001: /* ====================================================================
002: * Tea - Copyright (c) 1997-2000 Walt Disney Internet Group
003: * ====================================================================
004: * The Tea Software License, Version 1.1
005: *
006: * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
007: *
008: * Redistribution and use in source and binary forms, with or without
009: * modification, are permitted provided that the following conditions
010: * are met:
011: *
012: * 1. Redistributions of source code must retain the above copyright
013: * notice, this list of conditions and the following disclaimer.
014: *
015: * 2. Redistributions in binary form must reproduce the above copyright
016: * notice, this list of conditions and the following disclaimer in
017: * the documentation and/or other materials provided with the
018: * distribution.
019: *
020: * 3. The end-user documentation included with the redistribution,
021: * if any, must include the following acknowledgment:
022: * "This product includes software developed by the
023: * Walt Disney Internet Group (http://opensource.go.com/)."
024: * Alternately, this acknowledgment may appear in the software itself,
025: * if and wherever such third-party acknowledgments normally appear.
026: *
027: * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
028: * not be used to endorse or promote products derived from this
029: * software without prior written permission. For written
030: * permission, please contact opensource@dig.com.
031: *
032: * 5. Products derived from this software may not be called "Tea",
033: * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
034: * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
035: * written permission of the Walt Disney Internet Group.
036: *
037: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
038: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
039: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
040: * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS
041: * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
042: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
043: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
044: * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
045: * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
046: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
047: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
048: * ====================================================================
049: *
050: * For more information about Tea, please see http://opensource.go.com/.
051: */
052:
053: package com.go.tea.parsetree;
054:
055: import com.go.tea.compiler.SourceInfo;
056:
057: /******************************************************************************
058: * An IfStatement consists of a condition, a "then" part and an "else" part.
059: * Both the then and else parts are optional, but a parser should never
060: * create an IfStatement without a then part. An optimizer may detect that
061: * the then part never executes, and so eliminates it.
062: *
063: * @author Brian S O'Neill
064: * @version
065: * <!--$$Revision:--> 24 <!-- $-->, <!--$$JustDate:--> 5/31/01 <!-- $-->
066: */
067: public class IfStatement extends Statement {
068: private Expression mCondition;
069: private Block mThenPart;
070: private Block mElsePart;
071: private Variable[] mMergedVariables;
072:
073: public IfStatement(SourceInfo info, Expression condition,
074: Block thenPart) {
075: this (info, condition, thenPart, null);
076: }
077:
078: public IfStatement(SourceInfo info, Expression condition,
079: Block thenPart, Block elsePart) {
080: super (info);
081:
082: mCondition = condition;
083: mThenPart = thenPart;
084: mElsePart = elsePart;
085: }
086:
087: public Object accept(NodeVisitor visitor) {
088: return visitor.visit(this );
089: }
090:
091: public Object clone() {
092: IfStatement is = (IfStatement) super .clone();
093: is.mCondition = (Expression) mCondition.clone();
094: if (mThenPart != null) {
095: is.mThenPart = (Block) mThenPart.clone();
096: }
097: if (mElsePart != null) {
098: is.mElsePart = (Block) mElsePart.clone();
099: }
100: return is;
101: }
102:
103: public boolean isReturn() {
104: return mThenPart != null && mThenPart.isReturn()
105: && mElsePart != null && mElsePart.isReturn();
106: }
107:
108: public boolean isBreak() {
109: return mThenPart != null && mThenPart.isBreak()
110: && mElsePart != null && mElsePart.isBreak();
111: }
112:
113: public Expression getCondition() {
114: return mCondition;
115: }
116:
117: /**
118: * @return Null if no then part.
119: */
120: public Block getThenPart() {
121: return mThenPart;
122: }
123:
124: /**
125: * @return Null if no else part.
126: */
127: public Block getElsePart() {
128: return mElsePart;
129: }
130:
131: public void setCondition(Expression condition) {
132: mCondition = condition;
133: }
134:
135: public void setThenPart(Block block) {
136: mThenPart = block;
137: }
138:
139: public void setElsePart(Block block) {
140: mElsePart = block;
141: }
142:
143: /**
144: * Returns the variables that were commonly assigned in both the "then"
145: * and "else" parts of the if statement, were merged together and moved
146: * into the parent scope. Returns null if not set.
147: */
148: public Variable[] getMergedVariables() {
149: return mMergedVariables;
150: }
151:
152: public void setMergedVariables(Variable[] vars) {
153: mMergedVariables = vars;
154: }
155: }
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