scala sample

scala ML

trait PipeOperator[-T, +U]{
  def |> (data:T):Option[U]
}
class _FCT[+T](val _fct: T) {
  def map[U](c: T => U): _FCT[U] = new _FCT[U]( c(_fct))
  def flatMap[U](f: T =>_FCT[U]): _FCT[U] = f(_fct)
  //def filter(p: T =>Boolean): _FCT[T] = if( p(_fct) ) new _FCT[T](_fct) else zeroFCT(_fct)
  def reduceLeft[U](f: (U,T) => U)(implicit c: T=> U): U = f(c(_fct),_fct)
  def foldLeft[U](zero: U)(f: (U, T) => U)(implicit c: T=> U): U = f(c(_fct), _fct)
  def foreach(p: T => Unit): Unit = p(_fct)
}

class Transform[-T, +U](val op: PipeOperator[T, U]) extends _FCT[Function[T, Option[U]]](op.|>) {
  def |>(data: T): Option[U] = _fct(data)
}

object Operator{

  def main(args:Array[String]){
    val op = new PipeOperator[Int, Double] {
      def |> (n: Int):Option[Double] =Some(Math.sin(n.toDouble)) }
      def g(f: Int =>Option[Double]): (Int=> Long) = {
        (n: Int) => {
          f(n) match {
           case Some(x) => x.toLong
           case None => -1L
          }
        }
      }
    val gof = new Transform[Int,Double](op).map(g(_))
  }

}