Demonstrates how implicit parameters can be scoped in Scala

gistfile1.scala

class Jedi(val name: String, val force: Double) {
  override def toString = name + " with force " + force
}
def findMostPowerfulOf(jedies: Set[Jedi]) = {
  implicit val jediOrdering = Ordering by { x:Jedi => x.force }
  jedies.max
}
def findLastNameOf(jedies: Set[Jedi]) = {
  implicit val jediOrdering = Ordering by { x:Jedi => x.name }
  jedies.max
}
def findMaxOf(jedies: Set[Jedi], by: Symbol) = {
  if (by == 'Force) {
    implicit val jediOrdering = Ordering by { x:Jedi => x.force }
    "Max force has " + jedies.max
  } else {
    implicit val jediOrdering = Ordering by { x:Jedi => x.name }
    "Last name has " + jedies.max
  }
}

val jedies = Set( new Jedi("Skywalker", 100), new Jedi("Obi-Wan", 200), new Jedi("Yoda", 5000), new Jedi("Zal", 80) )
println( findMostPowerfulOf(jedies) ) // => Yoda with force 5000.0
println( findLastNameOf(jedies) )    //  => Zal with force 80.0
println( findMaxOf(jedies, 'Force) ) //  => Yoda with force 5000.0
println( findMaxOf(jedies, 'Name) ) //   => Zal with force 80.0