Gerard Maas maasg

Applied Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

	import spark.streaming.StreamingContext._
	import spark.streaming.{Seconds, StreamingContext}
	import spark.SparkContext._
	import spark.storage.StorageLevel
	import spark.streaming.examples.twitter.TwitterInputDStream
	import com.twitter.algebird.HyperLogLog._
	import com.twitter.algebird._

	/**
	* Example of using HyperLogLog monoid from Twitter's Algebird together with Spark Streaming's

	import concurrent.{Future, Await, Promise, ExecutionContext}
	import java.util.concurrent.{Future => JavaFuture, TimeUnit, Callable, CancellationException, ExecutorService}
	import concurrent.duration._
	import scala.util.Success
	import scala.util.Failure
	import scala.util.control.NonFatal
	import scala.collection.JavaConverters._
	import concurrent.duration.TimeUnit
	import java.{util => jutil}