(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(** Compatibility file depending on ocaml/camlp4 version *)

(** Misc module emulation *)

IFDEF CAMLP5 THEN

module CompatLoc = struct
  include Ploc
  let ghost = dummy
  let merge = encl
end

ELSE

module CompatLoc = Camlp4.PreCast.Loc

END

IFDEF CAMLP5 THEN

module PcamlSig = struct end

ELSE

module PcamlSig = Camlp4.Sig
module Ast = Camlp4.PreCast.Ast
module Pcaml = Camlp4.PreCast.Syntax
module MLast = Ast

END

(** Compatibility with camlp5 strict mode *)
IFDEF CAMLP5 THEN
  IFDEF STRICT THEN
    let vala x = Ploc.VaVal x
  ELSE
    let vala x = x
  END
ELSE
  let vala x = x
END

(** Fix a quotation difference in [str_item] *)

let declare_str_items loc l =
IFDEF CAMLP5 THEN
  MLast.StDcl (loc, vala l) (* correspond to <:str_item< declare $list:l'$ end >> *)
ELSE
  Ast.stSem_of_list l
END

(** Quotation difference for match clauses *)

let default_patt loc =
  (<:patt< _ >>, vala None, <:expr< failwith "Extension: cannot occur" >>)

IFDEF CAMLP5 THEN

let make_fun loc cl =
  let l = cl @ [default_patt loc] in
  MLast.ExFun (loc, vala l)  (* correspond to <:expr< fun [ $list:l$ ] >> *)

ELSE

let make_fun loc cl =
  let mk_when = function
    | Some w -> w
    | None -> Ast.ExNil loc
  in
  let mk_clause (patt,optwhen,expr) =
    (* correspond to <:match_case< ... when ... -> ... >> *)
    Ast.McArr (loc, patt, mk_when optwhen, expr) in
  let init = mk_clause (default_patt loc) in
  let add_clause x acc = Ast.McOr (loc, mk_clause x, acc) in
  let l = List.fold_right add_clause cl init in
  Ast.ExFun (loc,l) (* correspond to <:expr< fun [ $l$ ] >> *)

END