001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.collections.primitives;
018
019/**
020 * An iterator over <code>boolean</code> values.
021 *
022 * @see org.apache.commons.collections.primitives.adapters.BooleanIteratorIterator
023 * @see org.apache.commons.collections.primitives.adapters.IteratorBooleanIterator
024 *
025 * @since Commons Primitives 1.1
026 * @version $Revision: 480460 $ $Date: 2006-11-29 03:14:21 -0500 (Wed, 29 Nov 2006) $
027 */
028public interface BooleanIterator {
029    /** 
030     * Returns <code>true</code> iff I have more elements.  (In other words,
031     * returns <code>true</code> iff a subsequent call to {@link #next next}
032     * will return an element rather than throwing an exception.)
033     * 
034     * @return <code>true</code> iff I have more elements
035     */
036    boolean hasNext();
037    
038    /** 
039     * Returns the next element in me.
040     * 
041     * @return the next element in me
042     * @throws java.util.NoSuchElementException if there is no next element
043     */          
044    boolean next();
045    
046    /** 
047     * Removes from my underlying collection the last element {@link #next
048     * returned} by me (optional operation).
049     * 
050     * @throws UnsupportedOperationException if this operation is not supported
051     * @throws IllegalStateException if {@link #next} has not yet been called,
052     *         or {@link #remove} has already been called since the last call
053     *         to {@link #next}.
054     */          
055    void remove();
056}