1 /*
   2  * Copyright (c) 2005, 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.  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 section 14.11
  43  *
  44  * @author Peter von der Ah&eacute;
  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 lables, returns the first label.
  53      * @return the expression for the case, or null
  54      */
  55     ExpressionTree getExpression();
  56 
  57     /**
  58      * Returns the labels for this case.
  59      * For default case, returns an empty list.
  60      * 
  61      * @apiNote
  62      * This method is modeling a case with multiple labels,
  63      * which is part of a preview feature and may be removed
  64      * if the preview feature is removed.
  65      * 
  66      * @return labels for this case
  67      * @since 12
  68      */
  69     @Deprecated(forRemoval=true, since="12")
  70     List<? extends ExpressionTree> getExpressions();
  71 
  72     /**
  73      * Returns the statements labeled by the case.
  74      * If this is a case in switch expression in for
  75      * {@code case expression -> value}, returns a list
  76      * containing a single synthetic BreakTree with
  77      * the given value.
  78      * @return the statements labeled by the case or null
  79      */
  80     List<? extends StatementTree> getStatements();
  81 
  82     /**
  83      * For case with kind {@linkplain CaseKind#RULE},
  84      * return the statement or expression after the arrow.
  85      * Returns {@code null} for case with kind
  86      * {@linkplain CaseKind#STATEMENT}.
  87      * 
  88      * @apiNote
  89      * This method is modeling a rule case,
  90      * which is part of a preview feature and may be removed
  91      * if the preview feature is removed.
  92      * 
  93      * @return case value or null
  94      * @since 12
  95      */
  96     @Deprecated(forRemoval=true, since="12")
  97     public default Tree getBody() {
  98         return null;
  99     }
 100 
 101     /**
 102      * Returns the kind of this case.
 103      * 
 104      * @apiNote
 105      * This method is used to model a rule case,
 106      * which is part of a preview feature and may be removed
 107      * if the preview feature is removed.
 108      * 
 109      * @return the kind of this case
 110      * @since 12
 111      */
 112     @Deprecated(forRemoval=true, since="12")
 113     public default CaseKind getCaseKind() {
 114         return CaseKind.STATEMENT;
 115     }
 116 
 117     /**
 118      * The syntatic form of this case:
 119      * <ul>
 120      *     <li>STATEMENT: {@code case <expression>: <statements>}</li>
 121      *     <li>RULE: {@code case <expression> -> <expression>/<statement>}</li>
 122      * </ul>
 123      *
 124      * @apiNote
 125      * This enum is used to model a rule case,
 126      * which is part of a preview feature and may be removed
 127      * if the preview feature is removed.
 128      * 
 129      * @since 12
 130      */
 131     @Deprecated(forRemoval=true, since="12")
 132     public enum CaseKind {
 133         /**
 134          * Case is in the form: {@code case <expression>: <statements>}.
 135          */
 136         STATEMENT,
 137         /**
 138          * Case is in the form: {@code case <expression> -> <expression>}.
 139          */
 140         RULE;
 141     }
 142 }