Packages

t

scalaz.Foldable

FromFoldr

trait FromFoldr[F[_]] extends Foldable[F]

Template trait to define Foldable in terms of foldr

Example:

new Foldable[Option] with Foldable.FromFoldr[Option] {
  def foldr[A, B](fa: Option[A], z: B)(f: (A) => (=> B) => B) = fa match {
    case Some(a) => f(a)(z)
    case None => z
  }
}
Source
Foldable.scala
Linear Supertypes
Foldable[F], FoldableParent[F], AnyRef, Any
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Inherited
  1. FromFoldr
  2. Foldable
  3. FoldableParent
  4. AnyRef
  5. Any
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Visibility
  1. Public
  2. All

Type Members

  1. trait FoldableLaw extends AnyRef
    Definition Classes
    Foldable

Abstract Value Members

  1. abstract 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
    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[[α, β]F[G[α, β]]]

    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[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  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 distinct[A](fa: F[A])(implicit A: Order[A]): IList[A]

    O(n log n) complexity

    O(n log n) complexity

    Definition Classes
    Foldable
  15. def distinctBy[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Equal[B]): IList[A]
    Definition Classes
    FoldableParent
  16. def distinctE[A](fa: F[A])(implicit A: Equal[A]): IList[A]

    O(n2) complexity

    O(n2) complexity

    Definition Classes
    Foldable
  17. 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
  18. def empty[A](fa: F[A]): Boolean

    Deforested alias for toStream(fa).isEmpty.

    Deforested alias for toStream(fa).isEmpty.

    Definition Classes
    Foldable
  19. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  20. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  21. def extrema[A](fa: F[A])(implicit arg0: Order[A]): Option[(A, A)]

    The smallest and largest elements of fa or None if fa is empty

    The smallest and largest elements of fa or None if fa is empty

    Definition Classes
    FoldableParent
  22. def extremaBy[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[(A, A)]

    The elements (amin, amax) of fa which yield the smallest and largest values of f(a), respectively, or None if fa is empty

    The elements (amin, amax) of fa which yield the smallest and largest values of f(a), respectively, or None if fa is empty

    Definition Classes
    FoldableParent
  23. def extremaOf[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): Option[(B, B)]

    The smallest and largest values of f(a) for each element a of fa , or None if fa is empty

    The smallest and largest values of f(a) for each element a of fa , or None if fa is empty

    Definition Classes
    FoldableParent
  24. def filterLength[A](fa: F[A])(f: (A) ⇒ Boolean): Int
    Definition Classes
    FoldableParent
  25. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  26. def findLeft[A](fa: F[A])(f: (A) ⇒ Boolean): Option[A]
    Definition Classes
    Foldable
  27. final def findMapM[M[_], A, B](fa: F[A])(f: (A) ⇒ M[Option[B]])(implicit arg0: Monad[M]): M[Option[B]]

    map elements in a Foldable with a monadic function and return the first element that is mapped successfully

    map elements in a Foldable with a monadic function and return the first element that is mapped successfully

    Definition Classes
    Foldable
  28. def findRight[A](fa: F[A])(f: (A) ⇒ Boolean): Option[A]
    Definition Classes
    Foldable
  29. 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
  30. def fold1Opt[A](fa: F[A])(implicit arg0: Semigroup[A]): Option[A]

    Like fold but returning None if the foldable is empty and Some otherwise

    Like fold but returning None if the foldable is empty and Some otherwise

    Definition Classes
    FoldableParent
  31. 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
  32. def foldLeft1Opt[A](fa: F[A])(f: (A, A) ⇒ A): Option[A]
    Definition Classes
    Foldable
  33. 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
  34. 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
    FromFoldr → Foldable
  35. 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
  36. def foldMapLeft1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (B, A) ⇒ B): Option[B]
    Definition Classes
    Foldable
  37. 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
  38. def foldMapRight1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (A, ⇒ B) ⇒ B): Option[B]
    Definition Classes
    Foldable
  39. def foldRight1Opt[A](fa: F[A])(f: (A, ⇒ A) ⇒ A): Option[A]
    Definition Classes
    Foldable
  40. 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
  41. def foldableLaw: FoldableLaw
    Definition Classes
    Foldable
  42. val foldableSyntax: FoldableSyntax[F]
    Definition Classes
    Foldable
  43. 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
  44. def foldl1Opt[A](fa: F[A])(f: (A) ⇒ (A) ⇒ A): Option[A]
    Definition Classes
    Foldable
  45. 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
  46. 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
  47. def foldr1Opt[A](fa: F[A])(f: (A) ⇒ (⇒ A) ⇒ A): Option[A]
    Definition Classes
    Foldable
  48. 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
  49. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  50. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  51. 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
  52. 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
  53. 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
  54. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  55. def length[A](fa: F[A]): Int

    Deforested alias for toStream(fa).size.

    Deforested alias for toStream(fa).size.

    Definition Classes
    Foldable
  56. def longDigits[A](fa: F[A])(implicit d: <:<[A, Digit]): Long
    Definition Classes
    Foldable
  57. 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
  58. 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
  59. 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
  60. 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
  61. 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
  62. 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
  63. def msuml[G[_], A](fa: F[G[A]])(implicit G: PlusEmpty[G]): G[A]
    Definition Classes
    Foldable
  64. def msumlU[GA](fa: F[GA])(implicit G: Unapply[PlusEmpty, GA]): M[A]
    Definition Classes
    FoldableParent
  65. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  66. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  67. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  68. 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
  69. 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
  70. 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
  71. 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
  72. def sequenceS_[S, A](fga: F[State[S, A]]): State[S, Unit]

    sequence_ specialized to State *

    sequence_ specialized to State *

    Definition Classes
    Foldable
  73. 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
  74. def splitBy[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Equal[B]): IList[(B, NonEmptyList[A])]

    Splits the elements into groups that produce the same result by a function f.

    Splits the elements into groups that produce the same result by a function f.

    Definition Classes
    FoldableParent
  75. def splitByRelation[A](fa: F[A])(r: (A, A) ⇒ Boolean): IList[NonEmptyList[A]]

    Splits into groups of elements that are transitively dependant by a relation r.

    Splits into groups of elements that are transitively dependant by a relation r.

    Definition Classes
    FoldableParent
  76. 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
  77. def suml[A](fa: F[A])(implicit A: Monoid[A]): A
    Definition Classes
    Foldable
  78. def suml1Opt[A](fa: F[A])(implicit A: Semigroup[A]): Option[A]
    Definition Classes
    Foldable
  79. def sumr[A](fa: F[A])(implicit A: Monoid[A]): A
    Definition Classes
    Foldable
  80. def sumr1Opt[A](fa: F[A])(implicit A: Semigroup[A]): Option[A]
    Definition Classes
    Foldable
  81. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  82. def toEphemeralStream[A](fa: F[A]): EphemeralStream[A]
    Definition Classes
    Foldable
  83. def toIList[A](fa: F[A]): IList[A]
    Definition Classes
    Foldable
  84. def toList[A](fa: F[A]): List[A]
    Definition Classes
    Foldable
  85. def toSet[A](fa: F[A]): Set[A]
    Definition Classes
    Foldable
  86. def toStream[A](fa: F[A]): Stream[A]
    Definition Classes
    Foldable
  87. def toString(): String
    Definition Classes
    AnyRef → Any
  88. def toVector[A](fa: F[A]): Vector[A]
    Definition Classes
    Foldable
  89. 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
  90. 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
  91. 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
  92. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  93. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  94. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()

Deprecated Value Members

  1. def to[A, G[_]](fa: F[A])(implicit c: CanBuildFrom[Nothing, A, G[A]]): G[A]

    Definition Classes
    Foldable
    Annotations
    @deprecated
    Deprecated

    (Since version 7.2.22) removed in scalaz 7.3

    Exceptions thrown

    NoSuchMethodException if Scala 2.13 or later

Inherited from Foldable[F]

Inherited from FoldableParent[F]

Inherited from AnyRef

Inherited from Any

Ungrouped