com.sun.source.util.DocTreeScanner Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jdk.compiler Show documentation
Show all versions of jdk.compiler Show documentation
Maven repackaging of OpenJDK's jdk.compiler module
The newest version!
/*
* Copyright (c) 2011, 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 com.sun.source.util;
import com.sun.source.doctree.*;
/**
* A TreeVisitor that visits all the child tree nodes.
* To visit nodes of a particular type, just override the
* corresponding visitXYZ method.
* Inside your method, call super.visitXYZ to visit descendant
* nodes.
*
* The default implementation of the visitXYZ methods will determine
* a result as follows:
*
* - If the node being visited has no children, the result will be null.
*
- If the node being visited has one child, the result will be the
* result of calling {@code scan} on that child. The child may be a simple node
* or itself a list of nodes.
*
- If the node being visited has more than one child, the result will
* be determined by calling {@code scan} each child in turn, and then combining the
* result of each scan after the first with the cumulative result
* so far, as determined by the {@link #reduce} method. Each child may be either
* a simple node of a list of nodes. The default behavior of the {@code reduce}
* method is such that the result of the visitXYZ method will be the result of
* the last child scanned.
*
*
* Here is an example to count the number of erroneous nodes in a tree:
*
* class CountErrors extends DocTreeScanner<Integer,Void> {
* {@literal @}Override
* public Integer visitErroneous(ErroneousTree node, Void p) {
* return 1;
* }
* {@literal @}Override
* public Integer reduce(Integer r1, Integer r2) {
* return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
* }
* }
*
*
* @since 1.8
*/
@jdk.Exported
public class DocTreeScanner implements DocTreeVisitor {
/**
* Scan a single node.
*/
public R scan(DocTree node, P p) {
return (node == null) ? null : node.accept(this, p);
}
private R scanAndReduce(DocTree node, P p, R r) {
return reduce(scan(node, p), r);
}
/**
* Scan a list of nodes.
*/
public R scan(Iterable nodes, P p) {
R r = null;
if (nodes != null) {
boolean first = true;
for (DocTree node : nodes) {
r = (first ? scan(node, p) : scanAndReduce(node, p, r));
first = false;
}
}
return r;
}
private R scanAndReduce(Iterable nodes, P p, R r) {
return reduce(scan(nodes, p), r);
}
/**
* Reduces two results into a combined result.
* The default implementation is to return the first parameter.
* The general contract of the method is that it may take any action whatsoever.
*/
public R reduce(R r1, R r2) {
return r1;
}
/* ***************************************************************************
* Visitor methods
****************************************************************************/
@Override
public R visitAttribute(AttributeTree node, P p) {
return null;
}
@Override
public R visitAuthor(AuthorTree node, P p) {
return scan(node.getName(), p);
}
@Override
public R visitComment(CommentTree node, P p) {
return null;
}
@Override
public R visitDeprecated(DeprecatedTree node, P p) {
return scan(node.getBody(), p);
}
@Override
public R visitDocComment(DocCommentTree node, P p) {
R r = scan(node.getFirstSentence(), p);
r = scanAndReduce(node.getBody(), p, r);
r = scanAndReduce(node.getBlockTags(), p, r);
return r;
}
@Override
public R visitDocRoot(DocRootTree node, P p) {
return null;
}
@Override
public R visitEndElement(EndElementTree node, P p) {
return null;
}
@Override
public R visitEntity(EntityTree node, P p) {
return null;
}
@Override
public R visitErroneous(ErroneousTree node, P p) {
return null;
}
@Override
public R visitIdentifier(IdentifierTree node, P p) {
return null;
}
@Override
public R visitInheritDoc(InheritDocTree node, P p) {
return null;
}
@Override
public R visitLink(LinkTree node, P p) {
R r = scan(node.getReference(), p);
r = scanAndReduce(node.getLabel(), p, r);
return r;
}
@Override
public R visitLiteral(LiteralTree node, P p) {
return null;
}
@Override
public R visitParam(ParamTree node, P p) {
R r = scan(node.getName(), p);
r = scanAndReduce(node.getDescription(), p, r);
return r;
}
@Override
public R visitReference(ReferenceTree node, P p) {
return null;
}
@Override
public R visitReturn(ReturnTree node, P p) {
return scan(node.getDescription(), p);
}
@Override
public R visitSee(SeeTree node, P p) {
return scan(node.getReference(), p);
}
@Override
public R visitSerial(SerialTree node, P p) {
return scan(node.getDescription(), p);
}
@Override
public R visitSerialData(SerialDataTree node, P p) {
return scan(node.getDescription(), p);
}
@Override
public R visitSerialField(SerialFieldTree node, P p) {
R r = scan(node.getName(), p);
r = scanAndReduce(node.getType(), p, r);
r = scanAndReduce(node.getDescription(), p, r);
return r;
}
@Override
public R visitSince(SinceTree node, P p) {
return scan(node.getBody(), p);
}
@Override
public R visitStartElement(StartElementTree node, P p) {
return scan(node.getAttributes(), p);
}
@Override
public R visitText(TextTree node, P p) {
return null;
}
@Override
public R visitThrows(ThrowsTree node, P p) {
R r = scan(node.getExceptionName(), p);
r = scanAndReduce(node.getDescription(), p, r);
return r;
}
@Override
public R visitUnknownBlockTag(UnknownBlockTagTree node, P p) {
return scan(node.getContent(), p);
}
@Override
public R visitUnknownInlineTag(UnknownInlineTagTree node, P p) {
return scan(node.getContent(), p);
}
@Override
public R visitValue(ValueTree node, P p) {
return scan(node.getReference(), p);
}
@Override
public R visitVersion(VersionTree node, P p) {
return scan(node.getBody(), p);
}
@Override
public R visitOther(DocTree node, P p) {
return null;
}
}