/*
* 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.procedure ;
import org.apache.jena.graph.Node ;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.ExecutionContext ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.engine.binding.Binding ;
import org.apache.jena.sparql.expr.Expr ;
import org.apache.jena.sparql.expr.ExprList ;
import org.apache.jena.sparql.expr.NodeValue ;
public abstract class ProcedureEval extends ProcedureBase
{
@Override
public QueryIterator exec(Binding binding, Node name, ExprList args, ExecutionContext execCxt)
{
// Eval if possible.
ExprList evalArgs = new ExprList() ;
for (Expr e : args)
{
if ( e.isVariable() )
{
Var v = e.getExprVar().asVar() ;
// Special case - allow unevaluated variables.
if ( binding.contains(v) )
evalArgs.add(e.eval(binding, execCxt)) ;
else
evalArgs.add(e) ;
}
else
{
NodeValue x = e.eval(binding, execCxt) ;
evalArgs.add(x) ;
}
}
return execEval(binding, evalArgs, execCxt) ;
}
public abstract QueryIterator execEval(Binding binding, ExprList args, ExecutionContext execCxt) ;
}