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
/*******************************************************************************
 * 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;

Return statement AST node type.
ReturnStatement:
   return [ Expression ] ;

Since:
2.0
@noinstantiate
This class is not intended to be instantiated by clients./**
 * Return statement AST node type.
 *
 * <pre>
 * ReturnStatement:
 *    <b>return</b> [ Expression ] <b>;</b>
 * </pre>
 *
 * @since 2.0
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
@SuppressWarnings("rawtypes")
public class ReturnStatement extends Statement {

	
The "expression" structural property of this node type (child type: Expression). 
Since:
3.0/**
	 * The "expression" structural property of this node type (child type: {@link Expression}).
	 * @since 3.0
	 */
	public static final ChildPropertyDescriptor EXPRESSION_PROPERTY =
		new ChildPropertyDescriptor(ReturnStatement.class, "expression", Expression.class, OPTIONAL, CYCLE_RISK); //$NON-NLS-1$

	
A list of property descriptors (element type: StructuralPropertyDescriptor), or null if uninitialized. /**
	 * A list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor}),
	 * or null if uninitialized.
	 */
	private static final List PROPERTY_DESCRIPTORS;

	static {
		List propertyList = new ArrayList(2);
		createPropertyList(ReturnStatement.class, propertyList);
		addProperty(EXPRESSION_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS = reapPropertyList(propertyList);
	}

	
Returns a list of structural property descriptors for this node type.
Clients must not modify the result.
Params:
apiLevel – the API level; one of the
AST.JLS* constants
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)
Since:
3.0/**
	 * 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 expression; null for none; defaults to none.
/**
	 * The expression; <code>null</code> for none; defaults to none.
	 */
	private Expression optionalExpression = null;

	
Creates a new AST node for a return statement owned by the
given AST. By default, the statement has no expression.
Params:
ast – the AST that is to own this node/**
	 * Creates a new AST node for a return statement owned by the
	 * given AST. By default, the statement has no expression.
	 *
	 * @param ast the AST that is to own this node
	 */
	ReturnStatement(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 == EXPRESSION_PROPERTY) {
			if (get) {
				return getExpression();
			} else {
				setExpression((Expression) child);
				return null;
			}
		}
		// allow default implementation to flag the error
		return super.internalGetSetChildProperty(property, get, child);
	}

	@Override
	final int getNodeType0() {
		return RETURN_STATEMENT;
	}

	@Override
	ASTNode clone0(AST target) {
		ReturnStatement result = new ReturnStatement(target);
		result.setSourceRange(getStartPosition(), getLength());
		result.copyLeadingComment(this);
		result.setExpression(
			(Expression) ASTNode.copySubtree(target, getExpression()));
		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) {
			acceptChild(visitor, getExpression());
		}
		visitor.endVisit(this);
	}

	
Returns the expression of this return statement, or
null if there is none.
Returns:
the expression node, or null if there is none/**
	 * Returns the expression of this return statement, or
	 * <code>null</code> if there is none.
	 *
	 * @return the expression node, or <code>null</code> if there is none
	 */
	public Expression getExpression() {
		return this.optionalExpression;
	}

	
Sets or clears the expression of this return statement.
Params:
expression – the expression node, or null if
   there is none
Throws:
IllegalArgumentException – if:

the node belongs to a different AST
the node already has a parent
a cycle in would be created
/**
	 * Sets or clears the expression of this return statement.
	 *
	 * @param expression the expression node, or <code>null</code> if
	 *    there is none
	 * @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) {
		ASTNode oldChild = this.optionalExpression;
		preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
		this.optionalExpression = expression;
		postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
	}

	@Override
	int memSize() {
		return super.memSize() + 1 * 4;
	}

	@Override
	int treeSize() {
		return
			memSize()
			+ (this.optionalExpression == null ? 0 : getExpression().treeSize());
	}
}