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type verb = string
type encode =
| Request of { verb : verb; args : string list }
| Payload of { buf : Bytes.t; off : int; len : int }
type action =
| Recv_code of int
| Send of encode
| Waiting_payload
type decode =
| Response of { code : int; txts : string list }
| Payload of { buf : Bytes.t; off : int; len : int }
type error = ..
let pp_error : error Fmt.t = fun _ _ -> ()
module type CLIENT = sig
type t
type nonrec error = error
val pp_error : error Fmt.t
val ehlo : t -> string -> (t, error) result
val encode : t -> encode
val action : t -> action option
val decode : decode -> t -> (t, error) result
val handle : t -> t
val mail_from : t -> Reverse_path.t -> (string * string option) list
val rcpt_to : t -> Forward_path.t -> (string * string option) list
end
module Make (Functor : Sigs.FUNCTOR) = struct
type t = ..
module type S = sig
type x
type t += T of x
end
type 'a extension = (module S with type x = 'a)
type 'a ctor = 'a -> t
type instance = V : 'a * 'a Functor.t * 'a ctor -> instance
let handlers = Hashtbl.create 16
module Injection (X : sig
type t
val instance : t Functor.t
end) : S with type x = X.t = struct
type x = X.t
type t += T of x
let () =
let instance = X.instance in
Hashtbl.add handlers
(Obj.extension_id [%extension_constructor T])
(function T x -> V (x, instance, (fun x -> T x))
| _ -> raise Not_found)
end
let inj (type a) (f : a Functor.t) : a extension =
( module Injection (struct
type t = a
let instance = f
end) )
let prj (t : t) =
let rec go = function
| [] -> assert false
| x :: r -> ( try x t with Not_found -> go r )
in
go
(Hashtbl.find_all handlers
(Obj.extension_id (Obj.extension_constructor t)))
let eq
: type a. t -> a extension -> a option
= fun t (module E) -> match t with
| E.T v -> Some v
| _ -> None
end
type description =
{ name : string
; elho : string
; verb : verb list }
module W = struct type 'a t = (module CLIENT with type t = 'a) end
include Make(W)
type 'a client = (module CLIENT with type t = 'a)