1 /* 2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 /* 26 * Copyright (C) 2004-2011 27 * 28 * Permission is hereby granted, free of charge, to any person obtaining a copy 29 * of this software and associated documentation files (the "Software"), to deal 30 * in the Software without restriction, including without limitation the rights 31 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 32 * copies of the Software, and to permit persons to whom the Software is 33 * furnished to do so, subject to the following conditions: 34 * 35 * The above copyright notice and this permission notice shall be included in 36 * all copies or substantial portions of the Software. 37 * 38 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 39 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 40 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 41 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 42 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 43 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 44 * THE SOFTWARE. 45 */ 46 package com.sun.xml.internal.rngom.binary; 47 48 public class PatternBuilder { 49 private final EmptyPattern empty; 50 protected final NotAllowedPattern notAllowed; 51 protected final PatternInterner interner; 52 53 public PatternBuilder() { 54 empty = new EmptyPattern(); 55 notAllowed = new NotAllowedPattern(); 56 interner = new PatternInterner(); 57 } 58 59 public PatternBuilder(PatternBuilder parent) { 60 empty = parent.empty; 61 notAllowed = parent.notAllowed; 62 interner = new PatternInterner(parent.interner); 63 } 64 65 Pattern makeEmpty() { 66 return empty; 67 } 68 69 Pattern makeNotAllowed() { 70 return notAllowed; 71 } 72 73 Pattern makeGroup(Pattern p1, Pattern p2) { 74 if (p1 == empty) 75 return p2; 76 if (p2 == empty) 77 return p1; 78 if (p1 == notAllowed || p2 == notAllowed) 79 return notAllowed; 80 if (false && p1 instanceof GroupPattern) { 81 GroupPattern sp = (GroupPattern)p1; 82 return makeGroup(sp.p1, makeGroup(sp.p2, p2)); 83 } 84 Pattern p = new GroupPattern(p1, p2); 85 return interner.intern(p); 86 } 87 88 Pattern makeInterleave(Pattern p1, Pattern p2) { 89 if (p1 == empty) 90 return p2; 91 if (p2 == empty) 92 return p1; 93 if (p1 == notAllowed || p2 == notAllowed) 94 return notAllowed; 95 if (false && p1 instanceof InterleavePattern) { 96 InterleavePattern ip = (InterleavePattern)p1; 97 return makeInterleave(ip.p1, makeInterleave(ip.p2, p2)); 98 } 99 if (false) { 100 if (p2 instanceof InterleavePattern) { 101 InterleavePattern ip = (InterleavePattern)p2; 102 if (p1.hashCode() > ip.p1.hashCode()) 103 return makeInterleave(ip.p1, makeInterleave(p1, ip.p2)); 104 } 105 else if (p1.hashCode() > p2.hashCode()) 106 return makeInterleave(p2, p1); 107 } 108 Pattern p = new InterleavePattern(p1, p2); 109 return interner.intern(p); 110 } 111 112 Pattern makeChoice(Pattern p1, Pattern p2) { 113 if (p1 == empty && p2.isNullable()) 114 return p2; 115 if (p2 == empty && p1.isNullable()) 116 return p1; 117 Pattern p = new ChoicePattern(p1, p2); 118 return interner.intern(p); 119 } 120 121 Pattern makeOneOrMore(Pattern p) { 122 if (p == empty 123 || p == notAllowed 124 || p instanceof OneOrMorePattern) 125 return p; 126 Pattern p1 = new OneOrMorePattern(p); 127 return interner.intern(p1); 128 } 129 130 Pattern makeOptional(Pattern p) { 131 return makeChoice(p, empty); 132 } 133 134 Pattern makeZeroOrMore(Pattern p) { 135 return makeOptional(makeOneOrMore(p)); 136 } 137 }