conjugations.scala

import org.omg.CosNaming.NamingContextPackage.NotFound

// these are the data types
trait Tense{
}

case object Past extends Tense
case object Present extends Tense
case object Future extends Tense

trait Subject{

}

case object Je extends Subject
case object Ils extends Subject

trait Verb{
  protected val trim : Map[Tense, String]
  protected val infin: String
  protected val subjects : Map[Subject, Map[Tense,(String,String)]]
  protected def getConstructs(tense: Tense, subject:Subject) = subjects(subject)(tense)

  def conjugate(subject: Subject, tense: Tense)={
      val constructs = getConstructs(tense, subject)
      "%s %s%s".format(constructs._1, infin.stripSuffix(trim(tense)), constructs._2)
  }
}

case class ErVerb(infinitive:String) extends Verb{
      protected val trim :  Map[Tense, String] = Map(Present-> "er", Past->"er")
      protected val infin = infinitive
      protected val subjects: Map[Subject, Map[Tense,(String,String)]] = Map(
                               Je -> Map(Present -> ("Je","e"), Past -> ("J'ai", "e")),
                               Ils -> Map(Present -> ("Ils","ent"), Past ->("Ils ont","e"))
                              )
}
case class IrVerb(infinitive:String) extends Verb{
      protected val trim :  Map[Tense, String] = Map(Present->"ir", Past->"r")
      protected val infin = infinitive
      protected val subjects: Map[Subject, Map[Tense,(String,String)]] = Map(
                               Je -> Map(Present -> ("Je","is"), Past -> ("J'ai", "")),
                               Ils -> Map(Present -> ("Ils","issent"), Past ->("Ils ont",""))
                              )
}

implicit def stringToVerb(verb:String) = {
  if( verb.endsWith("ir")) IrVerb(verb)
  else  if( verb.endsWith("er")) ErVerb(verb)
      else throw new NullPointerException("") //just some random error
}


println {
    // je regarde
  "regarder" conjugate(Je, Past)
  "regarder" conjugate(Ils, Past)
  "finir" conjugate(Je, Past)
  "finir" conjugate(Ils, Past)

}