How can I use a user inputted value in my Function in F#

Question

So I\'m trying to make a simple factorial function in F# that uses a value inputted from the user (using the console, I don\'t know if that makes any difference) but I can\'

Answer 1

Since both:

somevalue |> int

and

System.Int32.Parse somevalue

Throw an exception on invalid input is it not better to prevent your app from blowing up at runtime?

Since I could not find any function that returns int option I wrote one:

let asInt32 numberString =
  let (success,num)  = 
    System.Int32.TryParse(numberString)
  if success then
    Some num
  else
    None
asInt32 "22"

(using TryParse as Gustavo suggested)