Attempt to simplify function composition from multiple partials using shapeless...

PartialShapeless.scala

import shapeless._
import HList._
import Record._

object Shapeless {
  type MyFunction = PartialFunction[Any, String]

  object behaviourA extends Field[MyFunction] { override def toString = "BehaviourA" }
  object behaviourB extends Field[MyFunction] { override def toString = "BehaviourB" }
  object behaviourC extends Field[MyFunction] { override def toString = "BehaviourC" }

  case object MessageA
  case object MessageB
  case object MessageC

  def behaviourAType1: MyFunction = { case MessageA => "behaviourA type 1" }
  def behaviourAType2: MyFunction = { case MessageA => "behaviourA type 2" }
  def behaviourBType1: MyFunction = { case MessageB => "behaviourB type 1" }
  def behaviourBType2: MyFunction = { case MessageB => "behaviourB type 2" }
  def behaviourCType1: MyFunction = { case MessageC => "behaviourC type 1" }
  def behaviourCType2: MyFunction = { case MessageC => "behaviourC type 2" }

  var function = (behaviourA -> behaviourAType1) ::
                 (behaviourB -> behaviourBType1) ::
                 (behaviourC -> behaviourCType1) :: HNil
  def func = function.get(behaviourA) orElse function.get(behaviourB) orElse function.get(behaviourC)
  def runfunc() {
    println("[MessageA]: " + func(MessageA))
    println("[MessageB]: " + func(MessageB))
    println("[MessageC]: " + func(MessageC))
  }
  def main(args: Array[String]) {
    println("Run 1")
    runfunc()
    println("Run 2")
    function = function + (behaviourA -> behaviourAType2)
    runfunc()
    println("Run 3")
    function = function + (behaviourB -> behaviourBType2)
    runfunc()
    println("Run 4")
    function = function + (behaviourC -> behaviourCType2)
    runfunc()
  }
}