ast_helper.ml

(**************************************************************************)
(*                                                                        *)
(*                                 OCaml                                  *)
(*                                                                        *)
(*                         Alain Frisch, LexiFi                           *)
(*                                                                        *)
(*   Copyright 2012 Institut National de Recherche en Informatique et     *)
(*     en Automatique.                                                    *)
(*                                                                        *)
(*   All rights reserved.  This file is distributed under the terms of    *)
(*   the GNU Lesser General Public License version 2.1, with the          *)
(*   special exception on linking described in the file LICENSE.          *)
(*                                                                        *)
(**************************************************************************)

(** Helpers to produce Parsetree fragments *)

open Asttypes
open Parsetree
open Docstrings

type lid = Longident.t loc
type str = string loc
type loc = Location.t
type attrs = attribute list

let default_loc = ref Location.none

let with_default_loc l f =
  let old = !default_loc in
  default_loc := l;
  try let r = f () in default_loc := old; r
  with exn -> default_loc := old; raise exn

module Const = struct
  let integer ?suffix i = Pconst_integer (i, suffix)
  let int ?suffix i = integer ?suffix (string_of_int i)
  let int32 ?(suffix='l') i = integer ~suffix (Int32.to_string i)
  let int64 ?(suffix='L') i = integer ~suffix (Int64.to_string i)
  let nativeint ?(suffix='n') i = integer ~suffix (Nativeint.to_string i)
  let float ?suffix f = Pconst_float (f, suffix)
  let char c = Pconst_char c
  let string ?quotation_delimiter s = Pconst_string (s, quotation_delimiter)
end

module Typ = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {ptyp_desc = d; ptyp_loc = loc; ptyp_attributes = attrs}
  let attr d a = {d with ptyp_attributes = d.ptyp_attributes @ [a]}

  let any ?loc ?attrs () = mk ?loc ?attrs Ptyp_any
  let var ?loc ?attrs a = mk ?loc ?attrs (Ptyp_var a)
  let arrow ?loc ?attrs a b c = mk ?loc ?attrs (Ptyp_arrow (a, b, c))
  let tuple ?loc ?attrs a = mk ?loc ?attrs (Ptyp_tuple a)
  let constr ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_constr (a, b))
  let object_ ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_object (a, b))
  let class_ ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_class (a, b))
  let alias ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_alias (a, b))
  let variant ?loc ?attrs a b c = mk ?loc ?attrs (Ptyp_variant (a, b, c))
  let poly ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_poly (a, b))
  let package ?loc ?attrs a b = mk ?loc ?attrs (Ptyp_package (a, b))
  let extension ?loc ?attrs a = mk ?loc ?attrs (Ptyp_extension a)

  let force_poly t =
    match t.ptyp_desc with
    | Ptyp_poly _ -> t
    | _ -> poly ~loc:t.ptyp_loc [] t (* -> ghost? *)

  let varify_constructors var_names t =
    let check_variable vl loc v =
      if List.mem v vl then
        raise Syntaxerr.(Error(Variable_in_scope(loc,v))) in
    let var_names = List.map (fun v -> v.txt) var_names in
    let rec loop t =
      let desc =
        match t.ptyp_desc with
        | Ptyp_any -> Ptyp_any
        | Ptyp_var x ->
            check_variable var_names t.ptyp_loc x;
            Ptyp_var x
        | Ptyp_arrow (label,core_type,core_type') ->
            Ptyp_arrow(label, loop core_type, loop core_type')
        | Ptyp_tuple lst -> Ptyp_tuple (List.map loop lst)
        | Ptyp_constr( { txt = Longident.Lident s }, [])
          when List.mem s var_names ->
            Ptyp_var s
        | Ptyp_constr(longident, lst) ->
            Ptyp_constr(longident, List.map loop lst)
        | Ptyp_object (lst, o) ->
            Ptyp_object (List.map loop_object_field lst, o)
        | Ptyp_class (longident, lst) ->
            Ptyp_class (longident, List.map loop lst)
        | Ptyp_alias(core_type, string) ->
            check_variable var_names t.ptyp_loc string;
            Ptyp_alias(loop core_type, string)
        | Ptyp_variant(row_field_list, flag, lbl_lst_option) ->
            Ptyp_variant(List.map loop_row_field row_field_list,
                         flag, lbl_lst_option)
        | Ptyp_poly(string_lst, core_type) ->
          List.iter (fun v ->
            check_variable var_names t.ptyp_loc v.txt) string_lst;
            Ptyp_poly(string_lst, loop core_type)
        | Ptyp_package(longident,lst) ->
            Ptyp_package(longident,List.map (fun (n,typ) -> (n,loop typ) ) lst)
        | Ptyp_extension (s, arg) ->
            Ptyp_extension (s, arg)
      in
      {t with ptyp_desc = desc}
    and loop_row_field  =
      function
        | Rtag(label,attrs,flag,lst) ->
            Rtag(label,attrs,flag,List.map loop lst)
        | Rinherit t ->
            Rinherit (loop t)
    and loop_object_field =
      function
        | Otag(label, attrs, t) ->
            Otag(label, attrs, loop t)
        | Oinherit t ->
            Oinherit (loop t)
    in
    loop t

end

module Pat = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {ppat_desc = d; ppat_loc = loc; ppat_attributes = attrs}
  let attr d a = {d with ppat_attributes = d.ppat_attributes @ [a]}

  let any ?loc ?attrs () = mk ?loc ?attrs Ppat_any
  let var ?loc ?attrs a = mk ?loc ?attrs (Ppat_var a)
  let alias ?loc ?attrs a b = mk ?loc ?attrs (Ppat_alias (a, b))
  let constant ?loc ?attrs a = mk ?loc ?attrs (Ppat_constant a)
  let interval ?loc ?attrs a b = mk ?loc ?attrs (Ppat_interval (a, b))
  let tuple ?loc ?attrs a = mk ?loc ?attrs (Ppat_tuple a)
  let construct ?loc ?attrs a b = mk ?loc ?attrs (Ppat_construct (a, b))
  let variant ?loc ?attrs a b = mk ?loc ?attrs (Ppat_variant (a, b))
  let record ?loc ?attrs a b = mk ?loc ?attrs (Ppat_record (a, b))
  let array ?loc ?attrs a = mk ?loc ?attrs (Ppat_array a)
  let or_ ?loc ?attrs a b = mk ?loc ?attrs (Ppat_or (a, b))
  let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Ppat_constraint (a, b))
  let type_ ?loc ?attrs a = mk ?loc ?attrs (Ppat_type a)
  let lazy_ ?loc ?attrs a = mk ?loc ?attrs (Ppat_lazy a)
  let unpack ?loc ?attrs a = mk ?loc ?attrs (Ppat_unpack a)
  let open_ ?loc ?attrs a b = mk ?loc ?attrs (Ppat_open (a, b))
  let exception_ ?loc ?attrs a = mk ?loc ?attrs (Ppat_exception a)
  let extension ?loc ?attrs a = mk ?loc ?attrs (Ppat_extension a)
end

module Exp = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {pexp_desc = d; pexp_loc = loc; pexp_attributes = attrs}
  let attr d a = {d with pexp_attributes = d.pexp_attributes @ [a]}

  let ident ?loc ?attrs a = mk ?loc ?attrs (Pexp_ident a)
  let constant ?loc ?attrs a = mk ?loc ?attrs (Pexp_constant a)
  let let_ ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_let (a, b, c))
  let fun_ ?loc ?attrs a b c d = mk ?loc ?attrs (Pexp_fun (a, b, c, d))
  let function_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_function a)
  let apply ?loc ?attrs a b = mk ?loc ?attrs (Pexp_apply (a, b))
  let match_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_match (a, b))
  let try_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_try (a, b))
  let tuple ?loc ?attrs a = mk ?loc ?attrs (Pexp_tuple a)
  let construct ?loc ?attrs a b = mk ?loc ?attrs (Pexp_construct (a, b))
  let variant ?loc ?attrs a b = mk ?loc ?attrs (Pexp_variant (a, b))
  let record ?loc ?attrs a b = mk ?loc ?attrs (Pexp_record (a, b))
  let field ?loc ?attrs a b = mk ?loc ?attrs (Pexp_field (a, b))
  let setfield ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_setfield (a, b, c))
  let array ?loc ?attrs a = mk ?loc ?attrs (Pexp_array a)
  let ifthenelse ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_ifthenelse (a, b, c))
  let sequence ?loc ?attrs a b = mk ?loc ?attrs (Pexp_sequence (a, b))
  let while_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_while (a, b))
  let for_ ?loc ?attrs a b c d e = mk ?loc ?attrs (Pexp_for (a, b, c, d, e))
  let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_constraint (a, b))
  let coerce ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_coerce (a, b, c))
  let send ?loc ?attrs a b = mk ?loc ?attrs (Pexp_send (a, b))
  let new_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_new a)
  let setinstvar ?loc ?attrs a b = mk ?loc ?attrs (Pexp_setinstvar (a, b))
  let override ?loc ?attrs a = mk ?loc ?attrs (Pexp_override a)
  let letmodule ?loc ?attrs a b c= mk ?loc ?attrs (Pexp_letmodule (a, b, c))
  let letexception ?loc ?attrs a b = mk ?loc ?attrs (Pexp_letexception (a, b))
  let assert_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_assert a)
  let lazy_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_lazy a)
  let poly ?loc ?attrs a b = mk ?loc ?attrs (Pexp_poly (a, b))
  let object_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_object a)
  let newtype ?loc ?attrs a b = mk ?loc ?attrs (Pexp_newtype (a, b))
  let pack ?loc ?attrs a = mk ?loc ?attrs (Pexp_pack a)
  let open_ ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_open (a, b, c))
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pexp_extension a)
  let unreachable ?loc ?attrs () = mk ?loc ?attrs Pexp_unreachable

  let case lhs ?guard rhs =
    {
     pc_lhs = lhs;
     pc_guard = guard;
     pc_rhs = rhs;
    }
end

module Mty = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {pmty_desc = d; pmty_loc = loc; pmty_attributes = attrs}
  let attr d a = {d with pmty_attributes = d.pmty_attributes @ [a]}

  let ident ?loc ?attrs a = mk ?loc ?attrs (Pmty_ident a)
  let alias ?loc ?attrs a = mk ?loc ?attrs (Pmty_alias a)
  let signature ?loc ?attrs a = mk ?loc ?attrs (Pmty_signature a)
  let functor_ ?loc ?attrs a b c = mk ?loc ?attrs (Pmty_functor (a, b, c))
  let with_ ?loc ?attrs a b = mk ?loc ?attrs (Pmty_with (a, b))
  let typeof_ ?loc ?attrs a = mk ?loc ?attrs (Pmty_typeof a)
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pmty_extension a)
end

module Mod = struct
let mk ?(loc = !default_loc) ?(attrs = []) d =
  {pmod_desc = d; pmod_loc = loc; pmod_attributes = attrs}
  let attr d a = {d with pmod_attributes = d.pmod_attributes @ [a]}

  let ident ?loc ?attrs x = mk ?loc ?attrs (Pmod_ident x)
  let structure ?loc ?attrs x = mk ?loc ?attrs (Pmod_structure x)
  let functor_ ?loc ?attrs arg arg_ty body =
    mk ?loc ?attrs (Pmod_functor (arg, arg_ty, body))
  let apply ?loc ?attrs m1 m2 = mk ?loc ?attrs (Pmod_apply (m1, m2))
  let constraint_ ?loc ?attrs m mty = mk ?loc ?attrs (Pmod_constraint (m, mty))
  let unpack ?loc ?attrs e = mk ?loc ?attrs (Pmod_unpack e)
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pmod_extension a)
end

module Sig = struct
  let mk ?(loc = !default_loc) d = {psig_desc = d; psig_loc = loc}

  let value ?loc a = mk ?loc (Psig_value a)
  let type_ ?loc rec_flag a = mk ?loc (Psig_type (rec_flag, a))
  let type_extension ?loc a = mk ?loc (Psig_typext a)
  let exception_ ?loc a = mk ?loc (Psig_exception a)
  let module_ ?loc a = mk ?loc (Psig_module a)
  let rec_module ?loc a = mk ?loc (Psig_recmodule a)
  let modtype ?loc a = mk ?loc (Psig_modtype a)
  let open_ ?loc a = mk ?loc (Psig_open a)
  let include_ ?loc a = mk ?loc (Psig_include a)

  let class_type ?loc a = mk ?loc (Psig_class_type a)
  let extension ?loc ?(attrs = []) a = mk ?loc (Psig_extension (a, attrs))
  let attribute ?loc a = mk ?loc (Psig_attribute a)
  let text txt =
    let f_txt = Ext_list.filter txt (fun ds -> docstring_body ds <> "") in
    List.map
      (fun ds -> attribute ~loc:(docstring_loc ds) (text_attr ds))
      f_txt
end

module Str = struct
  let mk ?(loc = !default_loc) d = {pstr_desc = d; pstr_loc = loc}

  let eval ?loc ?(attrs = []) a = mk ?loc (Pstr_eval (a, attrs))
  let value ?loc a b = mk ?loc (Pstr_value (a, b))
  let primitive ?loc a = mk ?loc (Pstr_primitive a)
  let type_ ?loc rec_flag a = mk ?loc (Pstr_type (rec_flag, a))
  let type_extension ?loc a = mk ?loc (Pstr_typext a)
  let exception_ ?loc a = mk ?loc (Pstr_exception a)
  let module_ ?loc a = mk ?loc (Pstr_module a)
  let rec_module ?loc a = mk ?loc (Pstr_recmodule a)
  let modtype ?loc a = mk ?loc (Pstr_modtype a)
  let open_ ?loc a = mk ?loc (Pstr_open a)
  let class_type ?loc a = mk ?loc (Pstr_class_type a)
  let include_ ?loc a = mk ?loc (Pstr_include a)
  let extension ?loc ?(attrs = []) a = mk ?loc (Pstr_extension (a, attrs))
  let attribute ?loc a = mk ?loc (Pstr_attribute a)
  let text txt =
    let f_txt = Ext_list.filter txt (fun ds -> docstring_body ds <> "") in
    List.map
      (fun ds -> attribute ~loc:(docstring_loc ds) (text_attr ds))
      f_txt
end

module Cl = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {
     pcl_desc = d;
     pcl_loc = loc;
     pcl_attributes = attrs;
    }
  let attr d a = {d with pcl_attributes = d.pcl_attributes @ [a]}

  let constr ?loc ?attrs a b = mk ?loc ?attrs (Pcl_constr (a, b))
  let structure ?loc ?attrs a = mk ?loc ?attrs (Pcl_structure a)
  let fun_ ?loc ?attrs a b c d = mk ?loc ?attrs (Pcl_fun (a, b, c, d))
  let apply ?loc ?attrs a b = mk ?loc ?attrs (Pcl_apply (a, b))
  let let_ ?loc ?attrs a b c = mk ?loc ?attrs (Pcl_let (a, b, c))
  let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pcl_constraint (a, b))
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pcl_extension a)
  let open_ ?loc ?attrs a b c = mk ?loc ?attrs (Pcl_open (a, b, c))
end

module Cty = struct
  let mk ?(loc = !default_loc) ?(attrs = []) d =
    {
     pcty_desc = d;
     pcty_loc = loc;
     pcty_attributes = attrs;
    }
  let attr d a = {d with pcty_attributes = d.pcty_attributes @ [a]}

  let constr ?loc ?attrs a b = mk ?loc ?attrs (Pcty_constr (a, b))
  let signature ?loc ?attrs a = mk ?loc ?attrs (Pcty_signature a)
  let arrow ?loc ?attrs a b c = mk ?loc ?attrs (Pcty_arrow (a, b, c))
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pcty_extension a)
  let open_ ?loc ?attrs a b c = mk ?loc ?attrs (Pcty_open (a, b, c))
end

module Ctf = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
           ?(docs = empty_docs) d =
    {
     pctf_desc = d;
     pctf_loc = loc;
     pctf_attributes = add_docs_attrs docs attrs;
    }

  let inherit_ ?loc ?attrs a = mk ?loc ?attrs (Pctf_inherit a)
  let val_ ?loc ?attrs a b c d = mk ?loc ?attrs (Pctf_val (a, b, c, d))
  let method_ ?loc ?attrs a b c d = mk ?loc ?attrs (Pctf_method (a, b, c, d))
  let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pctf_constraint (a, b))
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pctf_extension a)
  let attribute ?loc a = mk ?loc (Pctf_attribute a)
  let text txt =
   let f_txt = Ext_list.filter txt (fun ds -> docstring_body ds <> "")in
     List.map
      (fun ds -> attribute ~loc:(docstring_loc ds) (text_attr ds))
      f_txt

  let attr d a = {d with pctf_attributes = d.pctf_attributes @ [a]}

end

module Cf = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) d =
    {
     pcf_desc = d;
     pcf_loc = loc;
     pcf_attributes = add_docs_attrs docs attrs;
    }

  
  let val_ ?loc ?attrs a b c = mk ?loc ?attrs (Pcf_val (a, b, c))
  let method_ ?loc ?attrs a b c = mk ?loc ?attrs (Pcf_method (a, b, c))
  let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pcf_constraint (a, b))
  let initializer_ ?loc ?attrs a = mk ?loc ?attrs (Pcf_initializer a)
  let extension ?loc ?attrs a = mk ?loc ?attrs (Pcf_extension a)
  let attribute ?loc a = mk ?loc (Pcf_attribute a)
  let text txt =
    let f_txt = Ext_list.filter txt (fun ds -> docstring_body ds <> "")in
    List.map
      (fun ds -> attribute ~loc:(docstring_loc ds) (text_attr ds))
      f_txt

  let virtual_ ct = Cfk_virtual ct
  let concrete o e = Cfk_concrete (o, e)

  let attr d a = {d with pcf_attributes = d.pcf_attributes @ [a]}

end

module Val = struct
  let mk ?(loc = !default_loc) ?(attrs = []) ?(docs = empty_docs)
        ?(prim = []) name typ =
    {
     pval_name = name;
     pval_type = typ;
     pval_attributes = add_docs_attrs docs attrs;
     pval_loc = loc;
     pval_prim = prim;
    }
end

module Md = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(text = []) name typ =
    {
     pmd_name = name;
     pmd_type = typ;
     pmd_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     pmd_loc = loc;
    }
end

module Mtd = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(text = []) ?typ name =
    {
     pmtd_name = name;
     pmtd_type = typ;
     pmtd_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     pmtd_loc = loc;
    }
end

module Mb = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(text = []) name expr =
    {
     pmb_name = name;
     pmb_expr = expr;
     pmb_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     pmb_loc = loc;
    }
end

module Opn = struct
  let mk ?(loc = !default_loc) ?(attrs = []) ?(docs = empty_docs)
        ?(override = Fresh) lid =
    {
     popen_lid = lid;
     popen_override = override;
     popen_loc = loc;
     popen_attributes = add_docs_attrs docs attrs;
    }
end

module Incl = struct
  let mk ?(loc = !default_loc) ?(attrs = []) ?(docs = empty_docs) mexpr =
    {
     pincl_mod = mexpr;
     pincl_loc = loc;
     pincl_attributes = add_docs_attrs docs attrs;
    }

end

module Vb = struct
  let mk ?(loc = !default_loc) ?(attrs = []) ?(docs = empty_docs)
        ?(text = []) pat expr =
    {
     pvb_pat = pat;
     pvb_expr = expr;
     pvb_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     pvb_loc = loc;
    }
end

module Ci = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(text = [])
        ?(virt = Concrete) ?(params = []) name expr =
    {
     pci_virt = virt;
     pci_params = params;
     pci_name = name;
     pci_expr = expr;
     pci_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     pci_loc = loc;
    }
end

module Type = struct
  let mk ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(text = [])
      ?(params = [])
      ?(cstrs = [])
      ?(kind = Ptype_abstract)
      ?(priv = Public)
      ?manifest
      name =
    {
     ptype_name = name;
     ptype_params = params;
     ptype_cstrs = cstrs;
     ptype_kind = kind;
     ptype_private = priv;
     ptype_manifest = manifest;
     ptype_attributes =
       add_text_attrs text (add_docs_attrs docs attrs);
     ptype_loc = loc;
    }

  let constructor ?(loc = !default_loc) ?(attrs = []) ?(info = empty_info)
        ?(args = Pcstr_tuple []) ?res name =
    {
     pcd_name = name;
     pcd_args = args;
     pcd_res = res;
     pcd_loc = loc;
     pcd_attributes = add_info_attrs info attrs;
    }

  let field ?(loc = !default_loc) ?(attrs = []) ?(info = empty_info)
        ?(mut = Immutable) name typ =
    {
     pld_name = name;
     pld_mutable = mut;
     pld_type = typ;
     pld_loc = loc;
     pld_attributes = add_info_attrs info attrs;
    }

end

(** Type extensions *)
module Te = struct
  let mk ?(attrs = []) ?(docs = empty_docs)
        ?(params = []) ?(priv = Public) path constructors =
    {
     ptyext_path = path;
     ptyext_params = params;
     ptyext_constructors = constructors;
     ptyext_private = priv;
     ptyext_attributes = add_docs_attrs docs attrs;
    }

  let constructor ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(info = empty_info) name kind =
    {
     pext_name = name;
     pext_kind = kind;
     pext_loc = loc;
     pext_attributes = add_docs_attrs docs (add_info_attrs info attrs);
    }

  let decl ?(loc = !default_loc) ?(attrs = []) ?(docs = empty_docs)
             ?(info = empty_info) ?(args = Pcstr_tuple []) ?res name =
    {
     pext_name = name;
     pext_kind = Pext_decl(args, res);
     pext_loc = loc;
     pext_attributes = add_docs_attrs docs (add_info_attrs info attrs);
    }

  let rebind ?(loc = !default_loc) ?(attrs = [])
        ?(docs = empty_docs) ?(info = empty_info) name lid =
    {
     pext_name = name;
     pext_kind = Pext_rebind lid;
     pext_loc = loc;
     pext_attributes = add_docs_attrs docs (add_info_attrs info attrs);
    }

end

module Csig = struct
  let mk self fields =
    {
     pcsig_self = self;
     pcsig_fields = fields;
    }
end

module Cstr = struct
  let mk self fields =
    {
     pcstr_self = self;
     pcstr_fields = fields;
    }
end