Object scala.collection.immutable.Stream.Empty

object Empty extends Stream[Nothing]

Source: Stream.scala

Linear Supertypes

Type Members

class WithFilter extends FilterMonadic[A, Repr]

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

Definition Classes: TraversableLike

type Self = Stream[Nothing]

The type implementing this traversable

Attributes: protected[this]
Definition Classes: TraversableLike

Value Members

final def !=(arg0: Any): Boolean

Test two objects for inequality.

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

Definition Classes: AnyRef → Any

final def ##(): Int

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

def ++[B >: Nothing, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

Create a new stream which contains all elements of this stream followed by all elements of Traversable that.

B: The element type of the returned collection.That
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 scala.collection.GenTraversableOnce to be concatenated to this Stream.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns: A new collection containing the result of concatenating this with that.

Definition Classes: Stream → TraversableLike → GenTraversableLike
Note: It's subtle why this works. We know that if the target type of the scala.collection.mutable.Builder That is either a Stream, or one of its supertypes, or undefined, then StreamBuilder will be chosen for the implicit. We recognize that fact and optimize to get more laziness.
,
This method doesn't cause the Stream to be fully realized but it should be noted that using the ++ operator from another collection type could cause infinite realization of a Stream. For example, referring to the definition of fibs in the preamble, the following would never return: List(BigInt(12)) ++ fibs.

def ++:[B >: Nothing, That](that: collection.Traversable[B])(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

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 y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

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 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

def ++:[B](that: TraversableOnce[B]): Stream[B]

[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 y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

B: the element type of the returned collection.
that: the traversable to append.
returns: a new stream which contains all elements of this stream followed by all elements of that.

Definition Classes: TraversableLike

def +:(elem: A): Stream[A]

[use case]

A copy of the stream 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 stream 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 stream consisting of elem followed by all elements of this stream.

Definition Classes: Stream → SeqLike → GenSeqLike

def /:[B](z: B)(op: (B, Nothing) ⇒ B): B

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, ..., x_n are the elements of this traversable or iterator.

Definition Classes: TraversableOnce → GenTraversableOnce

def :+(elem: A): Stream[A]

[use case]

A copy of this stream 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 stream consisting of all elements of this stream followed by elem.

Definition Classes: SeqLike → GenSeqLike

def :\[B](z: B)(op: (Nothing, B) ⇒ B): B

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, ..., x_n are the elements of this traversable or iterator.

Definition Classes: TraversableOnce → GenTraversableOnce

final def ==(arg0: Any): Boolean

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

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

Definition Classes: AnyRef → Any

def addString(b: mutable.StringBuilder, start: String, sep: String, end: String): mutable.StringBuilder

Write all defined elements of this iterable into given string builder. The written text begins with the string start and is finished by the string end. Inside, the string representations of defined elements (w.r.t. the method toString()) are separated by the string sep. The method will not force evaluation of undefined elements. A tail of such elements will be represented by a "?" instead. A cyclic stream is represented by a "..." at the point where the cycle repeats.

b: The collection.mutable.StringBuilder factory to which we need to add the string elements.
start: The prefix of the resulting string (e.g. "Stream(")
sep: The separator between elements of the resulting string (e.g. ",")
end: The end of the resulting string (e.g. ")")
returns: The original collection.mutable.StringBuilder containing the resulting string.

Definition Classes: Stream → TraversableOnce

def addString(b: StringBuilder): StringBuilder

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 =

scala> val h = a.addString(b)
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

def addString(b: StringBuilder, sep: String): StringBuilder

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 =

scala> a.addString(b, ", ")
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

def aggregate[B](z: ⇒ B)(seqop: (B, Nothing) ⇒ B, combop: (B, B) ⇒ B): B

Aggregates the results of applying an operator to subsequent elements.

This is a more general form of fold and reduce. It is similar to foldLeft in that it doesn't require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.

aggregate splits the traversable or iterator into partitions and processes each partition by sequentially applying seqop, starting with z (like foldLeft). Those intermediate results are then combined by using combop (like fold). The implementation of this operation may operate on an arbitrary number of collection partitions (even 1), so combop may be invoked an arbitrary number of times (even 0).

As an example, consider summing up the integer values of a list of chars. The initial value for the sum is 0. First, seqop transforms each input character to an Int and adds it to the sum (of the partition). Then, combop just needs to sum up the intermediate results of the partitions:

List('a', 'b', 'c').aggregate(0)({ (sum, ch) => sum + ch.toInt }, { (p1, p2) => p1 + p2 })

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: TraversableOnce → GenTraversableOnce

def andThen[C](k: (Nothing) ⇒ C): PartialFunction[Int, C]

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: PartialFunction → Function1

def append[B >: Nothing](rest: ⇒ TraversableOnce[B]): Stream[B]

The stream resulting from the concatenation of this stream with the argument stream.

rest: The stream that gets appended to this stream
returns: The stream containing elements of this stream and the traversable object.

Definition Classes: Stream

def apply(n: Int): Nothing

Selects an element by its index in the sequence. Note: the execution of apply may take time proportional to the index value.

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

Definition Classes: LinearSeqOptimized → SeqLike → GenSeqLike
Exceptions thrown: IndexOutOfBoundsException if idx does not satisfy 0 <= idx < length.

def applyOrElse[A1 <: Int, B1 >: Nothing](x: A1, default: (A1) ⇒ B1): B1

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:

orElse

andThen

apply

isDefinedAt

lift

unlift

runWith

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

final def asInstanceOf[T0]: 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: the receiver object.

Definition Classes: Any
Exceptions thrown: ClassCastException if the receiver object is not an instance of the erasure of type T0.

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.

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: IterableLike → Equals

def clone(): AnyRef

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[lang]
Definition Classes: AnyRef
Annotations: @throws( ... ) @native()
Note: not specified by SLS as a member of AnyRef

final def collect[B](pf: PartialFunction[A, B]): Stream[B]

[use case]

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

B: the element type of the returned collection.
pf: the partial function which filters and maps the stream.
returns: a new stream 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: Stream → TraversableLike → GenTraversableLike

def collectFirst[B](pf: PartialFunction[Nothing, 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.

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

def combinations(n: Int): Iterator[Stream[Nothing]]

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: SeqLike

def companion: GenericCompanion[Stream]

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

Definition Classes: Stream → LinearSeq → LinearSeq → Seq → Iterable → Traversable → Seq → GenSeq → Iterable → GenIterable → Traversable → GenTraversable → GenericTraversableTemplate

def compose[A](g: (A) ⇒ Int): (A) ⇒ Nothing

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: @unspecialized()

def contains[A1 >: Nothing](elem: A1): Boolean

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: LinearSeqOptimized → SeqLike

def containsSlice[B](that: GenSeq[B]): Boolean

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

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

[use case]

Copies the elements of this stream to an array. Fills the given array xs with at most len elements of this stream, starting at position start. Copying will stop once either the end of the current stream is reached, or the end of the target 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: IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

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

[use case]

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

Note: will not terminate for infinite-sized collections.

xs: the array to fill.

Definition Classes: TraversableOnce → GenTraversableOnce

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

[use case]

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

Note: will not terminate for infinite-sized collections.

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

Definition Classes: TraversableOnce → GenTraversableOnce

def copyToBuffer[B >: Nothing](dest: Buffer[B]): Unit

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

final def corresponds[B](that: GenSeq[B])(p: (Nothing, B) ⇒ Boolean): Boolean

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: LinearSeqLike → SeqLike → GenSeqLike
Annotations: @tailrec()

def count(p: (Nothing) ⇒ Boolean): Int

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: TraversableOnce → GenTraversableOnce

def diff(that: collection.Seq[Nothing]): Stream[Nothing]

[use case]

Computes the multiset difference between this stream and another sequence.

Note: will not terminate for infinite-sized collections.

that: the sequence of elements to remove
returns: a new stream which contains all elements of this stream 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: SeqLike → GenSeqLike

def distinct: Stream[Nothing]

Builds a new stream from this stream in which any duplicates (as determined by ==) have been removed. Among duplicate elements, only the first one is retained in the resulting Stream.

returns: A new Stream representing the result of applying distinctness to the original Stream.

Definition Classes: Stream → SeqLike → GenSeqLike

final def drop(n: Int): Stream[Nothing]

Selects all elements except first n ones.

n: the number of elements to drop from this stream.
returns: a stream consisting of all elements of this stream except the first n ones, or else the empty stream, if this stream has less than n elements. If n is negative, don't drop any elements.

Definition Classes: Stream → LinearSeqOptimized → IterableLike → TraversableLike → GenTraversableLike
Annotations: @tailrec()

def dropRight(n: Int): Stream[Nothing]

Selects all elements except last n ones.

Note: lazily evaluated; will terminate for infinite-sized collections.

n: The number of elements to take
returns: a stream consisting of all elements of this stream except the last n ones, or else the empty stream, if this stream has less than n elements.

Definition Classes: Stream → LinearSeqOptimized → IterableLike

def dropWhile(p: (Nothing) ⇒ Boolean): Stream[Nothing]

Returns the a Stream representing the longest suffix of this iterable whose first element does not satisfy the predicate p.

p: the test predicate.
returns: A new Stream representing the results of applying p to the original Stream.

Definition Classes: Stream → TraversableLike → GenTraversableLike
Note: This method realizes the entire Stream beyond the truth value of the predicate p.

def endsWith[B](that: GenSeq[B]): Boolean

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: SeqLike → GenSeqLike

final def eq(arg0: AnyRef): Boolean

Tests whether the argument (that) 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:

x

y

AnyRef

x.eq(y)

true

false

x

AnyRef

x.eq(null)

null.eq(x)

false

null.eq(null)

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

def equals(that: Any): Boolean

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: Stream → GenSeqLike → Equals → AnyRef → Any

def exists(p: (Nothing) ⇒ Boolean): Boolean

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

Note: may not terminate for infinite-sized collections.

p: the predicate used to test elements.
returns: false if this sequence is empty, otherwise true if the given predicate p holds for some of the elements of this sequence, otherwise false

Definition Classes: LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

def filter(p: (Nothing) ⇒ Boolean): Stream[Nothing]

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

p: the predicate used to test elements.
returns: a new traversable collection consisting of all elements of this traversable collection that satisfy the given predicate p. The order of the elements is preserved.

Definition Classes: TraversableLike → GenTraversableLike

def filterNot(p: (Nothing) ⇒ Boolean): Stream[Nothing]

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

p: the predicate used to test elements.
returns: a new traversable collection consisting of all elements of this traversable collection that do not satisfy the given predicate p. The order of the elements is preserved.

Definition Classes: TraversableLike → GenTraversableLike

def finalize(): Unit

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[lang]
Definition Classes: AnyRef
Annotations: @throws( classOf[java.lang.Throwable] )
Note: not specified by SLS as a member of AnyRef

def find(p: (Nothing) ⇒ Boolean): Option[Nothing]

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

Note: may not terminate for infinite-sized collections.

p: the predicate used to test elements.
returns: an option value containing the first element in the sequence that satisfies p, or None if none exists.

Definition Classes: LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

final def flatMap[B, That](f: (Nothing) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

Applies the given function f to each element of this stream, then concatenates the results. As with map this function does not need to realize the entire Stream but continues to keep it as a lazy Stream.

B: The element type of the returned collection That.
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.
f: the function to apply on each element.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns: f(a₀) ::: ... ::: f(a_n) if this stream is [a₀, ..., a_n].

Definition Classes: Stream → TraversableLike → GenTraversableLike → FilterMonadic

def flatten[B](implicit asTraversable: (Nothing) ⇒ GenTraversableOnce[B]): Stream[B]

Evaluates and concatenates all elements within the Stream into a new flattened Stream.

B: The type of the elements of the resulting Stream.
asTraversable: an implicit conversion which asserts that the element type of this stream is a GenTraversable.
returns: A new Stream of type B of the flattened elements of this Stream.

Definition Classes: Stream → GenericTraversableTemplate

def fold[A1 >: Nothing](z: A1)(op: (A1, A1) ⇒ A1): A1

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.

Note: will not terminate for infinite-sized collections.

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 the fold operator op between all the elements and z, or z if this traversable or iterator is empty.

Definition Classes: TraversableOnce → GenTraversableOnce

final def foldLeft[B](z: B)(op: (B, Nothing) ⇒ B): B

Stream specialization of foldLeft which allows GC to collect along the way.

B: The type of value being accumulated.
z: The initial value seeded into the function op.
op: The operation to perform on successive elements of the Stream.
returns: The accumulated value from successive applications of op.

Definition Classes: Stream → LinearSeqOptimized → TraversableOnce → GenTraversableOnce
Annotations: @tailrec()

def foldRight[B](z: B)(op: (Nothing, B) ⇒ B): B

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

Note: will not terminate for infinite-sized collections.

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 sequence, going right to left with the start value z on the right:

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

where x₁, ..., x_n are the elements of this sequence. Returns z if this sequence is empty.

Definition Classes: LinearSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce

def forall(p: (Nothing) ⇒ Boolean): Boolean

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

Note: may not terminate for infinite-sized collections.

p: the predicate used to test elements.
returns: true if this sequence is empty or the given predicate p holds for all elements of this sequence, otherwise false.

Definition Classes: LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce

def force: Stream[Nothing]

Forces evaluation of the whole stream and returns it.

returns: The fully realized Stream.

Definition Classes: Stream
Note: Often we use Streams to represent an infinite set or series. If that's the case for your particular Stream then this function will never return and will probably crash the VM with an OutOfMemory exception. This function will not hang on a finite cycle, however.

final def foreach[U](f: (Nothing) ⇒ U): Unit

Apply the given function f to each element of this linear sequence (while respecting the order of the elements).

U: the type parameter describing the result of function f. This result will always be ignored. Typically U is Unit, but this is not necessary.
f: The treatment to apply to each element.

Definition Classes: Stream → LinearSeqOptimized → IterableLike → GenericTraversableTemplate → TraversableLike → GenTraversableLike → TraversableOnce → GenTraversableOnce → FilterMonadic
Annotations: @tailrec()
Note: Overridden here as final to trigger tail-call optimization, which replaces 'this' with 'tail' at each iteration. This is absolutely necessary for allowing the GC to collect the underlying stream as elements are consumed.
,
This function will force the realization of the entire stream unless the f throws an exception.

def genericBuilder[B]: Builder[B, Stream[B]]

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

Definition Classes: GenericTraversableTemplate

final def getClass(): Class[_]

Returns the runtime class representation of the object.

returns: a class object corresponding to the runtime type of the receiver.

Definition Classes: AnyRef → Any
Annotations: @native()

def groupBy[K](f: (Nothing) ⇒ K): Map[K, Stream[Nothing]]

Partitions this traversable collection into a map of traversable 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 traversable collection.

K

the type of keys returned by the discriminator function.

f

the discriminator function.

returns

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

Definition Classes: TraversableLike → GenTraversableLike

def grouped(size: Int): Iterator[Stream[Nothing]]

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: IterableLike
See also: scala.collection.Iterator, method grouped

def hasDefiniteSize: Boolean

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

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

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

Definition Classes: Stream → TraversableLike → TraversableOnce → GenTraversableOnce

def hashCode(): Int

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

returns: the hash code value for this object.

Definition Classes: LinearSeqLike → GenSeqLike → AnyRef → Any

def head: Nothing

Gives constant time access to the first element of this Stream. Using the fibs example from earlier:

println(fibs head)
// prints
// 0

returns: The first element of the Stream.

Definition Classes: Empty → Stream → LinearSeqOptimized → IterableLike → GenericTraversableTemplate → TraversableLike → GenTraversableLike
Exceptions thrown: java.util.NoSuchElementException if the stream is empty.

def headOption: Option[Nothing]

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

Definition Classes: TraversableLike → GenTraversableLike

def indexOf(elem: Nothing, from: Int): Int

[use case]

Finds index of first occurrence of some value in this stream 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 stream that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes: GenSeqLike

def indexOf(elem: Nothing): Int

[use case]

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

Note: may not terminate for infinite-sized collections.

elem: the element value to search for.
returns: the index of the first element of this stream that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes: GenSeqLike

def indexOfSlice[B >: Nothing](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.

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

def indexOfSlice[B >: Nothing](that: GenSeq[B]): Int

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

def indexWhere(p: (Nothing) ⇒ Boolean, from: Int): Int

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: LinearSeqOptimized → SeqLike → GenSeqLike

def indexWhere(p: (Nothing) ⇒ Boolean): Int

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

def indices: Range

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

def init: Stream[Nothing]

The stream without its last element.

returns: A new Stream containing everything but the last element. If your Stream represents an infinite series, this method will not return.

Definition Classes: Stream → TraversableLike → GenTraversableLike
Exceptions thrown: UnsupportedOperationException if the stream is empty.

def inits: Iterator[Stream[Nothing]]

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

returns: an iterator over all the inits of this traversable collection

Definition Classes: TraversableLike

def intersect(that: collection.Seq[Nothing]): Stream[Nothing]

[use case]

Computes the multiset intersection between this stream and another sequence.

Note: may not terminate for infinite-sized collections.

that: the sequence of elements to intersect with.
returns: a new stream which contains all elements of this stream 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: SeqLike → GenSeqLike

def isDefinedAt(x: Int): Boolean

Tests whether this sequence contains given index.

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

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

Definition Classes: LinearSeqOptimized → GenSeqLike

def isEmpty: Boolean

Indicates whether or not the Stream is empty.

returns: true if the Stream is empty and false otherwise.

Definition Classes: Empty → Stream → LinearSeqOptimized → SeqLike → IterableLike → GenericTraversableTemplate → TraversableLike → TraversableOnce → GenTraversableOnce

final def isInstanceOf[T0]: Boolean

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

final def isTraversableAgain: Boolean

Tests whether this traversable collection can be repeatedly traversed.

returns: true

Definition Classes: TraversableLike → GenTraversableLike → GenTraversableOnce

def iterator: Iterator[Nothing]

A lazier Iterator than LinearSeqLike's.

returns: the new iterator

Definition Classes: Stream → LinearSeqLike → IterableLike → GenIterableLike

def last: Nothing

Selects the last element.

returns: The last element of this sequence.

Definition Classes: LinearSeqOptimized → TraversableLike → GenTraversableLike
Exceptions thrown: NoSuchElementException If the sequence is empty.

def lastIndexOf(elem: Nothing, end: Int): Int

[use case]

Finds index of last occurrence of some value in this stream 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 stream that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes: GenSeqLike

def lastIndexOf(elem: Nothing): Int

[use case]

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

Note: will not terminate for infinite-sized collections.

elem: the element value to search for.
returns: the index of the last element of this stream that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes: GenSeqLike

def lastIndexOfSlice[B >: Nothing](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.

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

def lastIndexOfSlice[B >: Nothing](that: GenSeq[B]): Int

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

def lastIndexWhere(p: (Nothing) ⇒ Boolean, end: Int): Int

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: LinearSeqOptimized → SeqLike → GenSeqLike

def lastIndexWhere(p: (Nothing) ⇒ Boolean): Int

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

def lastOption: Option[Nothing]

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 traversable collection$ if it is nonempty, None if it is empty.

Definition Classes: TraversableLike → GenTraversableLike

def length: Int

Returns the length of this Stream.

returns: The length of this Stream.

Definition Classes: Stream → LinearSeqOptimized → SeqLike → GenSeqLike
Note: In order to compute the length of the Stream, it must first be fully realized, which could cause the complete evaluation of an infinite series, assuming that's what your Stream represents.

def lengthCompare(len: Int): Int

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: LinearSeqOptimized → SeqLike

def lift: (Int) ⇒ Option[Nothing]

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
See also: Function.unlift

final def map[B, That](f: (Nothing) ⇒ B)(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

Returns the stream resulting from applying the given function f to each element of this stream. This returns a lazy Stream such that it does not need to be fully realized.

B: The element type of the returned collection That.
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.
f: function to apply to each element.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns: f(a₀), ..., f(a_n) if this sequence is a₀, ..., a_n.

Definition Classes: Stream → TraversableLike → GenTraversableLike → FilterMonadic

def max: A

[use case]

Finds the largest element.

returns: the largest element of this stream.

Definition Classes: TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this stream is empty.

def maxBy[B](f: (A) ⇒ B): A

[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 stream with the largest value measured by function f.

Definition Classes: TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this stream is empty.

def min: A

[use case]

Finds the smallest element.

returns: the smallest element of this stream

Definition Classes: TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this stream is empty.

def minBy[B](f: (A) ⇒ B): A

[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 stream with the smallest value measured by function f.

Definition Classes: TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this stream is empty.

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

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

start: the starting string.
sep: the separator string.
end: the ending string.
returns: a string representation of this stream. The resulting string begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this stream are separated by the string sep.

Definition Classes: Stream → TraversableOnce → GenTraversableOnce

def mkString: String

Displays all elements of this stream in a string.

returns: a string representation of this stream. In the resulting string the string representations (w.r.t. the method toString) of all elements of this stream follow each other without any separator string.

Definition Classes: Stream → TraversableOnce → GenTraversableOnce

def mkString(sep: String): String

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

sep: the separator string.
returns: a string representation of this stream. In the resulting string the string representations (w.r.t. the method toString) of all elements of this stream are separated by the string sep.

Definition Classes: Stream → TraversableOnce → GenTraversableOnce

final def ne(arg0: AnyRef): Boolean

Equivalent to !(this eq that).

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

Definition Classes: AnyRef

def newBuilder: Builder[Nothing, Stream[Nothing]]

The builder that builds instances of type Traversable[A]

Attributes: protected[this]
Definition Classes: GenericTraversableTemplate → HasNewBuilder

def nonEmpty: Boolean

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: TraversableOnce → GenTraversableOnce

final def notify(): Unit

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

Definition Classes: AnyRef
Annotations: @native()
Note: not specified by SLS as a member of AnyRef

final def notifyAll(): Unit

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

Definition Classes: AnyRef
Annotations: @native()
Note: not specified by SLS as a member of AnyRef

def orElse[A1 <: Int, B1 >: Nothing](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.

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

def padTo[B >: Nothing, That](len: Int, elem: B)(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

Returns a new sequence of given length containing the elements of this sequence followed by zero or more occurrences of given elements.

B: The type of the value to pad with.
That: The type contained within the resulting Stream.
len: The number of elements to pad into the Stream.
elem: The value of the type B to use for padding.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns: A new Stream representing the collection with values padding off to the end. If your Stream represents an infinite series, this method will not return.

Definition Classes: Stream → SeqLike → GenSeqLike

def par: ParSeq[Nothing]

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

def parCombiner: Combiner[Nothing, ParSeq[Nothing]]

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: Seq → SeqLike → Iterable → TraversableLike → Parallelizable

def partition(p: (Nothing) ⇒ Boolean): (Stream[Nothing], Stream[Nothing])

Returns all the elements of this stream that satisfy the predicate p returning of scala.Tuple2 of Streams obeying the partition predicate p. The order of the elements is preserved.

p: the predicate used to filter the stream.
returns: the elements of this stream satisfying p.

Definition Classes: Stream → TraversableLike → GenTraversableLike

def patch(from: Int, that: GenSeq[A], replaced: Int): Stream[A]

[use case]

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

from: the index of the first replaced element
replaced: the number of elements to drop in the original stream
returns: a new stream consisting of all elements of this stream except that replaced elements starting from from are replaced by patch.

Definition Classes: SeqLike → GenSeqLike

def permutations: Iterator[Stream[Nothing]]

Iterates over distinct permutations.

returns: An Iterator which traverses the distinct permutations of this sequence.

Definition Classes: SeqLike

def prefixLength(p: (Nothing) ⇒ Boolean): Int

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

def print(sep: String): Unit

Prints elements of this stream one by one, separated by sep.

sep: The separator string printed between consecutive elements.

Definition Classes: Stream

def print(): Unit

Prints elements of this stream one by one, separated by commas.

Definition Classes: Stream

def product: A

[use case]

Multiplies up the elements of this collection.

returns: the product of all elements in this stream 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 stream and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes: TraversableOnce → GenTraversableOnce

def reduce[A1 >: Nothing](op: (A1, A1) ⇒ A1): A1

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: TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this traversable or iterator is empty.

final def reduceLeft[B >: Nothing](f: (B, Nothing) ⇒ B): B

Stream specialization of reduceLeft which allows GC to collect along the way.

B: The type of value being accumulated.
f: The operation to perform on successive elements of the Stream.
returns: The accumulated value from successive applications of f.

Definition Classes: Stream → LinearSeqOptimized → TraversableOnce

def reduceLeftOption[B >: Nothing](op: (B, Nothing) ⇒ B): Option[B]

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) if this traversable or iterator is nonempty, None otherwise.

Definition Classes: TraversableOnce → GenTraversableOnce

def reduceOption[A1 >: Nothing](op: (A1, A1) ⇒ A1): Option[A1]

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: TraversableOnce → GenTraversableOnce

def reduceRight[B >: Nothing](op: (Nothing, B) ⇒ B): B

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

Note: will not terminate for infinite-sized collections.

B

the result type of the binary operator.

op

the binary operator.

returns

the result of inserting op between consecutive elements of this sequence, going right to left:

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

where x₁, ..., x_n are the elements of this sequence.

Definition Classes: LinearSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce
Exceptions thrown: UnsupportedOperationException if this sequence is empty.

def reduceRightOption[B >: Nothing](op: (Nothing, B) ⇒ B): Option[B]

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) if this traversable or iterator is nonempty, None otherwise.

Definition Classes: TraversableOnce → GenTraversableOnce

def repr: Stream[Nothing]

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: TraversableLike → GenTraversableLike

def reverse: Stream[Nothing]

A list consisting of all elements of this list in reverse order.

returns: A new Stream containing the representing of the original Stream in reverse order.

Definition Classes: Stream → SeqLike → GenSeqLike
Note: This function must realize the entire Stream in order to perform this operation so if your Stream represents an infinite sequence then this function will never return.

def reverseIterator: Iterator[Nothing]

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

def reverseMap[B](f: (A) ⇒ B): Stream[B]

[use case]

Builds a new collection by applying a function to all elements of this stream 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 stream resulting from applying the given function f to each element of this stream and collecting the results in reversed order.

Definition Classes: SeqLike → GenSeqLike

def reversed: scala.List[Nothing]

Attributes: protected[this]
Definition Classes: TraversableOnce

def runWith[U](action: (Nothing) ⇒ U): (Int) ⇒ Boolean

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
See also: applyOrElse.

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

[use case]

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

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: LinearSeqOptimized → IterableLike → GenIterableLike

def scan[B >: Nothing, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[Stream[Nothing], B, That]): That

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: TraversableLike → GenTraversableLike

final def scanLeft[B, That](z: B)(op: (B, Nothing) ⇒ B)(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

Create a new stream which contains all intermediate results of applying the operator to subsequent elements left to right. scanLeft is analogous to foldLeft.

B: the type of the elements in the resulting collection
That: the actual type of the resulting collection
z: The initial value for the scan.
op: A function that will apply operations to successive values in the Stream against previous accumulated results.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns: A new collection containing the modifications from the application of op.

Definition Classes: Stream → TraversableLike → GenTraversableLike
Note: This works because the target type of the scala.collection.mutable.Builder That is a Stream.

def scanRight[B, That](z: B)(op: (Nothing, B) ⇒ B)(implicit bf: CanBuildFrom[Stream[Nothing], B, That]): That

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 the new element type B.
returns: collection with intermediate results

Definition Classes: TraversableLike → GenTraversableLike
Annotations: @migration
Migration: (Changed in version 2.9.0) The behavior of scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.

def segmentLength(p: (Nothing) ⇒ Boolean, from: Int): Int

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: LinearSeqOptimized → SeqLike → GenSeqLike

def seq: LinearSeq[Nothing]

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: LinearSeq → LinearSeq → LinearSeqLike → Seq → Seq → GenSeq → GenSeqLike → Iterable → Iterable → GenIterable → Traversable → Traversable → GenTraversable → Parallelizable → TraversableOnce → GenTraversableOnce

def size: Int

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: SeqLike → GenTraversableLike → TraversableOnce → GenTraversableOnce

def sizeHintIfCheap: Int

The size of this collection or iterator, if it can be cheaply computed

returns: the number of elements in this collection or iterator, or -1 if the size cannot be determined cheaply

Attributes: protected[collection]
Definition Classes: GenTraversableOnce

def slice(from: Int, until: Int): Stream[Nothing]

A substream starting at index from and extending up to (but not including) index until. This returns a Stream that is lazily evaluated.

from: The index of the first element of the returned subsequence
until: The index of the element following the returned subsequence
returns: A new string containing the elements requested from start until end.

Definition Classes: Stream → LinearSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

def sliding(size: Int, step: Int): Iterator[Stream[Nothing]]

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
returns: An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

Definition Classes: IterableLike
See also: scala.collection.Iterator, method sliding

def sliding(size: Int): Iterator[Stream[Nothing]]

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

size: the number of elements per group
returns: An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

Definition Classes: IterableLike
See also: scala.collection.Iterator, method sliding

def sortBy[B](f: (Nothing) ⇒ B)(implicit ord: math.Ordering[B]): Stream[Nothing]

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: SeqLike
See also: scala.math.Ordering Note: will not terminate for infinite-sized collections.

def sortWith(lt: (Nothing, Nothing) ⇒ Boolean): Stream[Nothing]

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: SeqLike

def sorted[B >: Nothing](implicit ord: math.Ordering[B]): Stream[Nothing]

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: SeqLike
See also: scala.math.Ordering

def span(p: (Nothing) ⇒ Boolean): (Stream[Nothing], Stream[Nothing])

Splits this sequence 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.

returns: a pair consisting of the longest prefix of this sequence whose elements all satisfy p, and the rest of this sequence.

Definition Classes: LinearSeqOptimized → TraversableLike → GenTraversableLike

def splitAt(n: Int): (Stream[Nothing], Stream[Nothing])

Splits this stream into two at a given position. Note: c splitAt n is equivalent to (but possibly more efficient than) (c take n, c drop n).

n: the position at which to split.
returns: a pair of streams consisting of the first n elements of this stream, and the other elements.

Definition Classes: Stream → TraversableLike → GenTraversableLike

def startsWith[B](that: GenSeq[B], offset: Int): Boolean

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: SeqLike → GenSeqLike

def startsWith[B](that: GenSeq[B]): Boolean

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

def stringPrefix: String

Defines the prefix of this object's toString representation as Stream.

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

Definition Classes: Stream → TraversableLike → GenTraversableLike

def sum: A

[use case]

Sums up the elements of this collection.

returns: the sum of all elements in this stream 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 stream and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes: TraversableOnce → GenTraversableOnce

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

Definition Classes: AnyRef

def tail: Nothing

A stream consisting of the remaining elements of this stream after the first one.

Note that this method does not force evaluation of the Stream but merely returns the lazy result.

returns: The tail of the Stream.

Definition Classes: Empty → Stream → LinearSeqOptimized → TraversableLike → GenTraversableLike
Exceptions thrown: UnsupportedOperationException if the stream is empty.

def tailDefined: Boolean

Is the tail of this stream defined?

Definition Classes: Empty → Stream

def tails: Iterator[Stream[Nothing]]

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

returns: an iterator over all the tails of this sequence

Definition Classes: LinearSeqOptimized → TraversableLike

def take(n: Int): Stream[Nothing]

Returns the n first elements of this Stream as another Stream, or else the whole Stream, if it has less than n elements.

The result of take is, again, a Stream meaning that it also does not make any needless evaluations of the Stream itself, delaying that until the usage of the resulting Stream.

n: the number of elements to take.
returns: the n first elements of this stream.

Definition Classes: Stream → LinearSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

def takeRight(n: Int): Stream[Nothing]

Returns the rightmost n elements from this iterable.

n: the number of elements to take
returns: The last n elements from this Stream.

Definition Classes: Stream → IterableLike
Note: Take serious caution here. If the Stream represents an infinite series then this function will not return. The right most elements of an infinite series takes an infinite amount of time to produce.

def takeWhile(p: (Nothing) ⇒ Boolean): Stream[Nothing]

Returns the longest prefix of this Stream whose elements satisfy the predicate p.

p: the test predicate.
returns: A new Stream representing the values that satisfy the predicate p.

Definition Classes: Stream → LinearSeqOptimized → IterableLike → TraversableLike → GenTraversableLike

def thisCollection: collection.LinearSeq[Nothing]

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: LinearSeqLike → SeqLike → IterableLike → TraversableLike

def to[Col[_]]: Col[A]

[use case]

Converts this stream 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 stream.

Definition Classes: TraversableLike → TraversableOnce → GenTraversableOnce

def toArray: Array[A]

[use case]

Converts this stream to an array.

Note: will not terminate for infinite-sized collections.

returns: an array containing all elements of this stream. An ClassTag must be available for the element type of this stream.

Definition Classes: TraversableOnce → GenTraversableOnce

def toBuffer[B >: Nothing]: Buffer[B]

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: TraversableOnce → GenTraversableOnce

def toCollection(repr: Stream[Nothing]): collection.LinearSeq[Nothing]

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: LinearSeqLike → SeqLike → IterableLike → TraversableLike

def toIndexedSeq: IndexedSeq[Nothing]

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: TraversableOnce → GenTraversableOnce

def toIterable: collection.Iterable[Nothing]

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: IterableLike → TraversableOnce → GenTraversableOnce

def toIterator: Iterator[Nothing]

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: IterableLike → TraversableLike → GenTraversableOnce
Annotations: @deprecatedOverriding( message = ... , since = "2.11.0" )

def toList: scala.List[Nothing]

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: TraversableOnce → GenTraversableOnce

def toMap[T, U]: collection.Map[T, U]

[use case]

Converts this stream 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 stream.

Definition Classes: TraversableOnce → GenTraversableOnce

def toSeq: Seq[Nothing]

Converts this immutable 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 immutable sequence.

Definition Classes: Seq → SeqLike → GenSeqLike → TraversableOnce → GenTraversableOnce

def toSet[B >: Nothing]: Set[B]

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: TraversableOnce → GenTraversableOnce

def toStream: Stream[Nothing]

Converts this stream to a stream.

returns: a stream containing all elements of this stream.

Definition Classes: Stream → IterableLike → TraversableLike → GenTraversableOnce

def toString(): String

Converts this stream to a string.

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

Definition Classes: Stream → SeqLike → Function1 → TraversableLike → AnyRef → Any

def toTraversable: collection.Traversable[Nothing]

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: TraversableLike → TraversableOnce → GenTraversableOnce
Annotations: @deprecatedOverriding( message = ... , since = "2.11.0" )

def toVector: scala.Vector[Nothing]

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: TraversableOnce → GenTraversableOnce

def transpose[B](implicit asTraversable: (Nothing) ⇒ GenTraversableOnce[B]): Stream[Stream[B]]

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.

def union(that: collection.Seq[Nothing]): Stream[Nothing]

[use case]

Produces a new sequence which contains all elements of this stream 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-preserving 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: the sequence to add.
returns: a new stream which contains all elements of this stream followed by all elements of that.

Definition Classes: SeqLike → GenSeqLike

def unzip[A1, A2](implicit asPair: (Nothing) ⇒ (A1, A2)): (Stream[A1], Stream[A2])

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: GenericTraversableTemplate

def unzip3[A1, A2, A3](implicit asTriple: (Nothing) ⇒ (A1, A2, A3)): (Stream[A1], Stream[A2], Stream[A3])

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: GenericTraversableTemplate

def updated(index: Int, elem: A): Stream[A]

[use case]

A copy of this stream with one single replaced element.

index: the position of the replacement
elem: the replacing element
returns: a copy of this stream with the element at position index replaced by elem.

Definition Classes: SeqLike → GenSeqLike

def view: StreamView[Nothing, Stream[Nothing]]

Creates a non-strict view of this stream.

returns: a non-strict view of this stream.

Definition Classes: Stream → SeqLike → IterableLike → TraversableLike

def view(from: Int, until: Int): SeqView[Nothing, Stream[Nothing]]

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: SeqLike → IterableLike → TraversableLike

final def wait(): Unit

Definition Classes: AnyRef
Annotations: @throws( ... )

final def wait(arg0: Long, arg1: Int): Unit

Definition Classes: AnyRef
Annotations: @throws( ... )

final def wait(arg0: Long): Unit

Definition Classes: AnyRef
Annotations: @throws( ... ) @native()

final def withFilter(p: (Nothing) ⇒ Boolean): FilterMonadic[Nothing, Stream[Nothing]]

A FilterMonadic which allows GC of the head of stream during processing

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 stream which satisfy the predicate p.

Definition Classes: Stream → TraversableLike → FilterMonadic
Annotations: @noinline()

final def zip[A1 >: Nothing, B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[Stream[Nothing], (A1, B), That]): That

Returns a stream formed from this stream and the specified stream that by associating each element of the former with the element at the same position in the latter.

If one of the two streams is longer than the other, its remaining elements are ignored.

The return type of this function may not be obvious. The lazy aspect of the returned value is different than that of partition. In partition we get back a scala.Tuple2 of two lazy Streams whereas here we get back a single lazy Stream of scala.Tuple2s where the scala.Tuple2's type signature is (A1, B).

A1: The type of the first parameter of the zipped tuple
B: The type of the second parameter of the zipped tuple
That: The type of the returned Stream.
that: The iterable providing the second half of each result pair
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type (A1, B).
returns: Stream({a₀,b₀}, ..., {a_min(m,n),b_min(m,n))} when Stream(a₀, ..., a_m) zip Stream(b₀, ..., b_n) is invoked.

Definition Classes: Stream → IterableLike → GenIterableLike

def zipAll[B](that: collection.Iterable[B], thisElem: A, thatElem: B): Stream[(A, B)]

[use case]

Returns a stream formed from this stream 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 stream is shorter than that.
thatElem: the element to be used to fill up the result if that is shorter than this stream.
returns: a new stream containing pairs consisting of corresponding elements of this stream and that. The length of the returned collection is the maximum of the lengths of this stream and that. If this stream is shorter than that, thisElem values are used to pad the result. If that is shorter than this stream, thatElem values are used to pad the result.

Definition Classes: IterableLike → GenIterableLike

def zipWithIndex[A1 >: Nothing, That](implicit bf: CanBuildFrom[Stream[Nothing], (A1, Int), That]): That

Zips this iterable with its indices. s.zipWithIndex is equivalent to s zip s.indices.

This method is much like zip in that it returns a single lazy Stream of scala.Tuple2.

A1: The type of the first element of the scala.Tuple2 in the resulting stream.
That: The type of the resulting Stream.
bf: an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type (A1, Int).
returns: Stream({a₀,0}, ..., {a_n,n)}

Definition Classes: Stream → IterableLike → GenIterableLike

© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/collection/immutable/Stream$$Empty$.html