Github user ajs6f commented on a diff in the pull request:
https://github.com/apache/jena/pull/331#discussion_r157378417
--- Diff:
jena-arq/src/main/java/org/apache/jena/sparql/function/library/FN_Error.java ---
@@ -0,0 +1,66 @@
+/*
+ * 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.library;
+
+import java.util.List ;
+
+import org.apache.jena.atlas.lib.Lib;
+import org.apache.jena.query.QueryBuildException;
+import org.apache.jena.sparql.ARQInternalErrorException;
+import org.apache.jena.sparql.expr.ExprEvalException ;
+import org.apache.jena.sparql.expr.ExprList ;
+import org.apache.jena.sparql.expr.NodeValue ;
+import org.apache.jena.sparql.expr.nodevalue.NodeFunctions;
+import org.apache.jena.sparql.function.FunctionBase;
+
+/** XPath and XQuery Functions and Operators 3.1
+ * <p>
+ * {@code fn:error()}
+ * <br/>
+ * {@code fn:error(message)}
+ */
+public class FN_Error extends FunctionBase {
+
+ @Override
+ public void checkBuild(String uri, ExprList args) {
+ if ( args.size() != 0 && args.size() != 1 )
+ throw new QueryBuildException("Function
'"+Lib.className(this)+"' takes zero or one arguments") ;
+ }
+
+ @Override
+ public NodeValue exec(List<NodeValue> args) {
+ if ( args == null )
+ // The contract on the function interface is that this should
not happen.
+ throw new ARQInternalErrorException("FunctionBase1: Null args
list") ;
+
+ int size = args.size();
--- End diff --
Did you mean to use this `size` var below? It doesn't seem to get used at
all...
---
