scala

trait Iterator

[source: scala/Iterator.scala]

trait Iterator[+A]
extends AnyRef
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:
BufferedIterator, CountedIterator, MutableIterator, Source, CharInputStreamIterator, SimpleTokenizer, XMLEventReader

Method Summary
def ++ [B >: A](that : => Iterator[B]) : Iterator[B]
Returns a new iterator that first yields the elements of this iterator followed by the elements provided by iterator that.
def /: [B](z : B)(op : (B, A) => B) : B
Similar to foldLeft but can be used as an operator with the order of iterator and zero arguments reversed. That is, z /: xs is the same as xs foldLeft z.
def :\ [B](z : B)(op : (A, B) => B) : B
An alias for foldRight. That is, xs :\ z is the same as xs foldRight z.
def addString (buf : StringBuilder, start : String, sep : String, end : String) : StringBuilder
Write all elements of this string into given string builder.
def append [B >: A](that : Iterator[B]) : Iterator[B]
Returns a new iterator that first yields the elements of this iterator followed by the elements provided by iterator that.
def buffered : BufferedIterator[A]
Returns a buffered iterator from this iterator.
def contains (elem : Any) : Boolean
Tests if the given value elem is a member of this iterator.
def copyToArray [B >: A](xs : Array[B], start : Int) : Unit
Fills the given array xs with the elements of this sequence starting at position start.
def copyToBuffer [B >: A](dest : Buffer[B]) : Unit
Copy all elements to a buffer
def counted : CountedIterator[A]
Returns a counted iterator from this iterator.
def drop (n : Int) : Iterator[A]
Removes the first n elements from this iterator.
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.
def duplicate : (Iterator[A], Iterator[A])
Creates two new iterators that both iterate over the same elements than this iterator (in the same order).
def exists (p : (A) => Boolean) : 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) => Boolean) : 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) => Boolean) : Option[A]
Find and return the first element of the iterable object satisfying a predicate, if any.
def flatMap [B](f : (A) => Iterator[B]) : 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 iterator 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 iterator together using the binary operator op, from right to left, and starting with the value z.
def forall (p : (A) => Boolean) : 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) => Unit) : Unit
Apply a function f to all elements of this iterable object.
abstract def hasNext : Boolean
Does this iterator provide another element?
def map [B](f : (A) => B) : Iterator[B]
Returns a new iterator that maps all elements of this iterator to new elements using function f.
def mkString (start : String, sep : String, end : String) : String
Returns a string representation of the elements in this iterator. The resulting string begins with the string start and is finished by the string end. Inside, the string representations of elements (w.r.t. the method toString()) are separated by the string sep.

Ex:
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"

def mkString (sep : String) : String
Returns a string representation of this iterable object. The string representations of elements (w.r.t. the method toString()) are separated by the string sep.
abstract def next : A
Returns the next element.
def readInto [B >: A](xs : Array[B], start : Int) : Unit
def readInto [B >: A](xs : Array[B]) : Unit
def readInto [B >: A](xs : Array[B], start : Int, sz : Int) : Unit
Fills the given array xs with the elements of this sequence starting at position start. Like copyToArray, but designed to accomodate IO stream operations.
def reduceLeft [B >: A](op : (B, B) => B) : B
Combines the elements of this iterator together using the binary operator op, from left to right
def reduceRight [B >: A](op : (B, B) => B) : B
Combines the elements of this iterator together using the binary operator op, from right to left
def take (n : Int) : Iterator[A]
Returns a new iterator that iterates only over the first n elements.
def takeWhile (p : (A) => Boolean) : Iterator[A]
Returns an iterator over the longest prefix of this iterator such that all elements of the result satisfy the predicate p. The order of the elements is preserved.
def toList : List[A]
Transform this iterator into a list of all elements.
override def toString : String
def zip [B](that : Iterator[B]) : Iterator[(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. If one of the two iterators is longer than the other, its remaining elements are ignored.
def zipWithIndex : Iterator[(A, Int)]
Return an iterator that pairs each element of this iterator with its index, counting from 0.
Methods inherited from AnyRef
getClass, hashCode, equals, clone, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized
Methods inherited from Any
==, !=, isInstanceOf, asInstanceOf
Class Summary
protected class PredicatedIterator (p : (A) => Boolean) extends Default[A]
protected class TakeWhileIterator (p : (A) => Boolean) extends PredicatedIterator