#!/usr/bin/env scala -feature

object EMail {
//object EMail extends ((String, String) => String) {
//object EMail extends Function2[String, String, String] {

  //def apply(user: String, domain: String) = user + "@" + domain

  def unapply(str: String): Option[(String,String)] = {
    val parts = str split "@"
    if (parts.length == 2) Some(parts(0), parts(1)) else None
  }
}

val s: Any = "[email protected]"
s match {
  case EMail(user, domain) => println(user + " at " + domain)
  case _ => println("not an email address")
}

//val ss = List(s, s, "[email protected]","[email protected]")
//val ss = List(s,"[email protected]","[email protected]")
val ss = List("[email protected]","[email protected]", s, s, s)
ss match {
  case EMail(u1, d1) :: EMail(u2, d2) :: _ if (u1 == u2) => println(s"$u1 has a dupe")
  case _ => println("not sure")
}