gt: 		postReplaceChild(oldChild, expression, INDEX_PROPERTY);
context: /*******************************************************************************
   * Copyright (c) 2000, 2010 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.ArrayList;
  import java.util.List;
  
  /**
   * Array access expression AST node type.
   *
   * <pre>
   * ArrayAccess:
   *    Expression <b>[</b> Expression <b>]</b>
   * </pre>
   *
   * @since 2.0
   * @noinstantiate This class is not intended to be instantiated by clients.
   */
  public class ArrayAccess extends Expression {
  
  	/**
  	 * The "array" structural property of this node type (child type: {@link Expression}).
  	 * @since 3.0
  	 */
  	public static final ChildPropertyDescriptor ARRAY_PROPERTY =
  		new ChildPropertyDescriptor(ArrayAccess.class, "array", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
  
  	/**
  	 * The "index" structural property of this node type (child type: {@link Expression}).
  	 * @since 3.0
  	 */
  	public static final ChildPropertyDescriptor INDEX_PROPERTY =
  		new ChildPropertyDescriptor(ArrayAccess.class, "index", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
  
  	/**
  	 * A list of property descriptors (element type:
  	 * {@link StructuralPropertyDescriptor}),
  	 * or null if uninitialized.
  	 */
  	private static final List PROPERTY_DESCRIPTORS;
  
  	static {
  		List properyList = new ArrayList(3);
  		createPropertyList(ArrayAccess.class, properyList);
  		addProperty(ARRAY_PROPERTY, properyList);
  		addProperty(INDEX_PROPERTY, properyList);
  		PROPERTY_DESCRIPTORS = reapPropertyList(properyList);
  	}
  
  	/**
  	 * Returns a list of structural property descriptors for this node type.
  	 * Clients must not modify the result.
  	 *
  	 * @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
  	 */
  	public static List propertyDescriptors(int apiLevel) {
  		return PROPERTY_DESCRIPTORS;
  	}
  
  	/**
  	 * The array expression; lazily initialized; defaults to an unspecified,
  	 * but legal, expression.
  	 */
  	private Expression arrayExpression = null;
  
  	/**
  	 * The index expression; lazily initialized; defaults to an unspecified,
  	 * but legal, expression.
  	 */
  	private Expression indexExpression = null;
  
  	/**
  	 * Creates a new unparented array access expression node owned by the given
  	 * AST. By default, the array and index expresssions are unspecified,
  	 * but legal.
  	 * <p>
  	 * N.B. This constructor is package-private.
  	 * </p>
  	 *
  	 * @param ast the AST that is to own this node
  	 */
  	ArrayAccess(AST ast) {
  		super(ast);
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	final List internalStructuralPropertiesForType(int apiLevel) {
  		return propertyDescriptors(apiLevel);
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
  		if (property == ARRAY_PROPERTY) {
  			if (get) {
  				return getArray();
  			} else {
  				setArray((Expression) child);
  				return null;
  			}
  		}
  		if (property == INDEX_PROPERTY) {
  			if (get) {
  				return getIndex();
  			} else {
  				setIndex((Expression) child);
  				return null;
  			}
  		}
  		// allow default implementation to flag the error
  		return super.internalGetSetChildProperty(property, get, child);
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	final int getNodeType0() {
  		return ARRAY_ACCESS;
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	ASTNode clone0(AST target) {
  		ArrayAccess result = new ArrayAccess(target);
  		result.setSourceRange(getStartPosition(), getLength());
  		result.setArray((Expression) getArray().clone(target));
  		result.setIndex((Expression) getIndex().clone(target));
  		return result;
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	final boolean subtreeMatch0(ASTMatcher matcher, Object other) {
  		// dispatch to correct overloaded match method
  		return matcher.match(this, other);
  	}
  
  	/* (omit javadoc for this method)
  	 * Method declared on ASTNode.
  	 */
  	void accept0(ASTVisitor visitor) {
  		boolean visitChildren = visitor.visit(this);
  		if (visitChildren) {
  			// visit children in normal left to right reading order
  			acceptChild(visitor, getArray());
  			acceptChild(visitor, getIndex());
  		}
  		visitor.endVisit(this);
  	}
  
  	/**
  	 * Returns the array expression of this array access expression.
  	 *
  	 * @return the array expression node
  	 */
  	public Expression getArray() {
  		if (this.arrayExpression == null) {
  			// lazy init must be thread-safe for readers
  			synchronized (this) {
  				if (this.arrayExpression == null) {
  					preLazyInit();
  					this.arrayExpression = new SimpleName(this.ast);
  					postLazyInit(this.arrayExpression, ARRAY_PROPERTY);
  				}
  			}
  		}
  		return this.arrayExpression;
  	}
  
  	/**
  	 * Sets the array expression of this array access expression.
  	 *
  	 * @param expression the array expression node
  	 * @exception IllegalArgumentException 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>
  	 * </ul>
  	 */
  	public void setArray(Expression expression) {
  		if (expression == null) {
  			throw new IllegalArgumentException();
  		}
  		// an ArrayAccess may occur inside an Expression
  		// must check cycles
  		ASTNode oldChild = this.arrayExpression;
  		preReplaceChild(oldChild, expression, ARRAY_PROPERTY);
  		this.arrayExpression = expression;
  		postReplaceChild(oldChild, expression, ARRAY_PROPERTY);
  	}
  
  	/**
  	 * Returns the index expression of this array access expression.
  	 *
  	 * @return the index expression node
  	 */
  	public Expression getIndex() {
  		if (this.indexExpression == null) {
  			// lazy init must be thread-safe for readers
  			synchronized (this) {
  				if (this.indexExpression == null) {
  					preLazyInit();
  					this.indexExpression = new SimpleName(this.ast);
  					postLazyInit(this.indexExpression, INDEX_PROPERTY);
  				}
  			}
  		}
  		return this.indexExpression;
  	}
  
  	/**
  	 * Sets the index expression of this array access expression.
  	 *
  	 * @param expression the index expression node
  	 * @exception IllegalArgumentException 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>
  	 * </ul>
  	 */
  	public void setIndex(Expression expression) {
  		if (expression == null) {
  			throw new IllegalArgumentException();
  		}
  		// an ArrayAccess may occur inside an Expression
  		// must check cycles
  		ASTNode oldChild = this.indexExpression;
  		preReplaceChild(oldChild, expression, INDEX_PROPERTY);
  		this.indexExpression = expression;
  