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; /** * Enhanced For statement AST node type (added in JLS3 API). * * <pre> * EnhancedForStatement: * <b>for</b> <b>(</b> FormalParameter <b>:</b> Expression <b>)</b> * Statement * </pre> * * <p>The FormalParameter is represented by a {@link SingleVariableDeclaration} * (without an initializer).</p> * * @since 3.1 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class EnhancedForStatement extends Statement { /** * The "parameter" structural property of this node type (child type: {@link SingleVariableDeclaration}). */ public static final ChildPropertyDescriptor PARAMETER_PROPERTY = new ChildPropertyDescriptor( EnhancedForStatement.class, "parameter", SingleVariableDeclaration.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "expression" structural property of this node type (child type: {@link Expression}). */ public static final ChildPropertyDescriptor EXPRESSION_PROPERTY = new ChildPropertyDescriptor( EnhancedForStatement.class, "expression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "body" structural property of this node type (child type: {@link Statement}). */ public static final ChildPropertyDescriptor BODY_PROPERTY = new ChildPropertyDescriptor( EnhancedForStatement.class, "body", Statement.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(4); createPropertyList(EnhancedForStatement.class, properyList); addProperty(PARAMETER_PROPERTY, properyList); addProperty(EXPRESSION_PROPERTY, properyList); addProperty(BODY_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}) */ public static List propertyDescriptors(int apiLevel) { return PROPERTY_DESCRIPTORS; } /** * The parameter; lazily initialized; defaults to a unspecified, * legal node. */ private SingleVariableDeclaration parameter = null; /** * The expression; lazily initialized; defaults to a unspecified, but legal, * expression. */ private Expression expression = null; /** * The body statement; lazily initialized; defaults to an empty block * statement. */ private Statement body = null; /** * Creates a new AST node for an enchanced for statement owned by the * given AST. By default, the parameter and expression are unspecified * but legal subtrees, and the body is an empty block. * * @param ast the AST that is to own this node */ EnhancedForStatement(AST ast) { super(ast); unsupportedIn2(); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == PARAMETER_PROPERTY) { if (get) { return getParameter(); } else { setParameter((SingleVariableDeclaration) child); return null; } } if (property == EXPRESSION_PROPERTY) { if (get) { return getExpression(); } else { setExpression((Expression) child); return null; } } if (property == BODY_PROPERTY) { if (get) { return getBody(); } else { setBody((Statement) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } @Override final int getNodeType0() { return ENHANCED_FOR_STATEMENT; } @Override ASTNode clone0(AST target) { EnhancedForStatement result = new EnhancedForStatement(target); result.setSourceRange(getStartPosition(), getLength()); result.copyLeadingComment(this); result.setParameter((SingleVariableDeclaration) getParameter().clone(target)); result.setExpression((Expression) getExpression().clone(target)); result.setBody((Statement) ASTNode.copySubtree(target, getBody())); 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, getParameter()); acceptChild(visitor, getExpression()); acceptChild(visitor, getBody()); } visitor.endVisit(this); } /** * Returns the formal parameter in this enhanced for statement. * * @return the parameter */ public SingleVariableDeclaration getParameter() { if (this.parameter == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.parameter == null) { preLazyInit(); this.parameter = this.ast.newSingleVariableDeclaration(); postLazyInit(this.parameter, PARAMETER_PROPERTY); } } } return this.parameter; } /** * Sets the formal parameter in this enhanced for statement. * * @param parameter the new parameter * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * </ul> */ public void setParameter(SingleVariableDeclaration parameter) { if (parameter == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.parameter; preReplaceChild(oldChild, parameter, PARAMETER_PROPERTY); this.parameter = parameter; postReplaceChild(oldChild, parameter, PARAMETER_PROPERTY); } /** * Returns the expression of this enhanced for statement. * * @return the expression node */ public Expression getExpression() { if (this.expression == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.expression == null) { preLazyInit(); this.expression = new SimpleName(this.ast); postLazyInit(this.expression, EXPRESSION_PROPERTY); } } } return this.expression; } /** * Sets the expression of this enhanced for statement. * * @param expression the new 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 setExpression(Expression expression) { if (expression == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.expression; preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY); this.expression = expression; postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY); } /** * Returns the body of this enchanced for statement. * * @return the body statement node */ public Statement getBody() { if (this.body == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.body == null) { preLazyInit(); this.body = new Block(this.ast); postLazyInit(this.body, BODY_PROPERTY); } } } return this.body; } /** * Sets the body of this enhanced for statement. * * @param statement the body statement 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 setBody(Statement statement) { if (statement == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.body; preReplaceChild(oldChild, statement, BODY_PROPERTY); this.body = statement; postReplaceChild(oldChild, statement, BODY_PROPERTY); } @Override int memSize() { return super.memSize() + 3 * 4; } @Override int treeSize() { return memSize() + (this.parameter == null ? 0 : getParameter().treeSize()) + (this.expression == null ? 0 : getExpression().treeSize()) + (this.body == null ? 0 : getBody().treeSize()); } }