Class AbstractSequentialIterator<T>

java.lang.Object

com.google.common.collect.UnmodifiableIterator<T>

com.google.common.collect.AbstractSequentialIterator<T>

All Implemented Interfaces:

Iterator<T>

@GwtCompatible
public abstract class AbstractSequentialIterator<T>
extends UnmodifiableIterator<T>

This class provides a skeletal implementation of the Iterator interface for sequences whose next element can always be derived from the previous element. Null elements are not supported, nor is the UnmodifiableIterator.remove() method.

Example:

Iterator<Integer> powersOfTwo =
    new AbstractSequentialIterator<Integer>(1) {
      protected Integer computeNext(Integer previous) {
        return (previous == 1 << 30) ? null : previous * 2;
      }
    };

Since:

12.0 (in Guava as AbstractLinkedIterator since 8.0)

Author:

Chris Povirk

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractSequentialIterator(@Nullable T firstOrNull)	Creates a new iterator with the given first element, or, if firstOrNull is null, creates a new empty iterator.

Method Summary

Modifier and Type	Method	Description
protected abstract @Nullable T	computeNext(T previous)	Returns the element that follows previous, or returns null if no elements remain.
final boolean	hasNext()
final T	next()

Methods inherited from class com.google.common.collect.UnmodifiableIterator

remove

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 Details

AbstractSequentialIterator

protected AbstractSequentialIterator(@Nullable T firstOrNull)

Creates a new iterator with the given first element, or, if firstOrNull is null, creates a new empty iterator.

Method Details

computeNext

protected abstract @Nullable T computeNext(T previous)

Returns the element that follows previous, or returns null if no elements remain. This method is invoked during each call to next() in order to compute the result of a future call to next().

hasNext

public final boolean hasNext()

next

public final T next()