examples/src/main/scala/org/apache/ignite/scalar/examples/ScalarWorldShortestMapReduce.scala

/*
 * 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.ignite.scalar.examples

import org.apache.ignite.scalar.scalar
import org.apache.ignite.scalar.scalar._

/**
 * Shows the world's shortest MapReduce application that calculates non-space
 * length of the input string. This example works equally on one computer or
 * on thousands requiring no special configuration or deployment.
 * <p/>
 * Remote nodes should always be started with special configuration file which
 * enables P2P class loading: `'ignite.{sh|bat} examples/config/example-ignite.xml'`.
 * <p/>
 * Alternatively you can run `ExampleNodeStartup` in another JVM which will
 * start node with `examples/config/example-ignite.xml` configuration.
 */
object ScalarWorldShortestMapReduce extends App {
    scalar("examples/config/example-ignite.xml") {
        val input = "World shortest mapreduce application"

        println("Non-space characters count: " +
            ignite$.reduce$[Int, Int](for (w <- input.split(" ")) yield () => w.length, _.sum, null)
        )
    }
}