Once Arrow's code generation is configured, you can add the @lenses annotation to the data classes that you want to have lenses generated for:

import arrow.lenses
import arrow.optics.Lens
import arrow.optics.modify

typealias GB = Int

@lenses data class Memory(val size: GB)
@lenses data class MotherBoard(val brand: String, val memory: Memory)
@lenses data class Laptop(val price: Double, val motherBoard: MotherBoard)

fun main(args: Array<String>) {
   val laptopX8 = Laptop(500.0, MotherBoard("X", Memory(8)))

   val laptopMemorySize: Lens<Laptop, GB> = laptopMotherBoard() compose motherBoardMemory() compose memorySize()

   val laptopX16 = laptopMemorySize.modify(laptopPrice().set(laptopX8, 780.0)) { size ->
      size * 2
   }

   println("laptopX16 = $laptopX16")
}

Arrow generates as many lenses as constructor parameters our data classes have, with the name convention classProperty and in the same package, so no extra imports are needed.