sbt incremental task example

incremental.scala

import sbt._
import sbinary._
import DefaultProtocol._

object Incremental {
	val soupOfTheDay = taskKey[String]("Returns the soup of the day. If none is defined, asked for one and remembers until cleaned.")
	val showMenu = taskKey[Unit]("Displays the menu")
	def settings: Seq[Setting[_]] =
	  Seq(
         soupOfTheDay := {
            soupOfTheDay.previous match {
              case Some(soup) => soup
              case None =>  
                SimpleReader.readLine("Please enter next soup: ", None) getOrElse "Turtle Soup"
            }
         }
         showMenu := {
         	val log = streams.value.log
         	log.info("-- Menu --")
         	log.info(s"Soup of the Day: ${soupOfTheDay.value}")
         }
	  )

}