scala.collection.immutable

Stream

object Stream extends SeqFactory[Stream]

The object Stream provides helper functions to manipulate streams.

go to: companion
linear super types: SeqFactory[Stream], TraversableFactory[Stream], GenericCompanion[Stream], AnyRef, Any
source: Stream.scala
    version
  1. 1.1 08/08/03

    since
  1. 2.8

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Impl.
  1. Concrete
  2. Abstract

Type Members

  1. type Coll = scala.collection.immutable.Stream[_]

    The underlying collection type with unknown element type

    The underlying collection type with unknown element type

    definition classes: GenericCompanion
  2. class Cons [+A] extends Stream[A]

    A lazy cons cell, from which streams are built.

  3. class ConsWrapper [A] extends AnyRef

    A wrapper class that adds #:: for cons and #::: for concat as operations to streams.

  4. class GenericCanBuildFrom [A] extends CanBuildFrom[CC[_], A, CC[A]]

    A generic implementation of the CanBuildFrom trait, which forwards all calls to apply(from) to the genericBuilder method of collection from, and which forwards all calls of apply() to the newBuilder method of this factory.

  5. class StreamBuilder [A] extends LazyBuilder[A, Stream[A]]

    A builder for streams

  6. class StreamCanBuildFrom [A] extends GenericCanBuildFrom[A]

    The factory for streams.

Value Members

  1. def != (arg0: AnyRef) : Boolean

    attributes: final
    definition classes: AnyRef
  2. def != (arg0: Any) : Boolean

    o != arg0 is the same as !(o == (arg0)).

    o != arg0 is the same as !(o == (arg0)).

    arg0

    the object to compare against this object for dis-equality.

    returns

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

    attributes: final
    definition classes: Any
  3. def ## () : Int

    attributes: final
    definition classes: AnyRef → Any
  4. object #:: extends AnyRef

    An extractor that allows to pattern match streams with #::.

  5. def $asInstanceOf [T0] () : T0

    attributes: final
    definition classes: AnyRef
  6. def $isInstanceOf [T0] () : Boolean

    attributes: final
    definition classes: AnyRef
  7. def == (arg0: AnyRef) : Boolean

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

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

    attributes: final
    definition classes: AnyRef
  8. def == (arg0: Any) : Boolean

    o == arg0 is the same as o.equals(arg0).

    o == arg0 is the same as o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

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

    attributes: final
    definition classes: Any
  9. object Empty extends Stream[Nothing]

  10. def apply [A] (xs: A*) : Stream[A]

    A stream consisting of given elements@tparam A the type of the collection's elements

    A stream consisting of given elements@tparam A the type of the collection's elements

    returns

    a new collection with elements elems

    definition classes: StreamGenericCompanion
  11. def asInstanceOf [T0] : T0

    This method is used to cast the receiver object to be of type T0.

    This method is used to 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 expression1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expressionList(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 typed.

    returns

    the receiver object.

    attributes: final
    definition classes: Any
  12. implicit def canBuildFrom [A] : CanBuildFrom[Coll, A, Stream[A]]

    attributes: implicit
  13. def clone () : AnyRef

    This method creates and returns a copy of the receiver object.

    This method creates and returns 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
    definition classes: AnyRef
  14. def concat [A] (xs: Iterator[Stream[A]]) : Stream[A]

    The concatenation of all streams returned by an iterator

    The concatenation of all streams returned by an iterator

      deprecated:
    1. use xs.toStream.flatten instead

  15. def concat [A] (xs: Iterable[Stream[A]]) : Stream[A]

    The concatenation of a sequence of streams

    The concatenation of a sequence of streams

      deprecated:
    1. use xs.flatten instead

  16. def concat [A] (xss: Traversable[A]*) : Stream[A]

    Concatenates all argument collections into a single collection.

    Concatenates all argument collections into a single collection.

    xss

    the collections that are to be concatenated.

    returns

    the concatenation of all the collections.

    definition classes: TraversableFactory
  17. object cons extends AnyRef

    An alternative way of building and matching Streams using Stream.

  18. implicit def consWrapper [A] (stream: ⇒ Stream[A]) : ConsWrapper[A]

    A wrapper method that adds #:: for cons and #::: for concat as operations to streams.

    A wrapper method that adds #:: for cons and #::: for concat as operations to streams.

    attributes: implicit
  19. def const [A] (elem: A) : Stream[A]

    Create an infinite stream containing the given element.

    Create an infinite stream containing the given element.

    elem

    the element composing the resulting stream

    returns

    the stream containing an infinite number of elem

      deprecated:
    1. use continually' instead

  20. def continually [A] (elem: ⇒ A) : Stream[A]

    Create an infinite stream containing the given element expression (which is computed for each occurrence)

    Create an infinite stream containing the given element expression (which is computed for each occurrence)

    elem

    the element composing the resulting stream

    returns

    the stream containing an infinite number of elem

  21. def empty [A] : Stream[A]

    The empty stream@tparam A the type of the collection's elements

    The empty stream@tparam A the type of the collection's elements

    definition classes: StreamGenericCompanion
  22. def eq (arg0: AnyRef) : Boolean

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on non-null instances of AnyRef: * It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true. * It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and only if y.eq(x) returns true. * It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true and y.eq(z) returns true, then x.eq(z) returns true.

    Additionally, the eq method has three other 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).

    arg0

    the object to compare against this object for reference equality.

    returns

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

    attributes: final
    definition classes: AnyRef
  23. def equals (arg0: Any) : Boolean

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation]: * It is reflexive: for any instance x of type Any, x.equals(x) should return true. * It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true. * It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

    If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects that are "equal" (o1.equals(o2) returns true) hash to the same scala.Int (o1.hashCode.equals(o2.hashCode)).

    arg0

    the object to compare against this object for equality.

    returns

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

    definition classes: AnyRef → Any
  24. def fill [A] (n: Int)(elem: ⇒ A) : Stream[A]

    Produces a collection containing the results of some element computation a number of times.

    Produces a collection containing the results of some element computation a number of times.

    n

    the number of elements contained in the collection.

    elem

    the element computation

    returns

    A collection that contains the results of n evaluations of elem.

    definition classes: StreamTraversableFactory
  25. def fill [A] (n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: ⇒ A) : Stream[Stream[Stream[Stream[Stream[A]]]]]

    Produces a five-dimensional collection containing the results of some element computation a number of times.

    Produces a five-dimensional collection containing the results of some element computation a number of times.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    n4

    the number of elements in the 4th dimension

    n5

    the number of elements in the 5th dimension

    elem

    the element computation

    returns

    A collection that contains the results of n1 x n2 x n3 x n4 x n5 evaluations of elem.

    definition classes: TraversableFactory
  26. def fill [A] (n1: Int, n2: Int, n3: Int, n4: Int)(elem: ⇒ A) : Stream[Stream[Stream[Stream[A]]]]

    Produces a four-dimensional collection containing the results of some element computation a number of times.

    Produces a four-dimensional collection containing the results of some element computation a number of times.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    n4

    the number of elements in the 4th dimension

    elem

    the element computation

    returns

    A collection that contains the results of n1 x n2 x n3 x n4 evaluations of elem.

    definition classes: TraversableFactory
  27. def fill [A] (n1: Int, n2: Int, n3: Int)(elem: ⇒ A) : Stream[Stream[Stream[A]]]

    Produces a three-dimensional collection containing the results of some element computation a number of times.

    Produces a three-dimensional collection containing the results of some element computation a number of times.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    elem

    the element computation

    returns

    A collection that contains the results of n1 x n2 x n3 evaluations of elem.

    definition classes: TraversableFactory
  28. def fill [A] (n1: Int, n2: Int)(elem: ⇒ A) : Stream[Stream[A]]

    Produces a two-dimensional collection containing the results of some element computation a number of times.

    Produces a two-dimensional collection containing the results of some element computation a number of times.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    elem

    the element computation

    returns

    A collection that contains the results of n1 x n2 evaluations of elem.

    definition classes: TraversableFactory
  29. def finalize () : Unit

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

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

    attributes: protected
    definition classes: AnyRef
  30. def from (start: Int) : Stream[Int]

    Create an infinite stream starting at startand incrementing by 1.

    Create an infinite stream starting at startand incrementing by 1.

    start

    the start value of the stream

    returns

    the stream starting at value start.

  31. def from (start: Int, step: Int) : Stream[Int]

    Create an infinite stream starting at startand incrementing by step step

    Create an infinite stream starting at startand incrementing by step step

    start

    the start value of the stream

    step

    the increment value of the stream

    returns

    the stream starting at value start.

  32. def fromIterator [A] (it: Iterator[A]) : Stream[A]

    A stream containing all elements of a given iterator, in the order they are produced.

    A stream containing all elements of a given iterator, in the order they are produced.

    it

    The iterator producing the stream's elements

      deprecated:
    1. use it.toStream instead

  33. def getClass () : java.lang.Class[_]

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

    Returns 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.

    attributes: final
    definition classes: AnyRef
  34. def hashCode () : Int

    Returns a hash code value for the object.

    Returns a hash code value for the object.

    The default hashing algorithm is platform dependent.

    Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

    returns

    the hash code value for the object.

    definition classes: AnyRef → Any
  35. def isInstanceOf [T0] : Boolean

    This method is used to test whether the dynamic type of the receiver object is T0.

    This method is used to test whether the dynamic type of the receiver object is T0.

    Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.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 requested typed.

    returns

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

    attributes: final
    definition classes: Any
  36. def iterate [A] (start: A, len: Int)(f: (A) ⇒ A) : Stream[A]

    Produces a collection containing repeated applications of a function to a start value.

    Produces a collection containing repeated applications of a function to a start value.

    start

    the start value of the collection

    len

    the number of elements contained inthe collection

    f

    the function that's repeatedly applied

    returns

    a collection with len values in the sequence start, f(start), f(f(start)), ...

    definition classes: StreamTraversableFactory
  37. def iterate [A] (start: A)(f: (A) ⇒ A) : Stream[A]

    An infinite stream that repeatedly applies a given function to a start value.

    An infinite stream that repeatedly applies a given function to a start value.

    start

    the start value of the stream

    f

    the function that's repeatedly applied

    returns

    the stream returning the infinite sequence of values start, f(start), f(f(start)), ...

  38. lazy val lazy_:: : #::

      deprecated:
    1. use #:: instead

  39. def make [A] (n: Int, elem: A) : Stream[A]

    Create a stream containing several copies of an element.

    Create a stream containing several copies of an element.

    n

    the length of the resulting stream

    elem

    the element composing the resulting stream

    returns

    the stream composed of n elements all equal to elem

      deprecated:
    1. use fill(n, elem) instead

  40. def ne (arg0: AnyRef) : Boolean

    o.ne(arg0) is the same as !(o.eq(arg0)).

    o.ne(arg0) is the same as !(o.eq(arg0)).

    arg0

    the object to compare against this object for reference dis-equality.

    returns

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

    attributes: final
    definition classes: AnyRef
  41. def newBuilder [A] : Builder[A, Stream[A]]

    Creates a new builder for a stream@tparam A the type of the collection's elements

    Creates a new builder for a stream@tparam A the type of the collection's elements

    definition classes: StreamGenericCompanion
  42. 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.

    attributes: final
    definition classes: AnyRef
  43. 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.

    attributes: final
    definition classes: AnyRef
  44. def range (start: Int, end: Int, step: (Int) ⇒ Int) : Stream[Int]

    Create a stream with element valuesvn+1 = step(vn)where v0 = startand elements are in the range between start (inclusive) and end (exclusive)

    Create a stream with element valuesvn+1 = step(vn)where v0 = startand elements are in the range between start (inclusive) and end (exclusive)

    start

    the start value of the stream

    end

    the end value of the stream

    step

    the increment function of the stream, must be monotonically increasing or decreasing

    returns

    the stream starting at value start.

      deprecated:
    1. use iterate' instead.

  45. def range (start: Int, end: Int, step: Int) : Stream[Int]

    Produces a collection containing equally spaced values in some integer interval.

    Produces a collection containing equally spaced values in some integer interval.

    start

    the start value of the collection

    end

    the end value of the collection (the first value NOT contained)

    step

    the difference between successive elements of the collection (must be positive or negative)

    returns

    a collection with values start, start + step, ... up to, but excluding end

    definition classes: StreamTraversableFactory
  46. def range (start: Int, end: Int) : Stream[Int]

    Produces a collection containing a sequence of increasing of integers.

    Produces a collection containing a sequence of increasing of integers.

    end

    the end value of the collection (the first value NOT contained)

    returns

    a collection with values start, start + 1, ..., end - 1

    definition classes: TraversableFactory
  47. def synchronized [T0] (arg0: T0) : T0

    attributes: final
    definition classes: AnyRef
  48. def tabulate [A] (n: Int)(f: (Int) ⇒ A) : Stream[A]

    Produces a collection containing values of a given function over a range of integer values starting from 0.

    Produces a collection containing values of a given function over a range of integer values starting from 0.

    n

    The number of elements in the collection

    f

    The function computing element values

    returns

    A collection consisting of elements f(0), ..., f(n -1)

    definition classes: StreamTraversableFactory
  49. def tabulate [A] (n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) ⇒ A) : Stream[Stream[Stream[Stream[Stream[A]]]]]

    Produces a five-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    Produces a five-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    n4

    the number of elements in the 4th dimension

    n5

    the number of elements in the 5th dimension

    f

    The function computing element values

    returns

    A collection consisting of elements f(i1, i2, i3, i4, i5) for 0 <= i1 < n1, 0 <= i2 < n2, 0 <= i3 < n3, 0 <= i4 < n4, and 0 <= i5 < n5.

    definition classes: TraversableFactory
  50. def tabulate [A] (n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) ⇒ A) : Stream[Stream[Stream[Stream[A]]]]

    Produces a four-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    Produces a four-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    n4

    the number of elements in the 4th dimension

    f

    The function computing element values

    returns

    A collection consisting of elements f(i1, i2, i3, i4) for 0 <= i1 < n1, 0 <= i2 < n2, 0 <= i3 < n3, and 0 <= i4 < n4.

    definition classes: TraversableFactory
  51. def tabulate [A] (n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) ⇒ A) : Stream[Stream[Stream[A]]]

    Produces a three-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    Produces a three-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    n3

    the number of elements in the 3nd dimension

    f

    The function computing element values

    returns

    A collection consisting of elements f(i1, i2, i3) for 0 <= i1 < n1, 0 <= i2 < n2, and 0 <= i3 < n3.

    definition classes: TraversableFactory
  52. def tabulate [A] (n1: Int, n2: Int)(f: (Int, Int) ⇒ A) : Stream[Stream[A]]

    Produces a two-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    Produces a two-dimensional collection containing values of a given function over ranges of integer values starting from 0.

    n1

    the number of elements in the 1st dimension

    n2

    the number of elements in the 2nd dimension

    f

    The function computing element values

    returns

    A collection consisting of elements f(i1, i2) for 0 <= i1 < n1 and 0 <= i2 < n2.

    definition classes: TraversableFactory
  53. def toString () : String

    Returns a string representation of the object.

    Returns a string representation of the object.

    The default representation is platform dependent.

    returns

    a string representation of the object.

    definition classes: AnyRef → Any
  54. def unapplySeq [A] (x: Stream[A]) : Some[Stream[A]]

    This method is called in a pattern match { case Seq(.

    This method is called in a pattern match { case Seq(...) => }.

    x

    the selector value

    returns

    sequence wrapped in an option, if this is a Seq, otherwise none

    definition classes: SeqFactory
  55. def wait () : Unit

    attributes: final
    definition classes: AnyRef
  56. def wait (arg0: Long, arg1: Int) : Unit

    attributes: final
    definition classes: AnyRef
  57. def wait (arg0: Long) : Unit

    attributes: final
    definition classes: AnyRef

Inherited from SeqFactory[Stream]

Inherited from TraversableFactory[Stream]

Inherited from GenericCompanion[Stream]

Inherited from AnyRef

Inherited from Any