(****************************************************************************)
(*                                                                          *)
(*                                   OCaml                                  *)
(*                                                                          *)
(*                            INRIA Rocquencourt                            *)
(*                                                                          *)
(*  Copyright  2006  Institut  National  de  Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed under   *)
(*  the terms of the GNU Library General Public License, with the special   *)
(*  exception on linking described in LICENSE at the top of the Camlp4      *)
(*  source tree.                                                            *)
(*                                                                          *)
(****************************************************************************)

#default_quotation "expr";

open Camlp4.PreCast;
open Format;

module FV = Camlp4.Struct.FreeVars.Make Ast;
module PP = Camlp4.Printers.OCaml.Make Syntax;
module S = FV.S;

value _loc = Loc.ghost;

value pervasives =
  let list =
    [ "+"; "-"; "/"; "*" (* ... *) ]
  in List.fold_right S.add list S.empty;

value f e =
  let fv = FV.free_vars pervasives e in
  S.fold (fun x acc -> << fun ~ $x$ -> $acc$ >>) fv e;

value print_expr = (new PP.printer ())#expr;

printf "%a@." print_expr (f <<let z = x + 2 in x + 2 * y * x * z>>);