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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 java.util.function.Function;
import jdk.nashorn.internal.codegen.types.Type;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
import jdk.nashorn.internal.parser.TokenType;
/**
* TernaryNode represent the ternary operator {@code ?:}. Note that for control-flow calculation reasons its branch
* expressions (but not its test expression) are always wrapped in instances of {@link JoinPredecessorExpression}.
*/
@Immutable
public final class TernaryNode extends Expression {
private final Expression test;
private final JoinPredecessorExpression trueExpr;
private final JoinPredecessorExpression falseExpr;
/**
* Constructor
*
* @param token token
* @param test test expression
* @param trueExpr expression evaluated when test evaluates to true
* @param falseExpr expression evaluated when test evaluates to true
*/
public TernaryNode(final long token, final Expression test, final JoinPredecessorExpression trueExpr, final JoinPredecessorExpression falseExpr) {
super(token, falseExpr.getFinish());
this.test = test;
this.trueExpr = trueExpr;
this.falseExpr = falseExpr;
}
private TernaryNode(final TernaryNode ternaryNode, final Expression test, final JoinPredecessorExpression trueExpr,
final JoinPredecessorExpression falseExpr) {
super(ternaryNode);
this.test = test;
this.trueExpr = trueExpr;
this.falseExpr = falseExpr;
}
@Override
public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
if (visitor.enterTernaryNode(this)) {
final Expression newTest = (Expression)getTest().accept(visitor);
final JoinPredecessorExpression newTrueExpr = (JoinPredecessorExpression)trueExpr.accept(visitor);
final JoinPredecessorExpression newFalseExpr = (JoinPredecessorExpression)falseExpr.accept(visitor);
return visitor.leaveTernaryNode(setTest(newTest).setTrueExpression(newTrueExpr).setFalseExpression(newFalseExpr));
}
return this;
}
@Override
public void toString(final StringBuilder sb, final boolean printType) {
final TokenType tokenType = tokenType();
final boolean testParen = tokenType.needsParens(getTest().tokenType(), true);
final boolean trueParen = tokenType.needsParens(getTrueExpression().tokenType(), false);
final boolean falseParen = tokenType.needsParens(getFalseExpression().tokenType(), false);
if (testParen) {
sb.append('(');
}
getTest().toString(sb, printType);
if (testParen) {
sb.append(')');
}
sb.append(" ? ");
if (trueParen) {
sb.append('(');
}
getTrueExpression().toString(sb, printType);
if (trueParen) {
sb.append(')');
}
sb.append(" : ");
if (falseParen) {
sb.append('(');
}
getFalseExpression().toString(sb, printType);
if (falseParen) {
sb.append(')');
}
}
@Override
public boolean isLocal() {
return getTest().isLocal()
&& getTrueExpression().isLocal()
&& getFalseExpression().isLocal();
}
@Override
public Type getType(final Function<Symbol, Type> localVariableTypes) {
return Type.widestReturnType(getTrueExpression().getType(localVariableTypes), getFalseExpression().getType(localVariableTypes));
}
/**
* Get the test expression for this ternary expression, i.e. "x" in x ? y : z
* @return the test expression
*/
public Expression getTest() {
return test;
}
/**
* Get the true expression for this ternary expression, i.e. "y" in x ? y : z
* @return the true expression
*/
public JoinPredecessorExpression getTrueExpression() {
return trueExpr;
}
/**
* Get the false expression for this ternary expression, i.e. "z" in x ? y : z
* @return the false expression
*/
public JoinPredecessorExpression getFalseExpression() {
return falseExpr;
}
/**
* Set the test expression for this node
* @param test new test expression
* @return a node equivalent to this one except for the requested change.
*/
public TernaryNode setTest(final Expression test) {
if (this.test == test) {
return this;
}
return new TernaryNode(this, test, trueExpr, falseExpr);
}
/**
* Set the true expression for this node
* @param trueExpr new true expression
* @return a node equivalent to this one except for the requested change.
*/
public TernaryNode setTrueExpression(final JoinPredecessorExpression trueExpr) {
if (this.trueExpr == trueExpr) {
return this;
}
return new TernaryNode(this, test, trueExpr, falseExpr);
}
/**
* Set the false expression for this node
* @param falseExpr new false expression
* @return a node equivalent to this one except for the requested change.
*/
public TernaryNode setFalseExpression(final JoinPredecessorExpression falseExpr) {
if (this.falseExpr == falseExpr) {
return this;
}
return new TernaryNode(this, test, trueExpr, falseExpr);
}
}
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