| /* |
| * Copyright 2003-2007 the original author or authors. |
| * |
| * 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 groovy.util.slurpersupport; |
| |
| import java.util.Iterator; |
| |
| /** |
| * @author John Wilson |
| * |
| */ |
| public abstract class NodeIterator implements Iterator { |
| private static final Object DELAYED_INIT = new Object(); |
| private final Iterator iter; |
| private Object nextNode; |
| |
| public NodeIterator(final Iterator iter) { |
| this.iter = iter; |
| this.nextNode = DELAYED_INIT; |
| } |
| |
| private void initNextNode(){ |
| if (nextNode==DELAYED_INIT) nextNode = getNextNode(iter); |
| } |
| |
| public boolean hasNext() { |
| initNextNode(); |
| return this.nextNode != null; |
| } |
| |
| public Object next() { |
| initNextNode(); |
| try { |
| return this.nextNode; |
| } finally { |
| this.nextNode = getNextNode(this.iter); |
| } |
| } |
| |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| protected abstract Object getNextNode(final Iterator iter); |
| } |