Hi!
Your question inspired me to have a look at the modular implicits. I really like them. It seems that the argument of the implicit functor Show_logic also needs to be implicit, i.e., in
curly braces. At least this worked for me.
Thomas
module type SHOW = sig
type t
val show : t -> string
end
let show {S : SHOW} x = S.show x;;
implicit module Show_int : (SHOW with type t = int) = struct
type t = int
let show = string_of_int
end
module type CORE = sig
type 'a logic
implicit module Show_logic {X: SHOW} : (SHOW with type t = X.t logic)
end
module Make(MK: CORE) = struct
open MK
(* open implicit MK (* doesn't help *) *)
let foo (x: int logic) =
let s = show x in (* Error: No instance found for implicit S. *)
s
end
---
Dr. rer. nat. Thomas Martin Gawlitza, Diplom-Informatiker
Development Architect
Technology Office
office location:
Potsdam (DE), POT04, A2.01, SAP Innovation Center, Konrad-Zuse-Ring 10, 14469 Potsdam
email: Thomas.Gawlitza@sap.com
phone: +49 331 9799 5408
mobile: +49 151 168 10 726
From:
<caml-list-request@inria.fr> on behalf of Kakadu <kakadu.hafanana@gmail.com>
Reply-To: Kakadu <kakadu.hafanana@gmail.com>
Date: Wednesday 3 August 2016 at 01:17
To: Caml List <caml-list@inria.fr>
Subject: [Caml-list] Implicit question about searching for implicit module definition in the functor argument.