Stream

Instance Constructors

new Stream()

Type Members

type Self = Stream[A]

The type implementing this traversable
The type implementing this traversable

Attributes
protected
Definition Classes
TraversableLike
final class StreamWithFilter extends WithFilter

A lazier implementation of WithFilter than TraversableLike's.
class WithFilter extends FilterMonadic[A, Repr]

A class supporting filtered operations.

Abstract Value Members

abstract def tailDefined: Boolean

Is the tail of this stream defined?
Is the tail of this stream defined?

Attributes
protected

Concrete Value Members

final def !=(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def !=(arg0: Any): Boolean

Test two objects for inequality.
Test two objects for inequality.
returns
true if !(this == that), false otherwise.

Definition Classes
Any
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
def +(other: String): String

Implicit information
This member is added by an implicit conversion from Stream[A] to StringAdd performed by method any2stringadd in scala.Predef.
Definition Classes
StringAdd
def ++[B >: A, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

Create a new stream which contains all elements of this stream followed by all elements of Traversable 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 the be contatenated 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
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.
,
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.
def ++:[B >: A, That](that: collection.Traversable[B])(implicit bf: CanBuildFrom[Stream[A], 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 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 stream 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.
[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
Full Signature
def ++:[B >: A, That](that: TraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def +:(elem: A): Stream[A]

[use case] A copy of the stream with an element prepended.
[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 = LinkedList(1)
x: scala.collection.mutable.LinkedList[Int] = LinkedList(1)

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

scala> println(x)
LinkedList(1)
```
elem
the prepended element
returns
a new stream consisting of elem followed by all elements of this stream.

Definition Classes
Stream → SeqLike → GenSeqLike
Full Signature
def +:[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def ->[B](y: B): (Stream[A], B)

Implicit information
This member is added by an implicit conversion from Stream[A] to ArrowAssoc[Stream[A]] performed by method any2ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
@inline()
def /:[B](z: B)(op: (B, A) ⇒ B): B

Applies a binary operator to a start value and all elements of this stream, going left to right.
Applies a binary operator to a start value and all elements of this stream, 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 = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(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.
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 stream, 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 stream.
Definition Classes
TraversableOnce → GenTraversableOnce
def :+(elem: A): Stream[A]

[use case] A copy of this stream with an element appended.
[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> import scala.collection.mutable.LinkedList
import scala.collection.mutable.LinkedList

scala> val a = LinkedList(1)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1)

scala> val b = a :+ 2
b: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

scala> println(a)
LinkedList(1)
```
elem
the appended element
returns
a new stream consisting of all elements of this stream followed by elem.

Definition Classes
SeqLike → GenSeqLike
Full Signature
def :+[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def :\[B](z: B)(op: (A, B) ⇒ B): B

Applies a binary operator to all elements of this stream and a start value, going right to left.
Applies a binary operator to all elements of this stream 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.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
```
scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(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 stream, 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 stream.
Definition Classes
TraversableOnce → GenTraversableOnce
final def ==(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def ==(arg0: Any): Boolean

Test two objects for equality.
Test two objects for equality. 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
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.
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.
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 stream to a string builder.
Appends all elements of this stream to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this stream without any separator string.
Example:
```
scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

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

scala> val h = a.addString(b)
b: 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 stream to a string builder using a separator string.
Appends all elements of this stream 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 stream, separated by the string sep.
Example:
```
scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(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, A) ⇒ 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)
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: (A) ⇒ 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
PartialFunction → Function1
def append[B >: A](rest: ⇒ TraversableOnce[B]): Stream[B]

The stream resulting from the concatenation of this stream with the argument stream.
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.
def apply(n: Int): A

Selects an element by its index in the stream.
Selects an element by its index in the stream. Note: the execution of apply may take time proportial to the index value.
returns
the element of this stream 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 >: A](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 compiler generates 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
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
the receiver object.

Definition Classes
Any
Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of type T0.
def asParIterable: ParIterable[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
def asParSeq: ParSeq[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
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 stream should be compared
returns
true, if this stream 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.
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
@throws()
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.
[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
Full Signature
final def collect[B, That](pf: PartialFunction[A, B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def collectFirst[B](pf: PartialFunction[A, B]): Option[B]

Finds the first element of the stream for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the stream for which the given partial function is defined, and applies the partial function to it.
Note: may not terminate for infinite-sized collections.
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)
def combinations(n: Int): Iterator[Stream[A]]

Iterates over combinations.
Iterates over combinations.
returns
An Iterator which traverses the possible n-element combinations of this stream.
Definition Classes
SeqLike
Example:
1. "abbbc".combinations(2) = Iterator(ab, ac, bb, bc)
def companion: GenericCompanion[Stream]

The factory companion object that builds instances of class 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) ⇒ A

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
@unspecialized()
def contains(elem: Any): Boolean

Tests whether this stream contains a given value as an element.
Tests whether this stream contains a given value as an element.
Note: may not terminate for infinite-sized collections.
elem
the element to test.
returns
true if this stream 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 stream contains a given sequence as a slice.
Tests whether this stream contains a given sequence as a slice.
Note: may not terminate for infinite-sized collections.
that
the sequence to test
returns
true if this stream 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 elements of this stream to an array.
[use case]
Copies 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 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
Full Signature
def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Unit
def copyToArray(xs: Array[A]): Unit

[use case] Copies values of this stream to an array.
[use case]
Copies values 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 array is reached.
Note: will not terminate for infinite-sized collections.
xs
the array to fill.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def copyToArray[B >: A](xs: Array[B]): Unit
def copyToArray(xs: Array[A], start: Int): Unit

[use case] Copies values of this stream to an array.
[use case]
Copies values 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 array is reached.
Note: will not terminate for infinite-sized collections.
xs
the array to fill.
start
the starting index.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def copyToArray[B >: A](xs: Array[B], start: Int): Unit
def copyToBuffer[B >: A](dest: Buffer[B]): Unit

Copies all elements of this stream to a buffer.
Copies all elements of this stream 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: (A, B) ⇒ Boolean): Boolean

Tests whether every element of this stream relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this stream 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 stream and y of that, otherwise false.

Definition Classes
LinearSeqLike → SeqLike → GenSeqLike
Annotations
@tailrec()
def count(p: (A) ⇒ Boolean): Int

Counts the number of elements in the stream which satisfy a predicate.
Counts the number of elements in the stream 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[A]): Stream[A]

[use case] Computes the multiset difference between this stream and another sequence.
[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
Full Signature
def diff[B >: A](that: GenSeq[B]): Stream[A]
def distinct: Stream[A]

Builds a new stream from this stream in which any duplicates (as determined by ==) have been removed.
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
Example:
1. // Creates a Stream where every element is duplicated def naturalsFrom(i: Int): Stream[Int] = i #:: { i #:: naturalsFrom(i + 1) } naturalsFrom(1) take 6 mkString ", " // produces: "1, 1, 2, 2, 3, 3" (naturalsFrom(1) distinct) take 6 mkString ", " // produces: "1, 2, 3, 4, 5, 6"
final def drop(n: Int): Stream[A]

Selects all elements except first n ones.
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.

Definition Classes
Stream → LinearSeqOptimized → IterableLike → TraversableLike → GenTraversableLike
Annotations
@tailrec()
def dropRight(n: Int): Stream[A]

Selects all elements except last n ones.
Selects all elements except last n ones.
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
LinearSeqOptimized → IterableLike
def dropWhile(p: (A) ⇒ Boolean): Stream[A]

Returns the a Stream representing the longest suffix of this iterable whose first element does not satisfy the predicate p.
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 oringal Stream.
Definition Classes
Stream → TraversableLike → GenTraversableLike
Example:
1. // Assume we have a Stream that takes the first 20 natural numbers def naturalsLt50(i: Int): Stream[Int] = i #:: { if (i < 20) naturalsLt50(i * + 1) else Stream.Empty } naturalsLt50(0) dropWhile { _ < 10 } // produces: "10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20"
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 stream ends with the given sequence.
Tests whether this stream ends with the given sequence.
Note: will not terminate for infinite-sized collections.
that
the sequence to test
returns
true if this stream has that as a suffix, false otherwise.

Definition Classes
SeqLike → GenSeqLike
def ensuring(cond: (Stream[A]) ⇒ Boolean, msg: ⇒ Any): Stream[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to Ensuring[Stream[A]] performed by method any2Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: (Stream[A]) ⇒ Boolean): Stream[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to Ensuring[Stream[A]] performed by method any2Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: Boolean, msg: ⇒ Any): Stream[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to Ensuring[Stream[A]] performed by method any2Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: Boolean): Stream[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to Ensuring[Stream[A]] performed by method any2Ensuring in scala.Predef.
Definition Classes
Ensuring
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
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
GenSeqLike → Equals → Any
def exists(p: (A) ⇒ Boolean): Boolean

Tests whether a predicate holds for some of the elements of this stream.
Tests whether a predicate holds for some of the elements of this stream.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
returns
true if the given predicate p holds for some of the elements of this stream, otherwise false.

Definition Classes
LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
def filter(p: (A) ⇒ Boolean): Stream[A]

Returns all the elements of this Stream that satisfy the predicate p in a new Stream - i.
Returns all the elements of this Stream that satisfy the predicate p in a new Stream - i.e. it is still a lazy data structure. 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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) naturalsFrom(1) 10 } filter { _ % 5 == 0 } take 10 mkString(", ") // produces
def filterNot(p: (A) ⇒ Boolean): Stream[A]

Selects all elements of this stream which do not satisfy a predicate.
Selects all elements of this stream which do not satisfy a predicate.
p
the predicate used to test elements.
returns
a new stream consisting of all elements of this stream 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.
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
@throws()
Note
not specified by SLS as a member of AnyRef
def find(p: (A) ⇒ Boolean): Option[A]

Finds the first element of the stream satisfying a predicate, if any.
Finds the first element of the stream 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 stream that satisfies p, or None if none exists.

Definition Classes
LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
final def flatMap[B, That](f: (A) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

Applies the given function f to each element of this stream, then concatenates the results.
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
Example:
1. // Let's create a Stream of Vectors, each of which contains the // collection of Fibonacci numbers up to the current value. We // can then 'flatMap' that Stream. val fibVec: Stream[Vector[Int]] = Vector(0) #:: Vector(0, 1) #:: fibVec.zip(fibVec.tail).map(n => { n._2 ++ Vector(n._1.last + n._2.last) }) fibVec take 5 foreach println // prints // Vector(0) // Vector(0, 1) // Vector(0, 1, 1) // Vector(0, 1, 1, 2) // Vector(0, 1, 1, 2, 3) // If we now want to `flatMap` across that stream by adding 10 // we can see what the series turns into: fibVec.flatMap(_.map(_ + 10)) take 15 mkString(", ") // produces: 10, 10, 11, 10, 11, 11, 10, 11, 11, 12, 10, 11, 11, 12, 13
  Note: Currently flatMap will evaluate as much of the Stream as needed until it finds a non-empty element for the head, which is non-lazy.
def flatten[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): Stream[B]

Evaluates and concatenates all elements within the Stream into a new flattened Stream.
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
Example:
1. val sov: Stream[Vector[Int]] = Vector(0) #:: Vector(0, 0) #:: sov.zip(sov.tail).map { n => n._1 ++ n._2 } sov flatten take 10 mkString ", " // produces: "0, 0, 0, 0, 0, 0, 0, 0, 0, 0"
def fold[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

Folds the elements of this stream using the specified associative binary operator.
Folds the elements of this stream 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
TraversableOnce → GenTraversableOnce
final def foldLeft[B](z: B)(op: (B, A) ⇒ B): B

Stream specialization of foldLeft which allows GC to collect along the way.
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)(f: (A, B) ⇒ B): B

Applies a binary operator to all elements of this stream and a start value, going right to left.
Applies a binary operator to all elements of this stream 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.
returns
the result of inserting op between consecutive elements of this stream, 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 stream.
Definition Classes
LinearSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce
def forall(p: (A) ⇒ Boolean): Boolean

Tests whether a predicate holds for all elements of this stream.
Tests whether a predicate holds for all elements of this stream.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
returns
true if the given predicate p holds for all elements of this stream, otherwise false.

Definition Classes
LinearSeqOptimized → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
def force: Stream[A]

Forces evaluation of the whole stream and returns it.
Forces evaluation of the whole stream and returns it.
returns
The fully realized 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.
final def foreach[B](f: (A) ⇒ B): Unit

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

Definition Classes
Stream → LinearSeqOptimized → IterableLike → GenericTraversableTemplate → TraversableLike → GenTraversableLike → TraversableOnce → GenTraversableOnce → FilterMonadic
Annotations
@tailrec()
Note
This function will force the realization of the entire stream unless the f throws an exception.
,
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.
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 Stream[A] to StringFormat performed by method any2stringfmt in scala.Predef.
Definition Classes
StringFormat
Annotations
@inline()
def genericBuilder[B]: Builder[B, Stream[B]]

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

Definition Classes
GenericTraversableTemplate
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
def groupBy[K](f: (A) ⇒ K): Map[K, Stream[A]]

Partitions this stream into a map of streams according to some discriminator function.
Partitions this stream into a map of streams 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 stream.
K
the type of keys returned by the discriminator function.
f
the discriminator function.
returns
A map from keys to streams such that the following invariant holds:
```
(xs partition f)(k) = xs filter (x => f(x) == k)
```
That is, every key k is bound to a stream of those elements x for which f(x) equals k.
Definition Classes
TraversableLike → GenTraversableLike
def grouped(size: Int): Iterator[Stream[A]]

Partitions elements in fixed size streams.
Partitions elements in fixed size streams.
size
the number of elements per group
returns
An iterator producing streams of size size, except the last will be truncated 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.
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.
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
Stream → TraversableLike → TraversableOnce → GenTraversableOnce
def hashCode(): Int

Hashcodes for Stream produce a value from the hashcodes of all the elements of the stream.
Hashcodes for Stream produce a value from the hashcodes of all the elements of the stream.
returns
the hash code value for this object.

Definition Classes
LinearSeqLike → GenSeqLike → AnyRef → Any
def head: A

Selects the first element of this stream.
Selects the first element of this stream.
returns
the first element of this stream.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
Exceptions thrown
`NoSuchElementException`
if the stream is empty.
def headOption: Option[A]

Optionally selects the first element.
Optionally selects the first element.
returns
the first element of this stream if it is nonempty, None if it is empty.

Definition Classes
TraversableLike → GenTraversableLike
def ifParSeq[R](isbody: (ParSeq[A]) ⇒ R): (TraversableOps[A])#Otherwise[R]

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
def indexOf(elem: A, from: Int): Int

[use case] Finds index of first occurrence of some value in this stream after or at some start index.
[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
Full Signature
def indexOf[B >: A](elem: B, from: Int): Int
def indexOf(elem: A): Int

[use case] Finds index of first occurrence of some value in this stream.
[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
Full Signature
def indexOf[B >: A](elem: B): Int
def indexOfSlice[B >: A](that: GenSeq[B], from: Int): Int

Finds first index after or at a start index where this stream contains a given sequence as a slice.
Finds first index after or at a start index where this stream 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 stream starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Definition Classes
SeqLike
def indexOfSlice[B >: A](that: GenSeq[B]): Int

Finds first index where this stream contains a given sequence as a slice.
Finds first index where this stream 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 stream starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Definition Classes
SeqLike
def indexWhere(p: (A) ⇒ Boolean, from: Int): Int

Finds index of the first element satisfying some predicate after or at some start index.
Finds index of the first element satisfying some predicate after or at some start index.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
from
the start index
returns
the index >= from of the first element of this stream that satisfies the predicate p, or -1, if none exists.

Definition Classes
LinearSeqOptimized → SeqLike → GenSeqLike
def indexWhere(p: (A) ⇒ 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 stream 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.
Produces the range of all indices of this sequence.
returns
a Range value from 0 to one less than the length of this stream.

Definition Classes
SeqLike
def init: Stream[A]

The stream without its last element.
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
`Predef.UnsupportedOperationException`
if the stream is empty.
def inits: Iterator[Stream[A]]

Iterates over the inits of this stream.
Iterates over the inits of this stream. The first value will be this stream and the final one will be an empty stream, with the intervening values the results of successive applications of init.
returns
an iterator over all the inits of this stream
Definition Classes
TraversableLike
Example:
1. List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
def intersect(that: collection.Seq[A]): Stream[A]

[use case] Computes the multiset intersection between this stream and another sequence.
[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
Full Signature
def intersect[B >: A](that: GenSeq[B]): Stream[A]
def isDefinedAt(x: Int): Boolean

Tests whether this stream contains given index.
Tests whether this stream contains given index.
The implementations of methods apply and isDefinedAt turn a Seq[A] into a PartialFunction[Int, A].
returns
true if this stream contains an element at position idx, false otherwise.

Definition Classes
LinearSeqOptimized → GenSeqLike
def isEmpty: Boolean

Tests whether this stream is empty.
Tests whether this stream is empty.
returns
true if the stream contain no elements, false otherwise.

Definition Classes
SeqLike → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
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
def isParIterable: Boolean

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
def isParSeq: Boolean

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
def isParallel: Boolean

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
final def isTraversableAgain: Boolean

Tests whether this stream can be repeatedly traversed.
Tests whether this stream can be repeatedly traversed.
returns
true

Definition Classes
TraversableLike → GenTraversableLike → GenTraversableOnce
def iterator: Iterator[A]

A lazier Iterator than LinearSeqLike's.
A lazier Iterator than LinearSeqLike's.
returns
the new iterator

Definition Classes
Stream → LinearSeqLike → IterableLike → GenIterableLike
def last: A

Selects the last element.
Selects the last element.
returns
The last element of this stream.

Definition Classes
LinearSeqOptimized → TraversableLike → GenTraversableLike
Exceptions thrown
NoSuchElementException
If the stream is empty.
def lastIndexOf(elem: A, end: Int): Int

[use case] Finds index of last occurrence of some value in this stream before or at a given end index.
[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
Full Signature
def lastIndexOf[B >: A](elem: B, end: Int): Int
def lastIndexOf(elem: A): Int

[use case] Finds index of last occurrence of some value in this stream.
[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
Full Signature
def lastIndexOf[B >: A](elem: B): Int
def lastIndexOfSlice[B >: A](that: GenSeq[B], end: Int): Int

Finds last index before or at a given end index where this stream contains a given sequence as a slice.
Finds last index before or at a given end index where this stream 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 stream starting at this index match the elements of sequence that, or -1 of no such subsequence exists.

Definition Classes
SeqLike
def lastIndexOfSlice[B >: A](that: GenSeq[B]): Int

Finds last index where this stream contains a given sequence as a slice.
Finds last index where this stream 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 stream starting a this index match the elements of sequence that, or -1 of no such subsequence exists.

Definition Classes
SeqLike
def lastIndexWhere(p: (A) ⇒ Boolean, end: Int): Int

Finds index of last element satisfying some predicate before or at given end index.
Finds index of last element satisfying some predicate before or at given end index.
p
the predicate used to test elements.
returns
the index <= end of the last element of this stream that satisfies the predicate p, or -1, if none exists.

Definition Classes
LinearSeqOptimized → SeqLike → GenSeqLike
def lastIndexWhere(p: (A) ⇒ 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 stream that satisfies the predicate p, or -1, if none exists.

Definition Classes
GenSeqLike
def lastOption: Option[A]

Optionally selects the last element.
Optionally selects the last element.
returns
the last element of this stream$ 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.
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 stream to a test value.
Compares the length of this stream 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[A]

Turns this partial function into an plain function returning an Option result.
Turns this partial function into an 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: (A) ⇒ B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That

Returns the stream resulting from applying the given function f to each element of this stream.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) naturalsFrom(1).map(_ + 10) take 5 mkString(", ") // produces: "11, 12, 13, 14, 15"
def max: A

[use case] Finds the largest element.
[use case]
Finds the largest element.
returns
the largest element of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def max[B >: A](implicit cmp: Ordering[B]): A
def maxBy[B](f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

Definition Classes
TraversableOnce → GenTraversableOnce
def min: A

[use case] Finds the smallest element.
[use case]
Finds the smallest element.
returns
the smallest element of this stream

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def min[B >: A](implicit cmp: Ordering[B]): A
def minBy[B](f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

Definition Classes
TraversableOnce → GenTraversableOnce
def mkString(start: String, sep: String, end: String): String

Displays all elements of this stream in a string using start, end, and separator strings.
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
Example:
1. List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
def mkString: String

Displays all elements of this stream in a 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.
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
Example:
1. List(1, 2, 3).mkString("|") = "1|2|3"
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
def newBuilder: Builder[A, Stream[A]]

The builder that builds instances of type Stream[A]
The builder that builds instances of type Stream[A]

Attributes
protected[this]
Definition Classes
GenericTraversableTemplate → HasNewBuilder
def nonEmpty: Boolean

Tests whether the stream is not empty.
Tests whether the stream is not empty.
returns
true if the stream 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.
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
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
def orElse[A1 <: Int, B1 >: A](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
def padTo[B >: A, That](len: Int, elem: B)(implicit bf: CanBuildFrom[Stream[A], 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.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: { if (i < 5) naturalsFrom(i + 1) else Stream.Empty } naturalsFrom(1) padTo(10, 0) foreach println // prints // 1 // 2 // 3 // 4 // 5 // 0 // 0 // 0 // 0 // 0
def par: ParSeq[A]

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
def parCombiner: Combiner[A, ParSeq[A]]

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
Seq → SeqLike → Iterable → TraversableLike → Parallelizable
def partition(p: (A) ⇒ Boolean): (Stream[A], Stream[A])

Returns all the elements of this stream that satisfy the predicate p returning of scala.Tuple2 of Streams obeying the partition predicate p.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) val parts = naturalsFrom(1) partition { _ % 2 == 0 } parts._1 take 10 mkString ", " // produces: "2, 4, 6, 8, 10, 12, 14, 16, 18, 20" parts._2 take 10 mkString ", " // produces: "1, 3, 5, 7, 9, 11, 13, 15, 17, 19"
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.
[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
Full Signature
def patch[B >: A, That](from: Int, patch: GenSeq[B], replaced: Int)(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def permutations: Iterator[Stream[A]]

Iterates over distinct permutations.
Iterates over distinct permutations.
returns
An Iterator which traverses the distinct permutations of this stream.
Definition Classes
SeqLike
Example:
1. "abb".permutations = Iterator(abb, bab, bba)
def prefixLength(p: (A) ⇒ Boolean): Int

Returns the length of the longest prefix whose elements all satisfy some predicate.
Returns the length of the longest prefix whose elements all satisfy some predicate.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
returns
the length of the longest prefix of this stream 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.
Prints elements of this stream one by one, separated by sep.
sep
The separator string printed between consecutive elements.
def print(): Unit

Prints elements of this stream one by one, separated by commas.
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 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
Full Signature
def product[B >: A](implicit num: Numeric[B]): B
def reduce[A1 >: A](op: (A1, A1) ⇒ A1): A1

Reduces the elements of this stream using the specified associative binary operator.
Reduces the elements of this stream 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 stream is nonempty.

Definition Classes
TraversableOnce → GenTraversableOnce
Exceptions thrown
UnsupportedOperationException
if this stream is empty.
final def reduceLeft[B >: A](f: (B, A) ⇒ B): B

Stream specialization of reduceLeft which allows GC to collect along the way.
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 >: A](op: (B, A) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this stream, going left to right.
Optionally applies a binary operator to all elements of this stream, going left to right.
Note: will not terminate for infinite-sized collections.
B
the result type of the binary operator.
op
the binary operator.
returns
an option value containing the result of reduceLeft(op) is this stream is nonempty, None otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
def reduceOption[A1 >: A](op: (A1, A1) ⇒ A1): Option[A1]

Reduces the elements of this stream, if any, using the specified associative binary operator.
Reduces the elements of this stream, 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 >: A](op: (A, B) ⇒ B): B

Applies a binary operator to all elements of this stream, going right to left.
Applies a binary operator to all elements of this stream, 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 stream, 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 stream.
Definition Classes
LinearSeqOptimized → IterableLike → TraversableOnce → GenTraversableOnce
Exceptions thrown
`UnsupportedOperationException`
if this stream is empty.
def reduceRightOption[B >: A](op: (A, B) ⇒ B): Option[B]

Optionally applies a binary operator to all elements of this stream, going right to left.
Optionally applies a binary operator to all elements of this stream, 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
an option value containing the result of reduceRight(op) is this stream is nonempty, None otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
def repr: Stream[A]

The collection of type stream underlying this TraversableLike object.
The collection of type stream 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[A]

A list consisting of all elements of this list in reverse order.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: { if (i < 5) naturalsFrom(i + 1) else Stream.Empty } (naturalsFrom(1) reverse) foreach println // prints // 5 // 4 // 3 // 2 // 1
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[A]

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 stream 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.
[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
Full Signature
def reverseMap[B, That](f: (A) ⇒ B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def reversed: scala.List[A]

Attributes
protected[this]
Definition Classes
TraversableOnce
def runWith[U](action: (A) ⇒ 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
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.
[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
Full Signature
def sameElements[B >: A](that: GenIterable[B]): Boolean
def scan[B >: A, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[Stream[A], 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 stream containing the prefix scan of the elements in this stream

Definition Classes
TraversableLike → GenTraversableLike
final def scanLeft[B, That](z: B)(op: (B, A) ⇒ B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That

Create a new stream which contains all intermediate results of applying the operator to subsequent elements left to right.
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: (A, B) ⇒ B)(implicit bf: CanBuildFrom[Stream[A], 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.
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: (A) ⇒ 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 stream starting from index from such that every element of the segment satisfies the predicate p.

Definition Classes
LinearSeqOptimized → SeqLike → GenSeqLike
def seq: LinearSeq[A]

A version of this collection with all of the operations implemented sequentially (i.
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 stream, equivalent to length.
The size of this stream, equivalent to length.
Note: will not terminate for infinite-sized collections.
returns
the number of elements in this stream.

Definition Classes
SeqLike → GenTraversableLike → TraversableOnce → GenTraversableOnce
def slice(from: Int, until: Int): Stream[A]

A substream starting at index from and extending up to (but not including) index until.
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
Example:
1. naturalsFrom(0) slice(50, 60) mkString ", " // produces: "50, 51, 52, 53, 54, 55, 56, 57, 58, 59"
def sliding(size: Int, step: Int): Iterator[Stream[A]]

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 streams of size size, except the last and the only element will be truncated if there are fewer elements than size.

Definition Classes
IterableLike
See also
scala.collection.Iterator, method sliding
def sliding(size: Int): Iterator[Stream[A]]

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 streams of size size, except the last and the only element will be truncated if there are fewer elements than size.

Definition Classes
IterableLike
See also
scala.collection.Iterator, method sliding
def sortBy[B](f: (A) ⇒ B)(implicit ord: math.Ordering[B]): Stream[A]

Sorts this Stream according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
Sorts this Stream 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 stream consisting of the elements of this stream sorted according to the ordering where x < y if ord.lt(f(x), f(y)).
Definition Classes
SeqLike
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]] words.sortBy(x => (x.length, x.head)) res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)
See also
scala.math.Ordering
Note: will not terminate for infinite-sized collections.
def sortWith(lt: (A, A) ⇒ Boolean): Stream[A]

Sorts this stream according to a comparison function.
Sorts this stream 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 stream consisting of the elements of this stream sorted according to the comparison function lt.
Definition Classes
SeqLike
Example:
1. List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) = List("Bob", "John", "Steve", "Tom")
def sorted[B >: A](implicit ord: math.Ordering[B]): Stream[A]

Sorts this stream according to an Ordering.
Sorts this stream 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 stream consisting of the elements of this stream sorted according to the ordering ord.

Definition Classes
SeqLike
See also
scala.math.Ordering
def span(p: (A) ⇒ Boolean): (Stream[A], Stream[A])

Splits this stream into a prefix/suffix pair according to a predicate.
Splits this stream 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 stream whose elements all satisfy p, and the rest of this stream.

Definition Classes
LinearSeqOptimized → TraversableLike → GenTraversableLike
def splitAt(n: Int): (Stream[A], Stream[A])

Splits this stream into two at a given position.
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 stream contains the given sequence at a given index.
Tests whether this stream 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 stream at index offset, otherwise false.

Definition Classes
SeqLike → GenSeqLike
def startsWith[B](that: GenSeq[B]): Boolean

Tests whether this stream starts with the given sequence.
Tests whether this stream 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.
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.
[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
Full Signature
def sum[B >: A](implicit num: Numeric[B]): B
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def tail: Stream[A]

Selects all elements except the first.
Selects all elements except the first.
returns
a stream consisting of all elements of this stream except the first one.

Definition Classes
TraversableLike → GenTraversableLike
Exceptions thrown
`UnsupportedOperationException`
if the stream is empty.
def tails: Iterator[Stream[A]]

Iterates over the tails of this stream.
Iterates over the tails of this stream. The first value will be this stream and the final one will be an empty stream, with the intervening values the results of successive applications of tail.
returns
an iterator over all the tails of this stream
Definition Classes
TraversableLike
Example:
1. List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
def take(n: Int): Stream[A]

Returns the n first elements of this Stream as another Stream, or else the whole Stream, if it has less than n elements.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) scala> naturalsFrom(5) take 5 res1: scala.collection.immutable.Stream[Int] = Stream(5, ?) scala> naturalsFrom(5) take 5 mkString ", " // produces: "5, 6, 7, 8, 9"
def takeRight(n: Int): Stream[A]

Returns the rightmost n elements from this iterable.
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: (A) ⇒ Boolean): Stream[A]

Returns the longest prefix of this Stream whose elements satisfy the predicate p.
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
Example:
1. + naturalsFrom(0) takeWhile { _ < 5 } mkString ", " produces: "0, 1, 2, 3, 4"
def thisCollection: collection.LinearSeq[A]

The underlying collection seen as an instance of Stream.
The underlying collection seen as an instance of Stream. 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.
[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
Full Signature
def to[Col[_]](implicit cbf: CanBuildFrom[Nothing, A, Col[A]]): Col[A]
def toArray: Array[A]

[use case] Converts this stream to an array.
[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
Full Signature
def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
def toBuffer[B >: A]: Buffer[B]

Converts this stream to a mutable buffer.
Converts this stream to a mutable buffer.
Note: will not terminate for infinite-sized collections.
returns
a buffer containing all elements of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
def toCollection(repr: Stream[A]): collection.LinearSeq[A]

A conversion from collections of type Repr to Stream objects.
A conversion from collections of type Repr to Stream 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[A]

Converts this stream to an indexed sequence.
Converts this stream to an indexed sequence.
Note: will not terminate for infinite-sized collections.
returns
an indexed sequence containing all elements of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
def toIterable: collection.Iterable[A]

Converts this stream to an iterable collection.
Converts this stream to an iterable collection. Note that the choice of target Iterable is lazy in this default implementation as this TraversableOnce may be lazy and unevaluated (i.e. it may be an iterator which is only traversable once).
Note: will not terminate for infinite-sized collections.
returns
an Iterable containing all elements of this stream.

Definition Classes
IterableLike → TraversableOnce → GenTraversableOnce
def toIterator: Iterator[A]

Returns an Iterator over the elements in this stream.
Returns an Iterator over the elements in this stream. Will return the same Iterator if this instance is already an Iterator.
Note: will not terminate for infinite-sized collections.
returns
an Iterator containing all elements of this stream.

Definition Classes
IterableLike → TraversableLike → GenTraversableOnce
def toList: scala.List[A]

Converts this stream to a list.
Converts this stream to a list.
Note: will not terminate for infinite-sized collections.
returns
a list containing all elements of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
def toMap[T, U]: collection.Map[T, U]

[use case] Converts this stream to a map.
[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
Full Signature
def toMap[T, U](implicit ev: <:<[A, (T, U)]): Map[T, U]
def toParArray: ParArray[A]

Implicit information
This member is added by an implicit conversion from Stream[A] to TraversableOps[A] performed by method traversable2ops in scala.collection.parallel.
Definition Classes
TraversableOps
def toSeq: Seq[A]

Converts this stream to a sequence.
Converts this stream to a sequence.
Note: will not terminate for infinite-sized collections.
Overridden for efficiency.
returns
a sequence containing all elements of this stream.

Definition Classes
Seq → SeqLike → GenSeqLike → TraversableOnce → GenTraversableOnce
def toSet[B >: A]: Set[B]

Converts this stream to a set.
Converts this stream to a set.
Note: will not terminate for infinite-sized collections.
returns
a set containing all elements of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
def toStream: Stream[A]

Converts this stream to a stream.
Converts this stream to a stream.
Note: will not terminate for infinite-sized collections.
returns
a stream containing all elements of this stream.

Definition Classes
Stream → IterableLike → TraversableLike → GenTraversableOnce
def toString(): String

Converts this stream to a 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[A]

Converts this stream to an unspecified Traversable.
Converts this stream 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 stream.

Definition Classes
TraversableLike → TraversableOnce → GenTraversableOnce
def toVector: scala.Vector[A]

Converts this stream to a Vector.
Converts this stream to a Vector.
Note: will not terminate for infinite-sized collections.
returns
a vector containing all elements of this stream.

Definition Classes
TraversableOnce → GenTraversableOnce
def transpose[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): Stream[Stream[B]]

Transposes this stream of traversable collections into a stream of streams.
Transposes this stream of traversable collections into a stream of streams.
B
the type of the elements of each traversable collection.
asTraversable
an implicit conversion which asserts that the element type of this stream is a Traversable.
returns
a two-dimensional stream of streams which has as nth row the nth column of this stream.

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 stream are not of the same size.
def union(that: collection.Seq[A]): Stream[A]

[use case] Produces a new sequence which contains all elements of this stream and also all elements of a given sequence.
[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-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
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
Full Signature
def union[B >: A, That](that: GenSeq[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def unzip[A1, A2](implicit asPair: (A) ⇒ (A1, A2)): (Stream[A1], Stream[A2])

Converts this stream of pairs into two collections of the first and second half of each pair.
Converts this stream of pairs into two collections of the first and second half of each pair.
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 stream is a pair.
returns
a pair streams, containing the first, respectively second half of each element pair of this stream.

Definition Classes
GenericTraversableTemplate
def unzip3[A1, A2, A3](implicit asTriple: (A) ⇒ (A1, A2, A3)): (Stream[A1], Stream[A2], Stream[A3])

Converts this stream of triples into three collections of the first, second, and third element of each triple.
Converts this stream of triples into three collections of the first, second, and third element of each triple.
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 stream is a triple.
returns
a triple streams, containing the first, second, respectively third member of each element triple of this stream.

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

[use case] A copy of this stream with one single replaced element.
[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
Full Signature
def updated[B >: A, That](index: Int, elem: B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That
def view: StreamView[A, Stream[A]]

Creates a non-strict view of this stream.
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[A, Stream[A]]

Creates a non-strict view of a slice of this stream.
Creates a non-strict view of a slice of this stream.
Note: the difference between view and slice is that view produces a view of the current stream, whereas slice produces a new stream.
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 stream, 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()
final def withFilter(p: (A) ⇒ Boolean): StreamWithFilter

Creates a non-strict filter of this stream.
Creates a non-strict filter of this stream.
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.
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
final def zip[A1 >: A, B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[Stream[A], (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.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) naturalsFrom(1) zip naturalsFrom(2) take 5 foreach println // prints // (1,2) // (2,3) // (3,4) // (4,5) // (5,6)
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.
[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
Full Signature
def zipAll[B, A1 >: A, That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[Stream[A], (A1, B), That]): That
def zipWithIndex[A1 >: A, That](implicit bf: CanBuildFrom[Stream[A], (A1, Int), That]): That

Zips this iterable with its indices.
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
Example:
1. def naturalsFrom(i: Int): Stream[Int] = i #:: naturalsFrom(i + 1) (naturalsFrom(1) zipWithIndex) take 5 foreach println // prints // (1,0) // (2,1) // (3,2) // (4,3) // (5,4)
def →[B](y: B): (Stream[A], B)

Implicit information
This member is added by an implicit conversion from Stream[A] to ArrowAssoc[Stream[A]] performed by method any2ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc

Shadowed Implict Value Members

def filter(p: (A) ⇒ Boolean): TraversableOnce[A]
Implicit information
This member is added by an implicit conversion from Stream[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
Shadowing
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
(stream: MonadOps[A]).filter(p)
Definition Classes
MonadOps
def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): TraversableOnce[B]
Implicit information
This member is added by an implicit conversion from Stream[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
Shadowing
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
(stream: MonadOps[A]).flatMap(f)
Definition Classes
MonadOps
def map[B](f: (A) ⇒ B): TraversableOnce[B]
Implicit information
This member is added by an implicit conversion from Stream[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
Shadowing
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
(stream: MonadOps[A]).map(f)
Definition Classes
MonadOps
val self: Any
Implicit information
This member is added by an implicit conversion from Stream[A] to StringAdd performed by method any2stringadd in scala.Predef.
Shadowing
This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:
(stream: StringAdd).self
Definition Classes
StringAdd
val self: Any
Implicit information
This member is added by an implicit conversion from Stream[A] to StringFormat performed by method any2stringfmt in scala.Predef.
Shadowing
This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:
(stream: StringFormat).self
Definition Classes
StringFormat
def withFilter(p: (A) ⇒ Boolean): Iterator[A]
Implicit information
This member is added by an implicit conversion from Stream[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
Shadowing
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
(stream: MonadOps[A]).withFilter(p)
Definition Classes
MonadOps

Deprecated Value Members

def /:\[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold.
Example:
```
scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = (a /:\ 5)(_+_)
b: Int = 15
```
Definition Classes
GenTraversableOnce
Annotations
@deprecated
Deprecated
(Since version 2.10.0) use fold instead
def x: Stream[A]
Implicit information
This member is added by an implicit conversion from Stream[A] to ArrowAssoc[Stream[A]] performed by method any2ArrowAssoc in scala.Predef.
Shadowing
This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:
(stream: ArrowAssoc[Stream[A]]).x
Definition Classes
ArrowAssoc
Annotations
@deprecated
Deprecated
(Since version 2.10.0) Use leftOfArrow instead
def x: Stream[A]
Implicit information
This member is added by an implicit conversion from Stream[A] to Ensuring[Stream[A]] performed by method any2Ensuring in scala.Predef.
Shadowing
This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:
(stream: Ensuring[Stream[A]]).x
Definition Classes
Ensuring
Annotations
@deprecated
Deprecated
(Since version 2.10.0) Use resultOfEnsuring instead

Inherited from LinearSeqOptimized[A, Stream[A]]

Inherited from LinearSeq[A]

Inherited from collection.LinearSeq[A]

Inherited from LinearSeqLike[A, Stream[A]]

Inherited from Seq[A]

Inherited from Iterable[A]

Inherited from Traversable[A]

Inherited from Immutable

Inherited from AbstractSeq[A]

Inherited from collection.Seq[A]

Inherited from SeqLike[A, Stream[A]]

Inherited from GenSeq[A]

Inherited from GenSeqLike[A, Stream[A]]

Inherited from PartialFunction[Int, A]

Inherited from (Int) ⇒ A

Inherited from AbstractIterable[A]

Inherited from collection.Iterable[A]

Inherited from IterableLike[A, Stream[A]]

Inherited from Equals

Inherited from GenIterable[A]

Inherited from GenIterableLike[A, Stream[A]]

Inherited from AbstractTraversable[A]

Inherited from collection.Traversable[A]

Inherited from GenTraversable[A]

Inherited from GenericTraversableTemplate[A, Stream]

Inherited from TraversableLike[A, Stream[A]]

Inherited from GenTraversableLike[A, Stream[A]]

Inherited from Parallelizable[A, ParSeq[A]]

Inherited from TraversableOnce[A]

Inherited from GenTraversableOnce[A]

Inherited from FilterMonadic[A, Stream[A]]

Inherited from HasNewBuilder[A, scala.collection.immutable.Stream[A] @scala.annotation.unchecked.uncheckedVariance]

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion traversable2ops from Stream[A] to TraversableOps[A]

Inherited by implicit conversion MonadOps from Stream[A] to MonadOps[A]

Inherited by implicit conversion any2stringadd from Stream[A] to StringAdd

Inherited by implicit conversion any2stringfmt from Stream[A] to StringFormat

Inherited by implicit conversion any2ArrowAssoc from Stream[A] to ArrowAssoc[Stream[A]]

Inherited by implicit conversion any2Ensuring from Stream[A] to Ensuring[Stream[A]]

Inherited by implicit conversion alternateImplicit from Stream[A] to ForceImplicitAmbiguity

Ungrouped

abstract class Stream[+A] extends AbstractSeq[A] with LinearSeq[A] with GenericTraversableTemplate[A, Stream] with LinearSeqOptimized[A, Stream[A]]

Instance Constructors

new Stream()

Type Members

type Self = Stream[A]

final class StreamWithFilter extends WithFilter

class WithFilter extends FilterMonadic[A, Repr]

Abstract Value Members

abstract def tailDefined: Boolean

Concrete Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

def +(other: String): String

def ++[B >: A, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

def ++:[B >: A, That](that: collection.Traversable[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

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

def ++:[B >: A, That](that: TraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

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

def +:[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That

def ->[B](y: B): (Stream[A], B)

def /:[B](z: B)(op: (B, A) ⇒ B): B

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

def :+[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Stream[A], B, That]): That

def :\[B](z: B)(op: (A, B) ⇒ B): B

final def ==(arg0: AnyRef): Boolean

final def ==(arg0: Any): Boolean

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

def addString(b: StringBuilder): StringBuilder

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

def aggregate[B](z: B)(seqop: (B, A) ⇒ B, combop: (B, B) ⇒ B): B

def andThen[C](k: (A) ⇒ C): PartialFunction[Int, C]

def append[B >: A](rest: ⇒ TraversableOnce[B]): Stream[B]

def apply(n: Int): A

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

final def asInstanceOf[T0]: T0

def asParIterable: ParIterable[A]

def asParSeq: ParSeq[A]

def canEqual(that: Any): Boolean

def clone(): AnyRef

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

final def collect[B, That](pf: PartialFunction[A, B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

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

def combinations(n: Int): Iterator[Stream[A]]

def companion: GenericCompanion[Stream]

def compose[A](g: (A) ⇒ Int): (A) ⇒ A

def contains(elem: Any): Boolean

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

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

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

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

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

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

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

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

final def corresponds[B](that: GenSeq[B])(p: (A, B) ⇒ Boolean): Boolean

def count(p: (A) ⇒ Boolean): Int

def diff(that: collection.Seq[A]): Stream[A]

def diff[B >: A](that: GenSeq[B]): Stream[A]

def distinct: Stream[A]

final def drop(n: Int): Stream[A]

def dropRight(n: Int): Stream[A]

def dropWhile(p: (A) ⇒ Boolean): Stream[A]

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

def ensuring(cond: (Stream[A]) ⇒ Boolean, msg: ⇒ Any): Stream[A]

def ensuring(cond: (Stream[A]) ⇒ Boolean): Stream[A]

def ensuring(cond: Boolean, msg: ⇒ Any): Stream[A]

def ensuring(cond: Boolean): Stream[A]

final def eq(arg0: AnyRef): Boolean

def equals(that: Any): Boolean

def exists(p: (A) ⇒ Boolean): Boolean

def filter(p: (A) ⇒ Boolean): Stream[A]

def filterNot(p: (A) ⇒ Boolean): Stream[A]

def finalize(): Unit

def find(p: (A) ⇒ Boolean): Option[A]

final def flatMap[B, That](f: (A) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[Stream[A], B, That]): That

def flatten[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): Stream[B]

def fold[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

final def foldLeft[B](z: B)(op: (B, A) ⇒ B): B