Appended

Related Doc: package SeqViewLike

trait Appended[B >: A] extends SeqViewLike.Appended[B] with Transformed[B]

Source
SeqViewLike.scala
Linear Supertypes
Transformed[B], SeqView[B, Coll], SeqViewLike[B, Coll, SeqView[B, Coll]], Seq[B], SeqLike[B, SeqView[B, Coll]], GenSeq[B], GenSeqLike[B, SeqView[B, Coll]], PartialFunction[Int, B], (Int) ⇒ B, SeqViewLike.Appended[B], SeqViewLike.Transformed[B], IterableView[B, Coll], IterableViewLike[B, Coll, SeqView[B, Coll]], Iterable[B], IterableLike[B, SeqView[B, Coll]], Equals, GenIterable[B], GenIterableLike[B, SeqView[B, Coll]], SeqViewLike.Appended[B], SeqViewLike.Transformed[B], TraversableView[B, Coll], TraversableViewLike[B, Coll, SeqView[B, Coll]], ViewMkString[B], Traversable[B], GenTraversable[B], GenericTraversableTemplate[B, Seq], TraversableLike[B, SeqView[B, Coll]], GenTraversableLike[B, SeqView[B, Coll]], Parallelizable[B, ParSeq[B]], TraversableOnce[B], GenTraversableOnce[B], FilterMonadic[B, SeqView[B, Coll]], HasNewBuilder[B, SeqView[B, Coll]], AnyRef, Any
Known Subclasses
Ordering
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Inherited
1. Appended
2. Transformed
3. SeqView
4. SeqViewLike
5. Seq
6. SeqLike
7. GenSeq
8. GenSeqLike
9. PartialFunction
10. Function1
11. Appended
12. Transformed
13. IterableView
14. IterableViewLike
15. Iterable
16. IterableLike
17. Equals
18. GenIterable
19. GenIterableLike
20. Appended
21. Transformed
22. TraversableView
23. TraversableViewLike
24. ViewMkString
25. Traversable
26. GenTraversable
27. GenericTraversableTemplate
28. TraversableLike
29. GenTraversableLike
30. Parallelizable
31. TraversableOnce
32. GenTraversableOnce
34. HasNewBuilder
35. AnyRef
36. Any
Implicitly
1. by CollectionsHaveToParArray
4. by StringFormat
5. by Ensuring
6. by ArrowAssoc
7. by alternateImplicit
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Visibility
1. Public
2. All

Type Members

1. trait Appended[B >: A] extends SeqViewLike.Appended[B] with Transformed[B]

Definition Classes
SeqViewLike
2. trait DroppedWhile extends SeqViewLike.DroppedWhile with Transformed[A]

Definition Classes
SeqViewLike
3. trait EmptyView extends Transformed[Nothing] with SeqViewLike.EmptyView

Definition Classes
SeqViewLike
4. trait Filtered extends SeqViewLike.Filtered with Transformed[A]

Definition Classes
SeqViewLike
5. trait FlatMapped[B] extends SeqViewLike.FlatMapped[B] with Transformed[B]

Definition Classes
SeqViewLike
6. trait Forced[B] extends SeqViewLike.Forced[B] with Transformed[B]

Definition Classes
SeqViewLike
7. trait Mapped[B] extends SeqViewLike.Mapped[B] with Transformed[B]

Definition Classes
SeqViewLike
8. trait Patched[B >: A] extends Transformed[B]

Definition Classes
SeqViewLike
9. trait Prepended[B >: A] extends Transformed[B]

Definition Classes
SeqViewLike
10. trait Reversed extends Transformed[A]

Definition Classes
SeqViewLike
11. type Self = SeqView[B, Coll]

The type implementing this traversable

The type implementing this traversable

Attributes
protected[this]
Definition Classes
TraversableLike
12. trait Sliced extends SeqViewLike.Sliced with Transformed[A]

Definition Classes
SeqViewLike
13. trait TakenWhile extends SeqViewLike.TakenWhile with Transformed[A]

Definition Classes
SeqViewLike
14. trait Transformed[+B] extends SeqView[B, Coll] with SeqViewLike.Transformed[B]

Definition Classes
SeqViewLike
15. class WithFilter extends FilterMonadic[A, Repr]

A class supporting filtered operations.

A class supporting filtered operations. Instances of this class are returned by method `withFilter`.

Definition Classes
TraversableLike
16. trait Zipped[B] extends SeqViewLike.Zipped[B] with Transformed[(A, B)]

Definition Classes
SeqViewLike
17. trait ZippedAll[A1 >: A, B] extends SeqViewLike.ZippedAll[A1, B] with Transformed[(A1, B)]

Definition Classes
SeqViewLike

Abstract Value Members

1. abstract val rest: GenTraversable[B]

Attributes
protected[this]
Definition Classes
Appended

Concrete Value Members

1. final def !=(arg0: Any): Boolean

Test two objects for inequality.

Test two objects for inequality.

returns

`true` if !(this == that), false otherwise.

Definition Classes
AnyRef → Any
2. final def ##(): Int

Equivalent to `x.hashCode` except for boxed numeric types and `null`.

Equivalent to `x.hashCode` except for boxed numeric types and `null`. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For `null` returns a hashcode where `null.hashCode` throws a `NullPointerException`.

returns

a hash value consistent with ==

Definition Classes
AnyRef → Any
3. def +(other: String): String

Implicit information
This member is added by an implicit conversion from Appended[B] to any2stringadd[Appended[B]] performed by method any2stringadd in scala.Predef.
Definition Classes
4. def ++[B](that: GenTraversableOnce[B]): Seq[B]

[use case] Returns a new sequence containing the elements from the left hand operand followed by the elements from the right hand operand.

[use case]

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

Example:

```scala> val a = List(1)
a: List[Int] = List(1)

scala> val b = List(2)
b: List[Int] = List(2)

scala> val c = a ++ b
c: List[Int] = List(1, 2)

scala> val d = List('a')
d: List[Char] = List(a)

scala> val e = c ++ d
e: List[AnyVal] = List(1, 2, a)```
B

the element type of the returned collection.

that

the traversable to append.

returns

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

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
Full Signature

5. def ++:[B >: B, That](that: Traversable[B])(implicit bf: CanBuildFrom[SeqView[B, Coll], B, That]): That

As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

It differs from `++` in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

Example:

```scala> val x = List(1)
x: List[Int] = List(1)

scala> val z = x ++: y

This overload exists because: for the implementation of `++:` we should reuse that of `++` because many collections override it with more efficient versions.

Since `TraversableOnce` has no `++` method, we have to implement that directly, but `Traversable` and down can use the overload.

B

the element type of the returned collection.

That

the class of the returned collection. Where possible, `That` is the same class as the current collection class `Repr`, but this depends on the element type `B` being admissible for that class, which means that an implicit instance of type `CanBuildFrom[Repr, B, That]` is found.

that

the traversable to append.

bf

an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

returns

a new collection of type `That` which contains all elements of this traversable collection followed by all elements of `that`.

Definition Classes
TraversableLike
6. def ++:[B](that: TraversableOnce[B]): Seq[B]

[use case] As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

[use case]

As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

It differs from `++` in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

Example:

```scala> val x = List(1)
x: List[Int] = List(1)

scala> val z = x ++: y
B

the element type of the returned collection.

that

the traversable to append.

returns

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

Definition Classes
TraversableLike
Full Signature

7. def +:(elem: A): Seq[A]

[use case] A copy of the sequence with an element prepended.

[use case]

A copy of the sequence with an element prepended.

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

Also, the original sequence is not modified, so you will want to capture the result.

Example:

```scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = 2 +: x
y: List[Int] = List(2, 1)

scala> println(x)
List(1)```
elem

the prepended element

returns

a new sequence consisting of `elem` followed by all elements of this sequence.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

8. def ->[B](y: B): (Appended[B], B)

Implicit information
This member is added by an implicit conversion from Appended[B] to ArrowAssoc[Appended[B]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
()
9. def /:[B](z: B)(op: (B, B) ⇒ B): B

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

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

Note: `/:` is alternate syntax for `foldLeft`; `z /: xs` is the same as `xs foldLeft z`.

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

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

scala> val b = (5 /: a)(_+_)
b: Int = 15

scala> val c = (5 /: a)((x,y) => x + y)
c: Int = 15```

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.

B

the result type of the binary operator.

z

the start value.

op

the binary operator.

returns

the result of inserting `op` between consecutive elements of this traversable or iterator, going left to right with the start value `z` on the left:

`op(...op(op(z, x_1), x_2), ..., x_n)`

where `x1, ..., xn` are the elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
10. def :+(elem: A): Seq[A]

[use case] A copy of this sequence with an element appended.

[use case]

A copy of this sequence with an element appended.

A mnemonic for `+:` vs. `:+` is: the COLon goes on the COLlection side.

Note: will not terminate for infinite-sized collections.

Example:

```scala> val a = List(1)
a: List[Int] = List(1)

scala> val b = a :+ 2
b: List[Int] = List(1, 2)

scala> println(a)
List(1)```
elem

the appended element

returns

a new sequence consisting of all elements of this sequence followed by `elem`.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

11. def :\[B](z: B)(op: (B, B) ⇒ B): B

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

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

Note: `:\` is alternate syntax for `foldRight`; `xs :\ z` is the same as `xs foldRight z`.

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.

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

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

scala> val b = (a :\ 5)(_+_)
b: Int = 15

scala> val c = (a :\ 5)((x,y) => x + y)
c: Int = 15```
B

the result type of the binary operator.

z

the start value

op

the binary operator

returns

the result of inserting `op` between consecutive elements of this traversable or iterator, going right to left with the start value `z` on the right:

`op(x_1, op(x_2, ... op(x_n, z)...))`

where `x1, ..., xn` are the elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
12. final def ==(arg0: Any): Boolean

The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

arg0

the object to compare against this object for equality.

returns

`true` if the receiver object is equivalent to the argument; `false` otherwise.

Definition Classes
AnyRef → Any
13. def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder

Definition Classes
ViewMkString

Appends all elements of this traversable or iterator to a string builder.

Appends all elements of this traversable or iterator to a string builder. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this traversable or iterator 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 =

h: StringBuilder = 1234```
b

the string builder to which elements are appended.

returns

the string builder `b` to which elements were appended.

Definition Classes
TraversableOnce
15. def addString(b: StringBuilder, sep: String): StringBuilder

Appends all elements of this traversable or iterator to a string builder using a separator string.

Appends all elements of this traversable or iterator 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 traversable or iterator, 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 =

res0: StringBuilder = 1, 2, 3, 4```
b

the string builder to which elements are appended.

sep

the separator string.

returns

the string builder `b` to which elements were appended.

Definition Classes
TraversableOnce
16. def aggregate[B](z: ⇒ B)(seqop: (B, B) ⇒ B, combop: (B, B) ⇒ B): B

Aggregates the results of applying an operator to subsequent elements.

Aggregates the results of applying an operator to subsequent elements.

This is a more general form of `fold` and `reduce`. It has similar semantics, but does not require the result to be a supertype of the element type. It traverses the elements in different partitions sequentially, using `seqop` to update the result, and then applies `combop` to results from different partitions. The implementation of this operation may operate on an arbitrary number of collection partitions, so `combop` may be invoked an arbitrary number of times.

For example, one might want to process some elements and then produce a `Set`. In this case, `seqop` would process an element and append it to the list, while `combop` would concatenate two lists from different partitions together. The initial value `z` would be an empty set.

`pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)`

Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).

B

the type of accumulated results

z

the initial value for the accumulated result of the partition - this will typically be the neutral element for the `seqop` operator (e.g. `Nil` for list concatenation or `0` for summation) and may be evaluated more than once

seqop

an operator used to accumulate results within a partition

combop

an associative operator used to combine results from different partitions

Definition Classes
TraversableOnceGenTraversableOnce
17. def andThen[C](k: (B) ⇒ C): PartialFunction[Int, C]

Composes this partial function with a transformation function that gets applied to results of this partial function.

Composes this partial function with a transformation function that gets applied to results of this partial function.

C

the result type of the transformation function.

k

the transformation function

returns

a partial function with the same domain as this partial function, which maps arguments `x` to `k(this(x))`.

Definition Classes
PartialFunctionFunction1
18. def apply(idx: Int): B

Selects an element by its index in the sequence.

Selects an element by its index in the sequence.

Example:

```scala> val x = List(1, 2, 3, 4, 5)
x: List[Int] = List(1, 2, 3, 4, 5)

scala> x(3)
res1: Int = 4```
idx

The index to select.

returns

the element of this sequence at index `idx`, where `0` indicates the first element.

Definition Classes
AppendedTransformedSeqLikeGenSeqLikeFunction1
Exceptions thrown

`IndexOutOfBoundsException` if `idx` does not satisfy `0 <= idx < length`.

19. def applyOrElse[A1 <: Int, B1 >: B](x: A1, default: (A1) ⇒ B1): B1

Applies this partial function to the given argument when it is contained in the function domain.

Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.

Note that expression `pf.applyOrElse(x, default)` is equivalent to

`if(pf isDefinedAt x) pf(x) else default(x)`

except that `applyOrElse` method can be implemented more efficiently. For all partial function literals the compiler generates an `applyOrElse` implementation which avoids double evaluation of pattern matchers and guards. This makes `applyOrElse` the basis for the efficient implementation for many operations and scenarios, such as:

• combining partial functions into `orElse`/`andThen` chains does not lead to excessive `apply`/`isDefinedAt` evaluation
• `lift` and `unlift` do not evaluate source functions twice on each invocation
• `runWith` allows efficient imperative-style combining of partial functions with conditionally applied actions

For non-literal partial function classes with nontrivial `isDefinedAt` method it is recommended to override `applyOrElse` with custom implementation that avoids double `isDefinedAt` evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.

x

the function argument

default

the fallback function

returns

the result of this function or fallback function application.

Definition Classes
PartialFunction
Since

2.10

20. final def asInstanceOf[T0]: T0

Cast the receiver object to be of type `T0`.

Cast the receiver object to be of type `T0`.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression `1.asInstanceOf[String]` will throw a `ClassCastException` at runtime, while the expression `List(1).asInstanceOf[List[String]]` will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

returns

Definition Classes
Any
Exceptions thrown

`ClassCastException` if the receiver object is not an instance of the erasure of type `T0`.

21. def canEqual(that: Any): Boolean

Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

that

The object with which this iterable collection should be compared

returns

`true`, if this iterable collection can possibly equal `that`, `false` otherwise. The test takes into consideration only the run-time types of objects but ignores their elements.

Definition Classes
IterableLikeEquals
22. def clone(): AnyRef

Create a copy of the receiver object.

Create a copy of the receiver object.

The default implementation of the `clone` method is platform dependent.

returns

a copy of the receiver object.

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
( ... )
Note

not specified by SLS as a member of AnyRef

23. def collect[B](pf: PartialFunction[A, B]): Seq[B]

[use case] Builds a new collection by applying a partial function to all elements of this sequence on which the function is defined.

[use case]

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

B

the element type of the returned collection.

pf

the partial function which filters and maps the sequence.

returns

a new sequence 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.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
Full Signature

24. def collectFirst[B](pf: PartialFunction[B, B]): Option[B]

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

Finds the first element of the traversable or iterator 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.

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.

Definition Classes
TraversableOnce
Example:
1. `Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)`

25. def combinations(n: Int): Iterator[SeqView[B, Coll]]

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.

returns

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

Definition Classes
SeqViewLikeSeqLike
Example:
1. `"abbbc".combinations(2) = Iterator(ab, ac, bb, bc)`

26. def companion: GenericCompanion[Seq]

The factory companion object that builds instances of class `Seq`.

The factory companion object that builds instances of class `Seq`. (or its `Iterable` superclass where class `Seq` is not a `Seq`.)

Definition Classes
SeqGenSeqIterableGenIterableTraversableGenTraversableGenericTraversableTemplate
27. def compose[A](g: (A) ⇒ Int): (A) ⇒ B

Composes two instances of Function1 in a new Function1, with this function applied last.

Composes two instances of Function1 in a new Function1, with this function applied last.

A

the type to which function `g` can be applied

g

a function A => T1

returns

a new function `f` such that `f(x) == apply(g(x))`

Definition Classes
Function1
Annotations
()
28. def contains[A1 >: B](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.

elem

the element to test.

returns

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

Definition Classes
SeqLike
29. def containsSlice[B](that: GenSeq[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.

that

the sequence to test

returns

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

Definition Classes
SeqLike
30. def copyToArray(xs: Array[A], start: Int, len: Int): Unit

[use case] Copies elements of this sequence to an array.

[use case]

Copies elements of this sequence to an array. Fills the given array `xs` with at most `len` elements of this sequence, starting at position `start`. Copying will stop once either the end of the current sequence is reached, or the end of the array is reached, or `len` elements have been copied.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

start

the starting index.

len

the maximal number of elements to copy.

Definition Classes
IterableLikeTraversableLikeTraversableOnceGenTraversableOnce
Full Signature

31. def copyToArray(xs: Array[A]): Unit

[use case] Copies values of this sequence to an array.

[use case]

Copies values of this sequence to an array. Fills the given array `xs` with values of this sequence. Copying will stop once either the end of the current sequence is reached, or the end of the array is reached.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

32. def copyToArray(xs: Array[A], start: Int): Unit

[use case] Copies values of this sequence to an array.

[use case]

Copies values of this sequence to an array. Fills the given array `xs` with values of this sequence, beginning at index `start`. Copying will stop once either the end of the current sequence is reached, or the end of the array is reached.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

start

the starting index.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

33. def copyToBuffer[B >: B](dest: Buffer[B]): Unit

Copies all elements of this traversable or iterator to a buffer.

Copies all elements of this traversable or iterator to a buffer.

Note: will not terminate for infinite-sized collections.

dest

The buffer to which elements are copied.

Definition Classes
TraversableOnce
34. def corresponds[B](that: GenSeq[B])(p: (B, 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.

B

the type of the elements of `that`

that

the other sequence

p

the test predicate, which relates elements from both sequences

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`.

Definition Classes
SeqLikeGenSeqLike
35. def count(p: (B) ⇒ Boolean): Int

Counts the number of elements in the traversable or iterator which satisfy a predicate.

Counts the number of elements in the traversable or iterator which satisfy a predicate.

p

the predicate used to test elements.

returns

the number of elements satisfying the predicate `p`.

Definition Classes
TraversableOnceGenTraversableOnce
36. def diff(that: Seq[A]): Seq[A]

[use case] Computes the multiset difference between this sequence and another sequence.

[use case]

Computes the multiset difference between this sequence and another sequence.

Note: will not terminate for infinite-sized collections.

that

the sequence of elements to remove

returns

a new sequence which contains all elements of this sequence except some of occurrences of elements that also appear in `that`. If an element value `x` appears n times in `that`, then the first n occurrences of `x` will not form part of the result, but any following occurrences will.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

37. def distinct: SeqView[B, Coll]

Builds a new sequence from this sequence without any duplicate elements.

Builds a new sequence from this sequence without any duplicate elements.

Note: will not terminate for infinite-sized collections.

returns

A new sequence which contains the first occurrence of every element of this sequence.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
38. def drop(n: Int): SeqView[B, Coll]

Selects all elements except first n ones.

Selects all elements except first n ones.

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

n

the number of elements to drop from this iterable collection.

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.

Definition Classes
IterableViewLikeTraversableViewLikeIterableLikeTraversableLikeGenTraversableLike
39. def dropRight(n: Int): SeqView[B, Coll]

Selects all elements except last n ones.

Selects all elements except last n ones.

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

n

The number of elements to take

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.

Definition Classes
IterableViewLikeIterableLike
40. def dropWhile(p: (B) ⇒ Boolean): SeqView[B, Coll]

Drops longest prefix of elements that satisfy a predicate.

Drops longest prefix of elements that satisfy a predicate.

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

returns

the longest suffix of this collection whose first element does not satisfy the predicate `p`.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
41. def endsWith[B](that: GenSeq[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.

that

the sequence to test

returns

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

Definition Classes
SeqLikeGenSeqLike
42. def ensuring(cond: (Appended[B]) ⇒ Boolean, msg: ⇒ Any): Appended[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to Ensuring[Appended[B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
43. def ensuring(cond: (Appended[B]) ⇒ Boolean): Appended[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to Ensuring[Appended[B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
44. def ensuring(cond: Boolean, msg: ⇒ Any): Appended[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to Ensuring[Appended[B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
45. def ensuring(cond: Boolean): Appended[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to Ensuring[Appended[B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
46. final def eq(arg0: AnyRef): Boolean

Tests whether the argument (`arg0`) is a reference to the receiver object (`this`).

Tests whether the argument (`arg0`) is a reference to the receiver object (`this`).

The `eq` method implements an equivalence relation on non-null instances of `AnyRef`, and has three additional properties:

• It is consistent: for any non-null instances `x` and `y` of type `AnyRef`, multiple invocations of `x.eq(y)` consistently returns `true` or consistently returns `false`.
• For any non-null instance `x` of type `AnyRef`, `x.eq(null)` and `null.eq(x)` returns `false`.
• `null.eq(null)` returns `true`.

When overriding the `equals` or `hashCode` methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (`o1 eq o2`), they should be equal to each other (`o1 == o2`) and they should hash to the same value (`o1.hashCode == o2.hashCode`).

returns

`true` if the argument is a reference to the receiver object; `false` otherwise.

Definition Classes
AnyRef
47. def equals(that: Any): Boolean

The equals method for arbitrary sequences.

The equals method for arbitrary sequences. Compares this sequence to some other object.

that

The object to compare the sequence to

returns

`true` if `that` is a sequence that has the same elements as this sequence in the same order, `false` otherwise

Definition Classes
GenSeqLikeEqualsAny
48. def exists(p: (B) ⇒ Boolean): Boolean

Tests whether a predicate holds for some of the elements of this iterable collection.

Tests whether a predicate holds for some of the elements of this iterable collection.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

`false` if this iterable collection is empty, otherwise `true` if the given predicate `p` holds for some of the elements of this iterable collection, otherwise `false`

Definition Classes
IterableLikeTraversableLikeTraversableOnceGenTraversableOnce
49. def filter(p: (B) ⇒ Boolean): SeqView[B, Coll]

Selects all elements of this collection which satisfy a predicate.

Selects all elements of this collection which satisfy a predicate.

p

the predicate used to test elements.

returns

a new collection consisting of all elements of this collection that satisfy the given predicate `p`. The order of the elements is preserved.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
50. def filterNot(p: (B) ⇒ Boolean): SeqView[B, Coll]

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

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

p

the predicate used to test elements.

returns

a new collection consisting of all elements of this collection that do not satisfy the given predicate `p`. The order of the elements is preserved.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
51. def finalize(): Unit

Called by the garbage collector on the receiver object when there are no more references to the object.

Called by the garbage collector on the receiver object when there are no more references to the object.

The details of when and if the `finalize` method is invoked, as well as the interaction between `finalize` and non-local returns and exceptions, are all platform dependent.

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
( classOf[java.lang.Throwable] )
Note

not specified by SLS as a member of AnyRef

52. def find(p: (B) ⇒ Boolean): Option[B]

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

Finds the first element of the iterable 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.

p

the predicate used to test elements.

returns

an option value containing the first element in the iterable collection that satisfies `p`, or `None` if none exists.

Definition Classes
IterableLikeTraversableLikeTraversableOnceGenTraversableOnce
53. def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): Seq[B]

[use case] Builds a new collection by applying a function to all elements of this sequence and using the elements of the resulting collections.

[use case]

Builds a new collection by applying a function to all elements of this sequence 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 sequence. 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 => 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)```
B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new sequence resulting from applying the given collection-valued function `f` to each element of this sequence and concatenating the results.

Definition Classes
Full Signature

54. def flatten[B]: Seq[B]

[use case] Converts this sequence of traversable collections into a sequence formed by the elements of these traversable collections.

[use case]

Converts this sequence of traversable collections into a sequence formed by the elements of these traversable collections.

The resulting collection's type will be guided by the static type of sequence. 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)```
B

the type of the elements of each traversable collection.

returns

a new sequence resulting from concatenating all element sequences.

Definition Classes
TraversableViewLikeGenericTraversableTemplate
Full Signature

55. def fold[A1 >: B](z: A1)(op: (A1, A1) ⇒ A1): A1

Folds the elements of this traversable or iterator using the specified associative binary operator.

Folds the elements of this traversable or iterator using the specified associative binary operator.

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

A1

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

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.)

op

a binary operator that must be associative

returns

the result of applying fold operator `op` between all the elements and `z`

Definition Classes
TraversableOnceGenTraversableOnce
56. def foldLeft[B](z: B)(op: (B, B) ⇒ B): B

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

Applies a binary operator to a start value and all elements of this traversable or iterator, 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.

B

the result type of the binary operator.

z

the start value.

op

the binary operator.

returns

the result of inserting `op` between consecutive elements of this traversable or iterator, going left to right with the start value `z` on the left:

`op(...op(z, x_1), x_2, ..., x_n)`

where `x1, ..., xn` are the elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
57. def foldRight[B](z: B)(op: (B, B) ⇒ B): B

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

Applies a binary operator to all elements of this iterable 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.

B

the result type of the binary operator.

z

the start value.

op

the binary operator.

returns

the result of inserting `op` between consecutive elements of this iterable collection, going right to left with the start value `z` on the right:

`op(x_1, op(x_2, ... op(x_n, z)...))`

where `x1, ..., xn` are the elements of this iterable collection.

Definition Classes
IterableLikeTraversableOnceGenTraversableOnce
58. def forall(p: (B) ⇒ Boolean): Boolean

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

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

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

`true` if this iterable collection is empty, otherwise `true` if the given predicate `p` holds for all elements of this iterable collection, otherwise `false`.

Definition Classes
IterableLikeTraversableLikeTraversableOnceGenTraversableOnce
59. def force[B >: B, That](implicit bf: CanBuildFrom[Coll, B, That]): That

Definition Classes
TraversableViewLike
60. def foreach(f: (A) ⇒ Unit): Unit

[use case] Applies a function `f` to all elements of this sequence.

[use case]

Applies a function `f` to all elements of this sequence.

f

the function that is applied for its side-effect to every element. The result of function `f` is discarded.

Definition Classes
Full Signature

61. def formatted(fmtstr: String): String

Returns string formatted according to given `format` string.

Returns string formatted according to given `format` string. Format strings are as for `String.format` (@see java.lang.String.format).

Implicit information
This member is added by an implicit conversion from Appended[B] to StringFormat[Appended[B]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
()
62. def genericBuilder[B]: Builder[B, Seq[B]]

The generic builder that builds instances of Traversable at arbitrary element types.

The generic builder that builds instances of Traversable at arbitrary element types.

Definition Classes
GenericTraversableTemplate
63. final def getClass(): Class[_]

A representation that corresponds to the dynamic class of the receiver object.

A representation that corresponds to the dynamic class of the receiver object.

The nature of the representation is platform dependent.

returns

a representation that corresponds to the dynamic class of the receiver object.

Definition Classes
AnyRef → Any
Note

not specified by SLS as a member of AnyRef

64. def groupBy[K](f: (B) ⇒ K): immutable.Map[K, SeqView[B, Coll]]

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

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

Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new collection.

K

the type of keys returned by the discriminator function.

f

the discriminator function.

returns

A map from keys to 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 collection of those elements `x` for which `f(x)` equals `k`.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
65. def grouped(size: Int): Iterator[SeqView[B, Coll]]

Partitions elements in fixed size iterable collections.

Partitions elements in fixed size iterable collections.

size

the number of elements per group

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.

Definition Classes
IterableViewLikeIterableLike

scala.collection.Iterator, method `grouped`

66. def hasDefiniteSize: Boolean

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

Tests whether this traversable 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.

Note: many collection methods will not work on collections of infinite sizes.

returns

`true` if this collection is known to have finite size, `false` otherwise.

Definition Classes
TraversableLikeTraversableOnceGenTraversableOnce
67. def hashCode(): Int

Hashcodes for GenSeq produce a value from the hashcodes of all the elements of the general sequence.

Hashcodes for GenSeq produce a value from the hashcodes of all the elements of the general sequence.

returns

the hash code value for this object.

Definition Classes
GenSeqLikeAny

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.

Definition Classes
IterableLikeTraversableLikeGenTraversableLike
Exceptions thrown

`NoSuchElementException` if the iterable collection is empty.

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 collection if it is nonempty, `None` if it is empty.

Definition Classes
TransformedTraversableLikeGenTraversableLike
70. def indexOf(elem: B, from: Int): Int

[use case] Finds index of first occurrence of some value in this sequence after or at some start index.

[use case]

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

Note: may not terminate for infinite-sized collections.

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.

Definition Classes
GenSeqLike
Full Signature

71. def indexOf(elem: B): Int

[use case] Finds index of first occurrence of some value in this sequence.

[use case]

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

Note: may not terminate for infinite-sized collections.

elem

the element value to search for.

returns

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

Definition Classes
GenSeqLike
Full Signature

72. def indexOfSlice[B >: B](that: GenSeq[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.

that

the sequence to test

from

the start index

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.

Definition Classes
SeqLike
73. def indexOfSlice[B >: B](that: GenSeq[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.

that

the sequence to test

returns

the first 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.

Definition Classes
SeqLike
74. def indexWhere(p: (B) ⇒ 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.

p

the predicate used to test elements.

from

the start index

returns

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

Definition Classes
SeqLikeGenSeqLike
75. def indexWhere(p: (B) ⇒ Boolean): Int

Finds index of first element satisfying some predicate.

Finds index of first element satisfying some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

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

Definition Classes
GenSeqLike
76. def indices: immutable.Range

Produces the range of all indices of this sequence.

Produces the range of all indices of this sequence.

returns

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

Definition Classes
SeqLike
77. def init: SeqView[B, Coll]

Selects all elements except the last.

Selects all elements except the last.

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

returns

a collection consisting of all elements of this collection except the last one.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
Exceptions thrown

`UnsupportedOperationException` if the collection is empty.

78. def inits: Iterator[SeqView[B, Coll]]

Iterates over the inits of this collection.

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

returns

an iterator over all the inits of this collection

Definition Classes
TraversableViewLikeTraversableLike
Example:
1. `List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)`

79. def intersect(that: Seq[A]): Seq[A]

[use case] Computes the multiset intersection between this sequence and another sequence.

[use case]

Computes the multiset intersection between this sequence and another sequence.

Note: may not terminate for infinite-sized collections.

that

the sequence of elements to intersect with.

returns

a new sequence which contains all elements of this sequence which also appear in `that`. If an element value `x` appears n times in `that`, then the first n occurrences of `x` will be retained in the result, but any following occurrences will be omitted.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

80. def isDefinedAt(idx: Int): Boolean

Tests whether this general sequence contains given index.

Tests whether this general sequence contains given index.

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

idx

the index to test

returns

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

Definition Classes
GenSeqLike
81. def isEmpty: Boolean

Tests whether this sequence is empty.

Tests whether this sequence is empty.

returns

`true` if the sequence contain no elements, `false` otherwise.

Definition Classes
SeqLikeIterableLikeTraversableLikeTraversableOnceGenTraversableOnce
82. final def isInstanceOf[T0]: Boolean

Test whether the dynamic type of the receiver object is `T0`.

Test whether the dynamic type of the receiver object is `T0`.

Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression `1.isInstanceOf[String]` will return `false`, while the expression `List(1).isInstanceOf[List[String]]` will return `true`. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

returns

`true` if the receiver object is an instance of erasure of type `T0`; `false` otherwise.

Definition Classes
Any
83. final def isTraversableAgain: Boolean

Tests whether this traversable collection can be repeatedly traversed.

Tests whether this traversable collection can be repeatedly traversed.

returns

`true`

Definition Classes
TraversableLikeGenTraversableLikeGenTraversableOnce
84. def iterator: Iterator[B]

Creates a new iterator over all elements contained in this iterable object.

Creates a new iterator over all elements contained in this iterable object.

returns

the new iterator

Definition Classes
AppendedTransformedIterableLikeGenIterableLike
85. def last: B

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 traversable collection.

Definition Classes
TraversableLikeGenTraversableLike
Exceptions thrown

`NoSuchElementException` If the traversable collection is empty.

86. def lastIndexOf(elem: B, end: Int): Int

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

[use case]

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

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.

Definition Classes
GenSeqLike
Full Signature

87. def lastIndexOf(elem: B): Int

[use case] Finds index of last occurrence of some value in this sequence.

[use case]

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

Note: will not terminate for infinite-sized collections.

elem

the element value to search for.

returns

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

Definition Classes
GenSeqLike
Full Signature

88. def lastIndexOfSlice[B >: B](that: GenSeq[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.

that

the sequence to test

end

the end index

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.

Definition Classes
SeqLike
89. def lastIndexOfSlice[B >: B](that: GenSeq[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.

that

the sequence to test

returns

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

Definition Classes
SeqLike
90. def lastIndexWhere(p: (B) ⇒ 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.

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.

Definition Classes
SeqLikeGenSeqLike
91. def lastIndexWhere(p: (B) ⇒ Boolean): Int

Finds index of last element satisfying some predicate.

Finds index of last element satisfying some predicate.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

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

Definition Classes
GenSeqLike
92. def lastOption: Option[B]

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 collection\$ if it is nonempty, `None` if it is empty.

Definition Classes
TransformedTraversableLikeGenTraversableLike
93. def length: Int

The length of the sequence.

The length of the sequence.

Note: will not terminate for infinite-sized collections.

Note: `xs.length` and `xs.size` yield the same result.

returns

the number of elements in this sequence.

Definition Classes
AppendedTransformedSeqLikeGenSeqLike
94. 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.

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 overwritten if computing `length` is cheap.

Definition Classes
SeqLike
95. def lift: (Int) ⇒ Option[B]

Turns this partial function into a plain function returning an `Option` result.

Turns this partial function into a plain function returning an `Option` result.

returns

a function that takes an argument `x` to `Some(this(x))` if `this` is defined for `x`, and to `None` otherwise.

Definition Classes
PartialFunction

Function.unlift

96. def map[B](f: (A) ⇒ B): Seq[B]

[use case] Builds a new collection by applying a function to all elements of this sequence.

[use case]

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

B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new sequence resulting from applying the given function `f` to each element of this sequence and collecting the results.

Definition Classes
Full Signature

97. def max: A

[use case] Finds the largest element.

[use case]

Finds the largest element.

returns

the largest element of this sequence.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

98. def maxBy[B](f: (A) ⇒ B): A

[use case] Finds the first element which yields the largest value measured by function f.

[use case]

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

B

The result type of the function f.

f

The measuring function.

returns

the first element of this sequence with the largest value measured by function f.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

99. def min: A

[use case] Finds the smallest element.

[use case]

Finds the smallest element.

returns

the smallest element of this sequence

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

100. def minBy[B](f: (A) ⇒ B): A

[use case] Finds the first element which yields the smallest value measured by function f.

[use case]

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

B

The result type of the function f.

f

The measuring function.

returns

the first element of this sequence with the smallest value measured by function f.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

101. def mkString(start: String, sep: String, end: String): String

Definition Classes
ViewMkString
102. def mkString(sep: String): String

Definition Classes
ViewMkString
103. def mkString: String

Definition Classes
ViewMkString
104. final def ne(arg0: AnyRef): Boolean

Equivalent to `!(this eq that)`.

Equivalent to `!(this eq that)`.

returns

`true` if the argument is not a reference to the receiver object; `false` otherwise.

Definition Classes
AnyRef
105. def newAppended[B >: B](that: GenTraversable[B]): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
106. def newBuilder: Builder[B, SeqView[B, Coll]]

The builder that builds instances of type Traversable[A]

The builder that builds instances of type Traversable[A]

Attributes
protected[this]
Definition Classes
TraversableViewLikeGenericTraversableTemplateTraversableLikeHasNewBuilder
107. def newDropped(n: Int): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
108. def newDroppedWhile(p: (B) ⇒ Boolean): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
109. def newFiltered(p: (B) ⇒ Boolean): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
110. def newFlatMapped[B](f: (B) ⇒ GenTraversableOnce[B]): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
111. def newForced[B](xs: ⇒ GenSeq[B]): Transformed[B]

Boilerplate method, to override in each subclass This method could be eliminated if Scala had virtual classes

Boilerplate method, to override in each subclass This method could be eliminated if Scala had virtual classes

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
112. def newMapped[B](f: (B) ⇒ B): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
113. def newPatched[B >: B](_from: Int, _patch: GenSeq[B], _replaced: Int): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLike
114. def newPrepended[B >: B](elem: B): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLike
115. def newReversed: Transformed[B]

Attributes
protected
Definition Classes
SeqViewLike
116. def newSliced(_endpoints: SliceInterval): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
117. def newTaken(n: Int): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
118. def newTakenWhile(p: (B) ⇒ Boolean): Transformed[B]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLike
119. def newZipped[B](that: GenIterable[B]): Transformed[(B, B)]

Boilerplate method, to override in each subclass This method could be eliminated if Scala had virtual classes

Boilerplate method, to override in each subclass This method could be eliminated if Scala had virtual classes

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLike
120. def newZippedAll[A1 >: B, B](that: GenIterable[B], _thisElem: A1, _thatElem: B): Transformed[(A1, B)]

Attributes
protected
Definition Classes
SeqViewLikeIterableViewLike
121. def nonEmpty: Boolean

Tests whether the traversable or iterator is not empty.

Tests whether the traversable or iterator is not empty.

returns

`true` if the traversable or iterator contains at least one element, `false` otherwise.

Definition Classes
TraversableOnceGenTraversableOnce
122. final def notify(): Unit

Wakes up a single thread that is waiting on the receiver object's monitor.

Wakes up a single thread that is waiting on the receiver object's monitor.

Definition Classes
AnyRef
Note

not specified by SLS as a member of AnyRef

123. final def notifyAll(): Unit

Wakes up all threads that are waiting on the receiver object's monitor.

Wakes up all threads that are waiting on the receiver object's monitor.

Definition Classes
AnyRef
Note

not specified by SLS as a member of AnyRef

124. def orElse[A1 <: Int, B1 >: B](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]

Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.

Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.

A1

the argument type of the fallback function

B1

the result type of the fallback function

that

the fallback function

returns

a partial function which has as domain the union of the domains of this partial function and `that`. The resulting partial function takes `x` to `this(x)` where `this` is defined, and to `that(x)` where it is not.

Definition Classes
PartialFunction
125. def padTo(len: Int, elem: A): Seq[A]

[use case] A copy of this sequence with an element value appended until a given target length is reached.

[use case]

A copy of this sequence with an element value appended until a given target length is reached.

len

the target length

elem

returns

a new sequence consisting of all elements of this sequence followed by the minimal number of occurrences of `elem` so that the resulting sequence has a length of at least `len`.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

126. def par: ParSeq[B]

Returns a parallel implementation of this collection.

Returns a parallel implementation of this collection.

For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, `par` takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.

Specific collections (e.g. `ParArray` or `mutable.ParHashMap`) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, `par` takes constant or sublinear time.

All parallel collections return a reference to themselves.

returns

a parallel implementation of this collection

Definition Classes
Parallelizable
127. def parCombiner: Combiner[B, ParSeq[B]]

The default `par` implementation uses the combiner provided by this method to create a new parallel collection.

The default `par` implementation uses the combiner provided by this method to create a new parallel collection.

returns

a combiner for the parallel collection of type `ParRepr`

Attributes
protected[this]
Definition Classes
SeqLikeTraversableLikeParallelizable
128. def partition(p: (B) ⇒ Boolean): (SeqView[B, Coll], SeqView[B, Coll])

Partitions this collection in two collections according to a predicate.

Partitions this collection in two collections according to a predicate.

p

the predicate on which to partition.

returns

a pair of collections: the first collection consists of all elements that satisfy the predicate `p` and the second collection consists of all elements that don't. The relative order of the elements in the resulting collections is the same as in the original collection.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
129. def patch(from: Int, that: GenSeq[A], replaced: Int): Seq[A]

[use case] Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.

[use case]

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

from

the index of the first replaced element

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 `patch`.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

130. def permutations: Iterator[SeqView[B, Coll]]

Iterates over distinct permutations.

Iterates over distinct permutations.

returns

An Iterator which traverses the distinct permutations of this sequence.

Definition Classes
SeqViewLikeSeqLike
Example:
1. `"abb".permutations = Iterator(abb, bab, bba)`

131. def prefixLength(p: (B) ⇒ 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.

p

the predicate used to test elements.

returns

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

Definition Classes
GenSeqLike
132. def product: A

[use case] Multiplies up the elements of this collection.

[use case]

Multiplies up the elements of this collection.

returns

the product of all elements in this sequence of numbers of type `Int`. Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation can be used as element type of the sequence and as result type of `product`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

133. def reduce[A1 >: B](op: (A1, A1) ⇒ A1): A1

Reduces the elements of this traversable or iterator using the specified associative binary operator.

Reduces the elements of this traversable or iterator using the specified associative binary operator.

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

A1

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

op

A binary operator that must be associative.

returns

The result of applying reduce operator `op` between all the elements if the traversable or iterator is nonempty.

Definition Classes
TraversableOnceGenTraversableOnce
Exceptions thrown

`UnsupportedOperationException` if this traversable or iterator is empty.

134. def reduceLeft[B >: B](op: (B, B) ⇒ B): B

Applies a binary operator to all elements of this traversable or iterator, going left to right.

Applies a binary operator to all elements of this traversable or iterator, 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.

B

the result type of the binary operator.

op

the binary operator.

returns

the result of inserting `op` between consecutive elements of this traversable or iterator, going left to right:

`op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)`

where `x1, ..., xn` are the elements of this traversable or iterator.

Definition Classes
TraversableOnce
Exceptions thrown

`UnsupportedOperationException` if this traversable or iterator is empty.

135. def reduceLeftOption[B >: B](op: (B, B) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this traversable or iterator, going left to right.

Optionally applies a binary operator to all elements of this traversable or iterator, 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.

B

the result type of the binary operator.

op

the binary operator.

returns

an option value containing the result of `reduceLeft(op)` is this traversable or iterator is nonempty, `None` otherwise.

Definition Classes
TraversableOnceGenTraversableOnce
136. def reduceOption[A1 >: B](op: (A1, A1) ⇒ A1): Option[A1]

Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.

Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.

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

A1

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

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.

Definition Classes
TraversableOnceGenTraversableOnce
137. def reduceRight[B >: B](op: (B, B) ⇒ B): B

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

Applies a binary operator to all elements of this iterable 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.

B

the result type of the binary operator.

op

the binary operator.

returns

the result of inserting `op` between consecutive elements of this iterable collection, going right to left:

`op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))`

where `x1, ..., xn` are the elements of this iterable collection.

Definition Classes
IterableLikeTraversableOnceGenTraversableOnce
Exceptions thrown

`UnsupportedOperationException` if this iterable collection is empty.

138. def reduceRightOption[B >: B](op: (B, B) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this traversable or iterator, going right to left.

Optionally applies a binary operator to all elements of this traversable or iterator, 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.

B

the result type of the binary operator.

op

the binary operator.

returns

an option value containing the result of `reduceRight(op)` is this traversable or iterator is nonempty, `None` otherwise.

Definition Classes
TraversableOnceGenTraversableOnce
139. def repr: SeqView[B, Coll]

The collection of type traversable collection underlying this `TraversableLike` object.

The collection of type traversable collection underlying this `TraversableLike` object. By default this is implemented as the `TraversableLike` object itself, but this can be overridden.

Definition Classes
TraversableLikeGenTraversableLike
140. lazy val restSeq: GenSeq[B]

Attributes
protected[this]
141. def reverse: SeqView[B, Coll]

Returns new sequence with elements in reversed order.

Returns new sequence with elements in reversed order.

Note: will not terminate for infinite-sized collections.

returns

A new sequence with all elements of this sequence in reversed order.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
142. def reverseIterator: Iterator[B]

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

Definition Classes
SeqLike
143. def reverseMap[B](f: (A) ⇒ B): Seq[B]

[use case] Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.

[use case]

Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.

Note: will not terminate for infinite-sized collections.

Note: `xs.reverseMap(f)` is the same as `xs.reverse.map(f)` but might be more efficient.

B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new sequence resulting from applying the given function `f` to each element of this sequence and collecting the results in reversed order.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

144. def reversed: List[B]

Attributes
protected[this]
Definition Classes
TraversableOnce
145. def runWith[U](action: (B) ⇒ U): (Int) ⇒ Boolean

Composes this partial function with an action function which gets applied to results of this partial function.

Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.

Note that expression `pf.runWith(action)(x)` is equivalent to

`if(pf isDefinedAt x) { action(pf(x)); true } else false`

except that `runWith` is implemented via `applyOrElse` and thus potentially more efficient. Using `runWith` avoids double evaluation of pattern matchers and guards for partial function literals.

action

the action function

returns

a function which maps arguments `x` to `isDefinedAt(x)`. The resulting function runs `action(this(x))` where `this` is defined.

Definition Classes
PartialFunction
Since

2.10

`applyOrElse`.

146. def sameElements(that: GenIterable[A]): Boolean

[use case] Checks if the other iterable collection contains the same elements in the same order as this sequence.

[use case]

Checks if the other iterable collection contains the same elements in the same order as this sequence.

Note: will not terminate for infinite-sized collections.

that

the collection to compare with.

returns

`true`, if both collections contain the same elements in the same order, `false` otherwise.

Definition Classes
IterableLikeGenIterableLike
Full Signature

147. def scan[B >: B, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[SeqView[B, Coll], B, That]): That

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.

B

element type of the resulting collection

That

type of the resulting collection

z

neutral element for the operator `op`

op

the associative operator for the scan

cbf

combiner factory which provides a combiner

returns

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

Definition Classes
TraversableLikeGenTraversableLike
148. def scanLeft[B, That](z: B)(op: (B, B) ⇒ B)(implicit bf: CanBuildFrom[SeqView[B, Coll], B, That]): That

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

Produces a collection containing cumulative results of applying the operator 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.

B

the type of the elements in the resulting collection

That

the actual type of the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

bf

an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

returns

collection with intermediate results

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
149. def scanRight[B, That](z: B)(op: (B, B) ⇒ B)(implicit bf: CanBuildFrom[SeqView[B, Coll], B, That]): That

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.

Example:

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

the type of the elements in the resulting collection

That

the actual type of the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

bf

an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

returns

collection with intermediate results

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
Annotations
@migration
Migration

(Changed in version 2.9.0) The behavior of `scanRight` has changed. The previous behavior can be reproduced with scanRight.reverse.

150. def segmentLength(p: (B) ⇒ Boolean, from: Int): Int

Computes length of longest segment whose elements all satisfy some predicate.

Computes length of longest segment whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

from

the index where the search starts.

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`.

Definition Classes
SeqLikeGenSeqLike
151. def seq: Seq[B]

A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).

A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).

This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.

returns

a sequential view of the collection.

Definition Classes
SeqGenSeqGenSeqLikeIterableGenIterableTraversableGenTraversableParallelizableTraversableOnceGenTraversableOnce
152. def size: Int

The size of this sequence, equivalent to `length`.

The size of this sequence, equivalent to `length`.

Note: will not terminate for infinite-sized collections.

returns

the number of elements in this sequence.

Definition Classes
SeqLikeGenTraversableLikeTraversableOnceGenTraversableOnce
153. def slice(from: Int, until: Int): SeqView[B, Coll]

Selects an interval of elements.

Selects an interval of elements. The returned 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.

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.

Definition Classes
IterableLikeTraversableLikeGenTraversableLike
154. def sliding(size: Int): Iterator[SeqView[B, Coll]]

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.)

size

the number of elements per group

returns

An iterator producing iterable collections of size `size`, except the last and the only element will be truncated if there are fewer elements than size.

Definition Classes
IterableViewLikeIterableLike

scala.collection.Iterator, method `sliding`

155. def sliding(size: Int, step: Int): Iterator[SeqView[B, Coll]]

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.)

size

the number of elements per group

step

the distance between the first elements of successive groups (defaults to 1)

returns

An iterator producing iterable collections of size `size`, except the last and the only element will be truncated if there are fewer elements than size.

Definition Classes
IterableViewLikeIterableLike

scala.collection.Iterator, method `sliding`

156. def sortBy[B](f: (B) ⇒ B)(implicit ord: Ordering[B]): SeqView[B, Coll]

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

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

B

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

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))`.

Definition Classes
SeqViewLikeSeqLike
Example:
1. ```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]]
res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)```

scala.math.Ordering

Note: will not terminate for infinite-sized collections.

157. def sortWith(lt: (B, B) ⇒ Boolean): SeqView[B, Coll]

Sorts this sequence according to a comparison function.

Sorts this sequence according to a comparison function.

Note: will not terminate for infinite-sized collections.

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.

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`.

Definition Classes
SeqViewLikeSeqLike
Example:
1. ```List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) =
List("Bob", "John", "Steve", "Tom")```
158. def sorted[B >: B](implicit ord: Ordering[B]): SeqView[B, Coll]

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 `lt`) appear in the same order in the sorted sequence as in the original.

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`.

Definition Classes
SeqViewLikeSeqLike
159. def span(p: (B) ⇒ Boolean): (SeqView[B, Coll], SeqView[B, Coll])

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

Splits this 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.

returns

a pair consisting of the longest prefix of this collection whose elements all satisfy `p`, and the rest of this collection.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
160. def splitAt(n: Int): (SeqView[B, Coll], SeqView[B, Coll])

Splits this collection into two at a given position.

Splits this collection into two 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.

n

the position at which to split.

returns

a pair of collections consisting of the first `n` elements of this collection, and the other elements.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
161. def startsWith[B](that: GenSeq[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.

that

the sequence to test

offset

the index where the sequence is searched.

returns

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

Definition Classes
SeqLikeGenSeqLike
162. def startsWith[B](that: GenSeq[B]): Boolean

Tests whether this general sequence starts with the given sequence.

Tests whether this general sequence starts with the given sequence.

that

the sequence to test

returns

`true` if this collection has `that` as a prefix, `false` otherwise.

Definition Classes
GenSeqLike
163. def stringPrefix: String

Defines the prefix of this object's `toString` representation.

Defines the prefix of this object's `toString` representation.

returns

a string representation which starts the result of `toString` applied to this sequence. By default the string prefix is the simple name of the collection class sequence.

Definition Classes
SeqViewLikeIterableViewLikeTraversableViewLikeTraversableLikeGenTraversableLike
164. def sum: A

[use case] Sums up the elements of this collection.

[use case]

Sums up the elements of this collection.

returns

the sum of all elements in this sequence of numbers of type `Int`. Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation can be used as element type of the sequence and as result type of `sum`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

165. final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
166. def tail: SeqView[B, Coll]

Selects all elements except the first.

Selects all elements except the first.

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

returns

a collection consisting of all elements of this collection except the first one.

Definition Classes
TraversableViewLikeTraversableLikeGenTraversableLike
Exceptions thrown

``UnsupportedOperationException`` if the collection is empty.

167. def tails: Iterator[SeqView[B, Coll]]

Iterates over the tails of this collection.

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

returns

an iterator over all the tails of this collection

Definition Classes
TraversableViewLikeTraversableLike
Example:
1. `List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)`

168. def take(n: Int): SeqView[B, Coll]

Selects first n elements.

Selects first n elements.

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

n

the number of elements to take from this iterable collection.

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.

Definition Classes
IterableViewLikeTraversableViewLikeIterableLikeTraversableLikeGenTraversableLike
169. def takeRight(n: Int): SeqView[B, Coll]

Selects last n elements.

Selects last n elements.

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

n

the number of elements to take

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.

Definition Classes
IterableViewLikeIterableLike
170. def takeWhile(p: (B) ⇒ Boolean): SeqView[B, Coll]

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.

returns

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

Definition Classes
IterableLikeTraversableLikeGenTraversableLike
171. def thisCollection: Seq[B]

The underlying collection seen as an instance of `Seq`.

The underlying collection seen as an instance of `Seq`. By default this is implemented as the current collection object itself, but this can be overridden.

Attributes
protected[this]
Definition Classes
SeqLikeIterableLikeTraversableLike
172. def thisSeq: Seq[B]

Attributes
protected[this]
Definition Classes
ViewMkString
173. def to[Col[_]]: Col[A]

[use case] Converts this sequence into another by copying all elements.

[use case]

Converts this sequence into another by copying all elements.

Note: will not terminate for infinite-sized collections.

Col

The collection type to build.

returns

a new collection containing all elements of this sequence.

Definition Classes
TraversableLikeTraversableOnceGenTraversableOnce
Full Signature

174. def toArray: Array[A]

[use case] Converts this sequence to an array.

[use case]

Converts this sequence to an array.

Note: will not terminate for infinite-sized collections.

returns

an array containing all elements of this sequence. An `ClassTag` must be available for the element type of this sequence.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

175. def toBuffer[B >: B]: Buffer[B]

Uses the contents of this traversable or iterator to create a new mutable buffer.

Uses the contents of this traversable or iterator to create a new mutable buffer.

Note: will not terminate for infinite-sized collections.

returns

a buffer containing all elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
176. def toCollection(repr: SeqView[B, Coll]): Seq[B]

A conversion from collections of type `Repr` to `Seq` objects.

A conversion from collections of type `Repr` to `Seq` objects. By default this is implemented as just a cast, but this can be overridden.

Attributes
protected[this]
Definition Classes
SeqLikeIterableLikeTraversableLike
177. def toIndexedSeq: immutable.IndexedSeq[B]

Converts this traversable or iterator to an indexed sequence.

Converts this traversable or iterator to an indexed sequence.

Note: will not terminate for infinite-sized collections.

returns

an indexed sequence containing all elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
178. def toIterable: Iterable[B]

Returns this iterable collection as an iterable collection.

Returns this iterable collection as an iterable collection.

A new collection will not be built; lazy collections will stay lazy.

Note: will not terminate for infinite-sized collections.

returns

an `Iterable` containing all elements of this iterable collection.

Definition Classes
IterableLikeTraversableOnceGenTraversableOnce
179. def toIterator: Iterator[B]

Returns an Iterator over the elements in this iterable collection.

Returns an Iterator over the elements in this iterable collection. Produces the same result as `iterator`.

Note: will not terminate for infinite-sized collections.

returns

an Iterator containing all elements of this iterable collection.

Definition Classes
IterableLikeTraversableLikeGenTraversableOnce
Annotations
@deprecatedOverriding( ... , "2.11.0" )
180. def toList: List[B]

Converts this traversable or iterator to a list.

Converts this traversable or iterator to a list.

Note: will not terminate for infinite-sized collections.

returns

a list containing all elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
181. def toMap[T, U]: Map[T, U]

[use case] Converts this sequence to a map.

[use case]

Converts this sequence to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.

Note: will not terminate for infinite-sized collections.

returns

a map of type `immutable.Map[T, U]` containing all key/value pairs of type `(T, U)` of this sequence.

Definition Classes
TraversableOnceGenTraversableOnce
Full Signature

182. def toParArray: ParArray[T]

Implicit information
This member is added by an implicit conversion from Appended[B] to CollectionsHaveToParArray[Appended[B], T] performed by method CollectionsHaveToParArray in scala.collection.parallel. This conversion will take place only if an implicit value of type (Appended[B]) ⇒ GenTraversableOnce[T] is in scope.
Definition Classes
CollectionsHaveToParArray
183. def toSeq: Seq[B]

Converts this sequence to a sequence.

Converts this sequence to a sequence.

Note: will not terminate for infinite-sized collections.

A new collection will not be built; in particular, lazy sequences will stay lazy.

returns

a sequence containing all elements of this sequence.

Definition Classes
SeqLikeGenSeqLikeTraversableOnceGenTraversableOnce
184. def toSet[B >: B]: immutable.Set[B]

Converts this traversable or iterator to a set.

Converts this traversable or iterator to a set.

Note: will not terminate for infinite-sized collections.

returns

a set containing all elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
185. def toStream: immutable.Stream[B]

Converts this iterable collection to a stream.

Converts this iterable collection to a stream.

returns

a stream containing all elements of this iterable collection.

Definition Classes
IterableLikeTraversableLikeGenTraversableOnce
186. def toString(): String

Converts this sequence to a string.

Converts this sequence to a string.

returns

a string representation of this collection. By default this string consists of the `stringPrefix` of this sequence, followed by all elements separated by commas and enclosed in parentheses.

Definition Classes
TransformedTransformedTransformedTraversableViewLikeSeqLikeTraversableLikeFunction1 → AnyRef → Any
187. def toTraversable: Traversable[B]

Converts this traversable collection to an unspecified Traversable.

Converts this traversable collection to an unspecified Traversable. Will return the same collection if this instance is already Traversable.

Note: will not terminate for infinite-sized collections.

returns

a Traversable containing all elements of this traversable collection.

Definition Classes
TraversableLikeTraversableOnceGenTraversableOnce
Annotations
@deprecatedOverriding( ... , "2.11.0" )
188. def toVector: Vector[B]

Converts this traversable or iterator to a Vector.

Converts this traversable or iterator to a Vector.

Note: will not terminate for infinite-sized collections.

returns

a vector containing all elements of this traversable or iterator.

Definition Classes
TraversableOnceGenTraversableOnce
189. def transpose[B](implicit asTraversable: (B) ⇒ GenTraversableOnce[B]): Seq[Seq[B]]

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

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

The resulting collection's type will be guided by the static type of 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))```
B

the type of the elements of each traversable collection.

asTraversable

an implicit conversion which asserts that the element type of this collection is a `Traversable`.

returns

a two-dimensional collection of collections which has as nth row the nth column of this collection.

Definition Classes
GenericTraversableTemplate
Annotations
@migration
Migration

(Changed in version 2.9.0) `transpose` throws an `IllegalArgumentException` if collections are not uniformly sized.

Exceptions thrown

`IllegalArgumentException` if all collections in this collection are not of the same size.

190. lazy val underlying: Coll

Definition Classes
TransformedTraversableViewLike
191. def union(that: Seq[A]): Seq[A]

[use case] Produces a new sequence which contains all elements of this sequence and also all elements of a given sequence.

[use case]

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`.

Another way to express this is that `xs union ys` computes the order-presevring multi-set union of `xs` and `ys`. `union` is hence a counter-part of `diff` and `intersect` which also work on multi-sets.

Note: will not terminate for infinite-sized collections.

that

returns

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

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

192. def unzip[A1, A2](implicit asPair: (B) ⇒ (A1, A2)): (Appended.Transformed[A1], Appended.Transformed[A2])

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

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

```val xs = Traversable(
(1, "one"),
(2, "two"),
(3, "three")).unzip
// xs == (Traversable(1, 2, 3),
//        Traversable(one, two, three))```
A1

the type of the first half of the element pairs

A2

the type of the second half of the element pairs

asPair

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

returns

a pair of collections, containing the first, respectively second half of each element pair of this collection.

Definition Classes
TraversableViewLikeGenericTraversableTemplate
193. def unzip3[A1, A2, A3](implicit asTriple: (B) ⇒ (A1, A2, A3)): (Appended.Transformed[A1], Appended.Transformed[A2], Appended.Transformed[A3])

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

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

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

asTriple

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

returns

a triple of collections, containing the first, second, respectively third member of each element triple of this collection.

Definition Classes
TraversableViewLikeGenericTraversableTemplate
194. def updated(index: Int, elem: A): Seq[A]

[use case] A copy of this sequence with one single replaced element.

[use case]

A copy of this sequence with one single replaced element.

index

the position of the replacement

elem

the replacing element

returns

a copy of this sequence with the element at position `index` replaced by `elem`.

Definition Classes
SeqViewLikeSeqLikeGenSeqLike
Full Signature

195. def view(from: Int, until: Int): SeqView[B, SeqView[B, Coll]]

Creates a non-strict view of a slice of this sequence.

Creates a non-strict view of a slice of this sequence.

Note: the difference between `view` and `slice` is that `view` produces a view of the current sequence, whereas `slice` produces a new sequence.

Note: `view(from, to)` is equivalent to `view.slice(from, to)`

from

the index of the first element of the view

until

the index of the element following the view

returns

a non-strict view of a slice of this sequence, starting at index `from` and extending up to (but not including) index `until`.

Definition Classes
SeqLikeIterableLikeTraversableLike
196. def view: SeqView[B, SeqView[B, Coll]]

Creates a non-strict view of this sequence.

Creates a non-strict view of this sequence.

returns

a non-strict view of this sequence.

Definition Classes
SeqLikeIterableLikeTraversableLike
197. final def viewIdString: String

Attributes
protected[this]
Definition Classes
TransformedTraversableViewLike
198. final def viewIdentifier: String

Attributes
protected[this]
Definition Classes
AppendedTraversableViewLike
199. def viewToString: String

Definition Classes
TraversableViewLike
200. final def wait(): Unit

Definition Classes
AnyRef
Annotations
( ... )
201. final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
( ... )
202. final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
( ... )
203. def withFilter(p: (B) ⇒ Boolean): SeqView[B, Coll]

Creates a non-strict filter of this collection.

Creates a non-strict filter of this 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.

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 collection which satisfy the predicate `p`.

Definition Classes
204. def zip[B](that: GenIterable[B]): Seq[(A, B)]

[use case] Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.

[use case]

Returns a sequence formed from this sequence 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.

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

returns

a new sequence containing pairs consisting of corresponding elements of this sequence and `that`. The length of the returned collection is the minimum of the lengths of this sequence and `that`.

Definition Classes
IterableViewLikeIterableLikeGenIterableLike
Full Signature

205. def zipAll[B](that: Iterable[B], thisElem: A, thatElem: B): Seq[(A, B)]

[use case] Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.

[use case]

Returns a sequence formed from this sequence 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.

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

thisElem

the element to be used to fill up the result if this sequence is shorter than `that`.

thatElem

the element to be used to fill up the result if `that` is shorter than this sequence.

returns

a new sequence containing pairs consisting of corresponding elements of this sequence and `that`. The length of the returned collection is the maximum of the lengths of this sequence and `that`. If this sequence is shorter than `that`, `thisElem` values are used to pad the result. If `that` is shorter than this sequence, `thatElem` values are used to pad the result.

Definition Classes
IterableViewLikeIterableLikeGenIterableLike
Full Signature

206. def zipWithIndex: Seq[(A, Int)]

[use case] Zips this sequence with its indices.

[use case]

Zips this sequence with its indices.

returns

A new sequence containing pairs consisting of all elements of this sequence paired with their index. Indices start at `0`.

Definition Classes
IterableViewLikeIterableLikeGenIterableLike
Full Signature

def zipWithIndex[A1 >: B, That](implicit bf: CanBuildFrom[SeqView[B, Coll], (A1, Int), That]): That

Example:
1. `List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))`

207. def →[B](y: B): (Appended[B], B)

Implicit information
This member is added by an implicit conversion from Appended[B] to ArrowAssoc[Appended[B]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc

1. def filter(p: (B) ⇒ Boolean): TraversableOnce[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to MonadOps[B] performed by method MonadOps in scala.collection.TraversableOnce.
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
`(appended: MonadOps[B]).filter(p)`
Definition Classes
2. def flatMap[B](f: (B) ⇒ GenTraversableOnce[B]): TraversableOnce[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to MonadOps[B] performed by method MonadOps in scala.collection.TraversableOnce.
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
`(appended: MonadOps[B]).flatMap(f)`
Definition Classes
3. def map[B](f: (B) ⇒ B): TraversableOnce[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to MonadOps[B] performed by method MonadOps in scala.collection.TraversableOnce.
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
`(appended: MonadOps[B]).map(f)`
Definition Classes
4. def withFilter(p: (B) ⇒ Boolean): Iterator[B]

Implicit information
This member is added by an implicit conversion from Appended[B] to MonadOps[B] performed by method MonadOps in scala.collection.TraversableOnce.
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
`(appended: MonadOps[B]).withFilter(p)`
Definition Classes