Scala 3/scala/scala.collection/IterableOps

IterableOps

scala.collection.IterableOps

See theIterableOps companion object

trait IterableOps[+A, +CC[_], +C] extends IterableOnce[A], IterableOnceOps[A, CC, C]

Base trait for Iterable operations

VarianceNote

We require that for all child classes of Iterable the variance of the child class and the variance of the C parameter passed to IterableOps are the same. We cannot express this since we lack variance polymorphism. That's why we have to resort at some places to write C[A @uncheckedVariance].

Type parameters

C: type of the collection (e.g. List[Int], String, BitSet). Operations returning a collection with the same type of element (e.g. drop, filter) return a C.
CC: type constructor of the collection (e.g. List, Set). Operations returning a collection with a different type of element B (e.g. map) return a CC[B].

Attributes

Companion: object
Source: Iterable.scala
Graph
Supertypes: trait IterableOnceOps[A, CC, C]

trait IterableOnce[A]

class Any
Known subtypes: trait Iterable[A]

trait Map[K, V]

class AbstractMap[K, V]

class HashMap[K, V]

class IntMap[T]

class ListMap[K, V]

class LongMap[T]

class Map1[K, V]

class Map2[K, V]

class Map3[K, V]

class Map4[K, V]

class WithDefault[K, V]

class WithDefault[K, V]

class TreeMap[K, V]

class TreeSeqMap[K, V]

class VectorMap[K, V]

trait SeqMap[K, V]

trait SortedMap[K, V]

trait Seq[A]

class AbstractSeq[A]

class ArraySeq[A]

class ofBoolean

class ofByte

class ofChar

class ofDouble

class ofFloat

class ofInt

class ofLong

class ofRef[T]

class ofShort

class ofUnit

class LazyList[A]

class List[A]

class ::[A]

object Nil

class NumericRange[T]

class Exclusive[T]

class Inclusive[T]

class Queue[A]

class Range

class Exclusive

class Inclusive

class Stream[A]

class Cons[A]

object Empty

class Vector[A]

class WrappedString

trait IndexedSeq[A]

trait LinearSeq[A]

trait Set[A]

class AbstractSet[A]

class ImmutableKeySet

class BitSet

class BitSet1

class BitSet2

class BitSetN

class HashSet[A]

class ListSet[A]

class Set1[A]

class Set2[A]

class Set3[A]

class Set4[A]

class ImmutableKeySortedSet

class TreeSet[A]

class ValueSet

trait SortedSet[A]

trait MapOps[K, V, CC, C]

trait SortedMapOps[K, V, CC, C]

trait StrictOptimizedSortedMapOps[K, V, CC, C]

trait StrictOptimizedMapOps[K, V, CC, C]

trait Iterable[A]

class AbstractIterable[A]

class PriorityQueue[A]

trait Map[K, V]

trait Map[K, V]

class TrieMap[K, V]

class AbstractMap[K, V]

class AnyRefMap[K, V]

class CollisionProofHashMap[K, V]

class HashMap[K, V]

class LinkedHashMap[K, V]

class ListMap[K, V]

class LongMap[V]

class WithDefault[K, V]

class WithDefault[K, V]

class OpenHashMap[Key, Value]

class TreeMap[K, V]

class SystemProperties

trait MultiMap[K, V]

trait SeqMap[K, V]

trait SortedMap[K, V]

trait Seq[A]

class AbstractSeq[A]

class AbstractBuffer[A]

class ArrayBuffer[A]

class ArrayDeque[A]

class Queue[A]

class Stack[A]

class ListBuffer[A]

class UnrolledBuffer[T]

class ArraySeq[T]

class ofBoolean

class ofByte

class ofChar

class ofDouble

class ofFloat

class ofInt

class ofLong

class ofRef[T]

class ofShort

class ofUnit

class StringBuilder

trait Buffer[A]

trait IndexedBuffer[A]

trait IndexedSeq[T]

class Accumulator[A, CC, C]

class AnyAccumulator[A]

class DoubleAccumulator

class IntAccumulator

class LongAccumulator

trait Set[A]

class AbstractSet[A]

class BitSet

class HashSet[A]

class LinkedHashSet[A]

class TreeSet[A]

trait SortedSet[A]

trait MapOps[K, V, CC, C]

trait SortedMapOps[K, V, CC, C]

trait SetOps[A, CC, C]

trait SortedSetOps[A, CC, C]

trait EvidenceIterableFactoryDefaults[A, CC, Ev]

trait Iterable[A]

class AbstractIterable[A]

class AbstractMap[K, V]

class AbstractSeq[A]

class AbstractSet[A]

class AbstractView[A]

class AbstractMapView[K, V]

class Filter[K, V]

class FilterKeys[K, V]

class Id[K, V]

class MapValues[K, V, W]

class TapEach[K, V, U]

class AbstractSeqView[A]

class AbstractIndexedSeqView[A]

class ArrayBufferView[A]

class Slice[A]

class StringView

class Id[A]

class Id[A]

class Reverse[A]

class Reverse[A]

class Appended[A]

class Appended[A]

class Appended[A]

class Collect[A, B]

class Concat[A]

class Concat[A]

class Concat[A]

class DistinctBy[A, B]

class Drop[A]

class Drop[A]

class Drop[A]

class DropRight[A]

class DropRight[A]

class DropRight[A]

class DropWhile[A]

class Elems[A]

object Empty

class Fill[A]

class Filter[A]

class FlatMap[A, B]

class Iterate[A]

class LeftPartitionMapped[A, A1, A2]

class Map[A, B]

class Map[A, B]

class Map[A, B]

class PadTo[A]

class Prepended[A]

class Prepended[A]

class Prepended[A]

class RightPartitionMapped[A, A1, A2]

class ScanLeft[A, B]

class Single[A]

class Tabulate[A]

class Take[A]

class Take[A]

class Take[A]

class TakeRight[A]

class TakeRight[A]

class TakeRight[A]

class TakeWhile[A]

class Unfold[A, S]

class Updated[A]

class Zip[A, B]

class ZipAll[A, B]

class ZipWithIndex[A]

trait Map[K, V]

trait DefaultMap[K, V]

trait SeqMap[K, V]

trait SortedMap[K, V]

trait Seq[A]

trait IndexedSeq[A]

trait LinearSeq[A]

trait Set[A]

trait SortedSet[A]

trait BitSet

trait View[A]

trait MapView[K, V]

trait SeqView[A]

trait IndexedSeqView[A]

class Sorted[A, B]

trait IterableFactoryDefaults[A, CC]

trait MapFactoryDefaults[K, V, CC, WithFilterCC]

class WeakHashMap[K, V]

trait MapOps[K, V, CC, C]

trait SortedMapFactoryDefaults[K, V, CC, WithFilterCC, UnsortedCC]

trait SortedMapOps[K, V, CC, C]

trait StrictOptimizedSortedMapOps[K, V, CC, C]

trait StrictOptimizedMapOps[K, V, CC, C]

trait SeqOps[A, CC, C]

trait SeqOps[A, CC, C]

trait IndexedSeqOps[A, CC, C]

trait LinearSeqOps[A, CC, C]

trait StrictOptimizedSeqOps[A, CC, C]

trait SeqOps[A, CC, C]

trait IndexedSeqOps[A, CC, C]

trait IndexedSeqOps[A, CC, C]

trait LinearSeqOps[A, CC, C]

trait StrictOptimizedLinearSeqOps[A, CC, C]

trait StrictOptimizedSeqOps[A, CC, C]

trait ArrayDequeOps[A, CC, C]

trait SetOps[A, CC, C]

trait SetOps[A, CC, C]

trait SortedSetOps[A, CC, C]

trait StrictOptimizedSortedSetOps[A, CC, C]

trait StrictOptimizedSetOps[A, CC, C]

trait SortedSetOps[A, CC, C]

trait BitSetOps[C]

trait SortedSetFactoryDefaults[A, CC, WithFilterCC]

trait StrictOptimizedSortedSetOps[A, CC, C]

trait StrictOptimizedSetOps[A, CC, C]

trait StrictOptimizedIterableOps[A, CC, C]
Show all

Members list

Value members

Abstract methods

The companion object of this iterable collection, providing various factory methods.

Attributes

Note: When implementing a custom collection type and refining CC to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).
Source: Iterable.scala

Concrete methods

Alias for concat

Attributes

Source: Iterable.scala

Builds a new iterable collection by applying a partial function to all elements of this iterable collection on which the function is defined.

Type parameters

B: the element type of the returned iterable collection.

Value parameters

pf: the partial function which filters and maps the iterable collection.

Attributes

Returns: a new iterable collection resulting from applying the given partial function pf to each element on which it is defined and collecting the results. The order of the elements is preserved.
Source: Iterable.scala

Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand.

Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the iterable collection is the most specific superclass encompassing the element types of the two operands.

Type parameters

B: the element type of the returned collection.

Value parameters

suffix: the iterable to append.

Attributes

Returns: a new iterable collection which contains all elements of this iterable collection followed by all elements of suffix.
Source: Iterable.scala

Selects all elements except first n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

n: the number of elements to drop from this iterable collection.

Attributes

Returns: a iterable collection consisting of all elements of this iterable collection except the first n ones, or else the empty iterable collection, if this iterable collection has less than n elements. If n is negative, don't drop any elements.
Source: Iterable.scala

Selects all elements except last n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

n: the number of elements to drop from this iterable collection.

Attributes

Returns: a iterable collection consisting of all elements of this iterable collection except the last n ones, or else the empty iterable collection, if this iterable collection has less than n elements. If n is negative, don't drop any elements.
Source: Iterable.scala

Drops longest prefix of elements that satisfy a predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

p: The predicate used to test elements.

Attributes

Returns: the longest suffix of this iterable collection whose first element does not satisfy the predicate p.
Source: Iterable.scala

The empty iterable of the same type as this iterable

Attributes

Returns: an empty iterable of type C.
Source: Iterable.scala

Selects all elements of this iterable collection which satisfy a predicate.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: a new iterable collection consisting of all elements of this iterable collection that satisfy the given predicate p. The order of the elements is preserved.
Source: Iterable.scala

Selects all elements of this iterable collection which do not satisfy a predicate.

Value parameters

pred: the predicate used to test elements.

Attributes

Returns: a new iterable collection consisting of all elements of this iterable collection that do not satisfy the given predicate pred. Their order may not be preserved.
Source: Iterable.scala

Builds a new iterable collection by applying a function to all elements of this iterable collection and using the elements of the resulting collections.

For example:

def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")

The type of the resulting collection is guided by the static type of iterable collection. This might cause unexpected results sometimes. For example:

// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet)

// lettersOf will return a Set[Char], not a Seq
def lettersOf(words: Seq[String]) = words.toSet flatMap ((word: String) => word.toSeq)

// xs will be an Iterable[Int]
val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2)

// ys will be a Map[Int, Int]
val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)

Type parameters

B: the element type of the returned collection.

Value parameters

f: the function to apply to each element.

Attributes

Returns: a new iterable collection resulting from applying the given collection-valued function f to each element of this iterable collection and concatenating the results.
Source: Iterable.scala

Converts this iterable collection of iterable collections into a iterable collection formed by the elements of these iterable collections.

The resulting collection's type will be guided by the type of iterable collection. For example:

val xs = List(
           Set(1, 2, 3),
           Set(1, 2, 3)
         ).flatten
// xs == List(1, 2, 3, 1, 2, 3)

val ys = Set(
           List(1, 2, 3),
           List(3, 2, 1)
         ).flatten
// ys == Set(1, 2, 3)

Type parameters

B: the type of the elements of each iterable collection.

Value parameters

asIterable: an implicit conversion which asserts that the element type of this iterable collection is an Iterable.

Attributes

Returns: a new iterable collection resulting from concatenating all element iterable collections.
Source: Iterable.scala

Partitions this iterable collection into a map of iterable collections according to some discriminator function.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Type parameters

K: the type of keys returned by the discriminator function.

Value parameters

f: the discriminator function.

Attributes

Returns

A map from keys to iterable collections such that the following invariant holds:

(xs groupBy f)(k) = xs filter (x => f(x) == k)

That is, every key k is bound to a iterable collection of those elements x for which f(x) equals k.

Source

Iterable.scala

Partitions this iterable collection into a map of iterable collections according to a discriminator function key.

Partitions this iterable collection into a map of iterable collections according to a discriminator function key. Each element in a group is transformed into a value of type B using the value function.

It is equivalent to groupBy(key).mapValues(_.map(f)), but more efficient.

case class User(name: String, age: Int)

def namesByAge(users: Seq[User]): Map[Int, Seq[String]] =
  users.groupMap(_.age)(_.name)

Note: Even when applied to a view or a lazy collection it will always force the elements.

Type parameters

B: the type of values returned by the transformation function
K: the type of keys returned by the discriminator function

Value parameters

f: the element transformation function
key: the discriminator function

Attributes

Source: Iterable.scala

Partitions this iterable collection into a map according to a discriminator function key.

Partitions this iterable collection into a map according to a discriminator function key. All the values that have the same discriminator are then transformed by the f function and then reduced into a single value with the reduce function.

It is equivalent to groupBy(key).mapValues(_.map(f).reduce(reduce)), but more efficient.

def occurrences[A](as: Seq[A]): Map[A, Int] =
  as.groupMapReduce(identity)(_ => 1)(_ + _)

Note: Even when applied to a view or a lazy collection it will always force the elements.

Attributes

Source: Iterable.scala

Partitions elements in fixed size iterable collections.

Value parameters

size: the number of elements per group

Attributes

Returns: An iterator producing iterable collections of size size, except the last will be less than size size if the elements don't divide evenly.
See also: scala.collection.Iterator, method grouped
Source: Iterable.scala

Selects the first element of this iterable collection.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Attributes

Returns: the first element of this iterable collection.
Throws: NoSuchElementException if the iterable collection is empty.
Source: Iterable.scala

Optionally selects the first element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Attributes

Returns: the first element of this iterable collection if it is nonempty, None if it is empty.
Source: Iterable.scala

The initial part of the collection without its last element.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Attributes

Source: Iterable.scala

Iterates over the inits of this iterable collection.

Iterates over the inits of this iterable collection. The first value will be this iterable collection and the final one will be an empty iterable collection, with the intervening values the results of successive applications of init.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Attributes

Returns: an iterator over all the inits of this iterable collection
Example: List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Source: Iterable.scala

Tests whether this iterable collection can be repeatedly traversed.

Tests whether this iterable collection can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.

Attributes

Returns: true if it is repeatedly traversable, false otherwise.
Definition Classes: IterableOnceOps
Source: Iterable.scala

Selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Attributes

Returns: The last element of this iterable collection.
Throws: NoSuchElementException If the iterable collection is empty.
Source: Iterable.scala

Optionally selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Attributes

Returns: the last element of this iterable collection$ if it is nonempty, None if it is empty.
Source: Iterable.scala

Builds a new iterable collection by applying a function to all elements of this iterable collection.

Type parameters

B: the element type of the returned iterable collection.

Value parameters

f: the function to apply to each element.

Attributes

Returns: a new iterable collection resulting from applying the given function f to each element of this iterable collection and collecting the results.
Source: Iterable.scala

A pair of, first, all elements that satisfy predicate p and, second, all elements that do not.

A pair of, first, all elements that satisfy predicate p and, second, all elements that do not. Interesting because it splits a collection in two.

The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of partition in StrictOptimizedIterableOps, which requires only a single traversal.

Attributes

Source: Iterable.scala

Applies a function f to each element of the iterable collection and returns a pair of iterable collections: the first one made of those values returned by f that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

Example:

val xs = Iterable(1, "one", 2, "two", 3, "three") partitionMap {
 case i: Int => Left(i)
 case s: String => Right(s)
}
// xs == (Iterable(1, 2, 3),
//        Iterable(one, two, three))

Type parameters

A1: the element type of the first resulting collection
A2: the element type of the second resulting collection

Value parameters

f: the 'split function' mapping the elements of this iterable collection to an scala.util.Either

Attributes

Returns: a pair of iterable collections: the first one made of those values returned by f that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.
Source: Iterable.scala

Computes a prefix scan of the elements of the collection.

Note: The neutral element z may be applied more than once.

Type parameters

B: element type of the resulting collection

Value parameters

op: the associative operator for the scan
z: neutral element for the operator op

Attributes

Returns: a new iterable collection containing the prefix scan of the elements in this iterable collection
Source: Iterable.scala

Produces a iterable collection containing cumulative results of applying the operator going left to right, including the initial value.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Type parameters

B: the type of the elements in the resulting collection

Value parameters

op: the binary operator applied to the intermediate result and the element
z: the initial value

Attributes

Returns: collection with intermediate results
Source: Iterable.scala

Produces a collection containing cumulative results of applying the operator going right to left.

Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Example:

List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

Type parameters

B: the type of the elements in the resulting collection

Value parameters

op: the binary operator applied to the intermediate result and the element
z: the initial value

Attributes

Returns: collection with intermediate results
Source: Iterable.scala

Compares the size of this iterable collection to a test value.

Value parameters

otherSize: the test value that gets compared with the size.

Attributes

Returns

A value x where

x <  0       if this.size <  otherSize
x == 0       if this.size == otherSize
x >  0       if this.size >  otherSize

The method as implemented here does not call size directly; its running time is O(size min otherSize) instead of O(size). The method should be overridden if computing size is cheap and knownSize returns -1.

See also

sizeIs

Source

Iterable.scala

Compares the size of this iterable collection to the size of another Iterable.

Value parameters

that: the Iterable whose size is compared with this iterable collection's size.

Attributes

Returns

A value x where

x <  0       if this.size <  that.size
x == 0       if this.size == that.size
x >  0       if this.size >  that.size

The method as implemented here does not call size directly; its running time is O(this.size min that.size) instead of O(this.size + that.size). The method should be overridden if computing size is cheap and knownSize returns -1.

Source

Iterable.scala

Returns a value class containing operations for comparing the size of this iterable collection to a test value.

These operations are implemented in terms of sizeCompare(Int), and allow the following more readable usages:

this.sizeIs < size     // this.sizeCompare(size) < 0
this.sizeIs <= size    // this.sizeCompare(size) <= 0
this.sizeIs == size    // this.sizeCompare(size) == 0
this.sizeIs != size    // this.sizeCompare(size) != 0
this.sizeIs >= size    // this.sizeCompare(size) >= 0
this.sizeIs > size     // this.sizeCompare(size) > 0

Attributes

Source: Iterable.scala

Selects an interval of elements.

Selects an interval of elements. The returned iterable collection is made up of all elements x which satisfy the invariant:

from <= indexOf(x) < until

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

from: the lowest index to include from this iterable collection.
until: the lowest index to EXCLUDE from this iterable collection.

Attributes

Returns: a iterable collection containing the elements greater than or equal to index from extending up to (but not including) index until of this iterable collection.
Source: Iterable.scala

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.

Value parameters

size: the number of elements per group

Attributes

Returns: An iterator producing iterable collections of size size, except for a non-empty collection with less than size elements, which returns an iterator that produces the source collection itself as its only element.
See also: scala.collection.Iterator, method sliding
Example: List().sliding(2) = empty iterator

List(1).sliding(2) = Iterator(List(1))

List(1, 2).sliding(2) = Iterator(List(1, 2))

List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))
Source: Iterable.scala

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.

Value parameters

size: the number of elements per group
step: the distance between the first elements of successive groups

Attributes

Returns: An iterator producing iterable collections of size size, except the last element (which may be the only element) will be smaller if there are fewer than size elements remaining to be grouped.
See also: scala.collection.Iterator, method sliding
Example: List(1, 2, 3, 4, 5).sliding(2, 2) = Iterator(List(1, 2), List(3, 4), List(5))

List(1, 2, 3, 4, 5, 6).sliding(2, 3) = Iterator(List(1, 2), List(4, 5))
Source: Iterable.scala

Splits this iterable collection into a prefix/suffix pair according to a predicate.

Note: c span p is equivalent to (but possibly more efficient than) (c takeWhile p, c dropWhile p), provided the evaluation of the predicate p does not cause any side-effects.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

p: the test predicate

Attributes

Returns: a pair consisting of the longest prefix of this iterable collection whose elements all satisfy p, and the rest of this iterable collection.
Source: Iterable.scala

Splits this iterable collection into a prefix/suffix pair at a given position.

Note: c splitAt n is equivalent to (but possibly more efficient than) (c take n, c drop n).

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

n: the position at which to split.

Attributes

Returns: a pair of iterable collections consisting of the first n elements of this iterable collection, and the other elements.
Definition Classes: IterableOnceOps
Source: Iterable.scala

The rest of the collection without its first element.

Attributes

Source: Iterable.scala

Iterates over the tails of this iterable collection.

Iterates over the tails of this iterable collection. The first value will be this iterable collection and the final one will be an empty iterable collection, with the intervening values the results of successive applications of tail.

Attributes

Returns: an iterator over all the tails of this iterable collection
Example: List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Source: Iterable.scala

Selects the first n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

n: the number of elements to take from this iterable collection.

Attributes

Returns: a iterable collection consisting only of the first n elements of this iterable collection, or else the whole iterable collection, if it has less than n elements. If n is negative, returns an empty iterable collection.
Source: Iterable.scala

Selects the last n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

n: the number of elements to take from this iterable collection.

Attributes

Returns: a iterable collection consisting only of the last n elements of this iterable collection, or else the whole iterable collection, if it has less than n elements. If n is negative, returns an empty iterable collection.
Source: Iterable.scala

Takes longest prefix of elements that satisfy a predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

p: The predicate used to test elements.

Attributes

Returns: the longest prefix of this iterable collection whose elements all satisfy the predicate p.
Source: Iterable.scala

Applies a side-effecting function to each element in this collection.

Applies a side-effecting function to each element in this collection. Strict collections will apply f to their elements immediately, while lazy collections like Views and LazyLists will only apply f on each element if and when that element is evaluated, and each time that element is evaluated.

Type parameters

U: the return type of f

Value parameters

f: a function to apply to each element in this iterable collection

Attributes

Returns: The same logical collection as this
Definition Classes: IterableOnceOps
Source: Iterable.scala

Transposes this iterable collection of iterable collections into a iterable collection of iterable collections.

The resulting collection's type will be guided by the static type of iterable collection. For example:

val xs = List(
           Set(1, 2, 3),
           Set(4, 5, 6)).transpose
// xs == List(
//         List(1, 4),
//         List(2, 5),
//         List(3, 6))

val ys = Vector(
           List(1, 2, 3),
           List(4, 5, 6)).transpose
// ys == Vector(
//         Vector(1, 4),
//         Vector(2, 5),
//         Vector(3, 6))

Note: Even when applied to a view or a lazy collection it will always force the elements.

Type parameters

B: the type of the elements of each iterable collection.

Value parameters

asIterable: an implicit conversion which asserts that the element type of this iterable collection is an Iterable.

Attributes

Returns: a two-dimensional iterable collection of iterable collections which has as nth row the nth column of this iterable collection.
Throws: IllegalArgumentException if all collections in this iterable collection are not of the same size.
Source: Iterable.scala

Converts this iterable collection of pairs into two collections of the first and second half of each pair.

val xs = Iterable(
           (1, "one"),
           (2, "two"),
           (3, "three")).unzip
// xs == (Iterable(1, 2, 3),
//        Iterable(one, two, three))

Type parameters

A1: the type of the first half of the element pairs
A2: the type of the second half of the element pairs

Value parameters

asPair: an implicit conversion which asserts that the element type of this iterable collection is a pair.

Attributes

Returns: a pair of iterable collections, containing the first, respectively second half of each element pair of this iterable collection.
Source: Iterable.scala

Converts this iterable collection of triples into three collections of the first, second, and third element of each triple.

val xs = Iterable(
           (1, "one", '1'),
           (2, "two", '2'),
           (3, "three", '3')).unzip3
// xs == (Iterable(1, 2, 3),
//        Iterable(one, two, three),
//        Iterable(1, 2, 3))

Type parameters

A1: the type of the first member of the element triples
A2: the type of the second member of the element triples
A3: the type of the third member of the element triples

Value parameters

asTriple: an implicit conversion which asserts that the element type of this iterable collection is a triple.

Attributes

Returns: a triple of iterable collections, containing the first, second, respectively third member of each element triple of this iterable collection.
Source: Iterable.scala

A view over the elements of this collection.

Attributes

Source: Iterable.scala

Creates a non-strict filter of this iterable collection.

Note: the difference between c filter p and c withFilter p is that the former creates a new collection, whereas the latter only restricts the domain of subsequent map, flatMap, foreach, and withFilter operations.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: an object of class WithFilter, which supports map, flatMap, foreach, and withFilter operations. All these operations apply to those elements of this iterable collection which satisfy the predicate p.
Source: Iterable.scala

Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs.

Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

Type parameters

B: the type of the second half of the returned pairs

Value parameters

that: The iterable providing the second half of each result pair

Attributes

Returns: a new iterable collection containing pairs consisting of corresponding elements of this iterable collection and that. The length of the returned collection is the minimum of the lengths of this iterable collection and that.
Source: Iterable.scala

Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs.

Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

Value parameters

that: the iterable providing the second half of each result pair
thatElem: the element to be used to fill up the result if that is shorter than this iterable collection.
thisElem: the element to be used to fill up the result if this iterable collection is shorter than that.

Attributes

Returns: a new collection of type That containing pairs consisting of corresponding elements of this iterable collection and that. The length of the returned collection is the maximum of the lengths of this iterable collection and that. If this iterable collection is shorter than that, thisElem values are used to pad the result. If that is shorter than this iterable collection, thatElem values are used to pad the result.
Source: Iterable.scala

Zips this iterable collection with its indices.

Attributes

Returns: A new iterable collection containing pairs consisting of all elements of this iterable collection paired with their index. Indices start at 0.
Example: List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))
Source: Iterable.scala

Deprecated methods

Attributes

Deprecated: true
Source: Iterable.scala

Attributes

Deprecated: true
Source: Iterable.scala

Attributes

Deprecated: true
Source: Iterable.scala

Attributes

Returns: This collection as an Iterable[A]. No new collection will be built if this is already an Iterable[A].
Deprecated: true
Source: Iterable.scala

Converts this iterable collection to an unspecified Iterable.

Converts this iterable collection to an unspecified Iterable. Will return the same collection if this instance is already Iterable.

Attributes

Returns: An Iterable containing all elements of this iterable collection.
Deprecated: true
Source: Iterable.scala

A view over a slice of the elements of this collection.

Attributes

Deprecated: true
Source: Iterable.scala

Inherited methods

Appends all elements of this collection to a string builder.

Appends all elements of this collection to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this collection without any separator string.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> val h = a.addString(b)
h: StringBuilder = 1234

Value parameters

b: the string builder to which elements are appended.

Attributes

Returns: the string builder b to which elements were appended.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Appends all elements of this collection to a string builder using a separator string.

Appends all elements of this collection to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method toString) of all elements of this collection, separated by the string sep.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b, ", ")
res0: StringBuilder = 1, 2, 3, 4

Value parameters

b: the string builder to which elements are appended.
sep: the separator string.

Attributes

Returns: the string builder b to which elements were appended.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Appends all elements of this collection to a string builder using start, end, and separator strings.

Appends all elements of this collection to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this collection are separated by the string sep.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b , "List(" , ", " , ")")
res5: StringBuilder = List(1, 2, 3, 4)

Value parameters

b: the string builder to which elements are appended.
end: the ending string.
sep: the separator string.
start: the starting string.

Attributes

Returns: the string builder b to which elements were appended.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element of the collection for which the given partial function is defined, and applies the partial function to it.

Note: may not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

pf: the partial function

Attributes

Returns: an option value containing pf applied to the first value for which it is defined, or None if none exists.
Example: Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Copy elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with at most len elements of this collection.

Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached, or len elements have been copied.

Type parameters

B: the type of the elements of the array.

Value parameters

len: the maximal number of elements to copy.
start: the starting index of xs.
xs: the array to fill.

Attributes

Returns: the number of elements written to the array
Note: Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Copy elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with values of this collection.

Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached.

Type parameters

B: the type of the elements of the array.

Value parameters

start: the starting index of xs.
xs: the array to fill.

Attributes

Returns: the number of elements written to the array
Note: Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Copy elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with values of this collection.

Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached.

Type parameters

B: the type of the elements of the array.

Value parameters

xs: the array to fill.

Attributes

Returns: the number of elements written to the array
Note: Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

Note: will not terminate for infinite-sized collections.

Type parameters

B: the type of the elements of that

Value parameters

p: the test predicate, which relates elements from both collections
that: the other collection

Attributes

Returns: true if both collections have the same length and p(x, y) is true for all corresponding elements x of this iterator and y of that, otherwise false
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Counts the number of elements in the collection which satisfy a predicate.

Note: will not terminate for infinite-sized collections.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: the number of elements satisfying the predicate p.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether a predicate holds for at least one element of this collection.

Note: may not terminate for infinite-sized collections.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: true if the given predicate p is satisfied by at least one element of this collection, otherwise false
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element of the collection satisfying a predicate, if any.

Note: may not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: an option value containing the first element in the collection that satisfies p, or None if none exists.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Folds the elements of this collection using the specified associative binary operator.

Folds the elements of this collection using the specified associative binary operator. The default implementation in IterableOnce is equivalent to foldLeft but may be overridden for more efficient traversal orders.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Note: will not terminate for infinite-sized collections.

Type parameters

A1: a type parameter for the binary operator, a supertype of A.

Value parameters

op: a binary operator that must be associative.
z: a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation, 0 for addition, or 1 for multiplication).

Attributes

Returns: the result of applying the fold operator op between all the elements and z, or z if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Applies a binary operator to a start value and all elements of this collection, going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.
z: the start value.

Attributes

Returns: the result of inserting op between consecutive elements of this collection, going left to right with the start value z on the left: op(...op(z, x1), x2, ..., xn) where x1, ..., xn are the elements of this collection. Returns z if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Applies a binary operator to all elements of this collection and a start value, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.
z: the start value.

Attributes

Returns: the result of inserting op between consecutive elements of this collection, going right to left with the start value z on the right: op(x1, op(x2, ... op(xn, z)...)) where x1, ..., xn are the elements of this collection. Returns z if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether a predicate holds for all elements of this collection.

Note: may not terminate for infinite-sized collections.

Value parameters

p: the predicate used to test elements.

Attributes

Returns: true if this collection is empty or the given predicate p holds for all elements of this collection, otherwise false.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Apply f to each element for its side effects Note: [U] parameter needed to help scalac's type inference.

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether the collection is empty.

Note: Implementations in subclasses that are not repeatedly iterable must take care not to consume any elements when isEmpty is called.

Attributes

Returns: true if the collection contains no elements, false otherwise.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Iterator can be used only once

Attributes

Inherited from:: IterableOnce
Source: IterableOnce.scala

Attributes

Returns: The number of elements in this collection, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.
Inherited from:: IterableOnce
Source: IterableOnce.scala

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The type over which the ordering is defined.

Value parameters

ord: An ordering to be used for comparing elements.

Attributes

Returns: the largest element of this collection with respect to the ordering ord.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element which yields the largest value measured by function f.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The result type of the function f.

Value parameters

cmp: An ordering to be used for comparing elements.
f: The measuring function.

Attributes

Returns: the first element of this collection with the largest value measured by function f with respect to the ordering cmp.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element which yields the largest value measured by function f.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The result type of the function f.

Value parameters

cmp: An ordering to be used for comparing elements.
f: The measuring function.

Attributes

Returns: an option value containing the first element of this collection with the largest value measured by function f with respect to the ordering cmp.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The type over which the ordering is defined.

Value parameters

ord: An ordering to be used for comparing elements.

Attributes

Returns: an option value containing the largest element of this collection with respect to the ordering ord.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The type over which the ordering is defined.

Value parameters

ord: An ordering to be used for comparing elements.

Attributes

Returns: the smallest element of this collection with respect to the ordering ord.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element which yields the smallest value measured by function f.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The result type of the function f.

Value parameters

cmp: An ordering to be used for comparing elements.
f: The measuring function.

Attributes

Returns: the first element of this collection with the smallest value measured by function f with respect to the ordering cmp.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the first element which yields the smallest value measured by function f.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The result type of the function f.

Value parameters

cmp: An ordering to be used for comparing elements.
f: The measuring function.

Attributes

Returns: an option value containing the first element of this collection with the smallest value measured by function f with respect to the ordering cmp.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Type parameters

B: The type over which the ordering is defined.

Value parameters

ord: An ordering to be used for comparing elements.

Attributes

Returns: an option value containing the smallest element of this collection with respect to the ordering ord.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Displays all elements of this collection in a string.

Delegates to addString, which can be overridden.

Attributes

Returns: a string representation of this collection. In the resulting string the string representations (w.r.t. the method toString) of all elements of this collection follow each other without any separator string.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Displays all elements of this collection in a string using a separator string.

Delegates to addString, which can be overridden.

Value parameters

sep: the separator string.

Attributes

Returns: a string representation of this collection. In the resulting string the string representations (w.r.t. the method toString) of all elements of this collection are separated by the string sep.
Example: List(1, 2, 3).mkString("|") = "1|2|3"
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Displays all elements of this collection in a string using start, end, and separator strings.

Delegates to addString, which can be overridden.

Value parameters

end: the ending string.
sep: the separator string.
start: the starting string.

Attributes

Returns: a string representation of this collection. The resulting string begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this collection are separated by the string sep.
Example: List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether the collection is not empty.

Attributes

Returns: true if the collection contains at least one element, false otherwise.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Multiplies up the elements of this collection.

Note: will not terminate for infinite-sized collections.

Type parameters

B: the result type of the * operator.

Value parameters

num: an implicit parameter defining a set of numeric operations which includes the * operator to be used in forming the product.

Attributes

Returns: the product of all elements of this collection with respect to the * operator in num.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Reduces the elements of this collection using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Type parameters

B: A type parameter for the binary operator, a supertype of A.

Value parameters

op: A binary operator that must be associative.

Attributes

Returns: The result of applying reduce operator op between all the elements if the collection is nonempty.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Applies a binary operator to all elements of this collection, going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.

Attributes

Returns: the result of inserting op between consecutive elements of this collection, going left to right: op( op( ... op(x1, x2) ..., xn-1), xn) where x1, ..., xn are the elements of this collection.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Optionally applies a binary operator to all elements of this collection, going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.

Attributes

Returns: an option value containing the result of reduceLeft(op) if this collection is nonempty, None otherwise.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Reduces the elements of this collection, if any, using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Type parameters

B: A type parameter for the binary operator, a supertype of A.

Value parameters

op: A binary operator that must be associative.

Attributes

Returns: An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Applies a binary operator to all elements of this collection, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.

Attributes

Returns: the result of inserting op between consecutive elements of this collection, going right to left: op(x1, op(x2, ..., op(xn-1, xn)...)) where x1, ..., xn are the elements of this collection.
Throws: UnsupportedOperationException if this collection is empty.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Optionally applies a binary operator to all elements of this collection, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Type parameters

B: the result type of the binary operator.

Value parameters

op: the binary operator.

Attributes

Returns: an option value containing the result of reduceRight(op) if this collection is nonempty, None otherwise.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

The size of this collection.

Note: will not terminate for infinite-sized collections.

Attributes

Returns: the number of elements in this collection.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Returns a scala.collection.Stepper for the elements of this collection.

The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.

The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.

For collections of Int, Short, Byte or Char, an scala.collection.IntStepper is returned
For collections of Double or Float, a scala.collection.DoubleStepper is returned
For collections of Long a scala.collection.LongStepper is returned
For any other element type, an scala.collection.AnyStepper is returned

Note that this method is overridden in subclasses and the return type is refined to S with EfficientSplit, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.

Attributes

Inherited from:: IterableOnce
Source: IterableOnce.scala

Sums up the elements of this collection.

Note: will not terminate for infinite-sized collections.

Type parameters

B: the result type of the + operator.

Value parameters

num: an implicit parameter defining a set of numeric operations which includes the + operator to be used in forming the sum.

Attributes

Returns: the sum of all elements of this collection with respect to the + operator in num.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Given a collection factory factory, convert this collection to the appropriate representation for the current element type A.

Given a collection factory factory, convert this collection to the appropriate representation for the current element type A. Example uses:

xs.to(List) xs.to(ArrayBuffer) xs.to(BitSet) // for xs: Iterable[Int]

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Convert collection to array.

Implementation note: DO NOT call Array.from from this method.

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Returns: This collection as a Seq[A]. This is equivalent to to(Seq) but might be faster.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Deprecated and Inherited methods

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Tests whether this collection is known to have a finite size.

Tests whether this collection is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as Stream, the predicate returns true if all elements have been computed. It returns false if the stream is not yet evaluated to the end. Non-empty Iterators usually return false even if they were created from a collection with a known finite size.

Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that hasDefiniteSize returns true. However, checking hasDefiniteSize can provide an assurance that size is well-defined and non-termination is not a concern.

Attributes

Returns: true if this collection is known to have finite size, false otherwise.
See also: method knownSize for a more useful alternative
Deprecated: This method is deprecated in 2.13 because it does not provide any actionable information. As noted above, even the collection library itself does not use it. When there is no guarantee that a collection is finite, it is generally best to attempt a computation anyway and document that it will not terminate for infinite collections rather than backing out because this would prevent performing the computation on collections that are in fact finite even though hasDefiniteSize returns false.
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

Attributes

Deprecated: true
Inherited from:: IterableOnceOps
Source: IterableOnce.scala

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