jdk8-mips64-public/langtools: src/share/classes/javax/lang/model/util/ElementScanner6.java@2eb010b6cb22 (annotated)

src/share/classes/javax/lang/model/util/ElementScanner6.java@2eb010b6cb22 (annotated)

src/share/classes/javax/lang/model/util/ElementScanner6.java

Thu, 31 Aug 2017 15:17:03 +0800

author: aoqi
date: Thu, 31 Aug 2017 15:17:03 +0800
changeset 2525: 2eb010b6cb22
parent 1823: b7a10bc02e7a
parent 0: 959103a6100f
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package javax.lang.model.util;
 import javax.lang.model.element.*;
 import javax.annotation.processing.SupportedSourceVersion;
 import javax.lang.model.SourceVersion;
 import static javax.lang.model.SourceVersion.*;
 /**
  * A scanning visitor of program elements with default behavior
  * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
  * source version.  The <tt>visit<i>XYZ</i></tt> methods in this
  * class scan their component elements by calling {@code scan} on
  * their {@linkplain Element#getEnclosedElements enclosed elements},
  * {@linkplain ExecutableElement#getParameters parameters}, etc., as
  * indicated in the individual method specifications.  A subclass can
  * control the order elements are visited by overriding the
  * <tt>visit<i>XYZ</i></tt> methods.  Note that clients of a scanner
  * may get the desired behavior be invoking {@code v.scan(e, p)} rather
  * than {@code v.visit(e, p)} on the root objects of interest.
  *
  * <p>When a subclass overrides a <tt>visit<i>XYZ</i></tt> method, the
  * new method can cause the enclosed elements to be scanned in the
  * default way by calling <tt>super.visit<i>XYZ</i></tt>.  In this
  * fashion, the concrete visitor can control the ordering of traversal
  * over the component elements with respect to the additional
  * processing; for example, consistently calling
  * <tt>super.visit<i>XYZ</i></tt> at the start of the overridden
  * methods will yield a preorder traversal, etc.  If the component
  * elements should be traversed in some other order, instead of
  * calling <tt>super.visit<i>XYZ</i></tt>, an overriding visit method
  * should call {@code scan} with the elements in the desired order.
  *
  * <p> Methods in this class may be overridden subject to their
  * general contract.  Note that annotating methods in concrete
  * subclasses with {@link java.lang.Override @Override} will help
  * ensure that methods are overridden as intended.
  *
  * <p> <b>WARNING:</b> The {@code ElementVisitor} interface
  * implemented by this class may have methods added to it in the
  * future to accommodate new, currently unknown, language structures
  * added to future versions of the Java&trade; programming language.
  * Therefore, methods whose names begin with {@code "visit"} may be
  * added to this class in the future; to avoid incompatibilities,
  * classes which extend this class should not declare any instance
  * methods with names beginning with {@code "visit"}.
  *
  * <p>When such a new visit method is added, the default
  * implementation in this class will be to call the {@link
  * #visitUnknown visitUnknown} method.  A new element scanner visitor
  * class will also be introduced to correspond to the new language
  * level; this visitor will have different default behavior for the
  * visit method in question.  When the new visitor is introduced, all
  * or portions of this visitor may be deprecated.
  *
  * @param <R> the return type of this visitor's methods.  Use {@link
  *            Void} for visitors that do not need to return results.
  * @param <P> the type of the additional parameter to this visitor's
  *            methods.  Use {@code Void} for visitors that do not need an
  *            additional parameter.
  *
  * @author Joseph D. Darcy
  * @author Scott Seligman
  * @author Peter von der Ah&eacute;
  *
  * @see ElementScanner7
  * @see ElementScanner8
  * @since 1.6
  */
 @SupportedSourceVersion(RELEASE_6)
 public class ElementScanner6<R, P> extends AbstractElementVisitor6<R, P> {
     /**
      * The specified default value.
      */
     protected final R DEFAULT_VALUE;
     /**
      * Constructor for concrete subclasses; uses {@code null} for the
      * default value.
      */
     protected ElementScanner6(){
         DEFAULT_VALUE = null;
     }
     /**
      * Constructor for concrete subclasses; uses the argument for the
      * default value.
      *
      * @param defaultValue the default value
      */
     protected ElementScanner6(R defaultValue){
         DEFAULT_VALUE = defaultValue;
     }
     /**
      * Iterates over the given elements and calls {@link
      * #scan(Element, Object) scan(Element, P)} on each one.  Returns
      * the result of the last call to {@code scan} or {@code
      * DEFAULT_VALUE} for an empty iterable.
      *
      * @param iterable the elements to scan
      * @param  p additional parameter
      * @return the scan of the last element or {@code DEFAULT_VALUE} if no elements
      */
     public final R scan(Iterable<? extends Element> iterable, P p) {
         R result = DEFAULT_VALUE;
         for(Element e : iterable)
             result = scan(e, p);
         return result;
     }
     /**
      * Processes an element by calling {@code e.accept(this, p)};
      * this method may be overridden by subclasses.
      *
      * @param e the element to scan
      * @param p a scanner-specified parameter
      * @return the result of visiting {@code e}.
      */
     public R scan(Element e, P p) {
         return e.accept(this, p);
     }
     /**
      * Convenience method equivalent to {@code v.scan(e, null)}.
      *
      * @param e the element to scan
      * @return the result of scanning {@code e}.
      */
     public final R scan(Element e) {
         return scan(e, null);
     }
     /**
      * {@inheritDoc} This implementation scans the enclosed elements.
      *
      * @param e  {@inheritDoc}
      * @param p  {@inheritDoc}
      * @return the result of scanning
      */
     public R visitPackage(PackageElement e, P p) {
         return scan(e.getEnclosedElements(), p);
     }
     /**
      * {@inheritDoc} This implementation scans the enclosed elements.
      *
      * @param e  {@inheritDoc}
      * @param p  {@inheritDoc}
      * @return the result of scanning
      */
     public R visitType(TypeElement e, P p) {
         return scan(e.getEnclosedElements(), p);
     }
     /**
      * {@inheritDoc}
      *
      * This implementation scans the enclosed elements, unless the
      * element is a {@code RESOURCE_VARIABLE} in which case {@code
      * visitUnknown} is called.
      *
      * @param e  {@inheritDoc}
      * @param p  {@inheritDoc}
      * @return the result of scanning
      */
     public R visitVariable(VariableElement e, P p) {
         if (e.getKind() != ElementKind.RESOURCE_VARIABLE)
             return scan(e.getEnclosedElements(), p);
         else
             return visitUnknown(e, p);
     }
     /**
      * {@inheritDoc} This implementation scans the parameters.
      *
      * @param e  {@inheritDoc}
      * @param p  {@inheritDoc}
      * @return the result of scanning
      */
     public R visitExecutable(ExecutableElement e, P p) {
         return scan(e.getParameters(), p);
     }
     /**
      * {@inheritDoc} This implementation scans the enclosed elements.
      *
      * @param e  {@inheritDoc}
      * @param p  {@inheritDoc}
      * @return the result of scanning
      */
     public R visitTypeParameter(TypeParameterElement e, P p) {
         return scan(e.getEnclosedElements(), p);
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/javax/lang/model/util/ElementScanner6.java@2eb010b6cb22 (annotated)

src/share/classes/javax/lang/model/util/ElementScanner6.java