1/* 2 * Copyright (c) 1997, 2012, 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 26package com.sun.tools.internal.xjc.model; 27 28import java.math.BigInteger; 29 30 31 32/** 33 * represents a possible number of occurence. 34 * 35 * Usually, denoted by a pair of integers like (1,1) or (5,10). 36 * A special value "unbounded" is allowed as the upper bound. 37 * 38 * <p> 39 * For example, (0,unbounded) corresponds to the '*' occurence of DTD. 40 * (0,1) corresponds to the '?' occurence of DTD. 41 * 42 * @author 43 * <a href="mailto:kohsuke.kawaguchi@sun.com">Kohsuke KAWAGUCHI</a> 44 */ 45public final class Multiplicity { 46 public final BigInteger min; 47 public final BigInteger max; // null is used to represent "unbounded". 48 49 public static Multiplicity create(BigInteger min, BigInteger max ) { 50 if (BigInteger.ZERO.equals(min) && max==null) return STAR; 51 if (BigInteger.ONE.equals(min) && max==null) return PLUS; 52 if (max!=null) { 53 if(BigInteger.ZERO.equals(min) && BigInteger.ZERO.equals(max)) return ZERO; 54 if(BigInteger.ZERO.equals(min) && BigInteger.ONE.equals(max)) return OPTIONAL; 55 if(BigInteger.ONE.equals(min) && BigInteger.ONE.equals(max)) return ONE; 56 } 57 return new Multiplicity(min, max); 58 } 59 60 public static Multiplicity create(int min, Integer max ) { 61 return Multiplicity.create(BigInteger.valueOf(min), BigInteger.valueOf(max.intValue())); 62 } 63 64 private Multiplicity(BigInteger min, BigInteger max) { 65 this.min = min; 66 this.max = max; 67 } 68 69 private Multiplicity(int min, int max) { 70 this(BigInteger.valueOf(min), BigInteger.valueOf(max)); 71 } 72 73 private Multiplicity(int min, Integer max) { 74 this(BigInteger.valueOf(min), (max == null) ? null : BigInteger.valueOf(max)); 75 } 76 77 @Override 78 public boolean equals(Object o) { 79 if (!(o instanceof Multiplicity)) return false; 80 81 Multiplicity that = (Multiplicity) o; 82 83 if (!this.min.equals(that.min)) return false; 84 if (this.max != null ? !this.max.equals(that.max) : that.max != null) return false; 85 86 return true; 87 } 88 89 @Override 90 public int hashCode() { 91 return min.add(max).intValue(); 92 } 93 94 /** returns true if the multiplicity is (1,1). */ 95 public boolean isUnique() { 96 if(max==null) return false; 97 return BigInteger.ONE.equals(min) && BigInteger.ONE.equals(max); 98 } 99 100 /** returns true if the multiplicity is (0,1) */ 101 public boolean isOptional() { 102 if(max==null) return false; 103 return BigInteger.ZERO.equals(min) && BigInteger.ONE.equals(max); 104 } 105 106 /** returns true if the multiplicity is (0,1) or (1,1). */ 107 public boolean isAtMostOnce() { 108 if(max==null) return false; 109 return max.compareTo(BigInteger.ONE)<=0; 110 } 111 112 /** returns true if the multiplicity is (0,0). */ 113 public boolean isZero() { 114 if(max==null) return false; 115 return BigInteger.ZERO.equals(max); 116 } 117 118 /** 119 * Returns true if the multiplicity represented by this object 120 * completely includes the multiplicity represented by the 121 * other object. For example, we say [1,3] includes [1,2] but 122 * [2,4] doesn't include [1,3]. 123 */ 124 public boolean includes( Multiplicity rhs ) { 125 if (rhs.min.compareTo(min) == -1) return false; 126 if (max==null) return true; 127 if (rhs.max==null) return false; 128 return rhs.max.compareTo(max) <= 0; 129 } 130 131 /** 132 * Returns the string representation of the 'max' property. 133 * Either a number or a token "unbounded". 134 */ 135 public String getMaxString() { 136 if(max==null) return "unbounded"; 137 else return max.toString(); 138 } 139 140 /** gets the string representation. 141 * mainly debug purpose. 142 */ 143 @Override 144 public String toString() { 145 return "("+min+','+getMaxString()+')'; 146 } 147 148 /** the constant representing the (0,0) multiplicity. */ 149 public static final Multiplicity ZERO = new Multiplicity(0,0); 150 151 /** the constant representing the (1,1) multiplicity. */ 152 public static final Multiplicity ONE = new Multiplicity(1,1); 153 154 /** the constant representing the (0,1) multiplicity. */ 155 public static final Multiplicity OPTIONAL = new Multiplicity(0,1); 156 157 /** the constant representing the (0,unbounded) multiplicity. */ 158 public static final Multiplicity STAR = new Multiplicity(0,null); 159 160 /** the constant representing the (1,unbounded) multiplicity. */ 161 public static final Multiplicity PLUS = new Multiplicity(1,null); 162 163// arithmetic methods 164 public static Multiplicity choice( Multiplicity lhs, Multiplicity rhs ) { 165 return create( 166 lhs.min.min(rhs.min), 167 (lhs.max==null || rhs.max==null) ? null : lhs.max.max(rhs.max) ); 168 } 169 public static Multiplicity group( Multiplicity lhs, Multiplicity rhs ) { 170 return create( 171 lhs.min.add(rhs.min), 172 (lhs.max==null || rhs.max==null) ? null : lhs.max.add(rhs.max) ); 173 } 174 public static Multiplicity multiply( Multiplicity lhs, Multiplicity rhs ) { 175 BigInteger min = lhs.min.multiply(rhs.min); 176 BigInteger max; 177 if (isZero(lhs.max) || isZero(rhs.max)) 178 max = BigInteger.ZERO; 179 else 180 if (lhs.max==null || rhs.max==null) 181 max = null; 182 else 183 max = lhs.max.multiply(rhs.max); 184 return create(min,max); 185 } 186 187 private static boolean isZero(BigInteger i) { 188 return (i != null && BigInteger.ZERO.equals(i)); 189 } 190 191 public static Multiplicity oneOrMore( Multiplicity c ) { 192 if(c.max==null) return c; // (x,*) => (x,*) 193 if(BigInteger.ZERO.equals(c.max)) return c; // (0,0) => (0,0) 194 else return create( c.min, null ); // (x,y) => (x,*) 195 } 196 197 public Multiplicity makeOptional() { 198 if (BigInteger.ZERO.equals(min)) return this; 199 return create(BigInteger.ZERO, max); 200 } 201 202 public Multiplicity makeRepeated() { 203 if (max==null || BigInteger.ZERO.equals(max)) return this; // (0,0)* = (0,0) and (n,unbounded)* = (n,unbounded) 204 return create(min,null); 205 } 206} 207