https://gist.github.com/4166911

StringValidator.scala

import scala.util.matching.Regex

class StringValidator(strings: List[String]) {
  var or = false
  var not = false
  var result = true

  def judge = result

  def and = self(or = false)

  def matched(regex: Regex) = self {
    evaluate(string => regex.findFirstIn(string) match {
      case None => false
      case _    => true
    })
  }

  private def evaluate(validate: String => Boolean) {
    if (!(or ^ result)) return
    result = strings.forall(string => validate(string) ^ not)
    not = false
  }

  private def self(process: => Unit) = {
    process
    this
  }
}

object StringValidator {
  implicit def stringToStringValidator(string: String) = new StringValidator(List(string))
  implicit def listToStringValidator(list: List[String]) = new StringValidator(list)
  implicit def stringValidatorToBoolean(stringValidator: StringValidator) = stringValidator.judge
}

object Main {
  import StringValidator._

  def main(args: Array[String]) {
    val strings = args.toList
    val result = if (strings.matched("^nya".r).and.matched("nya$".r)) "true" else "false"
    println(result)
  }
}