001 /* 002 * Copyright 2005 John G. Wilson 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 */ 017 018 package groovy.util.slurpersupport; 019 020 import java.util.Iterator; 021 022 /** 023 * @author John Wilson 024 * 025 */ 026 027 public abstract class NodeIterator implements Iterator { 028 private final Iterator iter; 029 private Object nextNode; 030 031 public NodeIterator(final Iterator iter) { 032 this.iter = iter; 033 this.nextNode = getNextNode(iter); 034 } 035 036 public boolean hasNext() { 037 return this.nextNode != null; 038 } 039 040 public Object next() { 041 try { 042 return this.nextNode; 043 } finally { 044 this.nextNode = getNextNode(this.iter); 045 } 046 } 047 048 public void remove() { 049 throw new UnsupportedOperationException(); 050 } 051 052 protected abstract Object getNextNode(final Iterator iter); 053 }