/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.jena.atlas.iterator;

import java.util.Iterator ;
import java.util.NoSuchElementException ;

public class SingletonIterator<T> implements Iterator<T>
{
    private T thing = null ;
    private boolean yielded = false ;
    
    public static <T> SingletonIterator<T> create(T thing) { return new SingletonIterator<>(thing) ; }
    
    public SingletonIterator(T thing) { this.thing = thing ; }
    
    @Override
    public boolean hasNext()
    {
        return ! yielded ;
    }

    @Override
    public T next()
    {
        if ( yielded )
            throw new NoSuchElementException("SingletonIterator.next") ;
        yielded = true ;
        return thing ;
    }

    @Override
    public void remove()
    { throw new NoSuchElementException("SingletonIterator.remove") ;}
}