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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.tools.internal.xjc.model;
/**
* represents a possible number of occurence.
*
* Usually, denoted by a pair of integers like (1,1) or (5,10).
* A special value "unbounded" is allowed as the upper bound.
*
* <p>
* For example, (0,unbounded) corresponds to the '*' occurence of DTD.
* (0,1) corresponds to the '?' occurence of DTD.
*
* @author
* <a href="mailto:kohsuke.kawaguchi@sun.com">Kohsuke KAWAGUCHI</a>
*/
public final class Multiplicity {
public final int min;
public final Integer max; // null is used to represent "unbounded".
public static Multiplicity create( int min, Integer max ) {
if(min==0 && max==null) return STAR;
if(min==1 && max==null) return PLUS;
if(max!=null) {
if(min==0 && max==0) return ZERO;
if(min==0 && max==1) return OPTIONAL;
if(min==1 && max==1) return ONE;
}
return new Multiplicity(min,max);
}
private Multiplicity( int min, Integer max ) {
this.min = min; this.max = max;
}
public boolean equals(Object o) {
if (!(o instanceof Multiplicity)) return false;
Multiplicity that = (Multiplicity) o;
if (this.min != that.min) return false;
if (this.max != null ? !this.max.equals(that.max) : that.max != null) return false;
return true;
}
public int hashCode() {
int result;
result = min;
result = 29 * result + (max != null ? max.hashCode() : 0);
return result;
}
/** returns true if the multiplicity is (1,1). */
public boolean isUnique() {
if(max==null) return false;
return min==1 && max==1;
}
/** returns true if the multiplicity is (0,1) */
public boolean isOptional() {
if(max==null) return false;
return min==0 && max==1;
}
/** returns true if the multiplicity is (0,1) or (1,1). */
public boolean isAtMostOnce() {
if(max==null) return false;
return max<=1;
}
/** returns true if the multiplicity is (0,0). */
public boolean isZero() {
if(max==null) return false;
return max==0;
}
/**
* Returns true if the multiplicity represented by this object
* completely includes the multiplicity represented by the
* other object. For example, we say [1,3] includes [1,2] but
* [2,4] doesn't include [1,3].
*/
public boolean includes( Multiplicity rhs ) {
if( rhs.min<min ) return false;
if( max==null ) return true;
if( rhs.max==null ) return false;
return rhs.max <= max;
}
/**
* Returns the string representation of the 'max' property.
* Either a number or a token "unbounded".
*/
public String getMaxString() {
if(max==null) return "unbounded";
else return max.toString();
}
/** gets the string representation.
* mainly debug purpose.
*/
public String toString() {
return "("+min+','+getMaxString()+')';
}
/** the constant representing the (0,0) multiplicity. */
public static final Multiplicity ZERO = new Multiplicity(0,0);
/** the constant representing the (1,1) multiplicity. */
public static final Multiplicity ONE = new Multiplicity(1,1);
/** the constant representing the (0,1) multiplicity. */
public static final Multiplicity OPTIONAL = new Multiplicity(0,1);
/** the constant representing the (0,unbounded) multiplicity. */
public static final Multiplicity STAR = new Multiplicity(0,null);
/** the constant representing the (1,unbounded) multiplicity. */
public static final Multiplicity PLUS = new Multiplicity(1,null);
// arithmetic methods
//============================
public static Multiplicity choice( Multiplicity lhs, Multiplicity rhs ) {
return create(
Math.min(lhs.min,rhs.min),
(lhs.max==null||rhs.max==null)?
null:
(Integer)Math.max(lhs.max, rhs.max) );
}
public static Multiplicity group( Multiplicity lhs, Multiplicity rhs ) {
return create( lhs.min+rhs.min,
(lhs.max==null||rhs.max==null)?
null:
(Integer)(lhs.max + rhs.max) );
}
public static Multiplicity multiply( Multiplicity lhs, Multiplicity rhs ) {
int min = lhs.min*rhs.min;
Integer max;
if(isZero(lhs.max) || isZero(rhs.max))
max = 0;
else
if(lhs.max==null || rhs.max==null)
max = null;
else
max = lhs.max*rhs.max;
return create(min,max);
}
private static boolean isZero(Integer i) {
return i!=null && i==0;
}
public static Multiplicity oneOrMore( Multiplicity c ) {
if(c.max==null) return c; // (x,*) => (x,*)
if(c.max==0 ) return c; // (0,0) => (0,0)
else return create( c.min, null ); // (x,y) => (x,*)
}
public Multiplicity makeOptional() {
if(min==0) return this;
return create(0,max);
}
public Multiplicity makeRepeated() {
if(max==null || max==0) return this; // (0,0)* = (0,0) and (n,unbounded)* = (n,unbounded)
return create(min,null);
}
}