open Environment
open Value

let clock : native_function =
  let fn = function
    | [] ->
        let time = Unix.gettimeofday () in
        Number time |> Result.ok
    | _ -> assert false
  in
  { name = "clock"; arity = 0; fn }

let exit : native_function =
  let fn = function
    | [ n ] -> (
        match n with
        | Number n when Float.is_integer n -> Int.of_float n |> exit
        | _ ->
            Printf.sprintf "Must call exit with integer, received %s instead"
              (string_of_lox_value n)
            |> Result.error)
    | _ -> assert false
  in
  { name = "exit"; arity = 1; fn }

let init_std (env : environment) =
  let register_fn fn = Env.define_global env fn.name (NativeFunction fn) in
  let _ = List.map register_fn [ clock; exit ] in
  ()