fga: F[G[A]], lb: Eval[B])(f: (A, Eval[B]) ⇒ Eval[B]): Eval[B]

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    Right associative lazy fold on F using the folding function 'f'.

    Right associative lazy fold on F using the folding function 'f'.

    Definition Classes
    CompositeFoldableFoldable
  19. def forall[A](fa: F[G[A]])(p: (A) ⇒ Boolean): Boolean

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    Check whether all elements satisfy the predicate.

    Check whether all elements satisfy the predicate.

    If there are no elements, the result is true.

    Definition Classes
    Foldable
  20. final def getClass(): Class[_]

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

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    Definition Classes
    AnyRef → Any
  22. def isEmpty[A](fa: F[G[A]]): Boolean

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    Returns true if there are no elements.

    Returns true if there are no elements. Otherwise false.

    Definition Classes
    Foldable
  23. final def isInstanceOf[T0]: Boolean

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

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    Definition Classes
    AnyRef
  25. def nonEmpty[A](fa: F[G[A]]): Boolean

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    Definition Classes
    Foldable
  26. final def notify(): Unit

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

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    Definition Classes
    AnyRef
  28. def reduceLeftToOption[A, B](fa: F[G[A]])(f: (A) ⇒ B)(g: (B, A) ⇒ B): Option[B]

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    Definition Classes
    Foldable
  29. def reduceRightToOption[A, B](fa: F[G[A]])(f: (A) ⇒ B)(g: (A, Eval[B]) ⇒ Eval[B]): Eval[Option[B]]

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    Definition Classes
    Foldable
  30. def sequence_[G[_], A, B](fga: F[G[G[A]]])(implicit arg0: Applicative[G]): G[Unit]

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    Sequence F[G[A]] using Applicative[G].

    Sequence F[G[A]] using Applicative[G].

    This is similar to traverse_ except it operates on F[G[A]] values, so no additional functions are needed.

    For example:

    val F = Foldable[List]
    F.sequence_(List(Option(1), Option(2), Option(3))) // Some(())
    F.sequence_(List(Option(1), None, Option(3)))      // None
    Definition Classes
    Foldable
  31. final def synchronized[T0](arg0: ⇒ T0): T0

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    Definition Classes
    AnyRef
  32. def toList[A](fa: F[G[A]]): List[A]

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    Convert F[A] to a List[A].

    Convert F[A] to a List[A].

    Definition Classes
    Foldable
  33. def toString(): String

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    Definition Classes
    AnyRef → Any
  34. def traverse_[G[_], A, B](fa: F[G[A]])(f: (A) ⇒ G[B])(implicit G: Applicative[G]): G[Unit]

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    Traverse F[A] using Applicative[G].

    Traverse F[A] using Applicative[G].

    A values will be mapped into G[B] and combined using Applicative#map2.

    For example:

    def parseInt(s: String): Option[Int] = ...
    val F = Foldable[List]
    F.traverse_(List("333", "444"))(parseInt) // Some(())
    F.traverse_(List("333", "zzz"))(parseInt) // None

    This method is primarily useful when G[_] represents an action or effect, and the specific A aspect of G[A] is not otherwise needed.

    Definition Classes
    Foldable
  35. final def wait(): Unit

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

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

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from Foldable[[α]F[G[α]]]

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped