plume

Class IterableIterator<T>

java.lang.Object

plume.IterableIterator<T>

Type Parameters:

T - the element type of the IterableIterator

All Implemented Interfaces:

java.lang.Iterable<T>

Deprecated.

use UtilMDE.iteratorToIterable(java.util.Iterator<T>)

@Deprecated
public class IterableIterator<T>
extends java.lang.Object
implements java.lang.Iterable<T>

In Java, Iterators are not Iterable, so they cannot be used in new-style for loops. This wrapper works around that by making an Iterator that is also Iterable — that is, it implements the iterator() method.

As an example, suppose that you have a class with a method:

  public Iterator<String> backwardIterator() { ... }

Because this method is not named iterator(), which probably has a different meaning than backwardIterator(), it is not possible to use Java's new-style for loop (also known as the foreach loop). Instead, a client must do:

 for (Iterator<String> itor = myObject.backwardIterator(); itor.hasNext(); ) {
   String element = itor.next();
   ...
 }
 

The IterableIterator class lets you write this more compactly:

  for (String element : new IterableIterator(myObject.backwardIterator())) {
     ...
  }
 

Another advantage of this syntax is that it explicitly indicates that the Iterator is not being modified in the loop body, which is a common reason for not using the new-style for loop.

It's often better to use a real Iterable (e.g., a collections class) rather than an Iterator. But in some cases the overhead is undesirable, or there are multiple ways to iterate so it doesn't make sense to reserve the iterator() method for just one of them, or it is desirable to use an Iterator because it throws a ConcurrentModificationException in case of errors, or for other reasons. This class can be appropriate in such circumstances.

Warning: Some clients might expect that calling Iterable.iterator() twice on a given Iterable results in two objects that can both iterate over the whole sequence, and that won't interfere with one another. That is not the case for this Iterable.

Constructor Summary

Constructors

Constructor and Description
IterableIterator(java.util.Iterator<T> iter) Deprecated. Create an IterableIterator.

Method Summary

Modifier and Type	Method and Description
java.util.Iterator<T>	iterator() Deprecated. Return the iterator.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

IterableIterator

public IterableIterator(java.util.Iterator<T> iter)

Deprecated.

Create an IterableIterator.

Parameters:

iter - the iterator to wrap

Method Detail

iterator

public java.util.Iterator<T> iterator()

Deprecated.

Return the iterator.

Specified by:

iterator in interface java.lang.Iterable<T>

Returns:

the iterator