1 /* 2 * Copyright (c) 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 javax.lang.model.util; 27 28 import javax.lang.model.element.*; 29 import javax.annotation.processing.SupportedSourceVersion; 30 import static javax.lang.model.SourceVersion.*; 31 import javax.lang.model.SourceVersion; 32 33 /** 34 * {@preview Associated with records, a preview feature of the Java language. 35 * 36 * This class is associated with <i>records</i>, a preview 37 * feature of the Java language. Preview features 38 * may be removed in a future release, or upgraded to permanent 39 * features of the Java language.} 40 * 41 * A visitor of program elements based on their {@linkplain 42 * ElementKind kind} with default behavior appropriate for the {@link 43 * SourceVersion#RELEASE_14 RELEASE_14} source version. 44 * 45 * For {@linkplain 46 * Element elements} <code><i>Xyz</i></code> that may have more than one 47 * kind, the <code>visit<i>Xyz</i></code> methods in this class delegate 48 * to the <code>visit<i>Xyz</i>As<i>Kind</i></code> method corresponding to the 49 * first argument's kind. The <code>visit<i>Xyz</i>As<i>Kind</i></code> methods 50 * call {@link #defaultAction defaultAction}, passing their arguments 51 * to {@code defaultAction}'s corresponding parameters. 52 * 53 * <p> Methods in this class may be overridden subject to their 54 * general contract. Note that annotating methods in concrete 55 * subclasses with {@link java.lang.Override @Override} will help 56 * ensure that methods are overridden as intended. 57 * 58 * <p> <b>WARNING:</b> The {@code ElementVisitor} interface 59 * implemented by this class may have methods added to it or the 60 * {@code ElementKind} {@code enum} used in this case may have 61 * constants added to it in the future to accommodate new, currently 62 * unknown, language structures added to future versions of the 63 * Java™ programming language. Therefore, methods whose names 64 * begin with {@code "visit"} may be added to this class in the 65 * future; to avoid incompatibilities, classes which extend this class 66 * should not declare any instance methods with names beginning with 67 * {@code "visit"}. 68 * 69 * <p>When such a new visit method is added, the default 70 * implementation in this class will be to call the {@link 71 * #visitUnknown visitUnknown} method. A new abstract element kind 72 * visitor class will also be introduced to correspond to the new 73 * language level; this visitor will have different default behavior 74 * for the visit method in question. When the new visitor is 75 * introduced, all or portions of this visitor may be deprecated. 76 * 77 * @param <R> the return type of this visitor's methods. Use {@link 78 * Void} for visitors that do not need to return results. 79 * @param <P> the type of the additional parameter to this visitor's 80 * methods. Use {@code Void} for visitors that do not need an 81 * additional parameter. 82 * 83 * @see ElementKindVisitor6 84 * @see ElementKindVisitor7 85 * @see ElementKindVisitor8 86 * @see ElementKindVisitor9 87 * @since 14 88 */ 89 @jdk.internal.PreviewFeature(feature=jdk.internal.PreviewFeature.Feature.RECORDS, 90 essentialAPI=false) 91 @SupportedSourceVersion(RELEASE_14) 92 public class ElementKindVisitor14<R, P> extends ElementKindVisitor9<R, P> { 93 /** 94 * Constructor for concrete subclasses; uses {@code null} for the 95 * default value. 96 */ 97 protected ElementKindVisitor14() { 98 super(null); 99 } 100 101 /** 102 * Constructor for concrete subclasses; uses the argument for the 103 * default value. 104 * 105 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE} 106 */ 107 protected ElementKindVisitor14(R defaultValue) { 108 super(defaultValue); 109 } 110 111 /** 112 * {@inheritDoc} 113 * 114 * @implSpec This implementation calls {@code defaultAction}. 115 * 116 * @param e the element to visit 117 * @param p a visitor-specified parameter 118 * @return the result of {@code defaultAction} 119 */ 120 @SuppressWarnings("preview") 121 @Override 122 public R visitRecordComponent(RecordComponentElement e, P p) { 123 return defaultAction(e, p); 124 } 125 126 /** 127 * {@inheritDoc} 128 * 129 * @implSpec This implementation calls {@code defaultAction}. 130 *. 131 * @param e the element to visit 132 * @param p a visitor-specified parameter 133 * @return the result of {@code defaultAction} 134 */ 135 @Override 136 public R visitTypeAsRecord(TypeElement e, P p) { 137 return defaultAction(e, p); 138 } 139 }