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/*
* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package jdk.nashorn.internal.ir;
import static jdk.nashorn.internal.parser.TokenType.RETURN;
import static jdk.nashorn.internal.parser.TokenType.YIELD;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
import jdk.nashorn.internal.runtime.Source;
/**
* IR representation for RETURN or YIELD statements.
*/
@Immutable
public class ReturnNode extends Node {
/** Optional expression. */
private final Node expression;
/**
* Constructor
*
* @param source the source
* @param token token
* @param finish finish
* @param expression expression to return
*/
public ReturnNode(final Source source, final long token, final int finish, final Node expression) {
super(source, token, finish);
this.expression = expression;
}
private ReturnNode(final ReturnNode returnNode, final Node expression) {
super(returnNode);
this.expression = expression;
}
@Override
public boolean isTerminal() {
return true;
}
/**
* Return true if is a RETURN node.
* @return true if is RETURN node.
*/
public boolean isReturn() {
return isTokenType(RETURN);
}
/**
* Check if this return node has an expression
* @return true if not a void return
*/
public boolean hasExpression() {
return expression != null;
}
/**
* Return true if is a YIELD node.
* @return TRUE if is YIELD node.
*/
public boolean isYield() {
return isTokenType(YIELD);
}
@Override
public Node accept(final NodeVisitor visitor) {
if (visitor.enterReturnNode(this)) {
if (expression != null) {
return visitor.leaveReturnNode(setExpression(expression.accept(visitor)));
}
return visitor.leaveReturnNode(this);
}
return this;
}
@Override
public void toString(final StringBuilder sb) {
sb.append(isYield() ? "yield" : "return ");
if (expression != null) {
expression.toString(sb);
}
}
/**
* Get the expression this node returns
* @return return expression, or null if void return
*/
public Node getExpression() {
return expression;
}
/**
* Reset the expression this node returns
* @param expression new expression, or null if void return
* @return new or same return node
*/
public ReturnNode setExpression(final Node expression) {
if (this.expression == expression) {
return this;
}
return new ReturnNode(this, expression);
}
}
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