Github user meiercaleb commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/257#discussion_r160009857
--- Diff:
common/rya.api.function/src/main/java/org/apache/rya/api/function/aggregation/SumFunction.java
---
@@ -0,0 +1,85 @@
+/*
+ * 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.rya.api.function.aggregation;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import java.math.BigInteger;
+
+import org.apache.rya.api.model.VisibilityBindingSet;
+import org.openrdf.model.Literal;
+import org.openrdf.model.Value;
+import org.openrdf.model.datatypes.XMLDatatypeUtil;
+import org.openrdf.model.impl.IntegerLiteralImpl;
+import org.openrdf.query.algebra.MathExpr.MathOp;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.util.MathUtil;
+import org.openrdf.query.impl.MapBindingSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * Add to the {@link AggregationState}'s sum if the child Binding Set
contains the binding name
+ * that is being summed by the {@link AggregationElement}.
+ */
+@DefaultAnnotation(NonNull.class)
+public final class SumFunction implements AggregationFunction {
+ private static final Logger log =
LoggerFactory.getLogger(SumFunction.class);
+
+ @Override
+ public void update(final AggregationElement aggregation, final
AggregationState state, final VisibilityBindingSet childBindingSet) {
+ checkArgument(aggregation.getAggregationType() ==
AggregationType.SUM, "The SumFunction only accepts SUM AggregationElements.");
--- End diff --
Preconditions
---
