/*
* 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 com.hp.hpl.jena.sparql.engine.binding;
import java.util.Iterator ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.sparql.core.Var ;
public class BindingFactory
{
public static final Binding noParent = null ;
/** Create a binding of no pairs */
public static Binding binding() { return binding(noParent) ; }
/** Create a binding of no pairs */
public static Binding binding(Binding parent) { return new Binding0(parent) ; }
public static Binding binding(Var var, Node node) { return binding(noParent, var, node) ; }
/** Create a binding of one (var, value) pair */
public static Binding binding(Binding parent, Var var, Node node)
{
if ( Var.isAnonVar(var) )
return new Binding0(parent) ;
return new Binding1(parent, var, node) ;
}
public static BindingMap create() { return create(noParent) ; }
public static BindingMap create(Binding parent) { return new BindingHashMap(parent) ; }
public static Binding root() { return BindingRoot.create() ; }
/** Create a new Binding as a copy of an existing one.
* Additionally, it guarantees to touch each element of the binding */
public static Binding materialize(Binding b)
{
Iterator<Var> vIter = b.vars() ;
BindingMap b2 = create() ;
while( vIter.hasNext() )
{
Var v = vIter.next();
b2.add(v, b.get(v)) ;
}
return b2 ;
}
}