/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package org.apache.jena.sdb.core;

import java.util.Collections;
import java.util.Set;

import org.apache.jena.sparql.core.Var ;

public class ScopeNull implements Scope 
{
    @Override
    public boolean          isEmpty()                   { return false ; }    
    @Override
    public boolean          hasColumnForVar(Var var)    { return false ; }
    @Override
    public ScopeEntry       findScopeForVar(Var var)    { return null ; }
    @Override
    public Set<Var>         getVars()                   { return Collections.emptySet()  ; }
    @Override
    public Set<ScopeEntry>  findScopes()                { return Collections.emptySet()  ; }
    
    @Override public String toString() { return "ScopeNull" ; }
}
