Learning about Scala's for comprehensions.

NotForYour.scala

// See http://stackoverflow.com/questions/1052476/what-is-scalas-yield/1059501#1059501

// Compilation error is:
// [error]  found   : Seq[String]
// [error]  required: Option[?]
// [error]     child <- foo.children
// [error]           ^
// [error] one error found


case class Foo(name: String, children: Seq[Foo])

object Yield extends App {

  val c1 = Foo("child1", Nil)
  val c2 = Foo("child2", Nil)
  val c3 = Foo("child3", Nil)
  val c4 = Foo("child4", Nil)
  val parent1 = Foo("parent1", List(c1,c2,c3))
  val parent2 = Foo("parent2", List(c4))
  val fooz = List(parent1, parent2)

  val found = for {
    foo   <- fooz.find(_.name == "parent1")
    child <- foo.children
    if child.name != "child2"
  } yield child.name 

  println(s"Found: $found")
}