Scala 3/API/scala.jdk/Accumulator

Accumulator

object Accumulator

Contains factory methods to build Accumulators.

Contains factory methods to build Accumulators.

Note that the Accumulator object itself is not a factory, but it is implicitly convert to a factory according to the element type, see Accumulator.toFactory.

This allows passing the Accumulator object as argument when a collection.Factory, and the implicit Accumulator.AccumulatorFactoryShape instance is used to build a specialized Accumulator according to the element type:

scala> val intAcc = Accumulator(1,2,3)
intAcc: scala.collection.convert.IntAccumulator = IntAccumulator(1, 2, 3)

scala> val anyAccc = Accumulator("K")
anyAccc: scala.collection.convert.AnyAccumulator[String] = AnyAccumulator(K)

scala> val intAcc2 = List(1,2,3).to(Accumulator)
intAcc2: scala.jdk.IntAccumulator = IntAccumulator(1, 2, 3)

scala> val anyAcc2 = List("K").to(Accumulator)
anyAcc2: scala.jdk.AnyAccumulator[String] = AnyAccumulator(K)
Companion
class
class Object
trait Matchable
class Any

Type members

Classlikes

sealed trait AccumulatorFactoryShape[A, C]

An implicit AccumulatorFactoryShape is used in Accumulator factory method to return specialized variants according to the element type.

An implicit AccumulatorFactoryShape is used in Accumulator factory method to return specialized variants according to the element type.

Companion
object
object AccumulatorFactoryShape extends LowPriorityAccumulatorFactoryShape
Companion
class
sealed trait LowPriorityAccumulatorFactoryShape

Value members

Concrete methods

def apply[A, C](elems: A*)(canAccumulate: AccumulatorFactoryShape[A, C]): C

Creates an Accumulator with the specified elements.

Creates an Accumulator with the specified elements.

Type Params
A

the type of the Accumulator's elements

C

the (inferred) specific type of the Accumulator

Value Params
elems

the elements of the created Accumulator

Returns

a new Accumulator with elements elems

def concat[A, C](xss: Iterable[A]*)(canAccumulate: AccumulatorFactoryShape[A, C]): C

Concatenates all argument collections into a single Accumulator.

Concatenates all argument collections into a single Accumulator.

Value Params
xss

the collections that are to be concatenated.

Returns

the concatenation of all the collections.

def empty[A, C](canAccumulate: AccumulatorFactoryShape[A, C]): C

An empty collection

An empty collection

Type Params
A

the type of the Accumulator's elements

def fill[A, C](n: Int)(elem: => A)(canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator containing the results of some element computation a number of times.

Produces an Accumulator containing the results of some element computation a number of times.

Value Params
elem

the element computation

n

the number of elements contained in the Accumulator.

Returns

An Accumulator that contains the results of n evaluations of elem.

def fill[A, C](n1: Int, n2: Int)(elem: => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[C]

Produces a two-dimensional Accumulator containing the results of some element computation a number of times.

Produces a two-dimensional Accumulator containing the results of some element computation a number of times.

Value Params
elem

the element computation

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

Returns

An Accumulator that contains the results of n1 x n2 evaluations of elem.

def fill[A, C](n1: Int, n2: Int, n3: Int)(elem: => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[C]]

Produces a three-dimensional Accumulator containing the results of some element computation a number of times.

Produces a three-dimensional Accumulator containing the results of some element computation a number of times.

Value Params
elem

the element computation

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

Returns

An Accumulator that contains the results of n1 x n2 x n3 evaluations of elem.

def fill[A, C](n1: Int, n2: Int, n3: Int, n4: Int)(elem: => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[AnyAccumulator[C]]]

Produces a four-dimensional Accumulator containing the results of some element computation a number of times.

Produces a four-dimensional Accumulator containing the results of some element computation a number of times.

Value Params
elem

the element computation

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

n4

the number of elements in the 4th dimension

Returns

An Accumulator that contains the results of n1 x n2 x n3 x n4 evaluations of elem.

def fill[A, C](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[AnyAccumulator[AnyAccumulator[C]]]]

Produces a five-dimensional Accumulator containing the results of some element computation a number of times.

Produces a five-dimensional Accumulator containing the results of some element computation a number of times.

Value Params
elem

the element computation

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

n4

the number of elements in the 4th dimension

n5

the number of elements in the 5th dimension

Returns

An Accumulator that contains the results of n1 x n2 x n3 x n4 x n5 evaluations of elem.

def from[A, C](source: IterableOnce[A])(canAccumulate: AccumulatorFactoryShape[A, C]): C

Creates a target Accumulator from an existing source collection

Creates a target Accumulator from an existing source collection

Type Params
A

the type of the Accumulator’s elements

C

the (inferred) specific type of the Accumulator

Value Params
source

Source collection

Returns

a new Accumulator with the elements of source

def iterate[A, C](start: A, len: Int)(f: A => A)(canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator containing repeated applications of a function to a start value.

Produces an Accumulator containing repeated applications of a function to a start value.

Value Params
f

the function that's repeatedly applied

len

the number of elements contained in the Accumulator

start

the start value of the Accumulator

Returns

an Accumulator with len values in the sequence start, f(start), f(f(start)), ...

def newBuilder[A, C](canAccumulate: AccumulatorFactoryShape[A, C]): Builder[A, C]
Type Params
A

the type of the Accumulator’s elements

C

the specific type of the Accumulator

Returns

A builder for Accumulator objects.

def range[A, C](start: A, end: A)(`evidence$1`: Integral[A], canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator containing a sequence of increasing of integers.

Produces an Accumulator containing a sequence of increasing of integers.

Value Params
end

the end value of the Accumulator (the first value NOT contained)

start

the first element of the Accumulator

Returns

an Accumulator with values start, start + 1, ..., end - 1

def range[A, C](start: A, end: A, step: A)(`evidence$2`: Integral[A], canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator containing equally spaced values in some integer interval.

Produces an Accumulator containing equally spaced values in some integer interval.

Value Params
end

the end value of the Accumulator (the first value NOT contained)

start

the start value of the Accumulator

step

the difference between successive elements of the Accumulator (must be positive or negative)

Returns

an Accumulator with values start, start + step, ... up to, but excluding end

def tabulate[A, C](n: Int)(f: Int => A)(canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator containing values of a given function over a range of integer values starting from 0.

Produces an Accumulator containing values of a given function over a range of integer values starting from 0.

Value Params
f

The function computing element values

n

The number of elements in the Accumulator

Returns

An Accumulator consisting of elements f(0), ..., f(n -1)

def tabulate[A, C](n1: Int, n2: Int)(f: (Int, Int) => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[C]

Produces a two-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Produces a two-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Value Params
f

The function computing element values

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

Returns

An Accumulator consisting of elements f(i1, i2) for 0 <= i1 < n1 and 0 <= i2 < n2.

def tabulate[A, C](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[C]]

Produces a three-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Produces a three-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Value Params
f

The function computing element values

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

Returns

An Accumulator consisting of elements f(i1, i2, i3) for 0 <= i1 < n1, 0 <= i2 < n2, and 0 <= i3 < n3.

def tabulate[A, C](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[AnyAccumulator[C]]]

Produces a four-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Produces a four-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Value Params
f

The function computing element values

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

n4

the number of elements in the 4th dimension

Returns

An Accumulator consisting of elements f(i1, i2, i3, i4) for 0 <= i1 < n1, 0 <= i2 < n2, 0 <= i3 < n3, and 0 <= i4 < n4.

def tabulate[A, C](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) => A)(canAccumulate: AccumulatorFactoryShape[A, C]): AnyAccumulator[AnyAccumulator[AnyAccumulator[AnyAccumulator[C]]]]

Produces a five-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Produces a five-dimensional Accumulator containing values of a given function over ranges of integer values starting from 0.

Value Params
f

The function computing element values

n1

the number of elements in the 1st dimension

n2

the number of elements in the 2nd dimension

n3

the number of elements in the 3rd dimension

n4

the number of elements in the 4th dimension

n5

the number of elements in the 5th dimension

Returns

An Accumulator consisting of elements f(i1, i2, i3, i4, i5) for 0 <= i1 < n1, 0 <= i2 < n2, 0 <= i3 < n3, 0 <= i4 < n4, and 0 <= i5 < n5.

def unfold[A, S, C](init: S)(f: S => Option[(A, S)])(canAccumulate: AccumulatorFactoryShape[A, C]): C

Produces an Accumulator that uses a function f to produce elements of type A and update an internal state of type S.

Produces an Accumulator that uses a function f to produce elements of type A and update an internal state of type S.

Type Params
A

Type of the elements

C

Type (usually inferred) of the Accumulator

S

Type of the internal state

Value Params
f

Computes the next element (or returns None to signal the end of the collection)

init

State initial value

Returns

an Accumulator that produces elements using f until f returns None

Implicits

Implicits

implicit def toFactory[A, C](sa: Accumulator)(canAccumulate: AccumulatorFactoryShape[A, C]): Factory[A, C]