/*
 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package com.sun.tools.sjavac.options;

import java.util.Iterator;

 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class ArgumentIterator implements Iterator<String> {

    
The underlying argument iterator /** The underlying argument iterator */
    private Iterator<String> iter;

    
Extra state used to implement peek and current /** Extra state used to implement peek and current */
    private String current;
    private String buffered;

    public ArgumentIterator(Iterable<String> iter) {
        this.iter = iter.iterator();
    }

    @Override
    public boolean hasNext() {
        return buffered != null || iter.hasNext();
    }

    @Override
    public String next() {
        fillBuffer();
        current = buffered;
        buffered = null;
        return current;
    }

    
Returns:
the last element returned by next() (or null if next has never been invoked on this iterator)./**
     * @return the last element returned by next() (or {@code null} if next has
     * never been invoked on this iterator).
     */
    public String current() {
        return current;
    }

    
Can't remove current element, since we may have buffered it. /** Can't remove current element, since we may have buffered it. */
    @Override
    public void remove() {
        throw new UnsupportedOperationException();
    }

    
Returns:
Returns the next element without advancing the iterator/**
     * @return Returns the next element without advancing the iterator
     */
    public String peek() {
        fillBuffer();
        return buffered;
    }

    private void fillBuffer() {
        if (buffered == null && iter.hasNext())
            buffered = iter.next();
    }

}