- /*
- * Copyright 2001-2004 The Apache Software Foundation.
- *
- * Licensed 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,v 1.5 2004/02/16 22:24:29 minchau Exp $
- */
-
- package com.sun.org.apache.xalan.internal.xsltc.compiler;
-
- import com.sun.org.apache.bcel.internal.generic.GOTO;
- import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
- import com.sun.org.apache.bcel.internal.generic.InstructionList;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
- import com.sun.org.apache.xalan.internal.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);
- }
- }