scala-for.scala

/**
 * This is a Scala script: scala-for.scala
 */

val xs: Array[Int] = Array(1, 2, 3)
val ys: Array[Int] = Array(1, 2, 3, 4, 5)


/** for comprehension: filter/map */
for (x <- xs if x % 2 == 0)
  yield x * 10

/** same as */
xs.filter(_ % 2 == 0).map(_ * 10)


/** for comprehension: destructuring bind */
for ((x,y) <- xs.zip(ys))
  yield x * y

/** same as */
(xs.zip(ys)).map { case (x, y) => x * y }


/** for comprehension: cross product */
for (x <- xs; y <- ys)
  yield x * y

/** same as */
xs.flatMap { x => ys.map {y => x * y} }


/** for comprehension: imperative-ish sprintf-style */
for (x <- xs; y <- ys) {
  println("%d * %d = %d".format(x, y, x * y))
}


/** for comprehension: iterate including the upper bound */
for (i <- 1 to 5) {
  println(i)
}


/** for comprehension: iterate omitting the upper bound */
for (i <- 1 until 5) {
  println(i)
}