(*
 * This is another implementation of product in F#.
 * We use pattern matching to select the correct
 * implementation depending on the value of nums.
 * Since we've more clearly defined the function
 * by cases, it is easier to read.
 *
 * @param nums A list of numbers.
 * @returns The result of multiplying all numbers in nums.
 *)
let rec product nums =
  match nums with
  | []    -> 1
  | x::xs -> x * product xs
  
// call product like this
product [1; 2; 3]