ArrayDequeOps

trait ArrayDequeOps[A, +CC[_], +C <: AnyRef] extends StrictOptimizedSeqOps[A, CC, C]
trait SeqOps[A, CC, C]
trait IterableOps[A, CC, C]
class Object
trait Matchable
class Any
class ArrayDeque[A]
class Queue[A]
class Stack[A]

Value members

Abstract methods

protected def array: Array[AnyRef]
protected def klone(): C
protected def ofArray(array: Array[AnyRef], end: Int): C
protected def start_+(idx: Int): Int

Concrete methods

final override def clone(): C
Definition Classes
Source
ArrayDeque.scala
def copySliceToArray(srcStart: Int, dest: Array[_], destStart: Int, maxItems: Int): dest

This is a more general version of copyToArray - this also accepts a srcStart unlike copyToArray This copies maxItems elements from this collections srcStart to dest's destStart If we reach the end of either collections before we could copy maxItems, we simply stop copying

This is a more general version of copyToArray - this also accepts a srcStart unlike copyToArray This copies maxItems elements from this collections srcStart to dest's destStart If we reach the end of either collections before we could copy maxItems, we simply stop copying

Source
ArrayDeque.scala
override def grouped(n: Int): Iterator[C]
Definition Classes
Source
ArrayDeque.scala
final protected def requireBounds(idx: Int, until: Int): Unit
override def reverse: C
Definition Classes
Source
ArrayDeque.scala
override def slice(from: Int, until: Int): C
Definition Classes
Source
ArrayDeque.scala
override def sliding(window: Int, step: Int): Iterator[C]
Definition Classes
Source
ArrayDeque.scala

Inherited methods

final def ++[B >: A](suffix: IterableOnce[B]): CC[B]

Alias for concat

Alias for concat

Inherited from
IterableOps
Source
Iterable.scala
final override def ++:[B >: A](prefix: IterableOnce[B]): CC[B]

Alias for prependedAll

Alias for prependedAll

Definition Classes
Inherited from
SeqOps
Source
Seq.scala
final def +:[B >: A](elem: B): CC[B]

Alias for prepended.

Alias for prepended.

Note that :-ending operators are right associative (see example). A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

Inherited from
SeqOps
Source
Seq.scala
final def :+[B >: A](elem: B): CC[B]

Alias for appended

Alias for appended

Note that :-ending operators are right associative (see example). A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

Inherited from
SeqOps
Source
Seq.scala
final def :++[B >: A](suffix: IterableOnce[B]): CC[B]

Alias for appendedAll

Alias for appendedAll

Inherited from
SeqOps
Source
Seq.scala

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 Params
b

the string builder to which elements are appended.

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 Params
b

the string builder to which elements are appended.

sep

the separator string.

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 Params
b

the string builder to which elements are appended.

end

the ending string.

sep

the separator string.

start

the starting string.

Returns

the string builder b to which elements were appended.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
override def appended[B >: A](elem: B): CC[B]
override def appendedAll[B >: A](suffix: IterableOnce[B]): CC[B]
@throws(scala.throws.$lessinit$greater$default$1[scala.IndexOutOfBoundsException])
def apply(i: Int): A

Get the element at the specified index.

Get the element at the specified index. This operation is provided for convenience in Seq. It should not be assumed to be efficient unless you have an IndexedSeq.

Inherited from
SeqOps
Source
Seq.scala
def collectFirst[B](pf: PartialFunction[A, B]): Option[B]

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

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 Params
pf

the partial function

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

Iterates over combinations.

Iterates over combinations. A _combination_ of length n is a subsequence of the original sequence, with the elements taken in order. Thus, "xy" and "yy" are both length-2 combinations of "xyy", but "yx" is not. If there is more than one way to generate the same subsequence, only one will be returned.

For example, "xyyy" has three different ways to generate "xy" depending on whether the first, second, or third "y" is selected. However, since all are identical, only one will be chosen. Which of the three will be taken is an implementation detail that is not defined.

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

Returns

An Iterator which traverses the possible n-element combinations of this sequence.

Example

"abbbc".combinations(2) = Iterator(ab, ac, bb, bc)

Inherited from
SeqOps
Source
Seq.scala
final override def concat[B >: A](suffix: IterableOnce[B]): CC[B]
Definition Classes
Inherited from
SeqOps
Source
Seq.scala
def contains[A1 >: A](elem: A1): Boolean

Tests whether this sequence contains a given value as an element.

Tests whether this sequence contains a given value as an element.

Note: may not terminate for infinite-sized collections.

Value Params
elem

the element to test.

Returns

true if this sequence has an element that is equal (as determined by ==) to elem, false otherwise.

Inherited from
SeqOps
Source
Seq.scala
def containsSlice[B >: A](that: Seq[B]): Boolean

Tests whether this sequence contains a given sequence as a slice.

Tests whether this sequence contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

Value Params
that

the sequence to test

Returns

true if this sequence contains a slice with the same elements as that, otherwise false.

Inherited from
SeqOps
Source
Seq.scala
def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Int

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

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 Params
B

the type of the elements of the array.

Value Params
len

the maximal number of elements to copy.

start

the starting index of xs.

xs

the array to fill.

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
@deprecatedOverriding("This should always forward to the 3-arg version of this method", since = "2.13.4")
def copyToArray[B >: A](xs: Array[B], start: Int): Int

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

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 Params
B

the type of the elements of the array.

Value Params
start

the starting index of xs.

xs

the array to fill.

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
@deprecatedOverriding("This should always forward to the 3-arg version of this method", since = "2.13.4")
def copyToArray[B >: A](xs: Array[B]): Int

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

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 Params
B

the type of the elements of the array.

Value Params
xs

the array to fill.

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
def corresponds[B](that: IterableOnce[B])(p: (A, B) => Boolean): Boolean

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

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 Params
B

the type of the elements of that

Value Params
p

the test predicate, which relates elements from both collections

that

the other collection

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
def corresponds[B](that: Seq[B])(p: (A, B) => Boolean): Boolean

Tests whether every element of this sequence relates to the corresponding element of another sequence by satisfying a test predicate.

Tests whether every element of this sequence relates to the corresponding element of another sequence by satisfying a test predicate.

Type Params
B

the type of the elements of that

Value Params
p

the test predicate, which relates elements from both sequences

that

the other sequence

Returns

true if both sequences have the same length and p(x, y) is true for all corresponding elements x of this sequence and y of that, otherwise false.

Inherited from
SeqOps
Source
Seq.scala
def count(p: A => Boolean): Int

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

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

Note: will not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the number of elements satisfying the predicate p.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
override def diff[B >: A](that: Seq[B]): C
def distinct: C

Selects all the elements of this sequence ignoring the duplicates.

Selects all the elements of this sequence ignoring the duplicates.

Returns

a new sequence consisting of all the elements of this sequence without duplicates.

Inherited from
SeqOps
Source
Seq.scala
override def distinctBy[B](f: A => B): C
def drop(n: Int): C
Inherited from
IterableOps
Source
Iterable.scala
override def dropRight(n: Int): C

The rest of the collection without its n last elements.

The rest of the collection without its n last elements. For linear, immutable collections this should avoid making a copy.

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

Definition Classes
Inherited from
StrictOptimizedIterableOps
Source
StrictOptimizedIterableOps.scala
def dropWhile(p: A => Boolean): C
Inherited from
IterableOps
Source
Iterable.scala
def empty: C

The empty iterable of the same type as this iterable

The empty iterable of the same type as this iterable

Returns

an empty iterable of type C.

Inherited from
IterableOps
Source
Iterable.scala
def endsWith[B >: A](that: Iterable[B]): Boolean

Tests whether this sequence ends with the given sequence.

Tests whether this sequence ends with the given sequence.

Note: will not terminate for infinite-sized collections.

Value Params
that

the sequence to test

Returns

true if this sequence has that as a suffix, false otherwise.

Inherited from
SeqOps
Source
Seq.scala
def exists(p: A => Boolean): Boolean

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

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

Note: may not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

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
def find(p: A => Boolean): Option[A]

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

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 Params
p

the predicate used to test elements.

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
def findLast(p: A => Boolean): Option[A]

Finds the last element of the sequence satisfying a predicate, if any.

Finds the last element of the sequence satisfying a predicate, if any.

Note: will not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

an option value containing the last element in the sequence that satisfies p, or None if none exists.

Inherited from
SeqOps
Source
Seq.scala
override def flatten[B](implicit toIterableOnce: A => IterableOnce[B]): CC[B]
def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1

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 Params
A1

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

Value Params
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).

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
def foldLeft[B](z: B)(op: (B, A) => B): B

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

z

the start value.

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
def foldRight[B](z: B)(op: (A, B) => B): B

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

z

the start value.

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
def forall(p: A => Boolean): Boolean

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

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

Note: may not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

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
def foreach[U](f: A => U): Unit

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

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

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def groupBy[K](f: A => K): Map[K, C]

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

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 Params
K

the type of keys returned by the discriminator function.

Value Params
f

the discriminator function.

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.

Inherited from
IterableOps
Source
Iterable.scala
def groupMap[K, B](key: A => K)(f: A => B): Map[K, CC[B]]

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 Params
B

the type of values returned by the transformation function

K

the type of keys returned by the discriminator function

Value Params
f

the element transformation function

key

the discriminator function

Inherited from
IterableOps
Source
Iterable.scala
def groupMapReduce[K, B](key: A => K)(f: A => B)(reduce: (B, B) => B): Map[K, B]

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.

Inherited from
IterableOps
Source
Iterable.scala
def head: A

Selects the first element of this iterable collection.

Selects the first element of this iterable collection.

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

Returns

the first element of this iterable collection.

Throws
NoSuchElementException

if the iterable collection is empty.

Inherited from
IterableOps
Source
Iterable.scala

Optionally selects the first element.

Optionally selects the first element.

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

Returns

the first element of this iterable collection if it is nonempty, None if it is empty.

Inherited from
IterableOps
Source
Iterable.scala
@deprecatedOverriding("Override indexOf(elem, from) instead - indexOf(elem) calls indexOf(elem, 0)", "2.13.0")
def indexOf[B >: A](elem: B): Int

Finds index of first occurrence of some value in this sequence.

Finds index of first occurrence of some value in this sequence.

Type Params
B

the type of the element elem.

Value Params
elem

the element value to search for.

Returns

the index >= 0 of the first element of this sequence that is equal (as determined by ==) to elem, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala
def indexOf[B >: A](elem: B, from: Int): Int

Finds index of first occurrence of some value in this sequence after or at some start index.

Finds index of first occurrence of some value in this sequence after or at some start index.

Type Params
B

the type of the element elem.

Value Params
elem

the element value to search for.

from

the start index

Returns

the index >= from of the first element of this sequence that is equal (as determined by ==) to elem, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala
@deprecatedOverriding("Override indexOfSlice(that, from) instead - indexOfSlice(that) calls indexOfSlice(that, 0)", "2.13.0")
def indexOfSlice[B >: A](that: Seq[B]): Int

Finds first index where this sequence contains a given sequence as a slice.

Finds first index where this sequence contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

Value Params
that

the sequence to test

Returns

the first index >= 0 such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Inherited from
SeqOps
Source
Seq.scala
def indexOfSlice[B >: A](that: Seq[B], from: Int): Int

Finds first index after or at a start index where this sequence contains a given sequence as a slice.

Finds first index after or at a start index where this sequence contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

Value Params
from

the start index

that

the sequence to test

Returns

the first index >= from such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Inherited from
SeqOps
Source
Seq.scala
@deprecatedOverriding("Override indexWhere(p, from) instead - indexWhere(p) calls indexWhere(p, 0)", "2.13.0")
def indexWhere(p: A => Boolean): Int

Finds index of the first element satisfying some predicate.

Finds index of the first element satisfying some predicate.

Note: may not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the index >= 0 of the first element of this sequence that satisfies the predicate p, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala
def indexWhere(p: A => Boolean, from: Int): Int

Finds index of the first element satisfying some predicate after or at some start index.

Finds index of the first element satisfying some predicate after or at some start index.

Note: may not terminate for infinite-sized collections.

Value Params
from

the start index

p

the predicate used to test elements.

Returns

the index >= from of the first element of this sequence that satisfies the predicate p, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala

Produces the range of all indices of this sequence.

Produces the range of all indices of this sequence.

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

Returns

a Range value from 0 to one less than the length of this sequence.

Inherited from
SeqOps
Source
Seq.scala
def init: C

The initial part of the collection without its last element.

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.

Inherited from
IterableOps
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.

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)

Inherited from
IterableOps
Source
Iterable.scala
override def intersect[B >: A](that: Seq[B]): C
def isDefinedAt(idx: Int): Boolean

Tests whether this sequence contains given index.

Tests whether this sequence contains given index.

The implementations of methods apply and isDefinedAt turn a Seq[A] into a PartialFunction[Int, A].

Value Params
idx

the index to test

Returns

true if this sequence contains an element at position idx, false otherwise.

Inherited from
SeqOps
Source
Seq.scala
override def isEmpty: Boolean
Definition Classes
Inherited from
SeqOps
Source
Seq.scala
Definition Classes
Inherited from
IterableOps
Source
Iterable.scala

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

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

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).

Inherited from
IterableOps
Source
Iterable.scala

Iterator can be used only once

Iterator can be used only once

Inherited from
IterableOnce
Source
IterableOnce.scala
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
def last: A

Selects the last element.

Selects the last element.

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

Returns

The last element of this iterable collection.

Throws
NoSuchElementException

If the iterable collection is empty.

Inherited from
IterableOps
Source
Iterable.scala
def lastIndexOf[B >: A](elem: B, end: Int): Int

Finds index of last occurrence of some value in this sequence before or at a given end index.

Finds index of last occurrence of some value in this sequence before or at a given end index.

Note: will not terminate for infinite-sized collections.

Type Params
B

the type of the element elem.

Value Params
elem

the element value to search for.

end

the end index.

Returns

the index <= end of the last element of this sequence that is equal (as determined by ==) to elem, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala
@deprecatedOverriding("Override lastIndexOfSlice(that, end) instead - lastIndexOfSlice(that) calls lastIndexOfSlice(that, Int.MaxValue)", "2.13.0")
def lastIndexOfSlice[B >: A](that: Seq[B]): Int

Finds last index where this sequence contains a given sequence as a slice.

Finds last index where this sequence contains a given sequence as a slice.

Note: will not terminate for infinite-sized collections.

Value Params
that

the sequence to test

Returns

the last index such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Inherited from
SeqOps
Source
Seq.scala
def lastIndexOfSlice[B >: A](that: Seq[B], end: Int): Int

Finds last index before or at a given end index where this sequence contains a given sequence as a slice.

Finds last index before or at a given end index where this sequence contains a given sequence as a slice.

Note: will not terminate for infinite-sized collections.

Value Params
end

the end index

that

the sequence to test

Returns

the last index <= end such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Inherited from
SeqOps
Source
Seq.scala
@deprecatedOverriding("Override lastIndexWhere(p, end) instead - lastIndexWhere(p) calls lastIndexWhere(p, Int.MaxValue)", "2.13.0")

Finds index of last element satisfying some predicate.

Finds index of last element satisfying some predicate.

Note: will not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the index of the last element of this sequence that satisfies the predicate p, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala
def lastIndexWhere(p: A => Boolean, end: Int): Int

Finds index of last element satisfying some predicate before or at given end index.

Finds index of last element satisfying some predicate before or at given end index.

Note: will not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the index <= end of the last element of this sequence that satisfies the predicate p, or -1, if none exists.

Inherited from
SeqOps
Source
Seq.scala

Optionally selects the last element.

Optionally selects the last element.

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

Returns

the last element of this iterable collection$ if it is nonempty, None if it is empty.

Inherited from
IterableOps
Source
Iterable.scala
def length: Int

The length (number of elements) of the sequence.

The length (number of elements) of the sequence. size is an alias for length in Seq collections.

Inherited from
SeqOps
Source
Seq.scala
def lengthCompare(that: Iterable[_]): Int

Compares the length of this sequence to the size of another Iterable.

Compares the length of this sequence to the size of another Iterable.

Value Params
that

the Iterable whose size is compared with this sequence's length.

Returns

A value x where

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

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

Inherited from
SeqOps
Source
Seq.scala
def lengthCompare(len: Int): Int

Compares the length of this sequence to a test value.

Compares the length of this sequence to a test value.

Value Params
len

the test value that gets compared with the length.

Returns

A value x where

x <  0       if this.length <  len
x == 0       if this.length == len
x >  0       if this.length >  len

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

See also
Inherited from
SeqOps
Source
Seq.scala

Returns a value class containing operations for comparing the length of this sequence to a test value.

Returns a value class containing operations for comparing the length of this sequence to a test value.

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

this.lengthIs < len     // this.lengthCompare(len) < 0
this.lengthIs <= len    // this.lengthCompare(len) <= 0
this.lengthIs == len    // this.lengthCompare(len) == 0
this.lengthIs != len    // this.lengthCompare(len) != 0
this.lengthIs >= len    // this.lengthCompare(len) >= 0
this.lengthIs > len     // this.lengthCompare(len) > 0
Inherited from
SeqOps
Source
Seq.scala
def max[B >: A](implicit ord: Ordering[B]): A

Finds the largest element.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Type Params
B

The type over which the ordering is defined.

Value Params
ord

An ordering to be used for comparing elements.

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
def maxBy[B](f: A => B)(implicit cmp: Ordering[B]): A

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

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

Note: will not terminate for infinite-sized collections.

Type Params
B

The result type of the function f.

Value Params
cmp

An ordering to be used for comparing elements.

f

The measuring function.

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
def maxByOption[B](f: A => B)(implicit cmp: Ordering[B]): Option[A]

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

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

Note: will not terminate for infinite-sized collections.

Type Params
B

The result type of the function f.

Value Params
cmp

An ordering to be used for comparing elements.

f

The measuring function.

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
def maxOption[B >: A](implicit ord: Ordering[B]): Option[A]

Finds the largest element.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Type Params
B

The type over which the ordering is defined.

Value Params
ord

An ordering to be used for comparing elements.

Returns

an option value containing the largest element of this collection with respect to the ordering ord.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def min[B >: A](implicit ord: Ordering[B]): A

Finds the smallest element.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Type Params
B

The type over which the ordering is defined.

Value Params
ord

An ordering to be used for comparing elements.

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
def minBy[B](f: A => B)(implicit cmp: Ordering[B]): A

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

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

Note: will not terminate for infinite-sized collections.

Type Params
B

The result type of the function f.

Value Params
cmp

An ordering to be used for comparing elements.

f

The measuring function.

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
def minByOption[B](f: A => B)(implicit cmp: Ordering[B]): Option[A]

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

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

Note: will not terminate for infinite-sized collections.

Type Params
B

The result type of the function f.

Value Params
cmp

An ordering to be used for comparing elements.

f

The measuring function.

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
def minOption[B >: A](implicit ord: Ordering[B]): Option[A]

Finds the smallest element.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Type Params
B

The type over which the ordering is defined.

Value Params
ord

An ordering to be used for comparing elements.

Returns

an option value containing the smallest element of this collection with respect to the ordering ord.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
final def mkString: String

Displays all elements of this collection in a string.

Displays all elements of this collection in a string.

Delegates to addString, which can be overridden.

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
final def mkString(sep: String): String

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

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

Delegates to addString, which can be overridden.

Value Params
sep

the separator string.

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
final def mkString(start: String, sep: String, end: String): String

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

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

Delegates to addString, which can be overridden.

Value Params
end

the ending string.

sep

the separator string.

start

the starting string.

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
@deprecatedOverriding("nonEmpty is defined as !isEmpty; override isEmpty instead", "2.13.0")

Tests whether the collection is not empty.

Tests whether the collection is not empty.

Returns

true if the collection contains at least one element, false otherwise.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
override def padTo[B >: A](len: Int, elem: B): CC[B]
override def partitionMap[A1, A2](f: A => Either[A1, A2]): (CC[A1], CC[A2])
def patch[B >: A](from: Int, other: IterableOnce[B], replaced: Int): CC[B]

Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.

Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.

Patching at negative indices is the same as patching starting at 0. Patching at indices at or larger than the length of the original sequence appends the patch to the end. If more values are replaced than actually exist, the excess is ignored.

Type Params
B

the element type of the returned sequence.

Value Params
from

the index of the first replaced element

other

the replacement sequence

replaced

the number of elements to drop in the original sequence

Returns

a new sequence consisting of all elements of this sequence except that replaced elements starting from from are replaced by all the elements of other.

Inherited from
SeqOps
Source
Seq.scala

Iterates over distinct permutations.

Iterates over distinct permutations.

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

Returns

An Iterator which traverses the distinct permutations of this sequence.

Example

"abb".permutations = Iterator(abb, bab, bba)

Inherited from
SeqOps
Source
Seq.scala
override def prepended[B >: A](elem: B): CC[B]
override def prependedAll[B >: A](prefix: IterableOnce[B]): CC[B]
def product[B >: A](implicit num: Numeric[B]): B

Multiplies up the elements of this collection.

Multiplies up the elements of this collection.

Note: will not terminate for infinite-sized collections.

Type Params
B

the result type of the * operator.

Value Params
num

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

Returns

the product of all elements of this collection with respect to the * operator in num.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def reduce[B >: A](op: (B, B) => B): B

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

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 Params
B

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

Value Params
op

A binary operator that must be associative.

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
def reduceLeft[B >: A](op: (B, A) => B): B

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

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
def reduceLeftOption[B >: A](op: (B, A) => B): Option[B]

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

Returns

an option value containing the result of reduceLeft(op) if this collection is nonempty, None otherwise.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def reduceOption[B >: A](op: (B, B) => B): Option[B]

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

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 Params
B

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

Value Params
op

A binary operator that must be associative.

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
def reduceRight[B >: A](op: (A, B) => B): B

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

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
def reduceRightOption[B >: A](op: (A, B) => B): Option[B]

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

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 Params
B

the result type of the binary operator.

Value Params
op

the binary operator.

Returns

an option value containing the result of reduceRight(op) if this collection is nonempty, None otherwise.

Inherited from
IterableOnceOps
Source
IterableOnce.scala

An iterator yielding elements in reversed order.

An iterator yielding elements in reversed order.

Note: will not terminate for infinite-sized collections.

Note: xs.reverseIterator is the same as xs.reverse.iterator but might be more efficient.

Returns

an iterator yielding the elements of this sequence in reversed order

Inherited from
SeqOps
Source
Seq.scala
protected def reversed: Iterable[A]
def sameElements[B >: A](that: IterableOnce[B]): Boolean

Are the elements of this collection the same (and in the same order) as those of that?

Are the elements of this collection the same (and in the same order) as those of that?

Inherited from
SeqOps
Source
Seq.scala
def scan[B >: A](z: B)(op: (B, B) => B): CC[B]

Computes a prefix scan of the elements of the collection.

Computes a prefix scan of the elements of the collection.

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

Type Params
B

element type of the resulting collection

Value Params
op

the associative operator for the scan

z

neutral element for the operator op

Returns

a new iterable collection containing the prefix scan of the elements in this iterable collection

Inherited from
IterableOps
Source
Iterable.scala
override def scanLeft[B](z: B)(op: (B, A) => B): CC[B]
def scanRight[B](z: B)(op: (A, B) => B): CC[B]

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 Params
B

the type of the elements in the resulting collection

Value Params
op

the binary operator applied to the intermediate result and the element

z

the initial value

Returns

collection with intermediate results

Inherited from
IterableOps
Source
Iterable.scala
def search[B >: A](elem: B, from: Int, to: Int)(implicit ord: Ordering[B]): SearchResult

Search within an interval in this sorted sequence for a specific element.

Search within an interval in this sorted sequence for a specific element. If this sequence is an IndexedSeq, a binary search is used. Otherwise, a linear search is used.

The sequence should be sorted with the same Ordering before calling; otherwise, the results are undefined.

Value Params
elem

the element to find.

from

the index where the search starts.

ord

the ordering to be used to compare elements.

to

the index following where the search ends.

Returns

a Found value containing the index corresponding to the element in the sequence, or the InsertionPoint where the element would be inserted if the element is not in the sequence.

See also
Note

if to <= from, the search space is empty, and an InsertionPoint at from is returned

Inherited from
SeqOps
Source
Seq.scala
def search[B >: A](elem: B)(implicit ord: Ordering[B]): SearchResult

Search this sorted sequence for a specific element.

Search this sorted sequence for a specific element. If the sequence is an IndexedSeq, a binary search is used. Otherwise, a linear search is used.

The sequence should be sorted with the same Ordering before calling; otherwise, the results are undefined.

Value Params
elem

the element to find.

ord

the ordering to be used to compare elements.

Returns

a Found value containing the index corresponding to the element in the sequence, or the InsertionPoint where the element would be inserted if the element is not in the sequence.

See also
Inherited from
SeqOps
Source
Seq.scala
def segmentLength(p: A => Boolean, from: Int): Int

Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.

Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

Value Params
from

the index where the search starts.

p

the predicate used to test elements.

Returns

the length of the longest segment of this sequence starting from index from such that every element of the segment satisfies the predicate p.

Inherited from
SeqOps
Source
Seq.scala
final def segmentLength(p: A => Boolean): Int

Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.

Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the length of the longest segment of this sequence that starts from the first element such that every element of the segment satisfies the predicate p.

Inherited from
SeqOps
Source
Seq.scala
final override def size: Int
Definition Classes
Inherited from
SeqOps
Source
Seq.scala
final override def sizeCompare(that: Iterable[_]): Int
Definition Classes
Inherited from
SeqOps
Source
Seq.scala
final override def sizeCompare(otherSize: Int): Int
Definition Classes
Inherited from
SeqOps
Source
Seq.scala

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

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
Inherited from
IterableOps
Source
Iterable.scala
def sliding(size: Int): Iterator[C]

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

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 Params
size

the number of elements per group

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
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))

Inherited from
IterableOps
Source
Iterable.scala
def sortBy[B](f: A => B)(implicit ord: Ordering[B]): C

Sorts this sequence according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

Sorts this sequence according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

Note: will not terminate for infinite-sized collections.

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

The sort is stable. That is, elements that are equal (as determined by ord.compare) appear in the same order in the sorted sequence as in the original.

Type Params
B

the target type of the transformation f, and the type where the ordering ord is defined.

Value Params
f

the transformation function mapping elements to some other domain B.

ord

the ordering assumed on domain B.

Returns

a sequence consisting of the elements of this sequence sorted according to the ordering where x < y if ord.lt(f(x), f(y)).

See also
Example

val words = "The quick brown fox jumped over the lazy dog".split(' ')
// this works because scala.Ordering will implicitly provide an Ordering[Tuple2[Int, Char]]
words.sortBy(x => (x.length, x.head))
res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)
Inherited from
SeqOps
Source
Seq.scala
def sortWith(lt: (A, A) => Boolean): C

Sorts this sequence according to a comparison function.

Sorts this sequence according to a comparison function.

Note: will not terminate for infinite-sized collections.

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

The sort is stable. That is, elements that are equal (as determined by lt) appear in the same order in the sorted sequence as in the original.

Value Params
lt

the comparison function which tests whether its first argument precedes its second argument in the desired ordering.

Returns

a sequence consisting of the elements of this sequence sorted according to the comparison function lt.

Example

List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) =
List("Bob", "John", "Steve", "Tom")
Inherited from
SeqOps
Source
Seq.scala
def sorted[B >: A](implicit ord: Ordering[B]): C

Sorts this sequence according to an Ordering.

Sorts this sequence according to an Ordering.

The sort is stable. That is, elements that are equal (as determined by ord.compare) appear in the same order in the sorted sequence as in the original.

Value Params
ord

the ordering to be used to compare elements.

Returns

a sequence consisting of the elements of this sequence sorted according to the ordering ord.

See also

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

Inherited from
SeqOps
Source
Seq.scala
override def splitAt(n: Int): (C, C)
Definition Classes
Inherited from
IterableOps
Source
Iterable.scala
def startsWith[B >: A](that: IterableOnce[B], offset: Int): Boolean

Tests whether this sequence contains the given sequence at a given index.

Tests whether this sequence contains the given sequence at a given index.

Note: If the both the receiver object this and the argument that are infinite sequences this method may not terminate.

Value Params
offset

the index where the sequence is searched.

that

the sequence to test

Returns

true if the sequence that is contained in this sequence at index offset, otherwise false.

Inherited from
SeqOps
Source
Seq.scala
def stepper[S <: Stepper[_]](implicit shape: StepperShape[A, S]): S

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

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.

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.

Inherited from
IterableOnce
Source
IterableOnce.scala
def sum[B >: A](implicit num: Numeric[B]): B

Sums up the elements of this collection.

Sums up the elements of this collection.

Note: will not terminate for infinite-sized collections.

Type Params
B

the result type of the + operator.

Value Params
num

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

Returns

the sum of all elements of this collection with respect to the + operator in num.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def tail: C

The rest of the collection without its first element.

The rest of the collection without its first element.

Inherited from
IterableOps
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.

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)

Inherited from
IterableOps
Source
Iterable.scala
def take(n: Int): C
Inherited from
IterableOps
Source
Iterable.scala
override def takeRight(n: Int): C

A collection containing the last n elements of this collection.

A collection containing the last n elements of this collection.

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

Definition Classes
Inherited from
StrictOptimizedIterableOps
Source
StrictOptimizedIterableOps.scala
def takeWhile(p: A => Boolean): C

Takes longest prefix of elements that satisfy a predicate.

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 Params
p

The predicate used to test elements.

Returns

the longest prefix of this iterable collection whose elements all satisfy the predicate p.

Inherited from
IterableOps
Source
Iterable.scala
def to[C1](factory: Factory[A, C1]): C1

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]

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def toArray[B >: A](implicit evidence$1: ClassTag[B]): Array[B]

Convert collection to array.

Convert collection to array.

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

Inherited from
IterableOnceOps
Source
IterableOnce.scala
final def toBuffer[B >: A]: Buffer[B]
Returns

This collection as an Iterable[A]. No new collection will be built if this is already an Iterable[A].

Inherited from
IterableOps
Source
Iterable.scala
def toMap[K, V](implicit ev: A <:< (K, V)): Map[K, V]
def toSeq: Seq[A]
Returns

This collection as a Seq[A]. This is equivalent to to(Seq) but might be faster.

Inherited from
IterableOnceOps
Source
IterableOnce.scala
def toSet[B >: A]: Set[B]
def transpose[B](implicit asIterable: A => Iterable[B]): CC[CC[B]]

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

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 Params
B

the type of the elements of each iterable collection.

Value Params
asIterable

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

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.

Inherited from
IterableOps
Source
Iterable.scala
override def unzip[A1, A2](implicit asPair: A => (A1, A2)): (CC[A1], CC[A2])
override def unzip3[A1, A2, A3](implicit asTriple: A => (A1, A2, A3)): (CC[A1], CC[A2], CC[A3])
def updated[B >: A](index: Int, elem: B): CC[B]

A copy of this sequence with one single replaced element.

A copy of this sequence with one single replaced element.

Type Params
B

the element type of the returned sequence.

Value Params
elem

the replacing element

index

the position of the replacement

Returns

a new sequence which is a copy of this sequence with the element at position index replaced by elem.

Throws
IndexOutOfBoundsException

if index does not satisfy 0 <= index < length. In case of a lazy collection this exception may be thrown at a later time or not at all (if the end of the collection is never evaluated).

Inherited from
SeqOps
Source
Seq.scala
override def view: SeqView[A]
Definition Classes
Inherited from
SeqOps
Source
Seq.scala

Creates a non-strict filter of this iterable collection.

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 Params
p

the predicate used to test elements.

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.

Inherited from
IterableOps
Source
Iterable.scala
override def zip[B](that: IterableOnce[B]): CC[(A, B)]
def zipAll[A1 >: A, B](that: Iterable[B], thisElem: A1, thatElem: B): CC[(A1, B)]

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 Params
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.

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.

Inherited from
IterableOps
Source
Iterable.scala

Deprecated and Inherited methods

@deprecated("Use foldLeft instead of /:", "2.13.0") @inline
final def /:[B](z: B)(op: (B, A) => B): B
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("Use foldRight instead of :\\", "2.13.0") @inline
final def :\[B](z: B)(op: (A, B) => B): B
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("`aggregate` is not relevant for sequential collections. Use `foldLeft(z)(seqop)` instead.", "2.13.0")
def aggregate[B](z: => B)(seqop: (B, A) => B, combop: (B, B) => B): B
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("Use iterableFactory instead", "2.13.0") @deprecatedOverriding("Use iterableFactory instead", "2.13.0") @inline
Deprecated
Inherited from
IterableOps
Source
Iterable.scala
@deprecated("Use `dest ++= coll` instead", "2.13.0") @inline
final def copyToBuffer[B >: A](dest: Buffer[B]): Unit
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)", "2.13.0")

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.

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
@deprecated("Use segmentLength instead of prefixLength", "2.13.0") @inline
final def prefixLength(p: A => Boolean): Int

Returns the length of the longest prefix whose elements all satisfy some predicate.

Returns the length of the longest prefix whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

Value Params
p

the predicate used to test elements.

Returns

the length of the longest prefix of this sequence such that every element of the segment satisfies the predicate p.

Deprecated
Inherited from
SeqOps
Source
Seq.scala
@deprecated("Use coll instead of repr in a collection implementation, use the collection value itself from the outside", "2.13.0")
final def repr: C
Deprecated
Inherited from
IterableOps
Source
Iterable.scala
@deprecated("Use .reverseIterator.map(f).to(...) instead of .reverseMap(f)", "2.13.0")
def reverseMap[B](f: A => B): CC[B]
Deprecated
Inherited from
SeqOps
Source
Seq.scala
@deprecated("Use .iterator instead of .toIterator", "2.13.0") @inline
final def toIterator: Iterator[A]
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("Use .to(LazyList) instead of .toStream", "2.13.0") @inline
final def toStream: Stream[A]
Deprecated
Inherited from
IterableOnceOps
Source
IterableOnce.scala
@deprecated("Use toIterable instead", "2.13.0")

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.

Returns

An Iterable containing all elements of this iterable collection.

Deprecated
Inherited from
IterableOps
Source
Iterable.scala
@deprecated("Use `concat` instead", "2.13.0") @inline
final def union[B >: A](that: Seq[B]): CC[B]

Produces a new sequence which contains all elements of this sequence and also all elements of a given sequence.

Produces a new sequence which contains all elements of this sequence and also all elements of a given sequence. xs union ys is equivalent to xs ++ ys.

Type Params
B

the element type of the returned sequence.

Value Params
that

the sequence to add.

Returns

a new collection which contains all elements of this sequence followed by all elements of that.

Deprecated
Inherited from
SeqOps
Source
Seq.scala
@deprecated("Use .view.slice(from, until) instead of .view(from, until)", "2.13.0")
def view(from: Int, until: Int): View[A]

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

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

Deprecated
Inherited from
IterableOps
Source
Iterable.scala