core/src/main/scala/org/apache/spark/api/java/function/Function.scala


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

/*
 * 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.spark.api.java.function

import scala.reflect.ClassTag
import org.apache.spark.api.java.JavaSparkContext

/**
 * Base class for functions whose return types do not create special RDDs. PairFunction and
 * DoubleFunction are handled separately, to allow PairRDDs and DoubleRDDs to be constructed
 * when mapping RDDs of other types.
 */
abstract class Function[T, R] extends WrappedFunction1[T, R] with Serializable {
  def returnType(): ClassTag[R] = JavaSparkContext.fakeClassTag
}