Packages

trait Iterator[+A] extends TraversableOnce[A]

Iterators are data structures that allow to iterate over a sequence of elements. They have a hasNext method for checking if there is a next element available, and a next method which returns the next element and advances the iterator.

An iterator is mutable: most operations on it change its state. While it is often used to iterate through the elements of a collection, it can also be used without being backed by any collection (see constructors on the companion object).

It is of particular importance to note that, unless stated otherwise, one should never use an iterator after calling a method on it. The two most important exceptions are also the sole abstract methods: next and hasNext.

Both these methods can be called any number of times without having to discard the iterator. Note that even hasNext may cause mutation -- such as when iterating from an input stream, where it will block until the stream is closed or some input becomes available.

Consider this example for safe and unsafe use:

def f[A](it: Iterator[A]) = {
  if (it.hasNext) {            // Safe to reuse "it" after "hasNext"
    it.next                    // Safe to reuse "it" after "next"
    val remainder = it.drop(2) // it is *not* safe to use "it" again after this line!
    remainder.take(2)          // it is *not* safe to use "remainder" after this line!
  } else it
}
Self Type
Iterator[A]
Source
Iterator.scala
Version

2.8

Since

1

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  1. Iterator
  2. TraversableOnce
  3. GenTraversableOnce
  4. AnyRef
  5. Any
Implicitly
  1. by MonadOps
  2. by any2stringadd
  3. by StringFormat
  4. by Ensuring
  5. by ArrowAssoc
  6. by alternateImplicit
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Type Members

  1. class GroupedIterator[B >: A] extends AbstractIterator[Seq[B]] with Iterator[Seq[B]]

    A flexible iterator for transforming an Iterator[A] into an Iterator[Seq[A]], with configurable sequence size, step, and strategy for dealing with elements which don't fit evenly.

    A flexible iterator for transforming an Iterator[A] into an Iterator[Seq[A]], with configurable sequence size, step, and strategy for dealing with elements which don't fit evenly.

    Typical uses can be achieved via methods grouped and sliding.

Abstract Value Members

  1. abstract def hasNext: Boolean

    Tests whether this iterator can provide another element.

    Tests whether this iterator can provide another element.

    returns

    true if a subsequent call to next will yield an element, false otherwise.

    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

  2. abstract def next(): A

    Produces the next element of this iterator.

    Produces the next element of this iterator.

    returns

    the next element of this iterator, if hasNext is true, undefined behavior otherwise.

    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

Concrete Value Members

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

    Test two objects for inequality.

    Test two objects for inequality.

    returns

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

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

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

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

    returns

    a hash value consistent with ==

    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Iterator[A] to any2stringadd[Iterator[A]] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ++(that: ⇒ Iterator[A]): Iterator[A]

    [use case] Concatenates this iterator with another.

    [use case]

    Concatenates this iterator with another.

    that

    the other iterator

    returns

    a new iterator that first yields the values produced by this iterator followed by the values produced by iterator that.

    Full Signature

    def ++[B >: A](that: ⇒ GenTraversableOnce[B]): Iterator[B]

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

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

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

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

    Examples:

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

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = (5 /: a)(_+_)
    b: Int = 15
    
    scala> val c = (5 /: a)((x,y) => x + y)
    c: Int = 15

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  7. def :\[B](z: B)(op: (A, B) ⇒ B): B

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    Examples:

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

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = (a :\ 5)(_+_)
    b: Int = 15
    
    scala> val c = (a :\ 5)((x,y) => x + y)
    c: Int = 15
    B

    the result type of the binary operator.

    z

    the start value

    op

    the binary operator

    returns

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

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

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

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

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

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

    returns

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

    Definition Classes
    AnyRef → Any
  9. def addString(b: StringBuilder): StringBuilder

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

    Appends all elements of this traversable or iterator to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this traversable or iterator without any separator string.

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    scala> val h = a.addString(b)
    h: StringBuilder = 1234
    b

    the string builder to which elements are appended.

    returns

    the string builder b to which elements were appended.

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

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

    Appends all elements of this traversable or iterator to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method toString) of all elements of this traversable or iterator, separated by the string sep.

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    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
  11. def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder

    Appends all elements of this traversable or iterator to a string builder using start, end, and separator strings.

    Appends all elements of this traversable or iterator to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    scala> a.addString(b , "List(" , ", " , ")")
    res5: StringBuilder = List(1, 2, 3, 4)
    b

    the string builder to which elements are appended.

    start

    the starting string.

    sep

    the separator string.

    end

    the ending string.

    returns

    the string builder b to which elements were appended.

    Definition Classes
    TraversableOnce
  12. 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 is similar to foldLeft in that it doesn't require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.

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

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

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

    the type of accumulated results

    z

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

    seqop

    an operator used to accumulate results within a partition

    combop

    an associative operator used to combine results from different partitions

    Definition Classes
    TraversableOnceGenTraversableOnce
  13. 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.

  14. def buffered: BufferedIterator[A]

    Creates a buffered iterator from this iterator.

    Creates a buffered iterator from this iterator.

    returns

    a buffered iterator producing the same values as this iterator.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

    See also

    scala.collection.BufferedIterator

  15. 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
    @native() @throws( ... )
    Note

    not specified by SLS as a member of AnyRef

  16. def collect[B](pf: PartialFunction[A, B]): Iterator[B]

    Creates an iterator by transforming values produced by this iterator with a partial function, dropping those values for which the partial function is not defined.

    Creates an iterator by transforming values produced by this iterator with a partial function, dropping those values for which the partial function is not defined.

    pf

    the partial function which filters and maps the iterator.

    returns

    a new iterator which yields each value x produced by this iterator for which pf is defined the image pf(x).

    Annotations
    @migration
    Migration

    (Changed in version 2.8.0) collect has changed. The previous behavior can be reproduced with toSeq.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

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

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

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

    Note: may not terminate for infinite-sized collections.

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

    pf

    the partial function

    returns

    an option value containing pf applied to the first value for which it is defined, or None if none exists.

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

  18. def contains(elem: Any): Boolean

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

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

    Note: may not terminate for infinite iterators.

    elem

    the element to test.

    returns

    true if this iterator produces some value that is is equal (as determined by ==) to elem, false otherwise.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

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

    [use case] Copies selected values produced by this iterator to an array.

    [use case]

    Copies selected values produced by this iterator to an array. Fills the given array xs starting at index start with at most len values produced by this iterator. Copying will stop once either the end of the current iterator is reached, or the end of the array is reached, or len elements have been copied.

    Note: will not terminate for infinite iterators.

    xs

    the array to fill.

    start

    the starting index.

    len

    the maximal number of elements to copy.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Full Signature

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

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

    [use case] Copies the elements of this traversable or iterator to an array.

    [use case]

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

    Note: will not terminate for infinite iterators.

    xs

    the array to fill.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

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

    [use case] Copies the elements of this traversable or iterator to an array.

    [use case]

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

    Note: will not terminate for infinite iterators.

    xs

    the array to fill.

    start

    the starting index.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

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

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

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

    Note: will not terminate for infinite-sized collections.

    dest

    The buffer to which elements are copied.

    Definition Classes
    TraversableOnce
  23. def corresponds[B](that: GenTraversableOnce[B])(p: (A, B) ⇒ Boolean): Boolean

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

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

    B

    the type of the elements of that

    that

    the other collection

    p

    the test predicate, which relates elements from both collections

    returns

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

  24. def count(p: (A) ⇒ Boolean): Int

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

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

    p

    the predicate used to test elements.

    returns

    the number of elements satisfying the predicate p.

    Definition Classes
    TraversableOnceGenTraversableOnce
  25. def drop(n: Int): Iterator[A]

    Advances this iterator past the first n elements, or the length of the iterator, whichever is smaller.

    Advances this iterator past the first n elements, or the length of the iterator, whichever is smaller.

    n

    the number of elements to drop

    returns

    an iterator which produces all values of the current iterator, except it omits the first n values.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  26. def dropWhile(p: (A) ⇒ Boolean): Iterator[A]

    Skips longest sequence of elements of this iterator which satisfy given predicate p, and returns an iterator of the remaining elements.

    Skips longest sequence of elements of this iterator which satisfy given predicate p, and returns an iterator of the remaining elements.

    p

    the predicate used to skip elements.

    returns

    an iterator consisting of the remaining elements

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  27. def duplicate: (Iterator[A], Iterator[A])

    Creates two new iterators that both iterate over the same elements as this iterator (in the same order).

    Creates two new iterators that both iterate over the same elements as this iterator (in the same order). The duplicate iterators are considered equal if they are positioned at the same element.

    Given that most methods on iterators will make the original iterator unfit for further use, this methods provides a reliable way of calling multiple such methods on an iterator.

    returns

    a pair of iterators

    Note

    The implementation may allocate temporary storage for elements iterated by one iterator but not yet by the other.

    ,

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.

  28. def ensuring(cond: (Iterator[A]) ⇒ Boolean, msg: ⇒ Any): Iterator[A]
    Implicit
    This member is added by an implicit conversion from Iterator[A] to Ensuring[Iterator[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  29. def ensuring(cond: (Iterator[A]) ⇒ Boolean): Iterator[A]
    Implicit
    This member is added by an implicit conversion from Iterator[A] to Ensuring[Iterator[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  30. def ensuring(cond: Boolean, msg: ⇒ Any): Iterator[A]
    Implicit
    This member is added by an implicit conversion from Iterator[A] to Ensuring[Iterator[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  31. def ensuring(cond: Boolean): Iterator[A]
    Implicit
    This member is added by an implicit conversion from Iterator[A] to Ensuring[Iterator[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  32. final def eq(arg0: AnyRef): Boolean

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

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

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

    • 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
  33. def equals(arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. Default implementation delegates to eq.

    See also equals in scala.Any.

    returns

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

    Definition Classes
    AnyRef → Any
  34. def exists(p: (A) ⇒ Boolean): Boolean

    Tests whether a predicate holds for some of the values produced by this iterator.

    Tests whether a predicate holds for some of the values produced by this iterator.

    Note: may not terminate for infinite iterators.

    p

    the predicate used to test elements.

    returns

    true if the given predicate p holds for some of the values produced by this iterator, otherwise false.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  35. def filter(p: (A) ⇒ Boolean): Iterator[A]

    Returns an iterator over all the elements of this iterator that satisfy the predicate p.

    Returns an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.

    p

    the predicate used to test values.

    returns

    an iterator which produces those values of this iterator which satisfy the predicate p.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  36. def filterNot(p: (A) ⇒ Boolean): Iterator[A]

    Creates an iterator over all the elements of this iterator which do not satisfy a predicate p.

    Creates an iterator over all the elements of this iterator which do not satisfy a predicate p.

    p

    the predicate used to test values.

    returns

    an iterator which produces those values of this iterator which do not satisfy the predicate p.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  37. 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( classOf[java.lang.Throwable] )
    Note

    not specified by SLS as a member of AnyRef

  38. def find(p: (A) ⇒ Boolean): Option[A]

    Finds the first value produced by the iterator satisfying a predicate, if any.

    Finds the first value produced by the iterator satisfying a predicate, if any.

    Note: may not terminate for infinite iterators.

    p

    the predicate used to test values.

    returns

    an option value containing the first value produced by the iterator that satisfies predicate p, or None if none exists.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  39. def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): Iterator[B]

    Creates a new iterator by applying a function to all values produced by this iterator and concatenating the results.

    Creates a new iterator by applying a function to all values produced by this iterator and concatenating the results.

    f

    the function to apply on each element.

    returns

    the iterator resulting from applying the given iterator-valued function f to each value produced by this iterator and concatenating the results.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

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

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

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

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

    Note: will not terminate for infinite-sized collections.

    A1

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

    z

    a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation, 0 for addition, or 1 for multiplication).

    op

    a binary operator that must be associative.

    returns

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

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

    where x1, ..., xn are the elements of this traversable or iterator. Returns z if this traversable or iterator is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

    where x1, ..., xn are the elements of this traversable or iterator. Returns z if this traversable or iterator is empty.

    Definition Classes
    TraversableOnceGenTraversableOnce
  43. def forall(p: (A) ⇒ Boolean): Boolean

    Tests whether a predicate holds for all values produced by this iterator.

    Tests whether a predicate holds for all values produced by this iterator.

    Note: may not terminate for infinite iterators.

    p

    the predicate used to test elements.

    returns

    true if the given predicate p holds for all values produced by this iterator, otherwise false.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  44. def foreach(f: (A) ⇒ Unit): Unit

    [use case] Applies a function f to all values produced by this iterator.

    [use case]

    Applies a function f to all values produced by this iterator.

    f

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

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Full Signature

    def foreach[U](f: (A) ⇒ U): Unit

  45. 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
    This member is added by an implicit conversion from Iterator[A] to StringFormat[Iterator[A]] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  46. final def getClass(): Class[_]

    Returns the runtime class representation of the object.

    Returns the runtime class representation of the object.

    returns

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

    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  47. def grouped[B >: A](size: Int): GroupedIterator[B]

    Returns an iterator which groups this iterator into fixed size blocks.

    Returns an iterator which groups this iterator into fixed size blocks. Example usages:

    // Returns List(List(1, 2, 3), List(4, 5, 6), List(7)))
    (1 to 7).iterator grouped 3 toList
    // Returns List(List(1, 2, 3), List(4, 5, 6))
    (1 to 7).iterator grouped 3 withPartial false toList
    // Returns List(List(1, 2, 3), List(4, 5, 6), List(7, 20, 25)
    // Illustrating that withPadding's argument is by-name.
    val it2 = Iterator.iterate(20)(_ + 5)
    (1 to 7).iterator grouped 3 withPadding it2.next toList
    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  48. def hasDefiniteSize: Boolean

    Tests whether this Iterator has a known size.

    Tests whether this Iterator has a known size.

    returns

    true for empty Iterators, false otherwise.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

  49. def hashCode(): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in scala.Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  50. def indexOf[B >: A](elem: B, from: Int): Int

    Returns the index of the first occurrence of the specified object in this iterable object after or at some start index.

    Returns the index of the first occurrence of the specified object in this iterable object after or at some start index.

    Note: may not terminate for infinite iterators.

    elem

    element to search for.

    from

    the start index

    returns

    the index >= from of the first occurrence of elem in the values produced by this iterator, or -1 if such an element does not exist until the end of the iterator is reached.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  51. def indexOf[B >: A](elem: B): Int

    Returns the index of the first occurrence of the specified object in this iterable object.

    Returns the index of the first occurrence of the specified object in this iterable object.

    Note: may not terminate for infinite iterators.

    elem

    element to search for.

    returns

    the index of the first occurrence of elem in the values produced by this iterator, or -1 if such an element does not exist until the end of the iterator is reached.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  52. def indexWhere(p: (A) ⇒ Boolean, from: Int): Int

    Returns the index of the first produced value satisfying a predicate, or -1, after or at some start index.

    Returns the index of the first produced value satisfying a predicate, or -1, after or at some start index.

    Note: may not terminate for infinite iterators.

    p

    the predicate to test values

    from

    the start index

    returns

    the index >= from of the first produced value satisfying p, or -1 if such an element does not exist until the end of the iterator is reached.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  53. def indexWhere(p: (A) ⇒ Boolean): Int

    Returns the index of the first produced value satisfying a predicate, or -1.

    Returns the index of the first produced value satisfying a predicate, or -1.

    Note: may not terminate for infinite iterators.

    p

    the predicate to test values

    returns

    the index of the first produced value satisfying p, or -1 if such an element does not exist until the end of the iterator is reached.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  54. def isEmpty: Boolean

    Tests whether this iterator is empty.

    Tests whether this iterator is empty.

    returns

    true if hasNext is false, false otherwise.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

  55. 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
  56. def isTraversableAgain: Boolean

    Tests whether this Iterator can be repeatedly traversed.

    Tests whether this Iterator can be repeatedly traversed.

    returns

    false

    Definition Classes
    IteratorGenTraversableOnce
    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

  57. def length: Int

    Returns the number of elements in this iterator.

    Returns the number of elements in this iterator.

    Note: will not terminate for infinite iterators.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

  58. def map[B](f: (A) ⇒ B): Iterator[B]

    Creates a new iterator that maps all produced values of this iterator to new values using a transformation function.

    Creates a new iterator that maps all produced values of this iterator to new values using a transformation function.

    f

    the transformation function

    returns

    a new iterator which transforms every value produced by this iterator by applying the function f to it.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  59. def max: A

    [use case] Finds the largest element.

    [use case]

    Finds the largest element.

    returns

    the largest element of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def max[B >: A](implicit cmp: Ordering[B]): A

    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

  60. def maxBy[B](f: (A) ⇒ B): A

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

    [use case]

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

    B

    The result type of the function f.

    f

    The measuring function.

    returns

    the first element of this traversable or iterator with the largest value measured by function f.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

  61. def min: A

    [use case] Finds the smallest element.

    [use case]

    Finds the smallest element.

    returns

    the smallest element of this traversable or iterator

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def min[B >: A](implicit cmp: Ordering[B]): A

    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

  62. def minBy[B](f: (A) ⇒ B): A

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

    [use case]

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

    B

    The result type of the function f.

    f

    The measuring function.

    returns

    the first element of this traversable or iterator with the smallest value measured by function f.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

  63. def mkString: String

    Displays all elements of this traversable or iterator in a string.

    Displays all elements of this traversable or iterator in a string.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  64. def mkString(sep: String): String

    Displays all elements of this traversable or iterator in a string using a separator string.

    Displays all elements of this traversable or iterator in a string using a separator string.

    sep

    the separator string.

    returns

    a string representation of this traversable or iterator. In the resulting string the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Example:
    1. List(1, 2, 3).mkString("|") = "1|2|3"

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

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

    Displays all elements of this traversable or iterator 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 traversable or iterator. 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 traversable or iterator are separated by the string sep.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Example:
    1. List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"

  66. 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
  67. def nonEmpty: Boolean

    Tests whether the traversable or iterator is not empty.

    Tests whether the traversable or iterator is not empty.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  68. 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
    Annotations
    @native()
    Note

    not specified by SLS as a member of AnyRef

  69. 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
    Annotations
    @native()
    Note

    not specified by SLS as a member of AnyRef

  70. def padTo(len: Int, elem: A): Iterator[A]

    [use case] Appends an element value to this iterator until a given target length is reached.

    [use case]

    Appends an element value to this iterator until a given target length is reached.

    len

    the target length

    elem

    the padding value

    returns

    a new iterator consisting of producing all values of this iterator, followed by the minimal number of occurrences of elem so that the number of produced values is at least len.

    Full Signature

    def padTo[A1 >: A](len: Int, elem: A1): Iterator[A1]

  71. def partition(p: (A) ⇒ Boolean): (Iterator[A], Iterator[A])

    Partitions this iterator in two iterators according to a predicate.

    Partitions this iterator in two iterators according to a predicate.

    p

    the predicate on which to partition

    returns

    a pair of iterators: the iterator that satisfies the predicate p and the iterator that does not. The relative order of the elements in the resulting iterators is the same as in the original iterator.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.

  72. def patch[B >: A](from: Int, patchElems: Iterator[B], replaced: Int): Iterator[B]

    Returns this iterator with patched values.

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

    from

    The start index from which to patch

    patchElems

    The iterator of patch values

    replaced

    The number of values in the original iterator that are replaced by the patch.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as a parameter, and use only the iterator that was returned. Using the old iterators is undefined, subject to change, and may result in changes to the new iterator as well.

  73. 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 traversable or iterator 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 traversable or iterator and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def product[B >: A](implicit num: Numeric[B]): B

  74. def reduce[A1 >: A](op: (A1, A1) ⇒ A1): A1

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

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

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

    A1

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

    op

    A binary operator that must be associative.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

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

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

    Definition Classes
    TraversableOnce
    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

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

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

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

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

    A1

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

    op

    A binary operator that must be associative.

    returns

    An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

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

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

    Definition Classes
    TraversableOnceGenTraversableOnce
    Exceptions thrown

    UnsupportedOperationException if this traversable or iterator is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  80. def reversed: List[A]
    Attributes
    protected[this]
    Definition Classes
    TraversableOnce
  81. def sameElements(that: Iterator[_]): Boolean

    Tests if another iterator produces the same values as this one.

    Tests if another iterator produces the same values as this one.

    Note: will not terminate for infinite iterators.

    that

    the other iterator

    returns

    true, if both iterators produce the same elements in the same order, false otherwise.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as parameter. Using the old iterators is undefined and subject to change.

  82. def scanLeft[B](z: B)(op: (B, A) ⇒ B): Iterator[B]

    Produces a collection containing cumulative results of applying the operator going left to right, including the initial value.

    Produces a collection containing cumulative results of applying the operator going left to right, including the initial value.

    Note: will not terminate for infinite iterators.

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

    B

    the type of the elements in the resulting collection

    z

    the initial value

    op

    the binary operator applied to the intermediate result and the element

    returns

    iterator with intermediate results

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  83. def scanRight[B](z: B)(op: (A, B) ⇒ B): Iterator[B]

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

    Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

    Note: will not terminate for infinite iterators.

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

    B

    the type of the elements in the resulting collection

    z

    the initial value

    op

    the binary operator applied to the intermediate result and the element

    returns

    iterator with intermediate results

    Example:
    1. Iterator(1, 2, 3, 4).scanRight(0)(_ + _).toList == List(10, 9, 7, 4, 0)
    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  84. def seq: Iterator[A]

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

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

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

    returns

    a sequential view of the collection.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
  85. def size: Int

    The size of this traversable or iterator.

    The size of this traversable or iterator.

    Note: will not terminate for infinite-sized collections.

    returns

    the number of elements in this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  86. def sizeHintIfCheap: Int

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

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

    returns

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

    Attributes
    protected[scala.collection]
    Definition Classes
    GenTraversableOnce
  87. def slice(from: Int, until: Int): Iterator[A]

    Creates an iterator returning an interval of the values produced by this iterator.

    Creates an iterator returning an interval of the values produced by this iterator.

    from

    the index of the first element in this iterator which forms part of the slice. If negative, the slice starts at zero.

    until

    the index of the first element following the slice. If negative, the slice is empty.

    returns

    an iterator which advances this iterator past the first from elements using drop, and then takes until - from elements, using take.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  88. def sliceIterator(from: Int, until: Int): Iterator[A]

    Creates an optionally bounded slice, unbounded if until is negative.

    Creates an optionally bounded slice, unbounded if until is negative.

    Attributes
    protected
  89. def sliding[B >: A](size: Int, step: Int = 1): GroupedIterator[B]

    Returns an iterator which presents a "sliding window" view of this iterator.

    Returns an iterator which presents a "sliding window" view of this iterator. The first argument is the window size, and the second argument step is how far to advance the window on each iteration. The step defaults to 1.

    The default GroupedIterator can be configured to either pad a partial result to size size or suppress the partial result entirely.

    Example usages:

    // Returns List(List(1, 2, 3), List(2, 3, 4), List(3, 4, 5))
    (1 to 5).iterator.sliding(3).toList
    // Returns List(List(1, 2, 3, 4), List(4, 5))
    (1 to 5).iterator.sliding(4, 3).toList
    // Returns List(List(1, 2, 3, 4))
    (1 to 5).iterator.sliding(4, 3).withPartial(false).toList
    // Returns List(List(1, 2, 3, 4), List(4, 5, 20, 25))
    // Illustrating that withPadding's argument is by-name.
    val it2 = Iterator.iterate(20)(_ + 5)
    (1 to 5).iterator.sliding(4, 3).withPadding(it2.next).toList
    returns

    An iterator producing Seq[B]s of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped. This behavior can be configured.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  90. def span(p: (A) ⇒ Boolean): (Iterator[A], Iterator[A])

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

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

    p

    the test predicate

    returns

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

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.

  91. 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 traversable or iterator 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 traversable or iterator and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def sum[B >: A](implicit num: Numeric[B]): B

  92. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  93. def take(n: Int): Iterator[A]

    Selects first n values of this iterator.

    Selects first n values of this iterator.

    n

    the number of values to take

    returns

    an iterator producing only the first n values of this iterator, or else the whole iterator, if it produces fewer than n values.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  94. def takeWhile(p: (A) ⇒ Boolean): Iterator[A]

    Takes longest prefix of values produced by this iterator that satisfy a predicate.

    Takes longest prefix of values produced by this iterator that satisfy a predicate.

    p

    The predicate used to test elements.

    returns

    An iterator returning the values produced by this iterator, until this iterator produces a value that does not satisfy the predicate p.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

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

    [use case] Converts this traversable or iterator into another by copying all elements.

    [use case]

    Converts this traversable or iterator into another by copying all elements.

    Note: will not terminate for infinite iterators.

    Col

    The collection type to build.

    returns

    a new collection containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def to[Col[_]](implicit cbf: CanBuildFrom[Nothing, A, Col[A]]): Col[A]

  96. def toArray: Array[A]

    [use case] Converts this traversable or iterator to an array.

    [use case]

    Converts this traversable or iterator to an array.

    Note: will not terminate for infinite iterators.

    returns

    an array containing all elements of this traversable or iterator. An ClassTag must be available for the element type of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]

  97. def toBuffer[B >: A]: Buffer[B]

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

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

    Note: will not terminate for infinite-sized collections.

    returns

    a buffer containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  98. def toIndexedSeq: immutable.IndexedSeq[A]

    Converts this traversable or iterator to an indexed sequence.

    Converts this traversable or iterator to an indexed sequence.

    Note: will not terminate for infinite-sized collections.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  99. def toIterable: Iterable[A]

    Converts this traversable or iterator to an iterable collection.

    Converts this traversable or iterator 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 traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  100. def toIterator: Iterator[A]

    Returns an Iterator over the elements in this traversable or iterator.

    Returns an Iterator over the elements in this traversable or iterator. Will return the same Iterator if this instance is already an Iterator.

    Note: will not terminate for infinite iterators.

    returns

    an Iterator containing all elements of this traversable or iterator.

    Definition Classes
    IteratorGenTraversableOnce
  101. def toList: List[A]

    Converts this traversable or iterator to a list.

    Converts this traversable or iterator to a list.

    Note: will not terminate for infinite-sized collections.

    returns

    a list containing all elements of this traversable or iterator.

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

    [use case] Converts this traversable or iterator to a map.

    [use case]

    Converts this traversable or iterator 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 iterators.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

    def toMap[T, U](implicit ev: <:<[A, (T, U)]): immutable.Map[T, U]

  103. def toSeq: Seq[A]

    Converts this traversable or iterator to a sequence.

    Converts this traversable or iterator to a sequence. As with toIterable, it's lazy in this default implementation, as this TraversableOnce may be lazy and unevaluated.

    Note: will not terminate for infinite-sized collections.

    returns

    a sequence containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  104. def toSet[B >: A]: immutable.Set[B]

    Converts this traversable or iterator to a set.

    Converts this traversable or iterator to a set.

    Note: will not terminate for infinite-sized collections.

    returns

    a set containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  105. def toStream: immutable.Stream[A]

    Converts this traversable or iterator to a stream.

    Converts this traversable or iterator to a stream.

    returns

    a stream containing all elements of this traversable or iterator.

    Definition Classes
    IteratorGenTraversableOnce
  106. def toString(): String

    Converts this iterator to a string.

    Converts this iterator to a string.

    returns

    "empty iterator" or "non-empty iterator", depending on whether or not the iterator is empty.

    Definition Classes
    Iterator → AnyRef → Any
    Note

    Reuse: The iterator remains valid for further use whatever result is returned.

  107. def toTraversable: Traversable[A]

    Converts this traversable or iterator to an unspecified Traversable.

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

    Note: will not terminate for infinite iterators.

    returns

    a Traversable containing all elements of this traversable or iterator.

    Definition Classes
    IteratorTraversableOnceGenTraversableOnce
  108. def toVector: Vector[A]

    Converts this traversable or iterator to a Vector.

    Converts this traversable or iterator to a Vector.

    Note: will not terminate for infinite-sized collections.

    returns

    a vector containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  109. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  110. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  111. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @throws( ... )
  112. def withFilter(p: (A) ⇒ Boolean): Iterator[A]

    Creates an iterator over all the elements of this iterator that satisfy the predicate p.

    Creates an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.

    Note: withFilter is the same as filter on iterators. It exists so that for-expressions with filters work over iterators.

    p

    the predicate used to test values.

    returns

    an iterator which produces those values of this iterator which satisfy the predicate p.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  113. def zip[B](that: Iterator[B]): Iterator[(A, B)]

    Creates an iterator formed from this iterator and another iterator by combining corresponding values in pairs.

    Creates an iterator formed from this iterator and another iterator by combining corresponding values in pairs. If one of the two iterators is longer than the other, its remaining elements are ignored.

    that

    The iterator providing the second half of each result pair

    returns

    a new iterator containing pairs consisting of corresponding elements of this iterator and that. The number of elements returned by the new iterator is the minimum of the number of elements returned by this iterator and that.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as a parameter, and use only the iterator that was returned. Using the old iterators is undefined, subject to change, and may result in changes to the new iterator as well.

  114. def zipAll[B](that: Iterator[B], thisElem: A, thatElem: B): Iterator[(A, B)]

    [use case] Creates an iterator formed from this iterator and another iterator by combining corresponding elements in pairs.

    [use case]

    Creates an iterator formed from this iterator and another iterator by combining corresponding elements in pairs. If one of the two iterators is shorter than the other, placeholder elements are used to extend the shorter iterator to the length of the longer.

    that

    iterator that may have a different length as the self iterator.

    thisElem

    element thisElem is used to fill up the resulting iterator if the self iterator is shorter than that

    thatElem

    element thatElem is used to fill up the resulting iterator if that is shorter than the self iterator

    returns

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

    Full Signature

    def zipAll[B, A1 >: A, B1 >: B](that: Iterator[B], thisElem: A1, thatElem: B1): Iterator[(A1, B1)]

  115. def zipWithIndex: Iterator[(A, Int)]

    Creates an iterator that pairs each element produced by this iterator with its index, counting from 0.

    Creates an iterator that pairs each element produced by this iterator with its index, counting from 0.

    returns

    a new iterator containing pairs consisting of corresponding elements of this iterator and their indices.

    Note

    Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.

  116. def [B](y: B): (Iterator[A], B)
    Implicit
    This member is added by an implicit conversion from Iterator[A] to ArrowAssoc[Iterator[A]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Shadowed Implicit Value Members

  1. def filter(p: (A) ⇒ Boolean): TraversableOnce[A]
    Implicit
    This member is added by an implicit conversion from Iterator[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:
    (iterator: MonadOps[A]).filter(p)
    Definition Classes
    MonadOps
  2. def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): TraversableOnce[B]
    Implicit
    This member is added by an implicit conversion from Iterator[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:
    (iterator: MonadOps[A]).flatMap(f)
    Definition Classes
    MonadOps
  3. def map[B](f: (A) ⇒ B): TraversableOnce[B]
    Implicit
    This member is added by an implicit conversion from Iterator[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:
    (iterator: MonadOps[A]).map(f)
    Definition Classes
    MonadOps
  4. def withFilter(p: (A) ⇒ Boolean): Iterator[A]
    Implicit
    This member is added by an implicit conversion from Iterator[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:
    (iterator: MonadOps[A]).withFilter(p)
    Definition Classes
    MonadOps

Inherited from TraversableOnce[A]

Inherited from GenTraversableOnce[A]

Inherited from AnyRef

Inherited from Any

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

Inherited by implicit conversion any2stringadd from Iterator[A] to any2stringadd[Iterator[A]]

Inherited by implicit conversion StringFormat from Iterator[A] to StringFormat[Iterator[A]]

Inherited by implicit conversion Ensuring from Iterator[A] to Ensuring[Iterator[A]]

Inherited by implicit conversion ArrowAssoc from Iterator[A] to ArrowAssoc[Iterator[A]]

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

Ungrouped