1 /* 2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.graph.iterators; 24 25 import java.util.Iterator; 26 import java.util.NoSuchElementException; 27 28 import org.graalvm.compiler.graph.Node; 29 30 public abstract class NodeIterator<T extends Node> implements Iterator<T> { 31 32 protected T current; 33 34 protected abstract void forward(); 35 36 @Override 37 public boolean hasNext() { 38 forward(); 39 return current != null; 40 } 41 42 @Override 43 public T next() { 44 forward(); 45 T ret = current; 46 if (current == null) { 47 throw new NoSuchElementException(); 48 } 49 current = null; 50 return ret; 51 } 52 53 @Override 54 public void remove() { 55 throw new UnsupportedOperationException(); 56 } 57 }