scalaz

Traverse

trait Traverse[F[_]] extends Functor[F] with Foldable[F]

Idiomatic traversal of a structure, as described in The Essence of the Iterator Pattern.

Self Type
Traverse[F]
Source
Traverse.scala
See also

TraverseLaw

Linear Supertypes
Foldable[F], Functor[F], InvariantFunctor[F], AnyRef, Any
Known Subclasses
Ordering
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Inherited
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  1. Traverse
  2. Foldable
  3. Functor
  4. InvariantFunctor
  5. AnyRef
  6. Any
Visibility
  1. Public
  2. All

Type Members

  1. trait FoldableLaw extends AnyRef

  2. trait FunctorLaw extends InvariantFunctorLaw

  3. trait InvariantFunctorLaw extends AnyRef

  4. class Traversal[G[_]] extends AnyRef

  5. trait TraverseLaw extends FunctorLaw

Abstract Value Members

  1. abstract def traverseImpl[G[_], A, B](fa: F[A])(f: (A) ⇒ G[B])(implicit arg0: Applicative[G]): G[F[B]]

    Transform fa using f, collecting all the Gs with ap.

Concrete Value Members

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

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

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

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

    Definition Classes
    Any
  6. 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
  7. 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
  8. 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
  9. 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
  10. def apply[A, B](fa: F[A])(f: (A) ⇒ B): F[B]

    Alias for map.

    Alias for map.

    Definition Classes
    Functor
  11. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  12. def bicompose[G[_, _]](implicit arg0: Bitraverse[G]): Bitraverse[[α, β]F[G[α, β]]]

    The composition of Traverse F and Bitraverse G, [x, y]F[G[x, y]], is a Bitraverse

  13. 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
  14. def bicompose[G[_, _]](implicit arg0: Bifunctor[G]): Bifunctor[[α, β]F[G[α, β]]]

    The composition of Functor F and Bifunctor G, [x, y]F[G[x, y]], is a Bifunctor

    The composition of Functor F and Bifunctor G, [x, y]F[G[x, y]], is a Bifunctor

    Definition Classes
    Functor
  15. def clone(): AnyRef

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

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

    The composition of Traverses F and G, [x]F[G[x]], is a Traverse

  18. 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
  19. def compose[G[_]](implicit G0: Functor[G]): Functor[[α]F[G[α]]]

    The composition of Functors F and G, [x]F[G[x]], is a Functor

    The composition of Functors F and G, [x]F[G[x]], is a Functor

    Definition Classes
    Functor
  20. final def count[A](fa: F[A]): Int

    Alias for length.

    Alias for length.

    Definition Classes
    Foldable
  21. def counzip[A, B](a: \/[F[A], F[B]]): F[\/[A, B]]

    Definition Classes
    Functor
  22. 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
  23. def empty[A](fa: F[A]): Boolean

    Deforested alias for toStream(fa).isEmpty.

    Deforested alias for toStream(fa).isEmpty.

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

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

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

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  27. 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
  28. def foldLShape[A, B](fa: F[A], z: B)(f: (B, A) ⇒ B): (B, F[Unit])

  29. 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
    TraverseFoldable
  30. def foldLeft1Opt[A](fa: F[A])(f: (A, A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  31. 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
  32. def foldMap[A, B](fa: F[A])(f: (A) ⇒ B)(implicit F: Monoid[B]): B

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

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

    Definition Classes
    TraverseFoldable
  33. 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
  34. def foldMapLeft1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (B, A) ⇒ B): Option[B]

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

    Definition Classes
    Foldable
  36. 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
    TraverseFoldable
  37. def foldRight1Opt[A](fa: F[A])(f: (A, ⇒ A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  38. 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
  39. def foldableLaw: FoldableLaw

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

    Definition Classes
    Foldable
  41. 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
  42. def foldl1Opt[A](fa: F[A])(f: (A) ⇒ (A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  43. 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
  44. 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
  45. def foldr1Opt[A](fa: F[A])(f: (A) ⇒ (⇒ A) ⇒ A): Option[A]

    Definition Classes
    Foldable
  46. 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
  47. def fpair[A](fa: F[A]): F[(A, A)]

    Twin all As in fa.

    Twin all As in fa.

    Definition Classes
    Functor
  48. def fproduct[A, B](fa: F[A])(f: (A) ⇒ B): F[(A, B)]

    Pair all As in fa with the result of function application.

    Pair all As in fa with the result of function application.

    Definition Classes
    Functor
  49. def functorLaw: FunctorLaw

    Definition Classes
    Functor
  50. val functorSyntax: FunctorSyntax[F]

    Definition Classes
    Functor
  51. final def getClass(): java.lang.Class[_]

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

    Definition Classes
    AnyRef → Any
  53. def icompose[G[_]](implicit G0: Contravariant[G]): Contravariant[[α]F[G[α]]]

    The composition of Functor F and Contravariant G, [x]F[G[x]], is contravariant.

    The composition of Functor F and Contravariant G, [x]F[G[x]], is contravariant.

    Definition Classes
    Functor
  54. 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
  55. 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
  56. 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
  57. def invariantFunctorLaw: InvariantFunctorLaw

    Definition Classes
    InvariantFunctor
  58. val invariantFunctorSyntax: InvariantFunctorSyntax[F]

    Definition Classes
    InvariantFunctor
  59. final def isInstanceOf[T0]: Boolean

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

    Deforested alias for toStream(fa).size.

    Deforested alias for toStream(fa).size.

    Definition Classes
    Foldable
  61. def lift[A, B](f: (A) ⇒ B): (F[A]) ⇒ F[B]

    Lift f into F.

    Lift f into F.

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

    Definition Classes
    Foldable
  63. def map[A, B](fa: F[A])(f: (A) ⇒ B): F[B]

    Lift f into F and apply to F[A].

    Lift f into F and apply to F[A].

    Definition Classes
    TraverseFunctor
  64. def mapAccumL[S, A, B](fa: F[A], z: S)(f: (S, A) ⇒ (S, B)): (S, F[B])

  65. def mapAccumR[S, A, B](fa: F[A], z: S)(f: (S, A) ⇒ (S, B)): (S, F[B])

  66. def mapply[A, B](a: A)(f: F[(A) ⇒ B]): F[B]

    Lift apply(a), and apply the result to f.

    Lift apply(a), and apply the result to f.

    Definition Classes
    Functor
  67. 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
  68. 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
  69. 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
  70. 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
  71. 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
  72. 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
  73. final def ne(arg0: AnyRef): Boolean

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

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

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

    The product of Traverses F and G, [x](F[x], G[x]]), is a Traverse

  77. 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
  78. def product[G[_]](implicit G0: Functor[G]): Functor[[α](F[α], G[α])]

    The product of Functors F and G, [x](F[x], G[x]]), is a Functor

    The product of Functors F and G, [x](F[x], G[x]]), is a Functor

    Definition Classes
    Functor
  79. def product0[G[_]](implicit G0: Traverse1[G]): Traverse1[[α](F[α], G[α])]

    The product of Traverse F and Traverse1 G, [x](F[x], G[x]]), is a Traverse1

  80. 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
  81. def reverse[A](fa: F[A]): F[A]

  82. def runTraverseS[S, A, B](fa: F[A], s: S)(f: (A) ⇒ State[S, B]): (S, F[B])

  83. 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
  84. def sequence[G[_], A](fga: F[G[A]])(implicit arg0: Applicative[G]): G[F[A]]

    Traverse with the identity function.

  85. 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
  86. def sequenceS[S, A](fga: F[State[S, A]]): State[S, F[A]]

    Traverse with State.

  87. def sequenceS_[S, A](fga: F[State[S, A]]): State[S, Unit]

    sequence_ specialized to State *

    sequence_ specialized to State *

    Definition Classes
    Foldable
  88. final def sequenceU[A](self: F[A])(implicit G: Unapply[Applicative, A]): M[F[A]]

    A version of sequence that infers the nested type constructor.

  89. 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
  90. 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
  91. def strengthL[A, B](a: A, f: F[B]): F[(A, B)]

    Inject a to the left of Bs in f.

    Inject a to the left of Bs in f.

    Definition Classes
    Functor
  92. def strengthR[A, B](f: F[A], b: B): F[(A, B)]

    Inject b to the right of As in f.

    Inject b to the right of As in f.

    Definition Classes
    Functor
  93. final def synchronized[T0](arg0: ⇒ T0): T0

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

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

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

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

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

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

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

    Definition Classes
    Foldable
  101. def toString(): String

    Definition Classes
    AnyRef → Any
  102. def traversal[G[_]](implicit arg0: Applicative[G]): Traversal[G]

  103. def traversalS[S]: Traversal[[x]IndexedStateT[[+X]X, S, S, x]]

  104. def traverse[G[_], A, B](fa: F[A])(f: (A) ⇒ G[B])(implicit arg0: Applicative[G]): G[F[B]]

  105. def traverseKTrampoline[S, G[_], A, B](fa: F[A])(f: (A) ⇒ Kleisli[G, S, B])(implicit arg0: Applicative[G]): Kleisli[G, S, F[B]]

    Traverse fa with a Kleisli[G, S, B], internally using a Trampoline to avoid stack overflow.

  106. def traverseLaw: TraverseLaw

  107. final def traverseM[A, G[_], B](fa: F[A])(f: (A) ⇒ G[F[B]])(implicit G: Applicative[G], F: Bind[F]): G[F[B]]

    A version of traverse where a subsequent monadic join is applied to the inner result.

  108. def traverseS[S, A, B](fa: F[A])(f: (A) ⇒ State[S, B]): State[S, F[B]]

    Traverse with State.

  109. def traverseSTrampoline[S, G[_], A, B](fa: F[A])(f: (A) ⇒ State[S, G[B]])(implicit arg0: Applicative[G]): State[S, G[F[B]]]

    Traverse fa with a State[S, G[B]], internally using a Trampoline to avoid stack overflow.

  110. 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
  111. val traverseSyntax: TraverseSyntax[F]

  112. final def traverseU[A, GB](fa: F[A])(f: (A) ⇒ GB)(implicit G: Unapply[Applicative, GB]): M[F[A]]

    A version of traverse that infers the type constructor G.

  113. 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
  114. 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
  115. def void[A](fa: F[A]): F[Unit]

    Empty fa of meaningful pure values, preserving its structure.

    Empty fa of meaningful pure values, preserving its structure.

    Definition Classes
    Functor
  116. final def wait(): Unit

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

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

    Definition Classes
    AnyRef
    Annotations
    @throws()
  119. def xmap[A, B](fa: F[A], f: (A) ⇒ B, g: (B) ⇒ A): F[B]

    Converts ma to a value of type F[B] using the provided functions f and g.

    Converts ma to a value of type F[B] using the provided functions f and g.

    Definition Classes
    FunctorInvariantFunctor
  120. def xmapb[A, B](ma: F[A])(b: Bijection[A, B]): F[B]

    Converts ma to a value of type F[B] using the provided bijection.

    Converts ma to a value of type F[B] using the provided bijection.

    Definition Classes
    InvariantFunctor
  121. def xmapi[A, B](ma: F[A])(iso: <=>[A, B]): F[B]

    Converts ma to a value of type F[B] using the provided isomorphism.

    Converts ma to a value of type F[B] using the provided isomorphism.

    Definition Classes
    InvariantFunctor
  122. def zipL[A, B](fa: F[A], fb: F[B]): F[(A, Option[B])]

  123. def zipR[A, B](fa: F[A], fb: F[B]): F[(Option[A], B)]

  124. def zipWith[A, B, C](fa: F[A], fb: F[B])(f: (A, Option[B]) ⇒ C): (List[B], F[C])

  125. def zipWithL[A, B, C](fa: F[A], fb: F[B])(f: (A, Option[B]) ⇒ C): F[C]

  126. def zipWithR[A, B, C](fa: F[A], fb: F[B])(f: (Option[A], B) ⇒ C): F[C]

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 Functor[F]

Inherited from InvariantFunctor[F]

Inherited from AnyRef

Inherited from Any