open! Base

let parse s =
  Stdlib.Scanf.sscanf s "%s@ t=%f" (fun _ t -> t /. 1000.)

let%test_unit  "parse temperature" = 
  [%test_eq: float ] (parse "brol\nmore junk text t=18241") 18.241  


let read_temperature file_name =
  let open Lwt.Infix in
  let rec aux () =
    Lwt_io.with_file ~mode:Lwt_io.Input file_name (fun ic ->
        Lwt_io.read_all ic >>= function
        | None -> aux ()
        | Some s -> Lwt.return (parse s)
      )
  in
  aux