validation.scala

validation.scala

 def trying[O](f: String => O)(msg: String) =
    Rule.fromMapping[String, O] { s =>
      Try(f(s))
        .map(Success[ValidationError, O](_))
        .getOrElse(Failure[ValidationError, O](Seq(ValidationError(msg, s))))
    }
    
val stringToDoubleR: Rule[String, Double] = trying(_.toDouble)("error.double")
val stringToLongR: Rule[String, Long] = trying(_.toLong)("error.long")
val stringToIntR: Rule[String, Int] = trying(_.toInt)("error.int")
  
def localDateR(formatter: DateTimeFormatter) = trying { str =>
  LocalDate.parse(str, formatter)
}("error.localdate")