/*******************************************************************************
* Copyright 2014 Analog Devices, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************/
package com.analog.lyric.collect;
import org.eclipse.jdt.annotation.Nullable;
import com.google.common.collect.UnmodifiableIterator;
/**
* An iterator that returns a single value.
* <p>
* Unlike Guava's {@link com.google.common.collect.Iterators#singletonIterator}
* this implementation will return null instead of throwing exception if
* {@link #next()} is called at end of iteration.
* <p>
* @since 0.08
* @author Christopher Barber
*/
public class SingleIterator<E> extends UnmodifiableIterator<E>
{
/*-------
* State
*/
private @Nullable E _value;
/*--------------
* Construction
*/
public SingleIterator(E value)
{
_value = value;
}
/*------------------
* Iterator methods
*/
@Override
public boolean hasNext()
{
return _value != null;
}
/**
* Returns the next element in the iterator or null.
*/
@Override
public @Nullable E next()
{
final E val = _value;
_value = null;
return val;
}
}