1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5/* 6 * Licensed to the Apache Software Foundation (ASF) under one or more 7 * contributor license agreements. See the NOTICE file distributed with 8 * this work for additional information regarding copyright ownership. 9 * The ASF licenses this file to You under the Apache License, Version 2.0 10 * (the "License"); you may not use this file except in compliance with 11 * the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 */ 21 22package com.sun.org.apache.xalan.internal.xsltc.compiler; 23 24import com.sun.org.apache.bcel.internal.generic.GOTO; 25import com.sun.org.apache.bcel.internal.generic.InstructionHandle; 26import com.sun.org.apache.bcel.internal.generic.InstructionList; 27import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator; 28import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator; 29import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type; 30import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError; 31 32/** 33 * @author Jacek Ambroziak 34 * @author Santiago Pericas-Geertsen 35 */ 36final class AlternativePattern extends Pattern { 37 private final Pattern _left; 38 private final Pattern _right; 39 40 /** 41 * Construct an alternative pattern. The method <code>setParent</code> 42 * should not be called in this case. 43 */ 44 public AlternativePattern(Pattern left, Pattern right) { 45 _left = left; 46 _right = right; 47 } 48 49 public void setParser(Parser parser) { 50 super.setParser(parser); 51 _left.setParser(parser); 52 _right.setParser(parser); 53 } 54 55 public Pattern getLeft() { 56 return _left; 57 } 58 59 public Pattern getRight() { 60 return _right; 61 } 62 63 /** 64 * The type of an '|' is not really defined, hence null is returned. 65 */ 66 public Type typeCheck(SymbolTable stable) throws TypeCheckError { 67 _left.typeCheck(stable); 68 _right.typeCheck(stable); 69 return null; 70 } 71 72 public double getPriority() { 73 double left = _left.getPriority(); 74 double right = _right.getPriority(); 75 76 if (left < right) 77 return(left); 78 else 79 return(right); 80 } 81 82 public String toString() { 83 return "alternative(" + _left + ", " + _right + ')'; 84 } 85 86 public void translate(ClassGenerator classGen, MethodGenerator methodGen) { 87 final InstructionList il = methodGen.getInstructionList(); 88 89 _left.translate(classGen, methodGen); 90 final InstructionHandle gotot = il.append(new GOTO(null)); 91 il.append(methodGen.loadContextNode()); 92 _right.translate(classGen, methodGen); 93 94 _left._trueList.backPatch(gotot); 95 _left._falseList.backPatch(gotot.getNext()); 96 97 _trueList.append(_right._trueList.add(gotot)); 98 _falseList.append(_right._falseList); 99 } 100} 101