public boolean contains(String name) 
{
        if (_isFinite)
            return _finiteSet.contains(name);
        else
            return !_finiteSet.contains(name);
}

 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 intersection of this NameSet with the 'with' NameSet

 public NameSet invert() 
{
        return newInstance(!_isFinite, _finiteSet);
}

Returns an inversion of this NameSet

 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);
        }
}

 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 the result of substracting 'what' NameSet from this NameSet

 public NameSet substractFrom(NameSet from) 
{
        return from.substract(this);
}

Returns the result of substracting this NameSet from 'from' 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 union of this NameSet with the 'with' NameSet.