Question

  def fibSeq(n: Int): List[Int] = {
    var ret = scala.collection.mutable.ListBuffer[Int](1, 2)
    while (ret(ret.length - 1) < n) {
      val temp = ret(ret.length - 1) + ret(ret.length - 2)
      if (temp >= n) {
        return ret.toList
      }
      ret += temp
    }
    ret.toList
  }

So the above is my code to generate a Fibonacci sequence using Scala to a value n. I am wondering if there is a more elegant way to do this in Scala?

Answer 1

There are many ways to define the Fibonacci sequence, but my favorite is this one:

val fibs:Stream[Int] = 0 #:: 1 #:: (fibs zip fibs.tail).map{ t => t._1 + t._2 }

This creates a stream that is evaluated lazily when you want a specific Fibonacci number.

EDIT:
First, as Luigi Plinge pointed out, the “lazy” at the beginning was unnecessary.
Second, go look at his answer, he pretty much did the same thing only more elegantly.