longcao

import java.io.InputStream

import org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
import org.apache.spark.sql.{ DataFrame, Row }

import org.postgresql.copy.CopyManager
import org.postgresql.core.BaseConnection

val jdbcUrl = s"jdbc:postgresql://..." // db credentials elided
val connectionProperties = {

longcao

/**
  * Intersperses words with spaces and trims ends, accounts for basic smilies.
  */
def wordsToSentence(words: Vector[String]): String = {
  val punctuation = Set(":", ";", ".", ",", "!", "?")
  val smilies = Set(":)", ":(", ":<", ":}", ":|", ":o")

  // @TODO really bad implementation probably, clean this up later
  words.zipWithIndex.foldLeft("") { case (acc, (word, i)) =>
    val isLastWordPairSmilie = if (words.isDefinedAt(i - 1)) {

longcao

1. Handling stacked monads and the like e.g. List[Option[T]], `Future[Option[T]``
2. Referentially transparent error handling
3. Error accumulation/'parallel' validation
4. Adding together Option[T]s (a la http://stackoverflow.com/a/16319667, not sure how to word this well)
5. More explicitly typesafe collections (e.g. non-empty, guarantee that list.head never throws, etc)

longcao

import akka.actor._

object Server extends App {
  val system = ActorSystem("serverSystem")
  val serverActor = system.actorOf(Props(new ServerActor), name = "ServerActor")
}

class ServerActor extends Actor {
  def receive = {
    case message: String =>

longcao

import akka.actor._

object Client extends App {
  val system = ActorSystem("clientSystem")
  val clientActor = system.actorOf(Props(new ClientActor), name = "ClientActor")

  clientActor ! SayHello
}

class ClientActor extends Actor {

longcao

# 'client' conf
akka {
  actor {
    provider = "akka.remote.RemoteActorRefProvider"
  }
  remote {
    enabled-transports = ["akka.remote.netty.tcp"]
    netty.tcp {
      hostname = "127.0.0.1"
      port = 2553

longcao

libraryDependencies ++= Seq(
  "com.typesafe.akka" %% "akka-actor" % "2.2.3",
  "com.typesafe.akka" %% "akka-remote" % "2.2.3"
)