org.apache.xmlbeans.impl.config.NameSet Maven / Gradle / Ivy
/* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Author: Cezar Andrei ( cezar.andrei at bea.com )
* Date: Apr 25, 2004
*/
package org.apache.xmlbeans.impl.config;
import java.util.Set;
import java.util.Collections;
import java.util.HashSet;
/**
* Reprezents a non finite set of names.
* @see NameSetBuilder
*/
public class NameSet
{
/**
* An empty NameSet, it doesn't contain any name
*/
public static NameSet EMPTY = new NameSet(true, Collections.EMPTY_SET);
/**
* The NameSet that contains any name
*/
public static NameSet EVERYTHING = new NameSet(false, Collections.EMPTY_SET);
/*
There are two big cases:
1) - it reprezents "*", ie all except a finite set of names: _isFinite==false
2) - if reprezents only a finite set of names: _isFinite==true
*/
private boolean _isFinite;
private Set _finiteSet;
private NameSet(boolean isFinite, Set finiteSet)
{
_isFinite = isFinite;
_finiteSet = finiteSet;
}
static NameSet newInstance(boolean isFinite, Set finiteSet)
{
if ( finiteSet.size()==0 )
if ( isFinite )
return NameSet.EMPTY;
else
return NameSet.EVERYTHING;
else
{
Set fs = new HashSet();
fs.addAll(finiteSet);
return new NameSet(isFinite, fs);
}
}
private static Set intersectFiniteSets(Set a, Set b)
{
Set intersection = new HashSet();
//compute the intersection of _finiteSet with withSet
while (a.iterator().hasNext())
{
String name = (String) a.iterator().next();
if (b.contains(name))
intersection.add(name);
}
return intersection;
}
/**
* Returns the union of this NameSet with the 'with' NameSet.
*/
public NameSet union(NameSet with)
{
if (_isFinite)
{
if (with._isFinite)
{
Set union = new HashSet();
union.addAll(_finiteSet);
union.addAll(with._finiteSet);
return newInstance(true, union);
}
else
{
Set subst = new HashSet();
subst.addAll(with._finiteSet);
subst.removeAll(_finiteSet);
return newInstance(false, subst);
}
}
else
{
if (with._isFinite)
{
Set subst = new HashSet();
subst.addAll(_finiteSet);
subst.removeAll(with._finiteSet);
return newInstance(false, subst);
}
else
{
return newInstance(false, intersectFiniteSets(_finiteSet, with._finiteSet));
}
}
}
/**
* Returns the intersection of this NameSet with the 'with' NameSet
*/
public NameSet intersect(NameSet with)
{
if (_isFinite)
{
if (with._isFinite)
{
return newInstance(true, intersectFiniteSets(_finiteSet, with._finiteSet));
}
else
{
Set subst = new HashSet();
subst.addAll(_finiteSet);
subst.removeAll(with._finiteSet);
return newInstance(false, subst);
}
}
else
{
if (with._isFinite)
{
Set subst = new HashSet();
subst.addAll(with._finiteSet);
subst.removeAll(_finiteSet);
return newInstance(true, subst);
}
else
{
Set union = new HashSet();
union.addAll(_finiteSet);
union.addAll(with._finiteSet);
return newInstance(false, union);
}
}
}
/**
* Returns the result of substracting this NameSet from 'from' NameSet
* @see NameSet#substract
*/
public NameSet substractFrom(NameSet from)
{
return from.substract(this);
}
/**
* Returns the result of substracting 'what' NameSet from this NameSet
* @see NameSet#substractFrom
*/
public NameSet substract(NameSet what)
{
if (_isFinite)
{
if ( what._isFinite )
{
// it's the subst of _finiteSet with what._finiteSet
Set subst = new HashSet();
subst.addAll(_finiteSet);
subst.removeAll(what._finiteSet);
return newInstance(true, subst);
}
else
{
return newInstance(true, intersectFiniteSets(_finiteSet, what._finiteSet));
}
}
else
{
if ( what._isFinite )
{
// it's the union of _finiteSet with what._finiteSet
Set union = new HashSet();
union.addAll(_finiteSet);
union.addAll(what._finiteSet);
return newInstance(false, union);
}
else
{
// what's in thisSet and it's not in whatSet
Set subst = new HashSet();
subst.addAll(what._finiteSet);
subst.removeAll(_finiteSet);
return newInstance(true, subst);
}
}
}
/**
* Returns an inversion of this NameSet
*/
public NameSet invert()
{
return newInstance(!_isFinite, _finiteSet);
}
public boolean contains(String name)
{
if (_isFinite)
return _finiteSet.contains(name);
else
return !_finiteSet.contains(name);
}
}
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