Just reinvented OOP

[Gopiandcode]

@hyphenrf

let (.:[;..]) s = function
  | [|start; finish|] -> String.sub s start (finish - start)
  | _ -> raise (Invalid_argument "slice takes exactly two indexes")

Oh wow, this is perfect! brb, off to reimplement the python slicing semantics in OCaml:

let (.@[;..]) ls = function[@warning "-8"]
  | [| start; -1 |] ->
    List.to_iter ls
    |> Iter.zip_i
    |> Iter.drop_while (Pair.fst_map ((>) start))
    |> Iter.map snd
  | [| start; finish |] ->
    List.to_iter ls
    |> Iter.zip_i
    |> Iter.drop_while (Pair.fst_map ((>) start))
    |> Iter.take_while (Pair.fst_map ((>) finish))
    |> Iter.map snd
  | [| start; finish; step |] ->
    List.to_iter ls
    |> Iter.zip_i
    |> Iter.drop_while (Pair.fst_map ((>) start))
    |> Iter.take_while (Pair.fst_map ((>) finish))
    |> Iter.filter (Pair.fst_map (fun ind -> (ind - start) mod step = 0))
    |> Iter.map snd