1 /* 2 * Copyright (c) 2005, 2019, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.source.tree; 27 28 import java.util.List; 29 30 /** 31 * A tree node for a {@code case} in a {@code switch} statement or expression. 32 * 33 * For example: 34 * <pre> 35 * case <em>expression</em> : 36 * <em>statements</em> 37 * 38 * default : 39 * <em>statements</em> 40 * </pre> 41 * 42 * @jls 14.11 The switch Statement 43 * 44 * @author Peter von der Ahé 45 * @author Jonathan Gibbons 46 * @since 1.6 47 */ 48 public interface CaseTree extends Tree { 49 /** 50 * Returns the expression for the case, or 51 * {@code null} if this is the default case. 52 * If this case has multiple labels, returns the first label. 53 * @return the expression for the case, or null 54 * @deprecated Please use {@link #getExpressions()}. 55 */ 56 @Deprecated 57 ExpressionTree getExpression(); 58 59 /** 60 * Returns the labels for this case. 61 * For default case, returns an empty list. 62 * 63 * @return labels for this case 64 * @since 12 65 */ 66 List<? extends ExpressionTree> getExpressions(); 67 68 /** 69 * For case with kind {@linkplain CaseKind#STATEMENT}, 70 * returns the statements labeled by the case. 71 * Returns {@code null} for case with kind 72 * {@linkplain CaseKind#RULE}. 73 * @return the statements labeled by the case or null 74 */ 75 List<? extends StatementTree> getStatements(); 76 77 /** 78 * For case with kind {@linkplain CaseKind#RULE}, 79 * returns the statement or expression after the arrow. 80 * Returns {@code null} for case with kind 81 * {@linkplain CaseKind#STATEMENT}. 82 * 83 * @return case value or null 84 * @since 12 85 */ 86 public default Tree getBody() { 87 return null; 88 } 89 90 /** 91 * Returns the kind of this case. 92 * 93 * @return the kind of this case 94 * @since 12 95 */ 96 public default CaseKind getCaseKind() { 97 return CaseKind.STATEMENT; 98 } 99 100 /** 101 * The syntatic form of this case: 102 * <ul> 103 * <li>STATEMENT: {@code case <expression>: <statements>}</li> 104 * <li>RULE: {@code case <expression> -> <expression>/<statement>}</li> 105 * </ul> 106 * 107 * @since 12 108 */ 109 public enum CaseKind { 110 /** 111 * Case is in the form: {@code case <expression>: <statements>}. 112 */ 113 STATEMENT, 114 /** 115 * Case is in the form: {@code case <expression> -> <expression>}. 116 */ 117 RULE; 118 } 119 }