vsuharnikov

import com.google.common.collect.ImmutableMap
import com.spotify.docker.client.messages.HostConfig
import com.spotify.docker.client.shaded.com.fasterxml.jackson.annotation.JsonProperty

class ExtendedHostConfig(h: HostConfig) extends HostConfig {
  @JsonProperty("Sysctls")
  def sysctls(): ImmutableMap[String, String] = ImmutableMap.of(
    "net.ipv4.tcp_keepalive_time", "15",
    "net.ipv4.tcp_keepalive_intvl", "5",
    "net.ipv4.tcp_keepalive_probes", "3"

vsuharnikov

import com.typesafe.config.ConfigObject
import pureconfig._
import pureconfig.error.{CannotParse, ConfigReaderFailures}

sealed trait Enigma
object Enigma {
  case class Foo(value: Int) extends Enigma
  case object Bar extends Enigma
}

vsuharnikov

import com.google.common.primitives.Ints
import scala.collection.breakOut

trait Serializable[From, To] {
  def serialize(x: From): To
}

trait Deserializable[From, To] {
  def deserialize(x: From): To
}

vsuharnikov

import scala.language.experimental.macros
import scala.reflect.macros.blackbox

object Test {
  def foo1[A, B]: Unit = macro impl[A, B]
  def foo2[A]: Unit = macro impl[A, Option[Int]]

  def impl[A: c.WeakTypeTag, B: c.WeakTypeTag](c: blackbox.Context): c.Expr[Unit] = {
    import c.universe._
    c.echo(c.enclosingPosition, s"A=${weakTypeOf[A]}, B=${weakTypeOf[B]}")

vsuharnikov

trait Lit[T] {
  def lit(x: Int): T
}

trait Add[T] {
  def add(x: T, y: T): T
}

trait Mul[T] {
  def mul(x: T, y: T): T

vsuharnikov

trait BinaryOperation[T] {
  def apply(a: T, b: T): T
}

trait AssociativeBinaryOperation[T] extends BinaryOperation[T]

trait Reduce[F[_]] {
  def apply[T](xs: F[T])(op: BinaryOperation[T]): T
}

vsuharnikov

Scala for comprehension translation helper

"For comprehension" is a another syntax to use map, flatMap and withFilter (or filter) methods.

yield keyword is used to aggregate values in the resulting structure.

This composition can be used on any type implementing this methods, like List, Option, Future...

Try it yourself!