Exiting a loop in F#

During our work on the Chip 8 emulator, we encountered some difficulties while learning the F# language:

One of these difficulties was that as a functional language, F# didn’t allow the use of a break keyword during while loops. Something like this won’t work:

let loop =
  for i in [0..8] do
    if i = 6 then
      printfn "%d" i
      break

Instead, you have to leave your imperative thinking behind and go functional, with recursive functions:

let rec loop_rec i =
  if i < 9 then
    if i != 6 then
      loop_rec (i + 1)
    else
      printfn "%d" i
  ()

let loop =
  loop_rec 0

This was a basic exemple, but you can see how we applied it to our work in this commit.