t

scalaz

# Foldable1 

### Companion object Foldable1

#### trait Foldable1[F[_]] extends Foldable[F]

A scalaz.Foldable where `foldMap` is total over semigroups. That is, `toList` cannot return an empty list.

Self Type
Foldable1[F]
Source
Foldable1.scala
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1. Foldable1
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### Type Members

1. trait FoldableLaw extends AnyRef
Definition Classes
Foldable
2. trait Foldable1Law extends FoldableLaw

### Abstract Value Members

1. abstract def foldMap1[A, B](fa: F[A])(f: (A) ⇒ B)(implicit F: Semigroup[B]): B

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

2. abstract def foldMapRight1[A, B](fa: F[A])(z: (A) ⇒ B)(f: (A, ⇒ B) ⇒ B): B

Right-associative fold of a structure.

### Concrete Value Members

1. final def !=(arg0: Any)
Definition Classes
AnyRef → Any
2. final def ##(): Int
Definition Classes
AnyRef → Any
3. final def ==(arg0: Any)
Definition Classes
AnyRef → Any
4. def all[A](fa: F[A])(p: (A) ⇒ Boolean)

Whether all `A`s in `fa` yield true from `p`.

Whether all `A`s 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)

Whether any `A`s in `fa` yield true from `p`.

Whether any `A`s 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. final def asum[G[_], A](fa: F[G[A]])(implicit G: PlusEmpty[G]): G[A]

Alias for psum.

Alias for psum. `asum` is the name used in Haskell.

Definition Classes
Foldable
10. 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
11. def clone()
Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@native() @throws( ... )
12. def collapse[X[_], A](x: F[A])(implicit A: ApplicativePlus[X]): X[A]
Definition Classes
Foldable
13. def compose[G[_]](implicit arg0: Foldable1[G]): Foldable1[[α]F[G[α]]]

The composition of Foldable1 `F` and `G`, `[x]F[G[x]]`, is a Foldable1

14. 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
15. final def count[A](fa: F[A]): Int

Alias for `length`.

Alias for `length`.

Definition Classes
Foldable
16. 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
17. def distinct1[A](fa: F[A])(implicit A: Order[A]): NonEmptyList[A]

`O(n log n)` complexity

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

`O(n2)` complexity

`O(n2)` complexity

Definition Classes
Foldable
20. def distinctE1[A](fa: F[A])(implicit A: Equal[A]): NonEmptyList[A]

`O(n2)` complexity

21. def element[A](fa: F[A], a: A)(implicit arg0: Equal[A])

Whether `a` is an element of `fa`.

Whether `a` is an element of `fa`.

Definition Classes
Foldable
22. final def empty[A](fa: F[A])

always return `false`

always return `false`

Definition Classes
Foldable1Foldable
23. final def eq(arg0: AnyRef)
Definition Classes
AnyRef
24. def equals(arg0: Any)
Definition Classes
AnyRef → Any
25. 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
Foldable
26. 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
Foldable
27. 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
Foldable
28. def filterLength[A](fa: F[A])(f: (A) ⇒ Boolean): Int
Definition Classes
Foldable
29. def finalize(): Unit
Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
30. def findLeft[A](fa: F[A])(f: (A) ⇒ Boolean): Option[A]
Definition Classes
Foldable
31. 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
32. def findRight[A](fa: F[A])(f: (A) ⇒ Boolean): Option[A]
Definition Classes
Foldable
33. 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
34. def fold1[M](t: F[M])(implicit arg0: Semigroup[M]): M
35. 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
Foldable
36. 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
37. def foldLeft1[A](fa: F[A])(f: (A, A) ⇒ A): A

Left-associative fold of a structure.

38. def foldLeft1Opt[A](fa: F[A])(f: (A, A) ⇒ A): Option[A]
Definition Classes
Foldable
39. 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
40. 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
Foldable1Foldable
41. 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
Foldable1Foldable
42. def foldMapLeft1[A, B](fa: F[A])(z: (A) ⇒ B)(f: (B, A) ⇒ B): B

Left-associative fold of a structure.

43. def foldMapLeft1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (B, A) ⇒ B): Option[B]
Definition Classes
Foldable1Foldable
44. 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
45. def foldMapRight1Opt[A, B](fa: F[A])(z: (A) ⇒ B)(f: (A, ⇒ B) ⇒ B): Option[B]
Definition Classes
Foldable1Foldable
46. 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
Foldable1Foldable
47. def foldRight1[A](fa: F[A])(f: (A, ⇒ A) ⇒ A): A

Right-associative fold of a structure.

48. def foldRight1Opt[A](fa: F[A])(f: (A, ⇒ A) ⇒ A): Option[A]
Definition Classes
Foldable
49. 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
50. def foldable1Law
51. val foldable1Syntax: Foldable1Syntax[F]
52. def foldableLaw
Definition Classes
Foldable
53. val foldableSyntax: FoldableSyntax[F]
Definition Classes
Foldable
54. 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
55. final def foldl1[A](fa: F[A])(f: (A) ⇒ (A) ⇒ A): A

Curried `foldLeft1`.

56. def foldl1Opt[A](fa: F[A])(f: (A) ⇒ (A) ⇒ A): Option[A]
Definition Classes
Foldable1Foldable
57. 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
58. 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
59. final def foldr1[A](fa: F[A])(f: (A) ⇒ (⇒ A) ⇒ A): A

Curried `foldRight1`.

60. def foldr1Opt[A](fa: F[A])(f: (A) ⇒ (⇒ A) ⇒ A): Option[A]
Definition Classes
Foldable1Foldable
61. 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
62. final def getClass(): Class[_]
Definition Classes
AnyRef → Any
Annotations
@native()
63. def hashCode(): Int
Definition Classes
AnyRef → Any
Annotations
@native()
64. 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
65. 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
66. def intercalate[A](fa: F[A], a: A)(implicit arg0: Monoid[A]): A

Insert an `A` between every A, yielding the sum.

Insert an `A` between every A, yielding the sum.

Definition Classes
Foldable1Foldable
67. def intercalate1[A](fa: F[A], a: A)(implicit A: Semigroup[A]): A

Insert an `A` between every A, yielding the sum.

68. final def isInstanceOf[T0]
Definition Classes
Any
69. def length[A](fa: F[A]): Int

Deforested alias for `toStream(fa).size`.

Deforested alias for `toStream(fa).size`.

Definition Classes
Foldable
70. def longDigits[A](fa: F[A])(implicit d: <:<[A, Digit]): Long
Definition Classes
Foldable
71. 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
Foldable1Foldable
72. def maximum1[A](fa: F[A])(implicit arg0: Order[A]): A

The greatest element of `fa`.

73. 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
Foldable1Foldable
74. def maximumBy1[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): A

The element `a` of `fa` which yield the greatest value of `f(a)`.

75. 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
Foldable1Foldable
76. def maximumOf1[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): B

The greatest value of `f(a)` for each element `a` of `fa`.

77. 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
Foldable1Foldable
78. def minimum1[A](fa: F[A])(implicit arg0: Order[A]): A

The smallest element of `fa`.

79. 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
Foldable1Foldable
80. def minimumBy1[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): A

The element `a` of `fa` which yield the smallest value of `f(a)`.

81. 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
Foldable1Foldable
82. def minimumOf1[A, B](fa: F[A])(f: (A) ⇒ B)(implicit arg0: Order[B]): B

The smallest value of `f(a)` for each element `a` of `fa`.

83. def msuml1[G[_], A](fa: F[G[A]])(implicit G: Plus[G]): G[A]
84. final def ne(arg0: AnyRef)
Definition Classes
AnyRef
85. final def notify(): Unit
Definition Classes
AnyRef
Annotations
@native()
86. final def notifyAll(): Unit
Definition Classes
AnyRef
Annotations
@native()
87. def product[G[_]](implicit G0: Foldable1[G]): Foldable1[[α](F[α], G[α])]

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

88. 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
89. def product0[G[_]](implicit G0: Foldable[G]): Foldable1[[α](F[α], G[α])]

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

90. 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
91. def psum[G[_], A](fa: F[G[A]])(implicit G: PlusEmpty[G]): G[A]

Sum using a polymorphic monoid (PlusEmpty).

Sum using a polymorphic monoid (PlusEmpty). Should support early termination, i.e. summing no more elements than is needed to determine the result.

Definition Classes
Foldable
92. def psum1[G[_], A](fa: F[G[A]])(implicit G: Plus[G]): G[A]
93. def psumMap[A, B, G[_]](fa: F[A])(f: (A) ⇒ G[B])(implicit G: PlusEmpty[G]): G[B]

Map elements to `G[B]` and sum using a polymorphic monoid (PlusEmpty).

Map elements to `G[B]` and sum using a polymorphic monoid (PlusEmpty). Should support early termination, i.e. mapping and summing no more elements than is needed to determine the result.

Definition Classes
Foldable
94. def psumMap1[A, B, G[_]](fa: F[A])(f: (A) ⇒ G[B])(implicit G: Plus[G]): G[B]
95. def scanLeft1[A](fa: F[A])(f: (A, A) ⇒ A): NonEmptyList[A]
96. def scanRight1[A](fa: F[A])(f: (A, A) ⇒ A): NonEmptyList[A]
97. 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
98. def sequence1_[M[_], A](fa: F[M[A]])(implicit a: Apply[M], x: Semigroup[M[A]]): M[Unit]
99. 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
100. def sequenceS_[S, A](fga: F[State[S, A]]): State[S, Unit]

`sequence_` specialized to `State` *

`sequence_` specialized to `State` *

Definition Classes
Foldable
101. 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
102. 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
Foldable
103. 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
Foldable
104. 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
105. def suml[A](fa: F[A])(implicit A: Monoid[A]): A
Definition Classes
Foldable
106. def suml1[A](fa: F[A])(implicit A: Semigroup[A]): A
107. def suml1Opt[A](fa: F[A])(implicit A: Semigroup[A]): Option[A]
Definition Classes
Foldable
108. def sumr[A](fa: F[A])(implicit A: Monoid[A]): A
Definition Classes
Foldable
109. def sumr1[A](fa: F[A])(implicit A: Semigroup[A]): A
110. def sumr1Opt[A](fa: F[A])(implicit A: Semigroup[A]): Option[A]
Definition Classes
Foldable
111. final def synchronized[T0](arg0: ⇒ T0): T0
Definition Classes
AnyRef
112. def toEphemeralStream[A](fa: F[A]): EphemeralStream[A]
Definition Classes
Foldable
113. def toIList[A](fa: F[A]): IList[A]
Definition Classes
Foldable
114. def toList[A](fa: F[A]): List[A]
Definition Classes
Foldable
115. def toNel[A](fa: F[A]): NonEmptyList[A]
116. def toSet[A](fa: F[A]): Set[A]
Definition Classes
Foldable
117. def toStream[A](fa: F[A]): Stream[A]
Definition Classes
Foldable
118. def toString()
Definition Classes
AnyRef → Any
119. def toVector[A](fa: F[A]): Vector[A]
Definition Classes
Foldable
120. def traverse1_[M[_], A, B](fa: F[A])(f: (A) ⇒ M[B])(implicit a: Apply[M], x: Semigroup[M[B]]): M[Unit]
121. 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
122. 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
123. 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
124. final def wait(): Unit
Definition Classes
AnyRef
Annotations
@throws( ... )
125. final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
Annotations
@throws( ... )
126. final def wait(arg0: Long): Unit
Definition Classes
AnyRef
Annotations
@native() @throws( ... )

### Deprecated Value Members

1. def msuml[G[_], A](fa: F[G[A]])(implicit G: PlusEmpty[G]): G[A]
Definition Classes
Foldable
Annotations
@deprecated
Deprecated

(Since version 7.3.0) use psum

2. def msumlU[GA](fa: F[GA])(implicit G: Unapply[PlusEmpty, GA]): M[A]
Definition Classes
Foldable
Annotations
@deprecated
Deprecated

(Since version 7.3.0) use psum