List reverse implementation

ListReverser

package fpexample


object ListReverser {
  
  // I don't see how this can be done in anything less than linear time
  // (ie proportional to the length of the list).
  //
  // Space usage shouldn't vary, since foldLeft is tail recursive, 
  // and the size of the accumulated list grows at the same rate 
  // as the original list shrinks.
  def reverseList[A](list: List[A]): List[A] = 
    list.foldLeft[List[A]](Nil)((a,b) => b :: a)

    
  def main(args: Array[String]): Unit = {
    val list = (1 to 1000000).toList
    println(s"Reverse of list: ${reverseList(list) take 5}")
  }
}