All permutations of all combinations of input

AllCombinations.scala

object AllCombinations extends App {

  /**
   * Returns all permutations of all combinations
   * of everything in the input data
   *
   * For example, given the `data` List('a', 'b', 'c')
   * will return the result:
   *
   * List(
   *   List(a),
   *   List(b),
   *   List(c),
   *   List(a, b),
   *   List(b, a),
   *   List(a, c),
   *   List(c, a),
   *   List(b, c),
   *   List(c, b),
   *   List(a, b, c),
   *   List(a, c, b),
   *   List(b, a, c),
   *   List(b, c, a),
   *   List(c, a, b),
   *   List(c, b, a)
   * )
   *
   * @param data The input data to calculate all permutations of
   *
   * @return All permutations of all combinations of the input data
   */
  def allCombinations[T](data: List[T]) : List[List[T]] = {
    (for(i <- 1 to data.length) yield
      data.combinations(i).toList.map(_.permutations.toList).flatten
    ).toList.flatten
  }

  
  //example use
  val stuff = List('a', 'b', 'c')
  for(x <- allCombinations(stuff))
    println(x)
}

Slightly simplified:

def allCombinations[T](data: List[T]): List[List[T]] = (
  for(i <- 1 to data.length)
  yield data.combinations(i).flatMap(_.permutations)).toList.flatten