(let dotProduct (fun (v1 v2) {
  (assert (= (len v1) (len v2)) "vectors should have the same length")

  (mut result 0)
  (mut i 0)
  (while (< i (len v1)) {
    (set result (+ result (* (@ v1 i) (@ v2 i))))
    (set i (+ 1 i)) })

  result }))

(print (dotProduct [1 3 -5] [4 -2 -1]))