How to generate recursive list in OCaml

Question

I would like to implement analog of Haskell cycle function.

If I pass list elements explicitly it seems trivial:

let cycle a b c =
  let rec         


        

Answer 1

You need streams as in another answer, or lazy lists:

type 'a llist = LNil | LCons of 'a * 'a llist Lazy.t
let cycle = function
| [] -> invalid_arg "cycle: empty list"
| hd::tl ->
  let rec result =
    LCons (hd, lazy (aux tl))
  and aux = function
    | [] -> result
    | x::xs -> LCons (x, lazy (aux xs)) in
  result