Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * 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. */ @SuppressWarnings("rawtypes") 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); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override 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); } @Override final int getNodeType0() { return ARRAY_ACCESS; } @Override 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; } @Override final boolean subtreeMatch0(ASTMatcher matcher, Object other) { // dispatch to correct overloaded match method return matcher.match(this, other); } @Override 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; postReplaceChild(oldChild, expression, INDEX_PROPERTY); } @Override int memSize() { return BASE_NODE_SIZE + 2 * 4; } @Override int treeSize() { return memSize() + (this.arrayExpression == null ? 0 : getArray().treeSize()) + (this.indexExpression == null ? 0 : getIndex().treeSize()); } }