org.eclipse.jdt.core.dom.ASTNode.java Source code

Java tutorial

Introduction

Here is the source code for org.eclipse.jdt.core.dom.ASTNode.java

Source

/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.jdt.core.dom;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.jdt.internal.core.dom.NaiveASTFlattener;

/**
 * Abstract superclass of all Abstract Syntax Tree (AST) node types.
 * <p>
 * An AST node represents a Java source code construct, such
 * as a name, type, expression, statement, or declaration.
 * </p>
 * <p>
 * Each AST node belongs to a unique AST instance, called the owning AST.
 * The children of an AST node always have the same owner as their parent node.
 * If a node from one AST is to be added to a different AST, the subtree must
 * be cloned first to ensure that the added nodes have the correct owning AST.
 * </p>
 * <p>
 * When an AST node is part of an AST, it has a unique parent node.
 * Clients can navigate upwards, from child to parent, as well as downwards,
 * from parent to child. Newly created nodes are unparented. When an
 * unparented node is set as a child of a node (using a
 * <code>set<i>CHILD</i></code> method), its parent link is set automatically
 * and the parent link of the former child is set to <code>null</code>.
 * For nodes with properties that include a list of children (for example,
 * <code>Block</code> whose <code>statements</code> property is a list
 * of statements), adding or removing an element to/for the list property
 * automatically updates the parent links. These lists support the
 * <code>List.set</code> method; however, the constraint that the same
 * node cannot appear more than once means that this method cannot be used
 * to swap elements without first removing the node.
 * </p>
 * <p>
 * ASTs must not contain cycles. All operations that could create a cycle
 * detect this possibility and fail.
 * </p>
 * <p>
 * ASTs do not contain "holes" (missing subtrees). If a node is required to
 * have a certain property, a syntactically plausible initial value is
 * always supplied.
 * </p>
 * <p>
 * The hierarchy of AST node types has some convenient groupings marked
 * by abstract superclasses:
 * <ul>
 * <li>expressions - <code>Expression</code></li>
 * <li>names - <code>Name</code> (a sub-kind of expression)</li>
 * <li>statements - <code>Statement</code></li>
 * <li>types - <code>Type</code></li>
 * <li>type body declarations - <code>BodyDeclaration</code></li>
 * </ul>
 * </p>
 * <p>
 * Abstract syntax trees may be hand constructed by clients, using the
 * <code>new<i>TYPE</i></code> factory methods (see <code>AST</code>) to
 * create new nodes, and the various <code>set<i>CHILD</i></code> methods
 * to connect them together.
 * </p>
 * <p>
 * The class {@link ASTParser} parses a string
 * containing a Java source code and returns an abstract syntax tree
 * for it. The resulting nodes carry source ranges relating the node back to
 * the original source characters. The source range covers the construct
 * as a whole.
 * </p>
 * <p>
 * Each AST node carries bit flags, which may convey additional information about
 * the node. For instance, the parser uses a flag to indicate a syntax error.
 * Newly created nodes have no flags set.
 * </p>
 * <p>
 * Each AST node is capable of carrying an open-ended collection of
 * client-defined properties. Newly created nodes have none.
 * <code>getProperty</code> and <code>setProperty</code> are used to access
 * these properties.
 * </p>
 * <p>
 * AST nodes are thread-safe for readers provided there are no active writers.
 * If one thread is modifying an AST, including creating new nodes or cloning
 * existing ones, it is <b>not</b> safe for another thread to read, visit,
 * write, create, or clone <em>any</em> of the nodes on the same AST.
 * When synchronization is required, consider using the common AST
 * object that owns the node; that is, use
 * <code>synchronize (node.getAST()) {...}</code>.
 * </p>
 * <p>
 * ASTs also support the visitor pattern; see the class <code>ASTVisitor</code>
 * for details. The <code>NodeFinder</code> class can be used to find a specific
 * node inside a tree.
 * </p>
 * <p>
 * Compilation units created by <code>ASTParser</code> from a
 * source document can be serialized after arbitrary modifications
 * with minimal loss of original formatting. See
 * {@link CompilationUnit#recordModifications()} for details.
 * See also {@link org.eclipse.jdt.core.dom.rewrite.ASTRewrite} for
 * an alternative way to describe and serialize changes to a
 * read-only AST.
 * </p>
 *
 * @see ASTParser
 * @see ASTVisitor
 * @see NodeFinder
 * @since 2.0
 * @noextend This class is not intended to be subclassed by clients.
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public abstract class ASTNode {
    /*
     * ATTENTION: When doing anything to the ASTNode hierarchy, do not try to
     * reinvent the wheel.
     * 
     * Look out for precedents with
     * - the same structural property type
     * - for child node properties: the same optionality (can be null / lazy initialization blurbs and impl.)
     * - the same declaring node type kind (abstract supertype or concrete type)
     * - a similar history (added in JLSx API, below JLSx only, replaced by {@link #xx})
     * ..., and copy what was done there. Most of the code and
     * Javadoc in this package should look like it was created by a code generator.
     * 
     * In subclasses of ASTNode, order properties by order of occurrence in source.
     * In general classes that list all AST node types, order alphabetically.  
     */

    /*
     * INSTRUCTIONS FOR ADDING NEW CONCRETE AST NODE TYPES
     *
     * There are several things that need to be changed when a
     * new concrete AST node type (call it "FooBar") is added:
     *
     * 1. Create the FooBar AST node type class.
     * The most effective way to do this is to copy a similar
     * existing concrete node class to get a template that
      * includes all the framework methods that must be implemented.
     *
     * 2. Add node type constant ASTNode.FOO_BAR.
     * Node constants are numbered consecutively. Add the
     * constant after the existing ones.
     *
     * 3. Add entry to ASTNode.nodeClassForType(int).
     *
     * 4. Add AST.newFooBar() factory method.
     *
     * 5. Add ASTVisitor.visit(FooBar) and endVisit(FooBar) methods. Same for DefaultASTVisitor.
     *
     * 6. Add ASTMatcher.match(FooBar,Object) method.
     *
     * 7. Ensure that SimpleName.isDeclaration() covers FooBar
     * nodes if required.
     *
     * 8. Add NaiveASTFlattener.visit(FooBar) method to illustrate
     * how these nodes should be serialized.
     *
     * 9. Update the AST test suites (ASTVisitorTest, etc.)
     *
     * The next steps are to update AST.parse* to start generating
     * the new type of nodes, and ASTRewrite to serialize them back out.
     */

    /*
     * INSTRUCTIONS FOR ADDING A NEW PROPERTY TO AN AST NODE TYPE
     * 
     * For concrete node types, use e.g. properties of SimpleName or ClassInstanceCreation
     * as templates:
     * 
     * 1. Copy/paste the field, property descriptor, and getter/setter.
     * 
     * 2. Adjust everything to the new property name and type. In the field's
     * Javadoc, properly document default value, initialization, and applicable
     * API levels.
     * 
     * 3. Add/remove @since tags as necessary.
     * 
     * 4. Search for references to the members in the template, and add similar
     * references in corresponding places for the new property.
     * 
     * 
     * For abstract node types, use AbstractTypeDeclaration as a template:
     * 
     * 1. Same steps as above, but take extra care to copy and adjust the
     * *internal*() methods as well. 
     * 
     * 2. Search for references to the members in the template, and add similar
     * references in corresponding places for the new property (e.g. property
     * descriptor in each leaf type).
     */

    /*
     * INSTRUCTIONS FOR REPLACING/DEPRECATING A PROPERTY OF AN AST NODE
     * 
     * To replace a simple property with a child list property, see e.g. how
     * SingleVariableDeclaration replaced MODIFIERS_PROPERTY with
     * MODIFIERS2_PROPERTY.
     * 
     * 1. Reuse the old property id.
     * 
     * 2. Deprecate all references to the old property, except for the old
     * getter, which should compute the value from the new property in
     * later API levels.
     * 
     * To completely replace a property, see how ClassInstanceCreation replaced
     * NAME_PROPERTY with TYPE_PROPERTY.
     */

    /**
     * Node type constant indicating a node of type
     * <code>AnonymousClassDeclaration</code>.
     * @see AnonymousClassDeclaration
     */
    public static final int ANONYMOUS_CLASS_DECLARATION = 1;

    /**
     * Node type constant indicating a node of type
     * <code>ArrayAccess</code>.
     * @see ArrayAccess
     */
    public static final int ARRAY_ACCESS = 2;

    /**
     * Node type constant indicating a node of type
     * <code>ArrayCreation</code>.
     * @see ArrayCreation
     */
    public static final int ARRAY_CREATION = 3;

    /**
     * Node type constant indicating a node of type
     * <code>ArrayInitializer</code>.
     * @see ArrayInitializer
     */
    public static final int ARRAY_INITIALIZER = 4;

    /**
     * Node type constant indicating a node of type
     * <code>ArrayType</code>.
     * @see ArrayType
     */
    public static final int ARRAY_TYPE = 5;

    /**
     * Node type constant indicating a node of type
     * <code>AssertStatement</code>.
     * @see AssertStatement
     */
    public static final int ASSERT_STATEMENT = 6;

    /**
     * Node type constant indicating a node of type
     * <code>Assignment</code>.
     * @see Assignment
     */
    public static final int ASSIGNMENT = 7;

    /**
     * Node type constant indicating a node of type
     * <code>Block</code>.
     * @see Block
     */
    public static final int BLOCK = 8;

    /**
     * Node type constant indicating a node of type
     * <code>BooleanLiteral</code>.
     * @see BooleanLiteral
     */
    public static final int BOOLEAN_LITERAL = 9;

    /**
     * Node type constant indicating a node of type
     * <code>BreakStatement</code>.
     * @see BreakStatement
     */
    public static final int BREAK_STATEMENT = 10;

    /**
     * Node type constant indicating a node of type
     * <code>CastExpression</code>.
     * @see CastExpression
     */
    public static final int CAST_EXPRESSION = 11;

    /**
     * Node type constant indicating a node of type
     * <code>CatchClause</code>.
     * @see CatchClause
     */
    public static final int CATCH_CLAUSE = 12;

    /**
     * Node type constant indicating a node of type
     * <code>CharacterLiteral</code>.
     * @see CharacterLiteral
     */
    public static final int CHARACTER_LITERAL = 13;

    /**
     * Node type constant indicating a node of type
     * <code>ClassInstanceCreation</code>.
     * @see ClassInstanceCreation
     */
    public static final int CLASS_INSTANCE_CREATION = 14;

    /**
     * Node type constant indicating a node of type
     * <code>CompilationUnit</code>.
     * @see CompilationUnit
     */
    public static final int COMPILATION_UNIT = 15;

    /**
     * Node type constant indicating a node of type
     * <code>ConditionalExpression</code>.
     * @see ConditionalExpression
     */
    public static final int CONDITIONAL_EXPRESSION = 16;

    /**
     * Node type constant indicating a node of type
     * <code>ConstructorInvocation</code>.
     * @see ConstructorInvocation
     */
    public static final int CONSTRUCTOR_INVOCATION = 17;

    /**
     * Node type constant indicating a node of type
     * <code>ContinueStatement</code>.
     * @see ContinueStatement
     */
    public static final int CONTINUE_STATEMENT = 18;

    /**
     * Node type constant indicating a node of type
     * <code>DoStatement</code>.
     * @see DoStatement
     */
    public static final int DO_STATEMENT = 19;

    /**
     * Node type constant indicating a node of type
     * <code>EmptyStatement</code>.
     * @see EmptyStatement
     */
    public static final int EMPTY_STATEMENT = 20;

    /**
     * Node type constant indicating a node of type
     * <code>ExpressionStatement</code>.
     * @see ExpressionStatement
     */
    public static final int EXPRESSION_STATEMENT = 21;

    /**
     * Node type constant indicating a node of type
     * <code>FieldAccess</code>.
     * @see FieldAccess
     */
    public static final int FIELD_ACCESS = 22;

    /**
     * Node type constant indicating a node of type
     * <code>FieldDeclaration</code>.
     * @see FieldDeclaration
     */
    public static final int FIELD_DECLARATION = 23;

    /**
     * Node type constant indicating a node of type
     * <code>ForStatement</code>.
     * @see ForStatement
     */
    public static final int FOR_STATEMENT = 24;

    /**
     * Node type constant indicating a node of type
     * <code>IfStatement</code>.
     * @see IfStatement
     */
    public static final int IF_STATEMENT = 25;

    /**
     * Node type constant indicating a node of type
     * <code>ImportDeclaration</code>.
     * @see ImportDeclaration
     */
    public static final int IMPORT_DECLARATION = 26;

    /**
     * Node type constant indicating a node of type
     * <code>InfixExpression</code>.
     * @see InfixExpression
     */
    public static final int INFIX_EXPRESSION = 27;

    /**
     * Node type constant indicating a node of type
     * <code>Initializer</code>.
     * @see Initializer
     */
    public static final int INITIALIZER = 28;

    /**
     * Node type constant indicating a node of type
     * <code>Javadoc</code>.
     * @see Javadoc
     */
    public static final int JAVADOC = 29;

    /**
     * Node type constant indicating a node of type
     * <code>LabeledStatement</code>.
     * @see LabeledStatement
     */
    public static final int LABELED_STATEMENT = 30;

    /**
     * Node type constant indicating a node of type
     * <code>MethodDeclaration</code>.
     * @see MethodDeclaration
     */
    public static final int METHOD_DECLARATION = 31;

    /**
     * Node type constant indicating a node of type
     * <code>MethodInvocation</code>.
     * @see MethodInvocation
     */
    public static final int METHOD_INVOCATION = 32;

    /**
     * Node type constant indicating a node of type
     * <code>NullLiteral</code>.
     * @see NullLiteral
     */
    public static final int NULL_LITERAL = 33;

    /**
     * Node type constant indicating a node of type
     * <code>NumberLiteral</code>.
     * @see NumberLiteral
     */
    public static final int NUMBER_LITERAL = 34;

    /**
     * Node type constant indicating a node of type
     * <code>PackageDeclaration</code>.
     * @see PackageDeclaration
     */
    public static final int PACKAGE_DECLARATION = 35;

    /**
     * Node type constant indicating a node of type
     * <code>ParenthesizedExpression</code>.
     * @see ParenthesizedExpression
     */
    public static final int PARENTHESIZED_EXPRESSION = 36;

    /**
     * Node type constant indicating a node of type
     * <code>PostfixExpression</code>.
     * @see PostfixExpression
     */
    public static final int POSTFIX_EXPRESSION = 37;

    /**
     * Node type constant indicating a node of type
     * <code>PrefixExpression</code>.
     * @see PrefixExpression
     */
    public static final int PREFIX_EXPRESSION = 38;

    /**
     * Node type constant indicating a node of type
     * <code>PrimitiveType</code>.
     * @see PrimitiveType
     */
    public static final int PRIMITIVE_TYPE = 39;

    /**
     * Node type constant indicating a node of type
     * <code>QualifiedName</code>.
     * @see QualifiedName
     */
    public static final int QUALIFIED_NAME = 40;

    /**
     * Node type constant indicating a node of type
     * <code>ReturnStatement</code>.
     * @see ReturnStatement
     */
    public static final int RETURN_STATEMENT = 41;

    /**
     * Node type constant indicating a node of type
     * <code>SimpleName</code>.
     * @see SimpleName
     */
    public static final int SIMPLE_NAME = 42;

    /**
     * Node type constant indicating a node of type
     * <code>SimpleType</code>.
     * @see SimpleType
     */
    public static final int SIMPLE_TYPE = 43;

    /**
     * Node type constant indicating a node of type
     * <code>SingleVariableDeclaration</code>.
     * @see SingleVariableDeclaration
     */
    public static final int SINGLE_VARIABLE_DECLARATION = 44;

    /**
     * Node type constant indicating a node of type
     * <code>StringLiteral</code>.
     * @see StringLiteral
     */
    public static final int STRING_LITERAL = 45;

    /**
     * Node type constant indicating a node of type
     * <code>SuperConstructorInvocation</code>.
     * @see SuperConstructorInvocation
     */
    public static final int SUPER_CONSTRUCTOR_INVOCATION = 46;

    /**
     * Node type constant indicating a node of type
     * <code>SuperFieldAccess</code>.
     * @see SuperFieldAccess
     */
    public static final int SUPER_FIELD_ACCESS = 47;

    /**
     * Node type constant indicating a node of type
     * <code>SuperMethodInvocation</code>.
     * @see SuperMethodInvocation
     */
    public static final int SUPER_METHOD_INVOCATION = 48;

    /**
     * Node type constant indicating a node of type
     * <code>SwitchCase</code>.
     * @see SwitchCase
     */
    public static final int SWITCH_CASE = 49;

    /**
     * Node type constant indicating a node of type
     * <code>SwitchStatement</code>.
     * @see SwitchStatement
     */
    public static final int SWITCH_STATEMENT = 50;

    /**
     * Node type constant indicating a node of type
     * <code>SynchronizedStatement</code>.
     * @see SynchronizedStatement
     */
    public static final int SYNCHRONIZED_STATEMENT = 51;

    /**
     * Node type constant indicating a node of type
     * <code>ThisExpression</code>.
     * @see ThisExpression
     */
    public static final int THIS_EXPRESSION = 52;

    /**
     * Node type constant indicating a node of type
     * <code>ThrowStatement</code>.
     * @see ThrowStatement
     */
    public static final int THROW_STATEMENT = 53;

    /**
     * Node type constant indicating a node of type
     * <code>TryStatement</code>.
     * @see TryStatement
     */
    public static final int TRY_STATEMENT = 54;

    /**
     * Node type constant indicating a node of type
     * <code>TypeDeclaration</code>.
     * @see TypeDeclaration
     */
    public static final int TYPE_DECLARATION = 55;

    /**
     * Node type constant indicating a node of type
     * <code>TypeDeclarationStatement</code>.
     * @see TypeDeclarationStatement
     */
    public static final int TYPE_DECLARATION_STATEMENT = 56;

    /**
     * Node type constant indicating a node of type
     * <code>TypeLiteral</code>.
     * @see TypeLiteral
     */
    public static final int TYPE_LITERAL = 57;

    /**
     * Node type constant indicating a node of type
     * <code>VariableDeclarationExpression</code>.
     * @see VariableDeclarationExpression
     */
    public static final int VARIABLE_DECLARATION_EXPRESSION = 58;

    /**
     * Node type constant indicating a node of type
     * <code>VariableDeclarationFragment</code>.
     * @see VariableDeclarationFragment
     */
    public static final int VARIABLE_DECLARATION_FRAGMENT = 59;

    /**
     * Node type constant indicating a node of type
     * <code>VariableDeclarationStatement</code>.
     * @see VariableDeclarationStatement
     */
    public static final int VARIABLE_DECLARATION_STATEMENT = 60;

    /**
     * Node type constant indicating a node of type
     * <code>WhileStatement</code>.
     * @see WhileStatement
     */
    public static final int WHILE_STATEMENT = 61;

    /**
     * Node type constant indicating a node of type
     * <code>InstanceofExpression</code>.
     * @see InstanceofExpression
     */
    public static final int INSTANCEOF_EXPRESSION = 62;

    /**
     * Node type constant indicating a node of type
     * <code>LineComment</code>.
     * @see LineComment
     * @since 3.0
     */
    public static final int LINE_COMMENT = 63;

    /**
     * Node type constant indicating a node of type
     * <code>BlockComment</code>.
     * @see BlockComment
     * @since 3.0
     */
    public static final int BLOCK_COMMENT = 64;

    /**
     * Node type constant indicating a node of type
     * <code>TagElement</code>.
     * @see TagElement
     * @since 3.0
     */
    public static final int TAG_ELEMENT = 65;

    /**
     * Node type constant indicating a node of type
     * <code>TextElement</code>.
     * @see TextElement
     * @since 3.0
     */
    public static final int TEXT_ELEMENT = 66;

    /**
     * Node type constant indicating a node of type
     * <code>MemberRef</code>.
     * @see MemberRef
     * @since 3.0
     */
    public static final int MEMBER_REF = 67;

    /**
     * Node type constant indicating a node of type
     * <code>MethodRef</code>.
     * @see MethodRef
     * @since 3.0
     */
    public static final int METHOD_REF = 68;

    /**
     * Node type constant indicating a node of type
     * <code>MethodRefParameter</code>.
     * @see MethodRefParameter
     * @since 3.0
     */
    public static final int METHOD_REF_PARAMETER = 69;

    /**
     * Node type constant indicating a node of type
     * <code>EnhancedForStatement</code>.
     * @see EnhancedForStatement
     * @since 3.1
     */
    public static final int ENHANCED_FOR_STATEMENT = 70;

    /**
     * Node type constant indicating a node of type
     * <code>EnumDeclaration</code>.
     * @see EnumDeclaration
     * @since 3.1
     */
    public static final int ENUM_DECLARATION = 71;

    /**
     * Node type constant indicating a node of type
     * <code>EnumConstantDeclaration</code>.
     * @see EnumConstantDeclaration
     * @since 3.1
     */
    public static final int ENUM_CONSTANT_DECLARATION = 72;

    /**
     * Node type constant indicating a node of type
     * <code>TypeParameter</code>.
     * @see TypeParameter
     * @since 3.1
     */
    public static final int TYPE_PARAMETER = 73;

    /**
     * Node type constant indicating a node of type
     * <code>ParameterizedType</code>.
     * @see ParameterizedType
     * @since 3.1
     */
    public static final int PARAMETERIZED_TYPE = 74;

    /**
     * Node type constant indicating a node of type
     * <code>QualifiedType</code>.
     * @see QualifiedType
     * @since 3.1
     */
    public static final int QUALIFIED_TYPE = 75;

    /**
     * Node type constant indicating a node of type
     * <code>WildcardType</code>.
     * @see WildcardType
     * @since 3.1
     */
    public static final int WILDCARD_TYPE = 76;

    /**
     * Node type constant indicating a node of type
     * <code>NormalAnnotation</code>.
     * @see NormalAnnotation
     * @since 3.1
     */
    public static final int NORMAL_ANNOTATION = 77;

    /**
     * Node type constant indicating a node of type
     * <code>MarkerAnnotation</code>.
     * @see MarkerAnnotation
     * @since 3.1
     */
    public static final int MARKER_ANNOTATION = 78;

    /**
     * Node type constant indicating a node of type
     * <code>SingleMemberAnnotation</code>.
     * @see SingleMemberAnnotation
     * @since 3.1
     */
    public static final int SINGLE_MEMBER_ANNOTATION = 79;

    /**
     * Node type constant indicating a node of type
     * <code>MemberValuePair</code>.
     * @see MemberValuePair
     * @since 3.1
     */
    public static final int MEMBER_VALUE_PAIR = 80;

    /**
     * Node type constant indicating a node of type
     * <code>AnnotationTypeDeclaration</code>.
     * @see AnnotationTypeDeclaration
     * @since 3.1
     */
    public static final int ANNOTATION_TYPE_DECLARATION = 81;

    /**
     * Node type constant indicating a node of type
     * <code>AnnotationTypeMemberDeclaration</code>.
     * @see AnnotationTypeMemberDeclaration
     * @since 3.1
     */
    public static final int ANNOTATION_TYPE_MEMBER_DECLARATION = 82;

    /**
     * Node type constant indicating a node of type
     * <code>Modifier</code>.
     * @see Modifier
     * @since 3.1
     */
    public static final int MODIFIER = 83;

    /**
     * Node type constant indicating a node of type
     * <code>UnionType</code>.
     * @see UnionType
     * @since 3.7.1
     */
    public static final int UNION_TYPE = 84;

    /**
     * Node type constant indicating a node of type
     * <code>Dimension</code>.
     *
     * @see Dimension
     * @since 3.10
     */
    public static final int DIMENSION = 85;

    /**
     * Node type constant indicating a node of type
     * <code>LambdaExpression</code>.
     * @see LambdaExpression
     * @since 3.10
     */
    public static final int LAMBDA_EXPRESSION = 86;

    /**
     * Node type constant indicating a node of type
     * <code>IntersectionType</code>.
     *
     * @see IntersectionType
     * @since 3.10
     */
    public static final int INTERSECTION_TYPE = 87;

    /**
     * Node type constant indicating a node of type
     * <code>NameQualifiedType</code>.
     * @see NameQualifiedType
     * @since 3.10
     */
    public static final int NAME_QUALIFIED_TYPE = 88;

    /**
     * Node type constant indicating a node of type
     * <code>CreationReference</code>.
     * @see CreationReference
     * @since 3.10
     */
    public static final int CREATION_REFERENCE = 89;

    /**
     * Node type constant indicating a node of type
     * <code>ExpressionMethodReference</code>.
     * @see ExpressionMethodReference
     * @since 3.10
     */
    public static final int EXPRESSION_METHOD_REFERENCE = 90;

    /**
     * Node type constant indicating a node of type
     * <code>SuperMethhodReference</code>.
     * @see SuperMethodReference
     * @since 3.10
     */
    public static final int SUPER_METHOD_REFERENCE = 91;

    /**
     * Node type constant indicating a node of type
     * <code>TypeMethodReference</code>.
     * @see TypeMethodReference
     * @since 3.10
     */
    public static final int TYPE_METHOD_REFERENCE = 92;

    /**
     * Returns the node class for the corresponding node type.
     *
     * @param nodeType AST node type
     * @return the corresponding <code>ASTNode</code> subclass
     * @exception IllegalArgumentException if <code>nodeType</code> is
     * not a legal AST node type
     * @see #getNodeType()
     * @since 3.0
     */
    public static Class nodeClassForType(int nodeType) {
        switch (nodeType) {
        case ANNOTATION_TYPE_DECLARATION:
            return AnnotationTypeDeclaration.class;
        case ANNOTATION_TYPE_MEMBER_DECLARATION:
            return AnnotationTypeMemberDeclaration.class;
        case ANONYMOUS_CLASS_DECLARATION:
            return AnonymousClassDeclaration.class;
        case ARRAY_ACCESS:
            return ArrayAccess.class;
        case ARRAY_CREATION:
            return ArrayCreation.class;
        case ARRAY_INITIALIZER:
            return ArrayInitializer.class;
        case ARRAY_TYPE:
            return ArrayType.class;
        case ASSERT_STATEMENT:
            return AssertStatement.class;
        case ASSIGNMENT:
            return Assignment.class;
        case BLOCK:
            return Block.class;
        case BLOCK_COMMENT:
            return BlockComment.class;
        case BOOLEAN_LITERAL:
            return BooleanLiteral.class;
        case BREAK_STATEMENT:
            return BreakStatement.class;
        case CAST_EXPRESSION:
            return CastExpression.class;
        case CATCH_CLAUSE:
            return CatchClause.class;
        case CHARACTER_LITERAL:
            return CharacterLiteral.class;
        case CLASS_INSTANCE_CREATION:
            return ClassInstanceCreation.class;
        case COMPILATION_UNIT:
            return CompilationUnit.class;
        case CONDITIONAL_EXPRESSION:
            return ConditionalExpression.class;
        case CONSTRUCTOR_INVOCATION:
            return ConstructorInvocation.class;
        case CONTINUE_STATEMENT:
            return ContinueStatement.class;
        case CREATION_REFERENCE:
            return CreationReference.class;
        case DIMENSION:
            return Dimension.class;
        case DO_STATEMENT:
            return DoStatement.class;
        case EMPTY_STATEMENT:
            return EmptyStatement.class;
        case ENHANCED_FOR_STATEMENT:
            return EnhancedForStatement.class;
        case ENUM_CONSTANT_DECLARATION:
            return EnumConstantDeclaration.class;
        case ENUM_DECLARATION:
            return EnumDeclaration.class;
        case EXPRESSION_METHOD_REFERENCE:
            return ExpressionMethodReference.class;
        case EXPRESSION_STATEMENT:
            return ExpressionStatement.class;
        case FIELD_ACCESS:
            return FieldAccess.class;
        case FIELD_DECLARATION:
            return FieldDeclaration.class;
        case FOR_STATEMENT:
            return ForStatement.class;
        case IF_STATEMENT:
            return IfStatement.class;
        case IMPORT_DECLARATION:
            return ImportDeclaration.class;
        case INFIX_EXPRESSION:
            return InfixExpression.class;
        case INITIALIZER:
            return Initializer.class;
        case INSTANCEOF_EXPRESSION:
            return InstanceofExpression.class;
        case INTERSECTION_TYPE:
            return IntersectionType.class;
        case JAVADOC:
            return Javadoc.class;
        case LABELED_STATEMENT:
            return LabeledStatement.class;
        case LAMBDA_EXPRESSION:
            return LambdaExpression.class;
        case LINE_COMMENT:
            return LineComment.class;
        case MARKER_ANNOTATION:
            return MarkerAnnotation.class;
        case MEMBER_REF:
            return MemberRef.class;
        case MEMBER_VALUE_PAIR:
            return MemberValuePair.class;
        case METHOD_DECLARATION:
            return MethodDeclaration.class;
        case METHOD_INVOCATION:
            return MethodInvocation.class;
        case METHOD_REF:
            return MethodRef.class;
        case METHOD_REF_PARAMETER:
            return MethodRefParameter.class;
        case MODIFIER:
            return Modifier.class;
        case NAME_QUALIFIED_TYPE:
            return NameQualifiedType.class;
        case NORMAL_ANNOTATION:
            return NormalAnnotation.class;
        case NULL_LITERAL:
            return NullLiteral.class;
        case NUMBER_LITERAL:
            return NumberLiteral.class;
        case PACKAGE_DECLARATION:
            return PackageDeclaration.class;
        case PARAMETERIZED_TYPE:
            return ParameterizedType.class;
        case PARENTHESIZED_EXPRESSION:
            return ParenthesizedExpression.class;
        case POSTFIX_EXPRESSION:
            return PostfixExpression.class;
        case PREFIX_EXPRESSION:
            return PrefixExpression.class;
        case PRIMITIVE_TYPE:
            return PrimitiveType.class;
        case QUALIFIED_NAME:
            return QualifiedName.class;
        case QUALIFIED_TYPE:
            return QualifiedType.class;
        case RETURN_STATEMENT:
            return ReturnStatement.class;
        case SIMPLE_NAME:
            return SimpleName.class;
        case SIMPLE_TYPE:
            return SimpleType.class;
        case SINGLE_MEMBER_ANNOTATION:
            return SingleMemberAnnotation.class;
        case SINGLE_VARIABLE_DECLARATION:
            return SingleVariableDeclaration.class;
        case STRING_LITERAL:
            return StringLiteral.class;
        case SUPER_CONSTRUCTOR_INVOCATION:
            return SuperConstructorInvocation.class;
        case SUPER_FIELD_ACCESS:
            return SuperFieldAccess.class;
        case SUPER_METHOD_INVOCATION:
            return SuperMethodInvocation.class;
        case SUPER_METHOD_REFERENCE:
            return SuperMethodReference.class;
        case SWITCH_CASE:
            return SwitchCase.class;
        case SWITCH_STATEMENT:
            return SwitchStatement.class;
        case SYNCHRONIZED_STATEMENT:
            return SynchronizedStatement.class;
        case TAG_ELEMENT:
            return TagElement.class;
        case TEXT_ELEMENT:
            return TextElement.class;
        case THIS_EXPRESSION:
            return ThisExpression.class;
        case THROW_STATEMENT:
            return ThrowStatement.class;
        case TRY_STATEMENT:
            return TryStatement.class;
        case TYPE_DECLARATION:
            return TypeDeclaration.class;
        case TYPE_DECLARATION_STATEMENT:
            return TypeDeclarationStatement.class;
        case TYPE_METHOD_REFERENCE:
            return TypeMethodReference.class;
        case TYPE_LITERAL:
            return TypeLiteral.class;
        case TYPE_PARAMETER:
            return TypeParameter.class;
        case UNION_TYPE:
            return UnionType.class;
        case VARIABLE_DECLARATION_EXPRESSION:
            return VariableDeclarationExpression.class;
        case VARIABLE_DECLARATION_FRAGMENT:
            return VariableDeclarationFragment.class;
        case VARIABLE_DECLARATION_STATEMENT:
            return VariableDeclarationStatement.class;
        case WHILE_STATEMENT:
            return WhileStatement.class;
        case WILDCARD_TYPE:
            return WildcardType.class;
        }
        throw new IllegalArgumentException();
    }

    /**
     * Owning AST.
      * <p>
      * N.B. This is a private field, but declared as package-visible
      * for more efficient access from inner classes.
      * </p>
     */
    final AST ast;

    /**
     * Parent AST node, or <code>null</code> if this node is a root.
     * Initially <code>null</code>.
     */
    private ASTNode parent = null;

    /**
     * An unmodifiable empty map (used to implement <code>properties()</code>).
     */
    private static final Map UNMODIFIABLE_EMPTY_MAP = Collections.unmodifiableMap(new HashMap(1));

    /**
     * Primary field used in representing node properties efficiently.
     * If <code>null</code>, this node has no properties.
     * If a {@link String}, this is the name of this node's sole property,
     * and <code>property2</code> contains its value.
     * If a {@link Map}, this is the table of property name-value
     * mappings; <code>property2</code>, if non-null is its unmodifiable
     * equivalent.
     * Initially <code>null</code>.
     *
     * @see #property2
     */
    private Object property1 = null;

    /**
     * Auxiliary field used in representing node properties efficiently.
     *
     * @see #property1
     */
    private Object property2 = null;

    /**
     * A character index into the original source string,
     * or <code>-1</code> if no source position information is available
     * for this node; <code>-1</code> by default.
     */
    private int startPosition = -1;

    /**
     * A character length, or <code>0</code> if no source position
     * information is recorded for this node; <code>0</code> by default.
     */
    private int length = 0;

    /**
     * Flag constant (bit mask, value 1) indicating that there is something
     * not quite right with this AST node.
     * <p>
     * The standard parser (<code>ASTParser</code>) sets this
     * flag on a node to indicate a syntax error detected in the vicinity.
     * </p>
     */
    public static final int MALFORMED = 1;

    /**
     * Flag constant (bit mask, value 2) indicating that this is a node
     * that was created by the parser (as opposed to one created by another
     * party).
     * <p>
     * The standard parser (<code>ASTParser</code>) sets this
     * flag on the nodes it creates.
     * </p>
     * @since 3.0
     */
    public static final int ORIGINAL = 2;

    /**
     * Flag constant (bit mask, value 4) indicating that this node
     * is unmodifiable. When a node is marked unmodifiable, the
     * following operations result in a runtime exception:
     * <ul>
     * <li>Change a simple property of this node.</li>
     * <li>Add or remove a child node from this node.</li>
     * <li>Parent (or reparent) this node.</li>
     * </ul>
     * <p>
     * The standard parser (<code>ASTParser</code>) does not set
     * this flag on the nodes it creates. However, clients may set
     * this flag on a node to prevent further modification of the
     * its structural properties.
     * </p>
     * @since 3.0
     */
    public static final int PROTECT = 4;

    /**
     * Flag constant (bit mask, value 8) indicating that this node
     * or a part of this node is recovered from source that contains
     * a syntax error detected in the vicinity.
     * <p>
     * The standard parser (<code>ASTParser</code>) sets this
     * flag on a node to indicate a recovered node.
     * </p>
     * @since 3.2
     */
    public static final int RECOVERED = 8;

    /**
     * int containing the node type in the top 16 bits and
     * flags in the bottom 16 bits; none set by default.
      * <p>
      * N.B. This is a private field, but declared as package-visible
      * for more efficient access from inner classes.
      * </p>
     *
     * @see #MALFORMED
     */
    int typeAndFlags = 0;

    /**
     * Property of parent in which this node is a child, or <code>null</code>
     * if this node is a root. Initially <code>null</code>.
     *
     * @see #getLocationInParent
     * @since 3.0
     */
    private StructuralPropertyDescriptor location = null;

    /** Internal convenience constant indicating that there is definite risk of cycles.
     * @see ChildPropertyDescriptor#cycleRisk()
     * @see ChildListPropertyDescriptor#cycleRisk()
     * @since 3.0
     */
    static final boolean CYCLE_RISK = true;

    /** Internal convenience constant indicating that there is no risk of cycles.
     * @see ChildPropertyDescriptor#cycleRisk()
     * @see ChildListPropertyDescriptor#cycleRisk()
     * @since 3.0
     */
    static final boolean NO_CYCLE_RISK = false;

    /** Internal convenience constant indicating that a structural property is mandatory.
     * @since 3.0
     */
    static final boolean MANDATORY = true;

    /** Internal convenience constant indicating that a structural property is optional.
     * @since 3.0
     */
    static final boolean OPTIONAL = false;

    /**
     * A specialized implementation of a list of ASTNodes. The
     * implementation is based on an ArrayList.
     */
    class NodeList extends AbstractList {

        /**
         * The underlying list in which the nodes of this list are
         * stored (element type: {@link ASTNode}).
         * <p>
         * Be stingy on storage - assume that list will be empty.
         * </p>
         * <p>
         * This field declared default visibility (rather than private)
         * so that accesses from <code>NodeList.Cursor</code> do not require
         * a synthetic accessor method.
         * </p>
         */
        ArrayList store = new ArrayList(0);

        /**
         * The property descriptor for this list.
         */
        ChildListPropertyDescriptor propertyDescriptor;

        /**
         * A cursor for iterating over the elements of the list.
         * Does not lose its position if the list is changed during
         * the iteration.
         */
        class Cursor implements Iterator {
            /**
             * The position of the cursor between elements. If the value
             * is N, then the cursor sits between the element at positions
             * N-1 and N. Initially just before the first element of the
             * list.
             */
            private int position = 0;

            /* (non-Javadoc)
             * Method declared on <code>Iterator</code>.
             */
            public boolean hasNext() {
                return this.position < NodeList.this.store.size();
            }

            /* (non-Javadoc)
             * Method declared on <code>Iterator</code>.
             */
            public Object next() {
                Object result = NodeList.this.store.get(this.position);
                this.position++;
                return result;
            }

            /* (non-Javadoc)
             * Method declared on <code>Iterator</code>.
             */
            public void remove() {
                throw new UnsupportedOperationException();
            }

            /**
             * Adjusts this cursor to accommodate an add/remove at the given
             * index.
             *
             * @param index the position at which the element was added
             *    or removed
             * @param delta +1 for add, and -1 for remove
             */
            void update(int index, int delta) {
                if (this.position > index) {
                    // the cursor has passed the added or removed element
                    this.position += delta;
                }
            }
        }

        /**
         * A list of currently active cursors (element type:
         * {@link Cursor}), or <code>null</code> if there are no
         * active cursors.
         * <p>
         * It is important for storage considerations to maintain the
         * null-means-empty invariant; otherwise, every NodeList instance
         * will waste a lot of space. A cursor is needed only for the duration
         * of a visit to the child nodes. Under normal circumstances, only a
         * single cursor is needed; multiple cursors are only required if there
         * are multiple visits going on at the same time.
         * </p>
         */
        private List cursors = null;

        /**
         * Creates a new empty list of nodes owned by this node.
         * This node will be the common parent of all nodes added to
         * this list.
         *
         * @param property the property descriptor
         * @since 3.0
         */
        NodeList(ChildListPropertyDescriptor property) {
            super();
            this.propertyDescriptor = property;
        }

        /* (non-javadoc)
         * @see java.util.AbstractCollection#size()
         */
        public int size() {
            return this.store.size();
        }

        /* (non-javadoc)
         * @see AbstractList#get(int)
         */
        public Object get(int index) {
            return this.store.get(index);
        }

        /* (non-javadoc)
         * @see List#set(int, java.lang.Object)
         */
        public Object set(int index, Object element) {
            if (element == null) {
                throw new IllegalArgumentException();
            }
            if ((ASTNode.this.typeAndFlags & PROTECT) != 0) {
                // this node is protected => cannot gain or lose children
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }
            // delink old child from parent, and link new child to parent
            ASTNode newChild = (ASTNode) element;
            ASTNode oldChild = (ASTNode) this.store.get(index);
            if (oldChild == newChild) {
                return oldChild;
            }
            if ((oldChild.typeAndFlags & PROTECT) != 0) {
                // old child is protected => cannot be unparented
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }
            ASTNode.checkNewChild(ASTNode.this, newChild, this.propertyDescriptor.cycleRisk,
                    this.propertyDescriptor.elementType);
            ASTNode.this.ast.preReplaceChildEvent(ASTNode.this, oldChild, newChild, this.propertyDescriptor);

            Object result = this.store.set(index, newChild);
            // n.b. setParent will call ast.modifying()
            oldChild.setParent(null, null);
            newChild.setParent(ASTNode.this, this.propertyDescriptor);
            ASTNode.this.ast.postReplaceChildEvent(ASTNode.this, oldChild, newChild, this.propertyDescriptor);
            return result;
        }

        /* (non-javadoc)
         * @see List#add(int, java.lang.Object)
         */
        public void add(int index, Object element) {
            if (element == null) {
                throw new IllegalArgumentException();
            }
            if ((ASTNode.this.typeAndFlags & PROTECT) != 0) {
                // this node is protected => cannot gain or lose children
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }
            // link new child to parent
            ASTNode newChild = (ASTNode) element;
            ASTNode.checkNewChild(ASTNode.this, newChild, this.propertyDescriptor.cycleRisk,
                    this.propertyDescriptor.elementType);
            ASTNode.this.ast.preAddChildEvent(ASTNode.this, newChild, this.propertyDescriptor);

            this.store.add(index, element);
            updateCursors(index, +1);
            // n.b. setParent will call ast.modifying()
            newChild.setParent(ASTNode.this, this.propertyDescriptor);
            ASTNode.this.ast.postAddChildEvent(ASTNode.this, newChild, this.propertyDescriptor);
        }

        /* (non-javadoc)
         * @see List#remove(int)
         */
        public Object remove(int index) {
            if ((ASTNode.this.typeAndFlags & PROTECT) != 0) {
                // this node is protected => cannot gain or lose children
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }
            // delink old child from parent
            ASTNode oldChild = (ASTNode) this.store.get(index);
            if ((oldChild.typeAndFlags & PROTECT) != 0) {
                // old child is protected => cannot be unparented
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }

            ASTNode.this.ast.preRemoveChildEvent(ASTNode.this, oldChild, this.propertyDescriptor);
            // n.b. setParent will call ast.modifying()
            oldChild.setParent(null, null);
            Object result = this.store.remove(index);
            updateCursors(index, -1);
            ASTNode.this.ast.postRemoveChildEvent(ASTNode.this, oldChild, this.propertyDescriptor);
            return result;

        }

        /**
         * Allocate a cursor to use for a visit. The client must call
         * <code>releaseCursor</code> when done.
         * <p>
         * This method is internally synchronized on this NodeList.
         * It is thread-safe to create a cursor.
         * </p>
         *
         * @return a new cursor positioned before the first element
         *    of the list
         */
        Cursor newCursor() {
            synchronized (this) {
                // serialize cursor management on this NodeList
                if (this.cursors == null) {
                    // convert null to empty list
                    this.cursors = new ArrayList(1);
                }
                Cursor result = new Cursor();
                this.cursors.add(result);
                return result;
            }
        }

        /**
         * Releases the given cursor at the end of a visit.
         * <p>
         * This method is internally synchronized on this NodeList.
         * It is thread-safe to release a cursor.
         * </p>
         *
         * @param cursor the cursor
         */
        void releaseCursor(Cursor cursor) {
            synchronized (this) {
                // serialize cursor management on this NodeList
                this.cursors.remove(cursor);
                if (this.cursors.isEmpty()) {
                    // important: convert empty list back to null
                    // otherwise the node will hang on to needless junk
                    this.cursors = null;
                }
            }
        }

        /**
         * Adjusts all cursors to accommodate an add/remove at the given
         * index.
         * <p>
         * This method is only used when the list is being modified.
         * The AST is not thread-safe if any of the clients are modifying it.
         * </p>
         *
         * @param index the position at which the element was added
         *    or removed
         * @param delta +1 for add, and -1 for remove
         */
        private synchronized void updateCursors(int index, int delta) {
            if (this.cursors == null) {
                // there are no cursors to worry about
                return;
            }
            for (Iterator it = this.cursors.iterator(); it.hasNext();) {
                Cursor c = (Cursor) it.next();
                c.update(index, delta);
            }
        }

        /**
         * Returns an estimate of the memory footprint of this node list
         * instance in bytes.
          * <ul>
          * <li>1 object header for the NodeList instance</li>
          * <li>5 4-byte fields of the NodeList instance</li>
          * <li>0 for cursors since null unless walk in progress</li>
          * <li>1 object header for the ArrayList instance</li>
          * <li>2 4-byte fields of the ArrayList instance</li>
          * <li>1 object header for an Object[] instance</li>
          * <li>4 bytes in array for each element</li>
          * </ul>
          *
         * @return the size of this node list in bytes
         */
        int memSize() {
            int result = HEADERS + 5 * 4;
            result += HEADERS + 2 * 4;
            result += HEADERS + 4 * size();
            return result;
        }

        /**
         * Returns an estimate of the memory footprint in bytes of this node
         * list and all its subtrees.
         *
         * @return the size of this list of subtrees in bytes
         */
        int listSize() {
            int result = memSize();
            for (Iterator it = iterator(); it.hasNext();) {
                ASTNode child = (ASTNode) it.next();
                result += child.treeSize();
            }
            return result;
        }
    }

    /**
     * Creates a new AST node owned by the given AST. Once established,
     * the relationship between an AST node and its owning AST does not change
     * over the lifetime of the node. The new node has no parent node,
     * and no properties.
     * <p>
     * N.B. This constructor is package-private; all subclasses my be
     * declared in the same package; clients are unable to declare
     * additional subclasses.
     * </p>
     *
     * @param ast the AST that is to own this node
     */
    ASTNode(AST ast) {
        if (ast == null) {
            throw new IllegalArgumentException();
        }

        this.ast = ast;
        setNodeType(getNodeType0());
        setFlags(ast.getDefaultNodeFlag());
        // setFlags calls modifying();
    }

    /**
     * Returns this node's AST.
     * <p>
     * Note that the relationship between an AST node and its owing AST does
     * not change over the lifetime of a node.
     * </p>
     *
     * @return the AST that owns this node
     */
    public final AST getAST() {
        return this.ast;
    }

    /**
     * Returns this node's parent node, or <code>null</code> if this is the
     * root node.
     * <p>
     * Note that the relationship between an AST node and its parent node
     * may change over the lifetime of a node.
     * </p>
     *
     * @return the parent of this node, or <code>null</code> if none
     */
    public final ASTNode getParent() {
        return this.parent;
    }

    /**
     * Returns the location of this node within its parent,
     * or <code>null</code> if this is a root node.
     * <p>
     * <pre>
     * ASTNode node = ...;
     * ASTNode parent = node.getParent();
     * StructuralPropertyDescriptor location = node.getLocationInParent();
     * assert (parent != null) == (location != null);
     * if ((location != null) && location.isChildProperty())
     *    assert parent.getStructuralProperty(location) == node;
     * if ((location != null) && location.isChildListProperty())
     *    assert ((List) parent.getStructuralProperty(location)).contains(node);
     * </pre>
     * </p>
     * <p>
     * Note that the relationship between an AST node and its parent node
     * may change over the lifetime of a node.
     * </p>
     *
     * @return the location of this node in its parent,
     * or <code>null</code> if this node has no parent
     * @since 3.0
     */
    public final StructuralPropertyDescriptor getLocationInParent() {
        return this.location;
    }

    /**
     * Returns the root node at or above this node; returns this node if
     * it is a root.
     *
     * @return the root node at or above this node
     */
    public final ASTNode getRoot() {
        ASTNode candidate = this;
        while (true) {
            ASTNode p = candidate.getParent();
            if (p == null) {
                // candidate has no parent - that's the guy
                return candidate;
            }
            candidate = p;
        }
    }

    /**
     * Returns the value of the given structural property for this node. The value
     * returned depends on the kind of property:
     * <ul>
     * <li>{@link SimplePropertyDescriptor} - the value of the given simple property,
     * or <code>null</code> if none; primitive values are "boxed"</li>
     * <li>{@link ChildPropertyDescriptor} - the child node (type <code>ASTNode</code>),
     * or <code>null</code> if none</li>
     * <li>{@link ChildListPropertyDescriptor} - the list (element type: {@link ASTNode})</li>
     * </ul>
     *
     * @param property the property
     * @return the value, or <code>null</code> if none
     * @exception RuntimeException if this node does not have the given property
     * @since 3.0
     */
    public final Object getStructuralProperty(StructuralPropertyDescriptor property) {
        if (property instanceof SimplePropertyDescriptor) {
            SimplePropertyDescriptor p = (SimplePropertyDescriptor) property;
            if (p.getValueType() == int.class) {
                int result = internalGetSetIntProperty(p, true, 0);
                return Integer.valueOf(result);
            } else if (p.getValueType() == boolean.class) {
                boolean result = internalGetSetBooleanProperty(p, true, false);
                return Boolean.valueOf(result);
            } else {
                return internalGetSetObjectProperty(p, true, null);
            }
        }
        if (property instanceof ChildPropertyDescriptor) {
            return internalGetSetChildProperty((ChildPropertyDescriptor) property, true, null);
        }
        if (property instanceof ChildListPropertyDescriptor) {
            return internalGetChildListProperty((ChildListPropertyDescriptor) property);
        }
        throw new IllegalArgumentException();
    }

    /**
     * Sets the value of the given structural property for this node. The value
     * passed depends on the kind of property:
     * <ul>
     * <li>{@link SimplePropertyDescriptor} - the new value of the given simple property,
     * or <code>null</code> if none; primitive values are "boxed"</li>
     * <li>{@link ChildPropertyDescriptor} - the new child node (type <code>ASTNode</code>),
     * or <code>null</code> if none</li>
     * <li>{@link ChildListPropertyDescriptor} - not allowed</li>
     * </ul>
     *
     * @param property the property
     * @param value the property value
     * @exception RuntimeException if this node does not have the
     * given property, or if the given property cannot be set
     * @since 3.0
     */
    public final void setStructuralProperty(StructuralPropertyDescriptor property, Object value) {
        if (property instanceof SimplePropertyDescriptor) {
            SimplePropertyDescriptor p = (SimplePropertyDescriptor) property;
            if (p.getValueType() == int.class) {
                int arg = ((Integer) value).intValue();
                internalGetSetIntProperty(p, false, arg);
                return;
            } else if (p.getValueType() == boolean.class) {
                boolean arg = ((Boolean) value).booleanValue();
                internalGetSetBooleanProperty(p, false, arg);
                return;
            } else {
                if (value == null && p.isMandatory()) {
                    throw new IllegalArgumentException();
                }
                internalGetSetObjectProperty(p, false, value);
                return;
            }
        }
        if (property instanceof ChildPropertyDescriptor) {
            ChildPropertyDescriptor p = (ChildPropertyDescriptor) property;
            ASTNode child = (ASTNode) value;
            if (child == null && p.isMandatory()) {
                throw new IllegalArgumentException();
            }
            internalGetSetChildProperty(p, false, child);
            return;
        }
        if (property instanceof ChildListPropertyDescriptor) {
            throw new IllegalArgumentException("Cannot set the list of child list property"); //$NON-NLS-1$
        }
    }

    /**
     * Sets the value of the given int-valued property for this node.
     * The default implementation of this method throws an exception explaining
     * that this node does not have such a property. This method should be
     * extended in subclasses that have at least one simple property whose value
     * type is int.
     *
     * @param property the property
     * @param get <code>true</code> for a get operation, and
     * <code>false</code> for a set operation
     * @param value the new property value; ignored for get operations
     * @return the value; always returns
     * <code>0</code> for set operations
     * @exception RuntimeException if this node does not have the
     * given property, or if the given value cannot be set as specified
     * @since 3.0
     */
    int internalGetSetIntProperty(SimplePropertyDescriptor property, boolean get, int value) {
        throw new RuntimeException("Node does not have this property"); //$NON-NLS-1$
    }

    /**
     * Sets the value of the given boolean-valued property for this node.
     * The default implementation of this method throws an exception explaining
     * that this node does not have such a property. This method should be
     * extended in subclasses that have at least one simple property whose value
     * type is boolean.
     *
     * @param property the property
     * @param get <code>true</code> for a get operation, and
     * <code>false</code> for a set operation
     * @param value the new property value; ignored for get operations
     * @return the value; always returns
     * <code>false</code> for set operations
     * @exception RuntimeException if this node does not have the
     * given property, or if the given value cannot be set as specified
     * @since 3.0
     */
    boolean internalGetSetBooleanProperty(SimplePropertyDescriptor property, boolean get, boolean value) {
        throw new RuntimeException("Node does not have this property"); //$NON-NLS-1$
    }

    /**
     * Sets the value of the given property for this node.
     * The default implementation of this method throws an exception explaining
     * that this node does not have such a property. This method should be
     * extended in subclasses that have at least one simple property whose value
     * type is a reference type.
     *
     * @param property the property
     * @param get <code>true</code> for a get operation, and
     * <code>false</code> for a set operation
     * @param value the new property value, or <code>null</code> if none;
     * ignored for get operations
     * @return the value, or <code>null</code> if none; always returns
     * <code>null</code> for set operations
     * @exception RuntimeException if this node does not have the
     * given property, or if the given value cannot be set as specified
     * @since 3.0
     */
    Object internalGetSetObjectProperty(SimplePropertyDescriptor property, boolean get, Object value) {
        throw new RuntimeException("Node does not have this property"); //$NON-NLS-1$
    }

    /**
     * Sets the child value of the given property for this node.
     * The default implementation of this method throws an exception explaining
     * that this node does not have such a property. This method should be
     * extended in subclasses that have at least one child property.
     *
     * @param property the property
     * @param get <code>true</code> for a get operation, and
     * <code>false</code> for a set operation
     * @param child the new child value, or <code>null</code> if none;
     * always <code>null</code> for get operations
     * @return the child, or <code>null</code> if none; always returns
     * <code>null</code> for set operations
     * @exception RuntimeException if this node does not have the
     * given property, or if the given child cannot be set as specified
     * @since 3.0
     */
    ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
        throw new RuntimeException("Node does not have this property"); //$NON-NLS-1$
    }

    /**
     * Returns the list value of the given property for this node.
     * The default implementation of this method throws an exception explaining
     * that this node does not have such a property. This method should be
     * extended in subclasses that have at least one child list property.
     *
     * @param property the property
     * @return the list (element type: {@link ASTNode})
     * @exception RuntimeException if the given node does not have the
     * given property
     * @since 3.0
     */
    List internalGetChildListProperty(ChildListPropertyDescriptor property) {
        throw new RuntimeException("Node does not have this property"); //$NON-NLS-1$
    }

    /**
     * Returns a list of structural property descriptors for nodes of the
     * same type as this node. Clients must not modify the result.
     * <p>
     * Note that property descriptors are a meta-level mechanism
     * for manipulating ASTNodes in a generic way. They are
     * unrelated to <code>get/setProperty</code>.
     * </p>
     *
     * @return a list of property descriptors (element type:
     * {@link StructuralPropertyDescriptor})
     * @since 3.0
     */
    public final List structuralPropertiesForType() {
        return internalStructuralPropertiesForType(this.ast.apiLevel);
    }

    /**
     * Returns a list of property descriptors for this node type.
     * Clients must not modify the result. This abstract method
     * must be implemented in each concrete AST node type.
     * <p>
     * N.B. This method is package-private, so that the implementations
     * of this method in each of the concrete AST node types do not
     * clutter up the API doc.
     * </p>
     *
     * @param apiLevel the API level; one of the <code>AST.JLS*</code> constants
     * @return a list of property descriptors (element type:
     * {@link StructuralPropertyDescriptor})
     * @since 3.0
     */
    abstract List internalStructuralPropertiesForType(int apiLevel);

    /**
     * Internal helper method that starts the building a list of
     * property descriptors for the given node type.
     *
     * @param nodeClass the class for a concrete node type with n properties
     * @param propertyList empty list, with capacity for n+1 elements
     */
    static void createPropertyList(Class nodeClass, List propertyList) {
        // stuff nodeClass at head of list for future ref
        propertyList.add(nodeClass);
    }

    /**
     * Internal helper method that adding a property descriptor.
     *
     * @param property the structural property descriptor
     * @param propertyList list beginning with the AST node class
     * followed by accumulated structural property descriptors
     */
    static void addProperty(StructuralPropertyDescriptor property, List propertyList) {
        Class nodeClass = (Class) propertyList.get(0);
        if (property.getNodeClass() != nodeClass) {
            // easily made cut-and-paste mistake
            throw new RuntimeException("Structural property descriptor has wrong node class!"); //$NON-NLS-1$
        }
        propertyList.add(property);
    }

    /**
     * Internal helper method that completes the building of
     * a node type's structural property descriptor list.
     *
     * @param propertyList list beginning with the AST node class
     * followed by accumulated structural property descriptors
     * @return unmodifiable list of structural property descriptors
     * (element type: {@link StructuralPropertyDescriptor})
     */
    static List reapPropertyList(List propertyList) {
        propertyList.remove(0); // remove nodeClass
        // compact
        ArrayList a = new ArrayList(propertyList.size());
        a.addAll(propertyList);
        return Collections.unmodifiableList(a);
    }

    /**
      * Checks that this AST operation is not used when
      * building JLS2 level ASTs.
      * <p>
      * Use this method to prevent access to new properties that have been added in JLS3.
      * </p>
      * 
     * @exception UnsupportedOperationException if this operation is used in a JLS2 AST
     * @since 3.0
      */
    final void unsupportedIn2() {
        if (this.ast.apiLevel == AST.JLS2_INTERNAL) {
            throw new UnsupportedOperationException("Operation not supported in JLS2 AST"); //$NON-NLS-1$
        }
    }

    /**
      * Checks that this AST operation is not used when
      * building JLS2 or JLS3 level ASTs.
      * <p>
      * Use this method to prevent access to new properties that have been added in JLS4.
      * </p>
      * 
     * @exception UnsupportedOperationException if this operation is used in a JLS2 or JLS3 AST
     * @since 3.7
     */
    final void unsupportedIn2_3() {
        if (this.ast.apiLevel <= AST.JLS3_INTERNAL) {
            throw new UnsupportedOperationException("Operation only supported in JLS4 and later AST"); //$NON-NLS-1$
        }
    }

    /**
      * Checks that this AST operation is not used when
      * building JLS2 or JLS3 or JLS4 level ASTs.
      * <p>
      * Use this method to prevent access to new properties that have been added in JLS8.
      * </p>
      * 
     * @exception UnsupportedOperationException if this operation is used below JLS8
     * @since 3.10
     */
    final void unsupportedIn2_3_4() {
        if (this.ast.apiLevel < AST.JLS8) {
            throw new UnsupportedOperationException("Operation only supported in JLS8 and later AST"); //$NON-NLS-1$
        }
    }

    /**
      * Checks that this AST operation is only used when
      * building JLS2 level ASTs.
      * <p>
      * Use this method to prevent access to deprecated properties (deprecated in JLS3).
      * </p>
      * 
     * @exception UnsupportedOperationException if this operation is used in an AST later than JLS2
     * @since 3.0
      */
    // In API Javadocs, add: * @deprecated In the JLS3 API, this method is replaced by {@link #replacement()}.
    final void supportedOnlyIn2() {
        if (this.ast.apiLevel != AST.JLS2_INTERNAL) {
            throw new UnsupportedOperationException("Operation only supported in JLS2 AST"); //$NON-NLS-1$
        }
    }

    /**
      * Checks that this AST operation is only used when
      * building JLS2, JLS3 or JLS4 level ASTs.
      * <p>
      * Use this method to prevent access to deprecated properties (deprecated in JLS8).
      * </p>
      * 
     * @exception UnsupportedOperationException if this operation is used in an AST later than JLS4
      * @since 3.10
      */
    // In API Javadocs, add: * @deprecated In the JLS8 API, this method is replaced by {@link #replacement()}.
    final void supportedOnlyIn2_3_4() {
        if (this.ast.apiLevel >= AST.JLS8) {
            throw new UnsupportedOperationException("Operation only supported in JLS2, JLS3 and JLS4 ASTs"); //$NON-NLS-1$
        }
    }

    /**
     * Sets or clears this node's parent node and location.
     * <p>
     * Note that this method is package-private. The pointer from a node
     * to its parent is set implicitly as a side effect of inserting or
     * removing the node as a child of another node. This method calls
     * <code>ast.modifying()</code>.
     * </p>
     *
     * @param parent the new parent of this node, or <code>null</code> if none
     * @param property the location of this node in its parent,
     * or <code>null</code> if <code>parent</code> is <code>null</code>
     * @see #getLocationInParent
     * @see #getParent
     * @since 3.0
     */
    final void setParent(ASTNode parent, StructuralPropertyDescriptor property) {
        this.ast.modifying();
        this.parent = parent;
        this.location = property;
    }

    /**
     * Removes this node from its parent. Has no effect if this node
     * is unparented. If this node appears as an element of a child list
     * property of its parent, then this node is removed from the
     * list using <code>List.remove</code>.
     * If this node appears as the value of a child property of its
     * parent, then this node is detached from its parent
     * by passing <code>null</code> to the appropriate setter method;
     * this operation fails if this node is in a mandatory property.
     *
     * @since 3.0
     */
    public final void delete() {
        StructuralPropertyDescriptor p = getLocationInParent();
        if (p == null) {
            // node is unparented
            return;
        }
        if (p.isChildProperty()) {
            getParent().setStructuralProperty(this.location, null);
            return;
        }
        if (p.isChildListProperty()) {
            List l = (List) getParent().getStructuralProperty(this.location);
            l.remove(this);
        }
    }

    /**
     * Checks whether the given new child node is a node
     * in a different AST from its parent-to-be, whether it is
     * already has a parent, whether adding it to its
     * parent-to-be would create a cycle, and whether the child is of
     * the right type. The parent-to-be is the enclosing instance.
     *
     * @param node the parent-to-be node
     * @param newChild the new child of the parent
     * @param cycleCheck <code>true</code> if cycles are possible and need
     *   to be checked, <code>false</code> if cycles are impossible and do
     *   not need to be checked
     * @param nodeType a type constraint on child nodes, or <code>null</code>
     *   if no special check is required
     * @exception IllegalArgumentException if:
     * <ul>
     * <li>the child is null</li>
     * <li>the node belongs to a different AST</li>
     * <li>the child has the incorrect node type</li>
     * <li>the node already has a parent</li>
     * <li>a cycle in would be created</li>
     * </ul>
     */
    static void checkNewChild(ASTNode node, ASTNode newChild, boolean cycleCheck, Class nodeType) {
        if (newChild.ast != node.ast) {
            // new child is from a different AST
            throw new IllegalArgumentException();
        }
        if (newChild.getParent() != null) {
            // new child currently has a different parent
            throw new IllegalArgumentException();
        }
        if (cycleCheck && newChild == node.getRoot()) {
            // inserting new child would create a cycle
            throw new IllegalArgumentException();
        }
        Class childClass = newChild.getClass();
        if (nodeType != null && !nodeType.isAssignableFrom(childClass)) {
            // new child is not of the right type
            throw new ClassCastException();
        }
        if ((newChild.typeAndFlags & PROTECT) != 0) {
            // new child node is protected => cannot be parented
            throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
        }
    }

    /**
      * Prelude portion of the "3 step program" for replacing the
     * old child of this node with another node.
      * Here is the code pattern found in all AST node subclasses:
      * <pre>
      * ASTNode oldChild = this.foo;
      * preReplaceChild(oldChild, newFoo, FOO_PROPERTY);
      * this.foo = newFoo;
      * postReplaceChild(oldChild, newFoo, FOO_PROPERTY);
      * </pre>
      * The first part (preReplaceChild) does all the precondition checks,
      * reports pre-delete events, and changes parent links.
     * The old child is delinked from its parent (making it a root node),
     * and the new child node is linked to its parent. The new child node
     * must be a root node in the same AST as its new parent, and must not
     * be an ancestor of this node. All three nodes must be
      * modifiable (not PROTECTED). The replace operation must fail
      * atomically; so it is crucial that all precondition checks
      * be done before any linking and delinking happens.
      * The final part (postReplaceChild )reports post-add events.
     * <p>
     * This method calls <code>ast.modifying()</code> for the nodes affected.
     * </p>
     *
     * @param oldChild the old child of this node, or <code>null</code> if
     *   there was no old child to replace
     * @param newChild the new child of this node, or <code>null</code> if
     *   there is no replacement child
     * @param property the property descriptor of this node describing
      * the relationship between node and child
     * @exception RuntimeException if:
     * <ul>
     * <li>the node belongs to a different AST</li>
     * <li>the node already has a parent</li>
     * <li>a cycle in would be created</li>
     * <li>any of the nodes involved are unmodifiable</li>
     * </ul>
     * @since 3.0
     */
    final void preReplaceChild(ASTNode oldChild, ASTNode newChild, ChildPropertyDescriptor property) {
        if ((this.typeAndFlags & PROTECT) != 0) {
            // this node is protected => cannot gain or lose children
            throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
        }
        if (newChild != null) {
            checkNewChild(this, newChild, property.cycleRisk, null);
        }
        // delink old child from parent
        if (oldChild != null) {
            if ((oldChild.typeAndFlags & PROTECT) != 0) {
                // old child node is protected => cannot be unparented
                throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
            }
            if (newChild != null) {
                this.ast.preReplaceChildEvent(this, oldChild, newChild, property);
            } else {
                this.ast.preRemoveChildEvent(this, oldChild, property);
            }
            oldChild.setParent(null, null);
        } else {
            if (newChild != null) {
                this.ast.preAddChildEvent(this, newChild, property);
            }
        }
        // link new child to parent
        if (newChild != null) {
            newChild.setParent(this, property);
            // cannot notify postAddChildEvent until parent is linked to child too
        }
    }

    /**
      * Postlude portion of the "3 step program" for replacing the
     * old child of this node with another node.
      * See {@link #preReplaceChild(ASTNode, ASTNode, ChildPropertyDescriptor)}
      * for details.
     * @since 3.0
     */
    final void postReplaceChild(ASTNode oldChild, ASTNode newChild, ChildPropertyDescriptor property) {
        // link new child to parent
        if (newChild != null) {
            if (oldChild != null) {
                this.ast.postReplaceChildEvent(this, oldChild, newChild, property);
            } else {
                this.ast.postAddChildEvent(this, newChild, property);
            }
        } else {
            this.ast.postRemoveChildEvent(this, oldChild, property);
        }
    }

    /**
      * Prelude portion of the "3 step program" for changing the
     * value of a simple property of this node.
      * Here is the code pattern found in all AST node subclasses:
      * <pre>
      * preValueChange(FOO_PROPERTY);
      * this.foo = newFoo;
      * postValueChange(FOO_PROPERTY);
      * </pre>
      * The first part (preValueChange) does the precondition check
      * to make sure the node is modifiable (not PROTECTED).
      * The change operation must fail atomically; so it is crucial
      * that the precondition checks are done before the field is
      * hammered. The final part (postValueChange)reports post-change
      * events.
     * <p>
     * This method calls <code>ast.modifying()</code> for the node affected.
     * </p>
     *
     * @param property the property descriptor of this node
     * @exception RuntimeException if:
     * <ul>
     * <li>this node is unmodifiable</li>
     * </ul>
     * @since 3.0
     */
    final void preValueChange(SimplePropertyDescriptor property) {
        if ((this.typeAndFlags & PROTECT) != 0) {
            // this node is protected => cannot change value of properties
            throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
        }
        this.ast.preValueChangeEvent(this, property);
        this.ast.modifying();
    }

    /**
      * Postlude portion of the "3 step program" for replacing the
     * old child of this node with another node.
      * See {@link #preValueChange(SimplePropertyDescriptor)} for details.
     * @since 3.0
     */
    final void postValueChange(SimplePropertyDescriptor property) {
        this.ast.postValueChangeEvent(this, property);
    }

    /**
      * Ensures that this node is modifiable (that is, not marked PROTECTED).
      * If successful, calls ast.modifying().
      * @exception RuntimeException is not modifiable
      */
    final void checkModifiable() {
        if ((this.typeAndFlags & PROTECT) != 0) {
            throw new IllegalArgumentException("AST node cannot be modified"); //$NON-NLS-1$
        }
        this.ast.modifying();
    }

    /**
      * Begin lazy initialization of this node.
      * Here is the code pattern found in all AST
      * node subclasses:
      * <pre>
      * if (this.foo == null) {
     *    // lazy init must be thread-safe for readers
      *    synchronized (this) {
      *       if (this.foo == null) {
      *          preLazyInit();
      *          this.foo = ...; // code to create new node
      *          postLazyInit(this.foo, FOO_PROPERTY);
      *       }
      *    }
      * }
      * </pre>
      * @since 3.0
      */
    final void preLazyInit() {
        // IMPORTANT: this method is called by readers
        // ASTNode.this is locked at this point
        this.ast.disableEvents();
        // will turn events back on in postLasyInit
    }

    /**
      * End lazy initialization of this node.
      *
     * @param newChild the new child of this node, or <code>null</code> if
     *   there is no replacement child
     * @param property the property descriptor of this node describing
      * the relationship between node and child
      * @since 3.0
      */
    final void postLazyInit(ASTNode newChild, ChildPropertyDescriptor property) {
        // IMPORTANT: this method is called by readers
        // ASTNode.this is locked at this point
        // newChild is brand new (so no chance of concurrent access)
        newChild.setParent(this, property);
        // turn events back on (they were turned off in corresponding preLazyInit)
        this.ast.reenableEvents();
    }

    /**
     * Returns the value of the named property of this node, or <code>null</code> if none.
     *
     * @param propertyName the property name
     * @return the property value, or <code>null</code> if none
     * @see #setProperty(String,Object)
     */
    public final Object getProperty(String propertyName) {
        if (propertyName == null) {
            throw new IllegalArgumentException();
        }
        if (this.property1 == null) {
            // node has no properties at all
            return null;
        }
        if (this.property1 instanceof String) {
            // node has only a single property
            if (propertyName.equals(this.property1)) {
                return this.property2;
            } else {
                return null;
            }
        }
        // otherwise node has table of properties
        Map m = (Map) this.property1;
        return m.get(propertyName);
    }

    /**
     * Sets the named property of this node to the given value,
     * or to <code>null</code> to clear it.
     * <p>
     * Clients should employ property names that are sufficiently unique
     * to avoid inadvertent conflicts with other clients that might also be
     * setting properties on the same node.
     * </p>
     * <p>
     * Note that modifying a property is not considered a modification to the
     * AST itself. This is to allow clients to decorate existing nodes with
     * their own properties without jeopardizing certain things (like the
     * validity of bindings), which rely on the underlying tree remaining static.
     * </p>
     *
     * @param propertyName the property name
     * @param data the new property value, or <code>null</code> if none
     * @see #getProperty(String)
     * @throws IllegalArgumentException if the given property name is <code>null</code>
     */
    public final void setProperty(String propertyName, Object data) {
        if (propertyName == null) {
            throw new IllegalArgumentException();
        }
        // N.B. DO NOT CALL ast.modifying();

        if (this.property1 == null) {
            // node has no properties at all
            if (data == null) {
                // we already know this
                return;
            }
            // node gets its fist property
            this.property1 = propertyName;
            this.property2 = data;
            return;
        }

        if (this.property1 instanceof String) {
            // node has only a single property
            if (propertyName.equals(this.property1)) {
                // we're in luck
                if (data == null) {
                    // just deleted last property
                    this.property1 = null;
                    this.property2 = null;
                } else {
                    this.property2 = data;
                }
                return;
            }
            if (data == null) {
                // we already know this
                return;
            }
            // node already has one property - getting its second
            // convert to more flexible representation
            Map m = new HashMap(3);
            m.put(this.property1, this.property2);
            m.put(propertyName, data);
            this.property1 = m;
            this.property2 = null;
            return;
        }

        // node has two or more properties
        Map m = (Map) this.property1;
        if (data == null) {
            m.remove(propertyName);
            // check for just one property left
            if (m.size() == 1) {
                // convert to more efficient representation
                Map.Entry[] entries = (Map.Entry[]) m.entrySet().toArray(new Map.Entry[1]);
                this.property1 = entries[0].getKey();
                this.property2 = entries[0].getValue();
            }
            return;
        } else {
            m.put(propertyName, data);
            // still has two or more properties
            return;
        }
    }

    /**
     * Returns an unmodifiable table of the properties of this node with
     * non-<code>null</code> values.
     *
     * @return the table of property values keyed by property name
     *   (key type: <code>String</code>; value type: <code>Object</code>)
     */
    public final Map properties() {
        if (this.property1 == null) {
            // node has no properties at all
            return UNMODIFIABLE_EMPTY_MAP;
        }
        if (this.property1 instanceof String) {
            // node has a single property
            return Collections.singletonMap(this.property1, this.property2);
        }

        // node has two or more properties
        if (this.property2 == null) {
            this.property2 = Collections.unmodifiableMap((Map) this.property1);
        }
        // property2 is unmodifiable wrapper for map in property1
        return (Map) this.property2;
    }

    /**
     * Returns the flags associated with this node.
     * <p>
     * No flags are associated with newly created nodes.
     * </p>
     * <p>
     * The flags are the bitwise-or of individual flags.
     * The following flags are currently defined:
     * <ul>
     * <li>{@link #MALFORMED} - indicates node is syntactically
     *   malformed</li>
     * <li>{@link #ORIGINAL} - indicates original node
     * created by ASTParser</li>
     * <li>{@link #PROTECT} - indicates node is protected
     * from further modification</li>
     * <li>{@link #RECOVERED} - indicates node or a part of this node
     *  is recovered from source that contains a syntax error</li>
     * </ul>
     * Other bit positions are reserved for future use.
     * </p>
     *
     * @return the bitwise-or of individual flags
     * @see #setFlags(int)
     */
    public final int getFlags() {
        return this.typeAndFlags & 0xFFFF;
    }

    /**
     * Sets the flags associated with this node to the given value.
     * <p>
     * The flags are the bitwise-or of individual flags.
     * The following flags are currently defined:
     * <ul>
     * <li>{@link #MALFORMED} - indicates node is syntactically
     *   malformed</li>
     * <li>{@link #ORIGINAL} - indicates original node
     * created by ASTParser</li>
     * <li>{@link #PROTECT} - indicates node is protected
     * from further modification</li>
     * <li>{@link #RECOVERED} - indicates node or a part of this node
     *  is recovered from source that contains a syntax error</li>
     * </ul>
     * Other bit positions are reserved for future use.
     * </p>
     * <p>
     * Note that the flags are <em>not</em> considered a structural
     * property of the node, and can be changed even if the
     * node is marked as protected.
     * </p>
     *
     * @param flags the bitwise-or of individual flags
     * @see #getFlags()
     */
    public final void setFlags(int flags) {
        this.ast.modifying();
        int old = this.typeAndFlags & 0xFFFF0000;
        this.typeAndFlags = old | (flags & 0xFFFF);
    }

    /**
     * Returns an integer value identifying the type of this concrete AST node.
     * The values are small positive integers, suitable for use in switch statements.
     * <p>
     * For each concrete node type there is a unique node type constant (name
     * and value). The unique node type constant for a concrete node type such as
     * <code>CastExpression</code> is <code>ASTNode.CAST_EXPRESSION</code>.
     * </p>
     *
     * @return one of the node type constants
     */
    public final int getNodeType() {
        return this.typeAndFlags >>> 16;
    }

    /**
     * Sets the integer value identifying the type of this concrete AST node.
     * The values are small positive integers, suitable for use in switch statements.
     *
     * @param nodeType one of the node type constants
     */
    private void setNodeType(int nodeType) {
        int old = this.typeAndFlags & 0xFFFF0000;
        this.typeAndFlags = old | (nodeType << 16);
    }

    /**
     * Returns an integer value identifying the type of this concrete AST node.
     * <p>
     * This internal method is implemented in each of the
     * concrete node subclasses.
     * </p>
     *
     * @return one of the node type constants
     */
    abstract int getNodeType0();

    /**
     * The <code>ASTNode</code> implementation of this <code>Object</code>
     * method uses object identity (==). Use <code>subtreeMatch</code> to
     * compare two subtrees for equality.
     *
     * @param obj {@inheritDoc}
     * @return {@inheritDoc}
     * @see #subtreeMatch(ASTMatcher matcher, Object other)
     */
    public final boolean equals(Object obj) {
        return this == obj; // equivalent to Object.equals
    }

    /*
     * (non-Javadoc)
     * This makes it consistent with the fact that a equals methods has been provided.
     * @see java.lang.Object#hashCode()
     */
    public final int hashCode() {
        return super.hashCode();
    }

    /**
     * Returns whether the subtree rooted at the given node matches the
     * given other object as decided by the given matcher.
     *
     * @param matcher the matcher
     * @param other the other object, or <code>null</code>
     * @return <code>true</code> if the subtree matches, or
     * <code>false</code> if they do not match
     */
    public final boolean subtreeMatch(ASTMatcher matcher, Object other) {
        return subtreeMatch0(matcher, other);
    }

    /**
     * Returns whether the subtree rooted at the given node matches the
     * given other object as decided by the given matcher.
     * <p>
     * This internal method is implemented in each of the
     * concrete node subclasses.
     * </p>
     *
     * @param matcher the matcher
     * @param other the other object, or <code>null</code>
     * @return <code>true</code> if the subtree matches, or
     * <code>false</code> if they do not match
     */
    abstract boolean subtreeMatch0(ASTMatcher matcher, Object other);

    /**
     * Returns a deep copy of the subtree of AST nodes rooted at the
     * given node. The resulting nodes are owned by the given AST,
     * which may be different from the ASTs of the given node.
     * Even if the given node has a parent, the result node will be unparented.
     * <p>
     * Source range information on the original nodes is automatically copied to the new
     * nodes. Client properties (<code>properties</code>) are not carried over.
     * </p>
     * <p>
     * The node's <code>AST</code> and the target <code>AST</code> must support
      * the same API level.
     * </p>
     *
     * @param target the AST that is to own the nodes in the result
     * @param node the node to copy, or <code>null</code> if none
     * @return the copied node, or <code>null</code> if <code>node</code>
     *    is <code>null</code>
     */
    public static ASTNode copySubtree(AST target, ASTNode node) {
        if (node == null) {
            return null;
        }
        if (target == null) {
            throw new IllegalArgumentException();
        }
        if (target.apiLevel() != node.getAST().apiLevel()) {
            throw new UnsupportedOperationException();
        }
        ASTNode newNode = node.clone(target);
        return newNode;
    }

    /**
     * Returns a deep copy of the subtrees of AST nodes rooted at the
     * given list of nodes. The resulting nodes are owned by the given AST,
     * which may be different from the ASTs of the nodes in the list.
     * Even if the nodes in the list have parents, the nodes in the result
     * will be unparented.
     * <p>
     * Source range information on the original nodes is automatically copied to the new
     * nodes. Client properties (<code>properties</code>) are not carried over.
     * </p>
     *
     * @param target the AST that is to own the nodes in the result
     * @param nodes the list of nodes to copy
     *    (element type: {@link ASTNode})
     * @return the list of copied subtrees
     *    (element type: {@link ASTNode})
     */
    public static List copySubtrees(AST target, List nodes) {
        List result = new ArrayList(nodes.size());
        for (Iterator it = nodes.iterator(); it.hasNext();) {
            ASTNode oldNode = (ASTNode) it.next();
            ASTNode newNode = oldNode.clone(target);
            result.add(newNode);
        }
        return result;
    }

    /**
     * Returns a deep copy of the subtree of AST nodes rooted at this node.
     * The resulting nodes are owned by the given AST, which may be different
     * from the AST of this node. Even if this node has a parent, the
     * result node will be unparented.
     * <p>
     * This method reports pre- and post-clone events, and dispatches
     * to <code>clone0(AST)</code> which is reimplemented in node subclasses.
     * </p>
     *
     * @param target the AST that is to own the nodes in the result
     * @return the root node of the copies subtree
     */
    final ASTNode clone(AST target) {
        this.ast.preCloneNodeEvent(this);
        ASTNode c = clone0(target);
        this.ast.postCloneNodeEvent(this, c);
        return c;
    }

    /**
     * Returns a deep copy of the subtree of AST nodes rooted at this node.
     * The resulting nodes are owned by the given AST, which may be different
     * from the AST of this node. Even if this node has a parent, the
     * result node will be unparented.
     * <p>
     * This method must be implemented in subclasses.
     * </p>
     * <p>
     * General template for implementation on each concrete ASTNode class:
     * <pre>
     * <code>
     * ConcreteNodeType result = new ConcreteNodeType(target);
     * result.setSourceRange(getStartPosition(), getLength());
     * result.setChildProperty(
     *         (ChildPropertyType) ASTNode.copySubtree(target, getChildProperty()));
     * result.setSimpleProperty(isSimpleProperty());
     * result.childrenProperty().addAll(
     *         ASTNode.copySubtrees(target, childrenProperty()));
     * return result;
     * </code>
     * </pre>
     * </p>
     * <p>
     * This method does not report pre- and post-clone events.
     * All callers should instead call <code>clone(AST)</code>
     * to ensure that pre- and post-clone events are reported.
     * </p>
     * <p>
     * N.B. This method is package-private, so that the implementations
     * of this method in each of the concrete AST node types do not
     * clutter up the API doc.
     * </p>
     *
     * @param target the AST that is to own the nodes in the result
     * @return the root node of the copies subtree
     */
    abstract ASTNode clone0(AST target);

    /**
     * Accepts the given visitor on a visit of the current node.
     *
     * @param visitor the visitor object
     * @exception IllegalArgumentException if the visitor is null
     */
    public final void accept(ASTVisitor visitor) {
        if (visitor == null) {
            throw new IllegalArgumentException();
        }
        // begin with the generic pre-visit
        if (visitor.preVisit2(this)) {
            // dynamic dispatch to internal method for type-specific visit/endVisit
            accept0(visitor);
        }
        // end with the generic post-visit
        visitor.postVisit(this);
    }

    /**
     * Accepts the given visitor on a type-specific visit of the current node.
     * This method must be implemented in all concrete AST node types.
     * <p>
     * General template for implementation on each concrete ASTNode class:
     * <pre>
     * <code>
     * boolean visitChildren = visitor.visit(this);
     * if (visitChildren) {
     *    // visit children in normal left to right reading order
     *    acceptChild(visitor, getProperty1());
     *    acceptChildren(visitor, this.rawListProperty);
     *    acceptChild(visitor, getProperty2());
     * }
     * visitor.endVisit(this);
     * </code>
     * </pre>
     * Note that the caller (<code>accept</code>) take cares of invoking
     * <code>visitor.preVisit(this)</code> and <code>visitor.postVisit(this)</code>.
     * </p>
     *
     * @param visitor the visitor object
     */
    abstract void accept0(ASTVisitor visitor);

    /**
     * Accepts the given visitor on a visit of the current node.
     * <p>
     * This method should be used by the concrete implementations of
     * <code>accept0</code> to traverse optional properties. Equivalent
     * to <code>child.accept(visitor)</code> if <code>child</code>
     * is not <code>null</code>.
     * </p>
     *
     * @param visitor the visitor object
     * @param child the child AST node to dispatch too, or <code>null</code>
     *    if none
     */
    final void acceptChild(ASTVisitor visitor, ASTNode child) {
        if (child == null) {
            return;
        }
        child.accept(visitor);
    }

    /**
     * Accepts the given visitor on a visit of the given live list of
     * child nodes.
     * <p>
     * This method must be used by the concrete implementations of
     * <code>accept</code> to traverse list-values properties; it
     * encapsulates the proper handling of on-the-fly changes to the list.
     * </p>
     *
     * @param visitor the visitor object
     * @param children the child AST node to dispatch too, or <code>null</code>
     *    if none
     */
    final void acceptChildren(ASTVisitor visitor, ASTNode.NodeList children) {
        // use a cursor to keep track of where we are up to
        // (the list may be changing under foot)
        NodeList.Cursor cursor = children.newCursor();
        try {
            while (cursor.hasNext()) {
                ASTNode child = (ASTNode) cursor.next();
                child.accept(visitor);
            }
        } finally {
            children.releaseCursor(cursor);
        }
    }

    /**
     * Returns the character index into the original source file indicating
     * where the source fragment corresponding to this node begins.
     * <p>
     * The parser supplies useful well-defined source ranges to the nodes it creates.
     * See {@link ASTParser#setKind(int)} for details
     * on precisely where source ranges begin and end.
     * </p>
     *
     * @return the 0-based character index, or <code>-1</code>
     *    if no source position information is recorded for this node
     * @see #getLength()
     * @see ASTParser
     */
    public final int getStartPosition() {
        return this.startPosition;
    }

    /**
     * Returns the length in characters of the original source file indicating
     * where the source fragment corresponding to this node ends.
     * <p>
     * The parser supplies useful well-defined source ranges to the nodes it creates.
     * See {@link ASTParser#setKind(int)} methods for details
     * on precisely where source ranges begin and end.
     * </p>
     *
     * @return a (possibly 0) length, or <code>0</code>
     *    if no source position information is recorded for this node
     * @see #getStartPosition()
     * @see ASTParser
     */
    public final int getLength() {
        return this.length;
    }

    /**
     * Sets the source range of the original source file where the source
     * fragment corresponding to this node was found.
     * <p>
     * See {@link ASTParser#setKind(int)} for details
     * on precisely where source ranges are supposed to begin and end.
     * </p>
     *
     * @param startPosition a 0-based character index,
     *    or <code>-1</code> if no source position information is
     *    available for this node
     * @param length a (possibly 0) length,
     *    or <code>0</code> if no source position information is recorded
     *    for this node
     * @see #getStartPosition()
     * @see #getLength()
     * @see ASTParser
     */
    public final void setSourceRange(int startPosition, int length) {
        if (startPosition >= 0 && length < 0) {
            throw new IllegalArgumentException();
        }
        if (startPosition < 0 && length != 0) {
            throw new IllegalArgumentException();
        }
        // source positions are not considered a structural property
        // but we protect them nevertheless
        checkModifiable();
        this.startPosition = startPosition;
        this.length = length;
    }

    /**
     * Returns a string representation of this node suitable for debugging
     * purposes only.
     *
     * @return a debug string
     */
    public final String toString() {
        StringBuffer buffer = new StringBuffer();
        int p = buffer.length();
        try {
            appendDebugString(buffer);
        } catch (RuntimeException e) {
            // since debugger sometimes call toString methods, problems can easily happen when
            // toString is called on an instance that is being initialized
            buffer.setLength(p);
            buffer.append("!"); //$NON-NLS-1$
            buffer.append(standardToString());
        }
        return buffer.toString();
    }

    /**
     * Returns the string representation of this node produced by the standard
     * <code>Object.toString</code> method.
     *
     * @return a debug string
     */
    final String standardToString() {
        return super.toString();
    }

    /**
     * Appends a debug representation of this node to the given string buffer.
     * <p>
     * The <code>ASTNode</code> implementation of this method prints out the entire
     * subtree. Subclasses may override to provide a more succinct representation.
     * </p>
     *
     * @param buffer the string buffer to append to
     */
    void appendDebugString(StringBuffer buffer) {
        // print the subtree by default
        appendPrintString(buffer);
    }

    /**
     * Appends a standard Java source code representation of this subtree to the given
     * string buffer.
     *
     * @param buffer the string buffer to append to
     */
    final void appendPrintString(StringBuffer buffer) {
        NaiveASTFlattener printer = new NaiveASTFlattener();
        accept(printer);
        buffer.append(printer.getResult());
    }

    /**
     * Estimate of size of an object header in bytes.
     */
    static final int HEADERS = 12;

    /**
     * Approximate base size of an AST node instance in bytes,
     * including object header and instance fields.
     * That is, HEADERS + (# instance vars in ASTNode)*4.
     */
    static final int BASE_NODE_SIZE = HEADERS + 7 * 4;

    /**
     * Returns an estimate of the memory footprint, in bytes,
     * of the given string.
     *
     * @param string the string to measure, or <code>null</code>
     * @return the size of this string object in bytes, or
     *   0 if the string is <code>null</code>
      * @since 3.0
     */
    static int stringSize(String string) {
        int size = 0;
        if (string != null) {
            // Strings usually have 4 instance fields, one of which is a char[]
            size += HEADERS + 4 * 4;
            // char[] has 2 bytes per character
            size += HEADERS + 2 * string.length();
        }
        return size;
    }

    /**
     * Returns an estimate of the memory footprint in bytes of the entire
     * subtree rooted at this node.
     *
     * @return the size of this subtree in bytes
     */
    public final int subtreeBytes() {
        return treeSize();
    }

    /**
     * Returns an estimate of the memory footprint in bytes of the entire
     * subtree rooted at this node.
     * <p>
     * N.B. This method is package-private, so that the implementations
     * of this method in each of the concrete AST node types do not
     * clutter up the API doc.
     * </p>
     *
     * @return the size of this subtree in bytes
     */
    abstract int treeSize();

    /**
     * Returns an estimate of the memory footprint of this node in bytes.
     * The estimate does not include the space occupied by child nodes.
     *
     * @return the size of this node in bytes
     */
    abstract int memSize();
}