/*
* 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.sparql.engine.binding;
import java.util.Iterator ;
import org.apache.jena.graph.Node ;
import org.apache.jena.sparql.core.Var ;
/** Interface encapsulating a mapping from a name to a value. */
public interface Binding
{
/** Iterate over all variables of this binding. */
public Iterator<Var> vars() ;
/** Test whether a variable is bound to some object */
public boolean contains(Var var) ;
/** Return the object bound to a variable, or null */
public Node get(Var var) ;
/** Number of (var, value) pairs. */
public int size() ;
/** Is this an empty binding? No variables. */
public boolean isEmpty() ;
}