Revert "Abandoning json conversion :("

This reverts commit 02780f5439.

compiler/catala_utils/dune

@@ -1,11 +1,7 @@
 (library
  (name catala_utils)
  (public_name catala.catala_utils)
- (libraries cmdliner ubase ANSITerminal re bindlib catala.runtime_ocaml)
- (lint
-  (pps ppx_yojson_conv))
- (preprocess
-  (pps ppx_yojson_conv)))
+ (libraries cmdliner ubase ANSITerminal re bindlib catala.runtime_ocaml))
 
 (documentation
  (package catala)

compiler/catala_utils/marked.ml

@@ -18,23 +18,6 @@
 type ('a, 'm) t = 'a * 'm
 type 'a pos = ('a, Pos.t) t
 
-let pos_of_yojson :
-      'a.
-      (Ppx_yojson_conv_lib.Yojson.Safe.t -> 'a) ->
-      Ppx_yojson_conv_lib.Yojson.Safe.t ->
-      'a pos =
- fun _of_a x -> _of_a x, Pos.no_pos
-
-let _ = pos_of_yojson
-
-let yojson_of_pos :
-      'a.
-      ('a -> Ppx_yojson_conv_lib.Yojson.Safe.t) ->
-      'a pos ->
-      Ppx_yojson_conv_lib.Yojson.Safe.t =
- fun of_a (a, _) -> of_a a
-
-let _ = yojson_of_pos
 let mark m e : ('a, 'm) t = e, m
 let unmark ((x, _) : ('a, 'm) t) : 'a = x
 let get_mark ((_, x) : ('a, 'm) t) : 'm = x

compiler/catala_utils/marked.mli

@@ -21,7 +21,7 @@ type ('a, 'm) t = 'a * 'm
 (** Everything related to the source code should keep at least its position
     stored, to improve error messages *)
 
-type 'a pos = ('a, Pos.t) t [@@deriving yojson]
+type 'a pos = ('a, Pos.t) t
 (** The type of marks containing only position information *)
 
 val mark : 'm -> 'a -> ('a, 'm) t