/*
* 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.function;
import java.util.ArrayList ;
import java.util.List ;
import org.apache.jena.sparql.ARQInternalErrorException ;
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 ;
/** Impleemntation root for custom function evaluation. */
public abstract class FunctionBase implements Function {
@Override
public final void build(String uri, ExprList args) {
// Rename for legacy reasons.
checkBuild(uri, args) ;
}
@Override
public NodeValue exec(Binding binding, ExprList args, String uri, FunctionEnv env) {
if ( args == null )
// The contract on the function interface is that this should not happen.
throw new ARQInternalErrorException("FunctionBase: Null args list") ;
List<NodeValue> evalArgs = new ArrayList<>() ;
for ( Expr e : args )
{
NodeValue x = e.eval( binding, env );
evalArgs.add( x );
}
NodeValue nv = exec(evalArgs) ;
return nv ;
}
/** Function call to a list of evaluated argument values */
public abstract NodeValue exec(List<NodeValue> args) ;
public abstract void checkBuild(String uri, ExprList args) ;
}