http://matsu-chara.hatenablog.com/entry/2015/07/12/110000

build.sbt

name := "OptionValueAccessor"

scalaVersion := "2.11.6"

libraryDependencies ++= Seq(
  "com.github.julien-truffaut" %% "monocle-core"  % "1.1.1",
  "com.github.julien-truffaut" %% "monocle-macro" % "1.1.1"
)

scalacOptions ++= Seq(
  "-feature",
  "-language:higherKinds",
  "-language:postfixOps"
)

EDCBA.scala

object EDCBA {

  case class A(value: Int)
  case class B(value: Option[A])
  case class C(value: B)
  case class D(value: Option[C])
  case class E(value: D)

  val edcba: Option[E] = Some(E(D(Some(C(B(Some(A(1))))))))
  
  val ednon: Option[E] = Some(E(D(None)))
}

Example1.scala

import monocle.syntax._
import monocle.std.option._
import monocle.macros.GenLens

object Example1 {
  import EDCBA._

  val _a = GenLens[A](_.value)
  val _b = GenLens[B](_.value)
  val _c = GenLens[C](_.value)
  val _d = GenLens[D](_.value)
  val _e = GenLens[E](_.value)

  def getAValue(edcba: Option[E]): Option[Int] =
    edcba &<-? some[E, E] ^|-> _e ^|-> _d ^<-? some ^|-> _c ^|-> _b ^<-? some ^|-> _a getOption

  def good: Option[Int] =
    getAValue(edcba)

  def bad: Option[Int] =
    getAValue(ednon)
}

Example2.scala

import monocle.Prism
import monocle.syntax._
import monocle.std.option._
import monocle.macros.GenLens

object Example2 {
  import EDCBA._

  val _a = GenLens[A](_.value)
  val _b = Prism[B, A](_.value)(a => B(Some(a)))
  val _c = GenLens[C](_.value)
  val _d = Prism[D, C](_.value)(c => D(Some(c)))
  val _e = GenLens[E](_.value)

  def getAValue(edcba: Option[E]) =
    edcba &<-? some[E, E] ^|-> _e ^<-? _d ^|-> _c ^<-? _b ^|-> _a getOption

  def good: Option[Int] =
    getAValue(edcba)

  def bad: Option[Int] =
    getAValue(ednon)
}

repl.scala

scala> import EDCBA._, Example2._
import EDCBA._
import Example2._

scala> import monocle._, Monocle._
import monocle._
import Monocle._

scala> edcba &<-? some[E, E] ^|-> _e ^<-? _d ^|-> _c ^<-? _b ^|-> _a set 999
res1: Option[EDCBA.E] = Some(E(D(Some(C(B(Some(A(999))))))))

scala> edcba &<-? some[E, E] ^|-> _e ^<-? _d ^|-> _c ^<-? _b ^|-> _a modify(_ + 200)
res2: Option[EDCBA.E] = Some(E(D(Some(C(B(Some(A(201))))))))