object Accumulator
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)
- Source
- Accumulator.scala
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Type Members
- sealed trait AccumulatorFactoryShape[A, C] extends AnyRef
An implicit
AccumulatorFactoryShape
is used in Accumulator factory method to return specialized variants according to the element type. - sealed trait LowPriorityAccumulatorFactoryShape extends AnyRef
Value Members
- def apply[A, C](elems: A*)(implicit canAccumulate: AccumulatorFactoryShape[A, C]): C
Creates an Accumulator with the specified elements.
Creates an Accumulator with the specified elements.
- A
the type of the Accumulator's elements
- C
the (inferred) specific type of the Accumulator
- elems
the elements of the created Accumulator
- returns
a new Accumulator with elements
elems
- def concat[A, C](xss: Iterable[A]*)(implicit canAccumulate: AccumulatorFactoryShape[A, C]): C
Concatenates all argument collections into a single Accumulator.
Concatenates all argument collections into a single Accumulator.
- xss
the collections that are to be concatenated.
- returns
the concatenation of all the collections.
- def empty[A, C](implicit canAccumulate: AccumulatorFactoryShape[A, C]): C
An empty collection
An empty collection
- A
the type of the Accumulator's elements
- def fill[A, C](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: => A)(implicit 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.
- 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
- elem
the element computation
- returns
An Accumulator that contains the results of
n1 x n2 x n3 x n4 x n5
evaluations ofelem
.
- def fill[A, C](n1: Int, n2: Int, n3: Int, n4: Int)(elem: => A)(implicit 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.
- 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
- elem
the element computation
- returns
An Accumulator that contains the results of
n1 x n2 x n3 x n4
evaluations ofelem
.
- def fill[A, C](n1: Int, n2: Int, n3: Int)(elem: => A)(implicit 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.
- 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
- elem
the element computation
- returns
An Accumulator that contains the results of
n1 x n2 x n3
evaluations ofelem
.
- def fill[A, C](n1: Int, n2: Int)(elem: => A)(implicit 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.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- elem
the element computation
- returns
An Accumulator that contains the results of
n1 x n2
evaluations ofelem
.
- def fill[A, C](n: Int)(elem: => A)(implicit 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.
- n
the number of elements contained in the Accumulator.
- elem
the element computation
- returns
An Accumulator that contains the results of
n
evaluations ofelem
.
- def from[A, C](source: IterableOnce[A])(implicit canAccumulate: AccumulatorFactoryShape[A, C]): C
Creates a target Accumulator from an existing source collection
Creates a target Accumulator from an existing source collection
- A
the type of the Accumulator’s elements
- C
the (inferred) specific type of the Accumulator
- source
Source collection
- returns
a new Accumulator with the elements of
source
- def iterate[A, C](start: A, len: Int)(f: (A) => A)(implicit 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.
- start
the start value of the Accumulator
- len
the number of elements contained in the Accumulator
- f
the function that's repeatedly applied
- returns
an Accumulator with
len
values in the sequencestart, f(start), f(f(start)), ...
- def newBuilder[A, C](implicit canAccumulate: AccumulatorFactoryShape[A, C]): Builder[A, C]
- 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, step: A)(implicit arg0: 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.
- start
the start value of the Accumulator
- end
the end value of the Accumulator (the first value NOT contained)
- 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 excludingend
- def range[A, C](start: A, end: A)(implicit arg0: 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.
- start
the first element of the Accumulator
- end
the end value of the Accumulator (the first value NOT contained)
- returns
an Accumulator with values
start, start + 1, ..., end - 1
- def tabulate[A, C](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) => A)(implicit 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.
- 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
- f
The function computing element values
- returns
An Accumulator consisting of elements
f(i1, i2, i3, i4, i5)
for0 <= i1 < n1
,0 <= i2 < n2
,0 <= i3 < n3
,0 <= i4 < n4
, and0 <= i5 < n5
.
- def tabulate[A, C](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) => A)(implicit 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.
- 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
- f
The function computing element values
- returns
An Accumulator consisting of elements
f(i1, i2, i3, i4)
for0 <= i1 < n1
,0 <= i2 < n2
,0 <= i3 < n3
, and0 <= i4 < n4
.
- def tabulate[A, C](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) => A)(implicit 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.
- 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
- f
The function computing element values
- returns
An Accumulator consisting of elements
f(i1, i2, i3)
for0 <= i1 < n1
,0 <= i2 < n2
, and0 <= i3 < n3
.
- def tabulate[A, C](n1: Int, n2: Int)(f: (Int, Int) => A)(implicit 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.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- f
The function computing element values
- returns
An Accumulator consisting of elements
f(i1, i2)
for0 <= i1 < n1
and0 <= i2 < n2
.
- def tabulate[A, C](n: Int)(f: (Int) => A)(implicit 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.
- n
The number of elements in the Accumulator
- f
The function computing element values
- returns
An Accumulator consisting of elements
f(0), ..., f(n -1)
- implicit def toFactory[A, C](sa: Accumulator.type)(implicit canAccumulate: AccumulatorFactoryShape[A, C]): Factory[A, C]
- def unfold[A, S, C](init: S)(f: (S) => Option[(A, S)])(implicit canAccumulate: AccumulatorFactoryShape[A, C]): C
Produces an Accumulator that uses a function
f
to produce elements of typeA
and update an internal state of typeS
.Produces an Accumulator that uses a function
f
to produce elements of typeA
and update an internal state of typeS
.- A
Type of the elements
- S
Type of the internal state
- C
Type (usually inferred) of the Accumulator
- init
State initial value
- f
Computes the next element (or returns
None
to signal the end of the collection)- returns
an Accumulator that produces elements using
f
untilf
returnsNone
- object AccumulatorFactoryShape extends LowPriorityAccumulatorFactoryShape
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
scala.Predef
object are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
List
is an alias forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.