aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package com.sun.tools.internal.xjc.model;
aoqi@0: 
aoqi@0: import java.math.BigInteger;
aoqi@0: 
aoqi@0: 
aoqi@0: 
aoqi@0: /**
aoqi@0:  * represents a possible number of occurence.
aoqi@0:  *
aoqi@0:  * Usually, denoted by a pair of integers like (1,1) or (5,10).
aoqi@0:  * A special value "unbounded" is allowed as the upper bound.
aoqi@0:  *
aoqi@0:  * <p>
aoqi@0:  * For example, (0,unbounded) corresponds to the '*' occurence of DTD.
aoqi@0:  * (0,1) corresponds to the '?' occurence of DTD.
aoqi@0:  *
aoqi@0:  * @author
aoqi@0:  *    <a href="mailto:kohsuke.kawaguchi@sun.com">Kohsuke KAWAGUCHI</a>
aoqi@0:  */
aoqi@0: public final class Multiplicity {
aoqi@0:     public final BigInteger min;
aoqi@0:     public final BigInteger max;    // null is used to represent "unbounded".
aoqi@0: 
aoqi@0:     public static Multiplicity create(BigInteger min, BigInteger max ) {
aoqi@0:         if (BigInteger.ZERO.equals(min) && max==null) return STAR;
aoqi@0:         if (BigInteger.ONE.equals(min) && max==null) return PLUS;
aoqi@0:         if (max!=null) {
aoqi@0:             if(BigInteger.ZERO.equals(min) && BigInteger.ZERO.equals(max))    return ZERO;
aoqi@0:             if(BigInteger.ZERO.equals(min) && BigInteger.ONE.equals(max))    return OPTIONAL;
aoqi@0:             if(BigInteger.ONE.equals(min) && BigInteger.ONE.equals(max))    return ONE;
aoqi@0:         }
aoqi@0:         return new Multiplicity(min, max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     public static Multiplicity create(int min, Integer max ) {
aoqi@0:         return Multiplicity.create(BigInteger.valueOf(min), BigInteger.valueOf(max.intValue()));
aoqi@0:     }
aoqi@0: 
aoqi@0:     private Multiplicity(BigInteger min, BigInteger max) {
aoqi@0:         this.min = min;
aoqi@0:         this.max = max;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private Multiplicity(int min, int max) {
aoqi@0:         this(BigInteger.valueOf(min), BigInteger.valueOf(max));
aoqi@0:     }
aoqi@0: 
aoqi@0:     private Multiplicity(int min, Integer max) {
aoqi@0:         this(BigInteger.valueOf(min), (max == null) ? null : BigInteger.valueOf(max));
aoqi@0:     }
aoqi@0: 
aoqi@0:     @Override
aoqi@0:     public boolean equals(Object o) {
aoqi@0:         if (!(o instanceof Multiplicity)) return false;
aoqi@0: 
aoqi@0:         Multiplicity that = (Multiplicity) o;
aoqi@0: 
aoqi@0:         if (!this.min.equals(that.min)) return false;
aoqi@0:         if (this.max != null ? !this.max.equals(that.max) : that.max != null) return false;
aoqi@0: 
aoqi@0:         return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     @Override
aoqi@0:     public int hashCode() {
aoqi@0:         return min.add(max).intValue();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** returns true if the multiplicity is (1,1). */
aoqi@0:     public boolean isUnique() {
aoqi@0:         if(max==null)    return false;
aoqi@0:         return BigInteger.ONE.equals(min) && BigInteger.ONE.equals(max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** returns true if the multiplicity is (0,1) */
aoqi@0:     public boolean isOptional() {
aoqi@0:         if(max==null) return false;
aoqi@0:         return BigInteger.ZERO.equals(min) && BigInteger.ONE.equals(max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** returns true if the multiplicity is (0,1) or (1,1). */
aoqi@0:     public boolean isAtMostOnce() {
aoqi@0:         if(max==null)    return false;
aoqi@0:         return max.compareTo(BigInteger.ONE)<=0;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** returns true if the multiplicity is (0,0). */
aoqi@0:     public boolean isZero() {
aoqi@0:         if(max==null)    return false;
aoqi@0:         return BigInteger.ZERO.equals(max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns true if the multiplicity represented by this object
aoqi@0:      * completely includes the multiplicity represented by the
aoqi@0:      * other object. For example, we say [1,3] includes [1,2] but
aoqi@0:      * [2,4] doesn't include [1,3].
aoqi@0:      */
aoqi@0:     public boolean includes( Multiplicity rhs ) {
aoqi@0:         if (rhs.min.compareTo(min) == -1)   return false;
aoqi@0:         if (max==null) return true;
aoqi@0:         if (rhs.max==null) return false;
aoqi@0:         return rhs.max.compareTo(max) <= 0;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns the string representation of the 'max' property.
aoqi@0:      * Either a number or a token "unbounded".
aoqi@0:      */
aoqi@0:     public String getMaxString() {
aoqi@0:         if(max==null)       return "unbounded";
aoqi@0:         else                return max.toString();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** gets the string representation.
aoqi@0:      * mainly debug purpose.
aoqi@0:      */
aoqi@0:     @Override
aoqi@0:     public String toString() {
aoqi@0:         return "("+min+','+getMaxString()+')';
aoqi@0:     }
aoqi@0: 
aoqi@0:     /** the constant representing the (0,0) multiplicity. */
aoqi@0:     public static final Multiplicity ZERO = new Multiplicity(0,0);
aoqi@0: 
aoqi@0:     /** the constant representing the (1,1) multiplicity. */
aoqi@0:     public static final Multiplicity ONE = new Multiplicity(1,1);
aoqi@0: 
aoqi@0:     /** the constant representing the (0,1) multiplicity. */
aoqi@0:     public static final Multiplicity OPTIONAL = new Multiplicity(0,1);
aoqi@0: 
aoqi@0:     /** the constant representing the (0,unbounded) multiplicity. */
aoqi@0:     public static final Multiplicity STAR = new Multiplicity(0,null);
aoqi@0: 
aoqi@0:     /** the constant representing the (1,unbounded) multiplicity. */
aoqi@0:     public static final Multiplicity PLUS = new Multiplicity(1,null);
aoqi@0: 
aoqi@0: // arithmetic methods
aoqi@0:     public static Multiplicity choice( Multiplicity lhs, Multiplicity rhs ) {
aoqi@0:         return create(
aoqi@0:             lhs.min.min(rhs.min),
aoqi@0:             (lhs.max==null || rhs.max==null) ? null : lhs.max.max(rhs.max) );
aoqi@0:     }
aoqi@0:     public static Multiplicity group( Multiplicity lhs, Multiplicity rhs ) {
aoqi@0:         return create(
aoqi@0:             lhs.min.add(rhs.min),
aoqi@0:             (lhs.max==null || rhs.max==null) ? null : lhs.max.add(rhs.max) );
aoqi@0:     }
aoqi@0:     public static Multiplicity multiply( Multiplicity lhs, Multiplicity rhs ) {
aoqi@0:         BigInteger min = lhs.min.multiply(rhs.min);
aoqi@0:         BigInteger max;
aoqi@0:         if (isZero(lhs.max) || isZero(rhs.max))
aoqi@0:             max = BigInteger.ZERO;
aoqi@0:         else
aoqi@0:         if (lhs.max==null || rhs.max==null)
aoqi@0:             max = null;
aoqi@0:         else
aoqi@0:             max = lhs.max.multiply(rhs.max);
aoqi@0:         return create(min,max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     private static boolean isZero(BigInteger i) {
aoqi@0:         return (i != null && BigInteger.ZERO.equals(i));
aoqi@0:     }
aoqi@0: 
aoqi@0:     public static Multiplicity oneOrMore( Multiplicity c ) {
aoqi@0:         if(c.max==null)  return c; // (x,*) => (x,*)
aoqi@0:         if(BigInteger.ZERO.equals(c.max)) return c; // (0,0) => (0,0)
aoqi@0:         else        return create( c.min, null );    // (x,y) => (x,*)
aoqi@0:     }
aoqi@0: 
aoqi@0:     public Multiplicity makeOptional() {
aoqi@0:         if (BigInteger.ZERO.equals(min)) return this;
aoqi@0:         return create(BigInteger.ZERO, max);
aoqi@0:     }
aoqi@0: 
aoqi@0:     public Multiplicity makeRepeated() {
aoqi@0:         if (max==null || BigInteger.ZERO.equals(max))  return this;   // (0,0)* = (0,0)  and (n,unbounded)* = (n,unbounded)
aoqi@0:         return create(min,null);
aoqi@0:     }
aoqi@0: }