in scala
trait Iterator

abstract trait Iterator [A]
extends java.lang.Object
with scala.ScalaObject
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 discards it from the iterator.
Author:
Martin Odersky, Matthias Zenger
Version:
1.2, 15/03/2004
Direct Known Subclasses:
XMLEventReader, SimpleTokenizer, CharInputStreamIterator, Source, CountedIterator, BufferedIterator

Def Summary
def /: [B] (z: B)(f: (B, A) => B) : B
Similar to foldLeft but can be used as an operator with the order of list and zero arguments reversed. That is, z /: xs is the same as xs foldLeft z.
def :\ [B] (z: B)(f: (A, B) => B) : B
An alias for foldRight. That is, xs :\ z is the same as xs foldRight z.
def append [B >: A] (that: scala.Iterator[B]) : java.lang.Object with scala.Iterator[B]
Returns a new iterator that first yields the elements of this iterator followed by the elements provided by iterator that.
def buffered : scala.BufferedIterator[A]
Returns a buffered iterator from this iterator.
def contains (elem: scala.Any) : scala.Boolean
Tests if the given value elem is a member of this list.
def copyToArray [B >: A] (xs: scala.Array[B], start: scala.Int) : scala.Array[B]
Fills the given array xs with the elements of this sequence starting at position start.
def counted : java.lang.Object with scala.CountedIterator[A]
Returns a counted iterator from this iterator.
def drop (n: scala.Int) : scala.Iterator[A]
Removes the first n elements from this iterator.
def duplicate : scala.Tuple2[scala.Iterator[A], scala.Iterator[A]]
Creates two new iterators that both iterate over the same elements than this iterator (in the same order).
def exists (p: (A) => scala.Boolean) : scala.Boolean
Apply a predicate p to all elements of this iterable object and return true, iff there is at least one element for which p yields true.
def filter (p: (A) => scala.Boolean) : scala.Iterator[A]
Returns an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.
def find (p: (A) => scala.Boolean) : scala.Option[A]
Find and return the first element of the iterable object satisfying a predicate, if any.
def flatMap [B] (f: (A) => scala.Iterator[B]) : scala.Iterator[B]
Applies the given function f to each element of this iterator, then concatenates the results.
def foldLeft [B] (z: B)(op: (B, A) => B) : B
Combines the elements of this list together using the binary operator op, from left to right, and starting with the value z.
def foldRight [B] (z: B)(op: (A, B) => B) : B
Combines the elements of this list together using the binary operator op, from rigth to left, and starting with the value z.
def forall (p: (A) => scala.Boolean) : scala.Boolean
Apply a predicate p to all elements of this iterable object and return true iff the predicate yields true for all elements.
def foreach (f: (A) => scala.Unit) : scala.Unit
Apply a function f to all elements of this iterable object.
abstract def hasNext : scala.Boolean
Does this iterator provide another element?
def map [B] (f: (A) => B) : scala.Iterator[B]
Returns a new iterator that maps all elements of this iterator to new elements using function f.
abstract def next : A
Returns the next element.
def take (n: scala.Int) : java.lang.Object with scala.Iterator[A]
Returns a new iterator that iterates only over the first n elements.
def toList : scala.List[A]
Transform this iterator into a list of all elements.
def zip [B] (that: scala.Iterator[B]) : java.lang.Object with scala.Iterator[scala.Tuple2[A,B]]
Return an iterator formed from this iterator and the specified iterator that by associating each element of the former with the element at the same position in the latter.
def zipWithIndex : java.lang.Object with scala.Iterator[scala.Tuple2[A,scala.Int]]
Return an iterator that pairs each element of this iterator with its index, counting from 0.
Def Detail
def /: [B](z: B)(f: (B, A) => B): B
Similar to foldLeft but can be used as an operator with the order of list and zero arguments reversed. That is, z /: xs is the same as xs foldLeft z.
Parameters:
z - the left argument of the first application of f (evaluation occurs from left to right).
Parameters:
f - the applied function.
Returns:
the result value
See Also:
foldLeft.

def :\ [B](z: B)(f: (A, B) => B): B
An alias for foldRight. That is, xs :\ z is the same as xs foldRight z.
Parameters:
z - the right argument of the first application of f (evaluation occurs from right to left).
Parameters:
f - the applied function.
Returns:
the result value.
See Also:
foldRight.

def append [B >: A](that: scala.Iterator[B]): java.lang.Object with scala.Iterator[B]
Returns a new iterator that first yields the elements of this iterator followed by the elements provided by iterator that.

def buffered : scala.BufferedIterator[A]
Returns a buffered iterator from this iterator.

def contains (elem: scala.Any): scala.Boolean
Tests if the given value elem is a member of this list.
Parameters:
elem - element whose membership has to be tested.
Returns:
true iff there is an element of this list which is equal (w.r.t. ==) to elem.

def copyToArray [B >: A](xs: scala.Array[B], start: scala.Int): scala.Array[B]
Fills the given array xs with the elements of this sequence starting at position start.
Parameters:
xs - the array to fill.
Parameters:
start - the starting index.
Returns:
the given array xs filled with the elements of this iterator.
Precondition:
the array must be large enough to hold all elements.

def counted : java.lang.Object with scala.CountedIterator[A]
Returns a counted iterator from this iterator.

def drop (n: scala.Int): scala.Iterator[A]
Removes the first n elements from this iterator.

def duplicate : scala.Tuple2[scala.Iterator[A], scala.Iterator[A]]
Creates two new iterators that both iterate over the same elements than this iterator (in the same order).
Returns:
a pair of iterators

def exists (p: (A) => scala.Boolean): scala.Boolean
Apply a predicate p to all elements of this iterable object and return true, iff there is at least one element for which p yields true.
Parameters:
p - the predicate
Returns:
true iff the predicate yields true for at least one element.

def filter (p: (A) => scala.Boolean): scala.Iterator[A]
Returns an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.
Parameters:
p - the predicate used to filter the iterator.
Returns:
the elements of this iterator satisfying p.

def find (p: (A) => scala.Boolean): scala.Option[A]
Find and return the first element of the iterable object satisfying a predicate, if any.
Parameters:
p - the predicate
Returns:
the first element in the iterable object satisfying p, or None if none exists.

def flatMap [B](f: (A) => scala.Iterator[B]): scala.Iterator[B]
Applies the given function f to each element of this iterator, then concatenates the results.
Parameters:
f - the function to apply on each element.
Returns:
an iterator over f(a0), ... , f(an) if this iterator yields the elements a0, ..., an.

def foldLeft [B](z: B)(op: (B, A) => B): B
Combines the elements of this list together using the binary operator op, from left to right, and starting with the value z.
Returns:
op(... (op(op(z,a0),a1) ...), an) if the list is List(a0, a1, ..., an).

def foldRight [B](z: B)(op: (A, B) => B): B
Combines the elements of this list together using the binary operator op, from rigth to left, and starting with the value z.
Returns:
a0 op (... op (an op z)...) if the list is List(a0, a1, ..., an).

def forall (p: (A) => scala.Boolean): scala.Boolean
Apply a predicate p to all elements of this iterable object and return true iff the predicate yields true for all elements.
Parameters:
p - the predicate
Returns:
true iff the predicate yields true for all elements.

def foreach (f: (A) => scala.Unit): scala.Unit
Apply a function f to all elements of this iterable object.
Parameters:
f - a function that is applied to every element.

abstract def hasNext : scala.Boolean
Does this iterator provide another element?

def map [B](f: (A) => B): scala.Iterator[B]
Returns a new iterator that maps all elements of this iterator to new elements using function f.

abstract def next : A
Returns the next element.

def take (n: scala.Int): java.lang.Object with scala.Iterator[A]
Returns a new iterator that iterates only over the first n elements.
Parameters:
n - the first n elements of the iterator
Returns:
the new iterator

def toList : scala.List[A]
Transform this iterator into a list of all elements.
Returns:
a list which enumerates all elements of this iterator.

def zip [B](that: scala.Iterator[B]): java.lang.Object with scala.Iterator[scala.Tuple2[A,B]]
Return an iterator formed from this iterator and the specified iterator that by associating each element of the former with the element at the same position in the latter.
Parameters:
that - list that must have the same number of elements as this iterator.
Returns:
an iterator yielding (a0,b0), ..., (an,bn) where ai are the elements from this iterator and bi are the elements from iterator that.

def zipWithIndex : java.lang.Object with scala.Iterator[scala.Tuple2[A,scala.Int]]
Return an iterator that pairs each element of this iterator with its index, counting from 0.
Parameters:
start - the index of the first element.
Returns:
an iterator yielding (a0,0), (a0,1)... where ai are the elements from this iterator.