/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: AlternativePattern.java 468650 2006-10-28 07:03:30Z minchau $
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.bcel.generic.GOTO;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.InstructionList;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*/
final class AlternativePattern extends Pattern {
private final Pattern _left;
private final Pattern _right;
/**
* Construct an alternative pattern. The method <code>setParent</code>
* should not be called in this case.
*/
public AlternativePattern(Pattern left, Pattern right) {
_left = left;
_right = right;
}
public void setParser(Parser parser) {
super.setParser(parser);
_left.setParser(parser);
_right.setParser(parser);
}
public Pattern getLeft() {
return _left;
}
public Pattern getRight() {
return _right;
}
/**
* The type of an '|' is not really defined, hence null is returned.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
_left.typeCheck(stable);
_right.typeCheck(stable);
return null;
}
public double getPriority() {
double left = _left.getPriority();
double right = _right.getPriority();
if (left < right)
return(left);
else
return(right);
}
public String toString() {
return "alternative(" + _left + ", " + _right + ')';
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final InstructionList il = methodGen.getInstructionList();
_left.translate(classGen, methodGen);
final InstructionHandle gotot = il.append(new GOTO(null));
il.append(methodGen.loadContextNode());
_right.translate(classGen, methodGen);
_left._trueList.backPatch(gotot);
_left._falseList.backPatch(gotot.getNext());
_trueList.append(_right._trueList.add(gotot));
_falseList.append(_right._falseList);
}
}