beranradek

import Contexts.myDbOperationContext
concurrent.Future {
  // Nejaky blokujici kod pristupujici k databazi
}

beranradek

play {
  my-db-context {
    fork-join-executor {
      parallelism-factor = 1.0
      parallelism-max = 200
    }
  }
}

beranradek

object Contexts {
  implicit val myDbOperationContext: ExecutionContext = 
    Akka.system.dispatchers.lookup("my-db-context")
}

beranradek

import play.api.libs.concurrent.Execution.Implicits._

def someAsyncAction = Action {
  Async {
    WS.get("http://www.someservice.com").get().map { 
      response =>
        Ok("Response code: " + response.status)
    }
  }
}

beranradek

package dojo

import java.net.URL
import java.io.File
import scala.io.Source
import java.io.InputStream
import scala.util.Try
import scala.util.Success

trait Resource[R] {

beranradek

case class Person(firstName: String, lastName: String, male: Boolean)

val people = List(
  Person("Veronika", "Skalova", false),
  Person("Jana", "Heroutova", false),
  Person("Miroslav", "Klepis", true))

for (Person(_, lastName, false) <- people) yield "Pani " + lastName
// Pani Skalova, Pani Heroutova

beranradek

val myTuple = (1, 2)
val (x, y) = myTuple // (x, y) je constructor pattern pro tuple
println(x) // 1

val addOperation = Add(Number(1), Add(Number(2), Number(3)))
val Add(Number(_), secondOperand @ Add(_, b)) = addOperation
// Add(Number(_), secondOperand @ Add(_, b)) je constructor pattern 
// s vnořenými constructor patterny pro první a druhý parametr,
// b je matchováno variable patternem a match. hodnota je do něj uložena
println(b) // Number(3)

beranradek

// Pattern matching for defining partial functions
val numToRoman: PartialFunction[Int, String] = {
  case 4 => "IV"
  case 5 => "V"
  case 6 => "VI"
}
println(numToRoman.isDefinedAt(7)) // false

beranradek

try {
  processFile("input.txt")
} catch {
  case ex: FileNotFoundException => println("Missing file exception: " + 
    ex.getMessage())
  case ex: IOException => println("IO exception: " + ex.getMessage())
}

beranradek

val n: Any = -20
n match {
  case i : Int if (i > 0) => "positive int"
  case s : String if (s.length() > 0) => "non-empty string"
}