Scala example source code file (t3152.scala)

This example Scala source code file (t3152.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

a, a, applicative, applicative, b, list, listma, ma, ma, n, n, nil, option

The Scala t3152.scala source code

trait Applicative[M[_]]

sealed trait MA[M[_], A] {
  def sequence[N[_], B](implicit a: A <:< N[B], n: Applicative[N]): N[M[B]] = error("stub")
  // def sequence3[N[_], B]()(implicit a: A <:< N[B], n: Applicative[N]): N[M[B]] = error("stub")
}

object test {
  implicit def ListMA[A](l: List[A]): MA[List, A] = error("stub")
  implicit val ao: Applicative[Option] = error("stub")

  /* This compiles OK:
  (Nil: List[Option[Int]]).sequence3(): Option[List[Int]]
  */

  // BUG: error: immutable is not an enclosing class
  // !!! No line number is reported with the error
  (Nil: List[Option[Int]]).sequence: Option[List[Int]]
  (List[Option[Int]]()).sequence: Option[List[Int]]
}