/*
* 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.algebra;
import java.util.HashMap ;
import java.util.Map ;
import org.apache.jena.sparql.ARQException ;
import org.apache.jena.sparql.algebra.op.OpExt ;
import org.apache.jena.sparql.sse.ItemList ;
import org.apache.jena.sparql.sse.Tags ;
import org.apache.jena.sparql.sse.builders.BuilderOp ;
/** Manage extension algebra operations */
public class OpExtRegistry
{
// Known extensions.
static Map<String, OpExtBuilder> extensions = new HashMap<>() ;
// Wire in (ext NAME ...) form
static { BuilderOp.add(Tags.tagExt, new BuildExtExt()) ; }
public static void register(OpExtBuilder builder)
{
extensions.put(builder.getTagName(), builder) ;
if ( BuilderOp.contains(builder.getTagName()) )
throw new ARQException("Tag '"+builder.getTagName()+"' already defined") ;
BuilderOp.add(builder.getTagName(), new BuildExt2()) ;
}
public static void unregister(String subtag)
{
extensions.remove(subtag) ;
}
public static OpExtBuilder builder(String tag) { return extensions.get(tag) ; }
public static Op buildExt(String tag, ItemList args)
{
OpExtBuilder b = builder(tag) ;
OpExt ext = b.make(args) ; // Arguments 2 onwards
return ext ;
}
// (ext NAME ...) form
static public class BuildExtExt implements BuilderOp.Build
{
@Override
public Op make(ItemList list)
{
// 0 is the "ext"
String subtag = list.get(1).getSymbol() ;
list = list.sublist(2) ;
return buildExt(subtag, list) ;
}
}
// (NAME ...) form
static public class BuildExt2 implements BuilderOp.Build
{
@Override
public Op make(ItemList list)
{
String subtag = list.get(0).getSymbol() ;
list = list.sublist(1) ;
return buildExt(subtag, list) ;
}
}
}