1 /* 2 * Copyright (c) 2014, 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.phases; 24 25 import org.graalvm.compiler.debug.Debug; 26 27 /** 28 * A name whose {@link String} value is computed only when it is needed. This is useful in 29 * combination with debugging facilities such as {@link Debug#scope(Object)} where the 30 * {@link String} value of a name is only needed if debugging is enabled. 31 */ 32 public abstract class LazyName implements CharSequence { 33 34 private String value; 35 36 @Override 37 public int length() { 38 return toString().length(); 39 } 40 41 @Override 42 public char charAt(int index) { 43 return toString().charAt(index); 44 } 45 46 @Override 47 public CharSequence subSequence(int start, int end) { 48 return toString().subSequence(start, end); 49 } 50 51 @Override 52 public final String toString() { 53 if (value == null) { 54 value = createString(); 55 } 56 return value; 57 } 58 59 /** 60 * Creates the {@link String} value of this name. 61 */ 62 protected abstract String createString(); 63 }