ExpressionStatement.java revision 1068:34ef988d5959
1/* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.internal.ir; 27 28import jdk.nashorn.internal.ir.annotations.Immutable; 29import jdk.nashorn.internal.ir.visitor.NodeVisitor; 30 31/** 32 * IR representation for executing bare expressions. Basically, an expression 33 * node means "this code will be executed" and evaluating it results in 34 * statements being added to the IR 35 */ 36@Immutable 37public final class ExpressionStatement extends Statement { 38 private static final long serialVersionUID = 1L; 39 40 /** Expression to execute. */ 41 private final Expression expression; 42 43 /** 44 * Constructor 45 * 46 * @param lineNumber line number 47 * @param token token 48 * @param finish finish 49 * @param expression the expression to execute 50 */ 51 public ExpressionStatement(final int lineNumber, final long token, final int finish, final Expression expression) { 52 super(lineNumber, token, finish); 53 this.expression = expression; 54 } 55 56 private ExpressionStatement(final ExpressionStatement expressionStatement, final Expression expression) { 57 super(expressionStatement); 58 this.expression = expression; 59 } 60 61 @Override 62 public Node accept(final NodeVisitor<? extends LexicalContext> visitor) { 63 if (visitor.enterExpressionStatement(this)) { 64 return visitor.leaveExpressionStatement(setExpression((Expression)expression.accept(visitor))); 65 } 66 67 return this; 68 } 69 70 @Override 71 public void toString(final StringBuilder sb, final boolean printTypes) { 72 expression.toString(sb, printTypes); 73 } 74 75 /** 76 * Return the expression to be executed 77 * @return the expression 78 */ 79 public Expression getExpression() { 80 return expression; 81 } 82 83 /** 84 * Reset the expression to be executed 85 * @param expression the expression 86 * @return new or same execute node 87 */ 88 public ExpressionStatement setExpression(final Expression expression) { 89 if (this.expression == expression) { 90 return this; 91 } 92 return new ExpressionStatement(this, expression); 93 } 94} 95