com.github.robtimus.util.iterator

Class LookaheadIterator<E>

java.lang.Object

com.github.robtimus.util.iterator.LookaheadIterator<E>

Type Parameters:

E - The element type.

All Implemented Interfaces:

Iterator<E>

public abstract class LookaheadIterator<E>
extends Object
implements Iterator<E>

A base class for Iterator implementations that need to calculate the next value in order to let Iterator.hasNext() return whether or not there is a next value.

Sub classes should implement findNext(Consumer) to find the next element. Furthermore, sub classes should support the Iterator.remove() operation should also override remove() .

API Note:

Removing elements has not been implemented. It is up to sub classes to implement it if removing elements needs to be supported.

Author:

Rob Spoor

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LookaheadIterator() Creates a new lookahead iterator.

Method Summary

Modifier and Type	Method and Description
protected abstract void	findNext(Consumer<E> next) Tries to finds the next element.
boolean	hasNext()
E	next()
void	remove()
protected void	remove(E element) Removes the latest element returned by Iterator.next().

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

LookaheadIterator

protected LookaheadIterator()

Creates a new lookahead iterator.

Method Detail

findNext

protected abstract void findNext(Consumer<E> next)

Tries to finds the next element. If the next element could be found, the provided consumer should be called with the next element. Otherwise, the method can end without calling the consumer.

Parameters:

next - The consumer to call with the next element.

hasNext

public final boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

next

public final E next()

Specified by:

next in interface Iterator<E>

remove

protected void remove(E element)

Removes the latest element returned by Iterator.next().

Implementation Requirements:

The default implementation always throws an UnsupportedOperationException.

Parameters:

element - The element to remove.

remove

public final void remove()

Specified by:

remove in interface Iterator<E>