scalaz.Foldable

FromFoldMap

Related Doc: package Foldable

trait FromFoldMap[F[_]] extends Foldable[F]

Template trait to define Foldable in terms of foldMap.

Example:

new Foldable[Option] with Foldable.FromFoldMap[Option] {
  def foldMap[A, B](fa: Option[A])(f: A => B)(implicit F: Monoid[B]) = fa match {
    case Some(a) => f(a)
    case None    => F.zero
  }
}
Source
Foldable.scala
Linear Supertypes
Foldable[F], AnyRef, Any
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  1. FromFoldMap
  2. Foldable
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Type Members

  1. trait FoldableLaw extends AnyRef

    Definition Classes
    Foldable

Abstract Value Members

  1. abstract def foldMap[A, B](fa: F[A])(f: (A) ⇒ B)(implicit F: Monoid[B]): B

    Map each element of the structure to a scalaz.Monoid, and combine the results.

    Map each element of the structure to a scalaz.Monoid, and combine the results.

    Definition Classes
    Foldable

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. def all[A](fa: F[A])(p: (A) ⇒ Boolean): Boolean

    Whether all As in fa yield true from p.

    Whether all As in fa yield true from p.

    Definition Classes
    Foldable
  5. def allM[G[_], A](fa: F[A])(p: (A) ⇒ G[Boolean])(implicit G: Monad[G]): G[Boolean]

    all with monadic traversal.

    all with monadic traversal.

    Definition Classes
    Foldable
  6. def any[A](fa: F[A])(p: (A) ⇒ Boolean): Boolean

    Whether any As in fa yield true from p.

    Whether any As in fa yield true from p.

    Definition Classes
    Foldable
  7. def anyM[G[_], A](fa: F[A])(p: (A) ⇒ G[Boolean])(implicit G: Monad[G]): G[Boolean]

    any with monadic traversal.

    any with monadic traversal.

    Definition Classes
    Foldable
  8. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  9. def bicompose[G[_, _]](implicit arg0: Bifoldable[G]): Bifoldable[[a, b]F[G[a, b]]]

    The composition of Foldable F and Bifoldable G, [x, y]F[G[x, y]], is a Bifoldable

    The composition of Foldable F and Bifoldable G, [x, y]F[G[x, y]], is a Bifoldable

    Definition Classes
    Foldable
  10. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  11. def collapse[X[_], A](x: F[A])(implicit A: ApplicativePlus[X]): X[A]

    Definition Classes
    Foldable
  12. def compose[G[_]](implicit G0: Foldable[G]): Foldable[[α]F[G[α]]]

    The composition of Foldables F and G, [x]F[G[x]], is a Foldable

    The composition of Foldables F and G, [x]F[G[x]], is a Foldable

    Definition Classes
    Foldable
  13. final def count[A](fa: F[A]): Int

    Alias for length.

    Alias for length.

    Definition Classes
    Foldable
  14. def element[A](fa: F[A], a: A)(implicit arg0: Equal[A]): Boolean

    Whether a is an element of fa.

    Whether a is an element of fa.

    Definition Classes
    Foldable
  15. def empty[A](fa: F[A]): Boolean

    Deforested alias for toStream(fa).isEmpty.

    Deforested alias for toStream(fa).isEmpty.

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

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

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

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  19. def fold[M](t: F[M])(implicit arg0: Monoid[M]): M

    Combine the elements of a structure using a monoid.

    Combine the elements of a structure using a monoid.

    Definition Classes
    Foldable
  20. def foldLeft[A, B](fa: F[A], z: B)(f: (B, A) ⇒ B): B

    Left-associative fold of a structure.

    Left-associative fold of a structure.

    Definition Classes
    Foldable
  21. def foldLeft1Opt[A](fa: F[A])(f: (A, A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  22. def foldLeftM[G[_], A, B](fa: F[A], z: B)(f: (B, A) ⇒ G[B])(implicit M: Monad[G]): G[B]

    Left-associative, monadic fold of a structure.

    Left-associative, monadic fold of a structure.

    Definition Classes
    Foldable
  23. def foldMap1Opt[A, B](fa: F[A])(f: (A) ⇒ B)(implicit F: Semigroup[B]): Option[B]

    As foldMap but returning None if the foldable is empty and Some otherwise

    As foldMap but returning None if the foldable is empty and Some otherwise

    Definition Classes
    Foldable
  24. def foldMapLeft1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (B, A) ⇒ B): Option[B]

    Definition Classes
    Foldable
  25. def foldMapM[G[_], A, B](fa: F[A])(f: (A) ⇒ G[B])(implicit B: Monoid[B], G: Monad[G]): G[B]

    Specialization of foldRightM when B has a Monoid.

    Specialization of foldRightM when B has a Monoid.

    Definition Classes
    Foldable
  26. def foldMapRight1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (A, ⇒ B) ⇒ B): Option[B]

    Definition Classes
    Foldable
  27. def foldRight[A, B](fa: F[A], z: ⇒ B)(f: (A, ⇒ B) ⇒ B): B

    Right-associative fold of a structure.

    Right-associative fold of a structure.

    Definition Classes
    FromFoldMapFoldable
  28. def foldRight1Opt[A](fa: F[A])(f: (A, ⇒ A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  29. def foldRightM[G[_], A, B](fa: F[A], z: ⇒ B)(f: (A, ⇒ B) ⇒ G[B])(implicit M: Monad[G]): G[B]

    Right-associative, monadic fold of a structure.

    Right-associative, monadic fold of a structure.

    Definition Classes
    Foldable
  30. def foldableLaw: FoldableLaw

    Definition Classes
    Foldable
  31. val foldableSyntax: FoldableSyntax[F]

    Definition Classes
    Foldable
  32. final def foldl[A, B](fa: F[A], z: B)(f: (B) ⇒ (A) ⇒ B): B

    Curried version of foldLeft

    Curried version of foldLeft

    Definition Classes
    Foldable
  33. def foldl1Opt[A](fa: F[A])(f: (A) ⇒ (A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  34. final def foldlM[G[_], A, B](fa: F[A], z: ⇒ B)(f: (B) ⇒ (A) ⇒ G[B])(implicit M: Monad[G]): G[B]

    Curried version of foldLeftM

    Curried version of foldLeftM

    Definition Classes
    Foldable
  35. final def foldr[A, B](fa: F[A], z: ⇒ B)(f: (A) ⇒ (⇒ B) ⇒ B): B

    Curried version of foldRight

    Curried version of foldRight

    Definition Classes
    Foldable
  36. def foldr1Opt[A](fa: F[A])(f: (A) ⇒ (⇒ A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  37. final def foldrM[G[_], A, B](fa: F[A], z: ⇒ B)(f: (A) ⇒ (⇒ B) ⇒ G[B])(implicit M: Monad[G]): G[B]

    Curried version of foldRightM

    Curried version of foldRightM

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

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

    Definition Classes
    AnyRef → Any
  40. def index[A](fa: F[A], i: Int): Option[A]

    returns

    the element at index i in a Some, or None if the given index falls outside of the range

    Definition Classes
    Foldable
  41. def indexOr[A](fa: F[A], default: ⇒ A, i: Int): A

    returns

    the element at index i, or default if the given index falls outside of the range

    Definition Classes
    Foldable
  42. def intercalate[A](fa: F[A], a: A)(implicit A: Monoid[A]): A

    Insert an A between every A, yielding the sum.

    Insert an A between every A, yielding the sum.

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

    Definition Classes
    Any
  44. def length[A](fa: F[A]): Int

    Deforested alias for toStream(fa).size.

    Deforested alias for toStream(fa).size.

    Definition Classes
    Foldable
  45. def longDigits[A](fa: F[A])(implicit d: <:<[A, Digit]): Long

    Definition Classes
    Foldable
  46. def maximum[A](fa: F[A])(implicit arg0: Order[A]): Option[A]

    The greatest element of fa, or None if fa is empty.

    The greatest element of fa, or None if fa is empty.

    Definition Classes
    Foldable
  47. def maximumBy[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[A]

    The element a of fa which yields the greatest value of f(a), or None if fa is empty.

    The element a of fa which yields the greatest value of f(a), or None if fa is empty.

    Definition Classes
    Foldable
  48. def maximumOf[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[B]

    The greatest value of f(a) for each element a of fa, or None if fa is empty.

    The greatest value of f(a) for each element a of fa, or None if fa is empty.

    Definition Classes
    Foldable
  49. def minimum[A](fa: F[A])(implicit arg0: Order[A]): Option[A]

    The smallest element of fa, or None if fa is empty.

    The smallest element of fa, or None if fa is empty.

    Definition Classes
    Foldable
  50. def minimumBy[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[A]

    The element a of fa which yields the smallest value of f(a), or None if fa is empty.

    The element a of fa which yields the smallest value of f(a), or None if fa is empty.

    Definition Classes
    Foldable
  51. def minimumOf[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[B]

    The smallest value of f(a) for each element a of fa, or None if fa is empty.

    The smallest value of f(a) for each element a of fa, or None if fa is empty.

    Definition Classes
    Foldable
  52. final def ne(arg0: AnyRef): Boolean

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

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

    Definition Classes
    AnyRef
  55. def product[G[_]](implicit G0: Foldable[G]): Foldable[[α](F[α], G[α])]

    The product of Foldables F and G, [x](F[x], G[x]]), is a Foldable

    The product of Foldables F and G, [x](F[x], G[x]]), is a Foldable

    Definition Classes
    Foldable
  56. def product0[G[_]](implicit G0: Foldable1[G]): Foldable1[[α](F[α], G[α])]

    The product of Foldable F and Foldable1 G, [x](F[x], G[x]]), is a Foldable1

    The product of Foldable F and Foldable1 G, [x](F[x], G[x]]), is a Foldable1

    Definition Classes
    Foldable
  57. def selectSplit[A](fa: F[A])(p: (A) ⇒ Boolean): List[NonEmptyList[A]]

    Selects groups of elements that satisfy p and discards others.

    Selects groups of elements that satisfy p and discards others.

    Definition Classes
    Foldable
  58. def sequenceF_[M[_], A](ffa: F[Free[M, A]]): Free[M, Unit]

    sequence_ for Free.

    sequence_ for Free. collapses into a single Free *

    Definition Classes
    Foldable
  59. def sequenceS_[S, A](fga: F[State[S, A]]): State[S, Unit]

    sequence_ specialized to State *

    sequence_ specialized to State *

    Definition Classes
    Foldable
  60. def sequence_[M[_], A](fa: F[M[A]])(implicit a: Applicative[M]): M[Unit]

    Strict sequencing in an applicative functor M that ignores the value in fa.

    Strict sequencing in an applicative functor M that ignores the value in fa.

    Definition Classes
    Foldable
  61. def splitWith[A](fa: F[A])(p: (A) ⇒ Boolean): List[NonEmptyList[A]]

    Splits the elements into groups that alternatively satisfy and don't satisfy the predicate p.

    Splits the elements into groups that alternatively satisfy and don't satisfy the predicate p.

    Definition Classes
    Foldable
  62. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  63. def to[A, G[_]](fa: F[A])(implicit c: CanBuildFrom[Nothing, A, G[A]]): G[A]

    Definition Classes
    Foldable
  64. def toEphemeralStream[A](fa: F[A]): EphemeralStream[A]

    Definition Classes
    Foldable
  65. def toIList[A](fa: F[A]): IList[A]

    Definition Classes
    Foldable
  66. def toIndexedSeq[A](fa: F[A]): IndexedSeq[A]

    Definition Classes
    Foldable
  67. def toList[A](fa: F[A]): List[A]

    Definition Classes
    Foldable
  68. def toSet[A](fa: F[A]): Set[A]

    Definition Classes
    Foldable
  69. def toStream[A](fa: F[A]): Stream[A]

    Definition Classes
    Foldable
  70. def toString(): String

    Definition Classes
    AnyRef → Any
  71. def traverseS_[S, A, B](fa: F[A])(f: (A) ⇒ State[S, B]): State[S, Unit]

    traverse_ specialized to State *

    traverse_ specialized to State *

    Definition Classes
    Foldable
  72. final def traverseU_[A, GB](fa: F[A])(f: (A) ⇒ GB)(implicit G: Unapply[Applicative, GB]): M[Unit]

    A version of traverse_ that infers the type constructor M.

    A version of traverse_ that infers the type constructor M.

    Definition Classes
    Foldable
  73. def traverse_[M[_], A, B](fa: F[A])(f: (A) ⇒ M[B])(implicit a: Applicative[M]): M[Unit]

    Strict traversal in an applicative functor M that ignores the result of f.

    Strict traversal in an applicative functor M that ignores the result of f.

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

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

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

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Deprecated Value Members

  1. def foldMapIdentity[A](fa: F[A])(implicit F: Monoid[A]): A

    Unbiased sum of monoidal values.

    Unbiased sum of monoidal values.

    Definition Classes
    Foldable
    Annotations
    @deprecated
    Deprecated

    (Since version 7.1) use fold, it has the exact same signature and implementation

Inherited from Foldable[F]

Inherited from AnyRef

Inherited from Any

Ungrouped