You can use loops instead of compex maps

For example:

Using this 'for' loop the 'yield' function acts like a flatmap:

  def loopMe() = {
    val numbers = for( i <- 1 to 10; if i % 2 == 0; 
                       j <- i to 10 if j % 2 == 1) yield i * j
    println(numbers)
  }

Here is the equivalent with traditional maps and filters:

  def mapMe() = {
    val num2 = (1 to 10).filter( a => a % 2 == 0)
    val num3 = num2.flatMap( a => (a to 10).filter(b => b % 2 == 1).map(c =>  c * a ) )

    println(num3)
  }