ocaml/camlp4/Camlp4/Struct/FreeVars.ml

128 lines
4.7 KiB
OCaml

(* camlp4r *)
(****************************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* 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 Objective *)
(* Caml source tree. *)
(* *)
(****************************************************************************)
(* Authors:
* - Nicolas Pouillard: initial version
*)
module Make (Ast : Sig.Camlp4Ast) = struct
module S = Set.Make String;
value rec fold_binding_vars f bi acc =
match bi with
[ <:binding< $bi1$ and $bi2$ >> ->
fold_binding_vars f bi1 (fold_binding_vars f bi2 acc)
| <:binding< $lid:i$ = $_$ >> -> f i acc
| _ -> assert False ];
class c_fold_pattern_vars ['accu] f init =
object
inherit Ast.fold as super;
value acc = init;
method acc : 'accu = acc;
method patt =
fun
[ <:patt< $lid:s$ >> | <:patt< ~ $s$ >> | <:patt< ? $s$ >> ->
{< acc = f s acc >}
| p -> super#patt p ];
end;
value fold_pattern_vars f p init = ((new c_fold_pattern_vars f init)#patt p)#acc;
class fold_free_vars ['accu] (f : string -> 'accu -> 'accu) ?(env_init = S.empty) free_init =
object (o)
inherit Ast.fold as super;
value free : 'accu = free_init;
value env : S.t = env_init;
method free = free;
method set_env env = {< env = env >};
method add_atom s = {< env = S.add s env >};
method add_patt p = {< env = fold_pattern_vars S.add p env >};
method add_binding bi = {< env = fold_binding_vars S.add bi env >};
method expr =
fun
[ <:expr< $lid:s$ >> | <:expr< ~ $s$ >> | <:expr< ? $s$ >> ->
if S.mem s env then o else {< free = f s free >}
| <:expr< let $bi$ in $e$ >> ->
(((o#add_binding bi)#expr e)#set_env env)#binding bi
| <:expr< let rec $bi$ in $e$ >> ->
(((o#add_binding bi)#expr e)#binding bi)#set_env env
| <:expr< for $s$ = $e1$ $to:_$ $e2$ do { $e3$ } >> ->
((((o#expr e1)#expr e2)#add_atom s)#expr e3)#set_env env
| <:expr< $id:_$ >> | <:expr< new $_$ >> -> o
| <:expr< object ($p$) $cst$ end >> ->
((o#add_patt p)#class_str_item cst)#set_env env
| e -> super#expr e ];
method match_case =
fun
[ <:match_case< $p$ when $e1$ -> $e2$ >> ->
(((o#add_patt p)#expr e1)#expr e2)#set_env env
| m -> super#match_case m ];
method str_item =
fun
[ <:str_item< external $s$ : $t$ = $_$ >> ->
(o#ctyp t)#add_atom s
| <:str_item< value $bi$ >> ->
(o#binding bi)#add_binding bi
| <:str_item< value rec $bi$ >> ->
(o#add_binding bi)#binding bi
| st -> super#str_item st ];
method class_expr =
fun
[ <:class_expr< fun $p$ -> $ce$ >> ->
((o#add_patt p)#class_expr ce)#set_env env
| <:class_expr< let $bi$ in $ce$ >> ->
(((o#binding bi)#add_binding bi)#class_expr ce)#set_env env
| <:class_expr< let rec $bi$ in $ce$ >> ->
(((o#add_binding bi)#binding bi)#class_expr ce)#set_env env
| <:class_expr< object ($p$) $cst$ end >> ->
((o#add_patt p)#class_str_item cst)#set_env env
| ce -> super#class_expr ce ];
method class_str_item =
fun
[ <:class_str_item< inherit $_$ >> as cst -> super#class_str_item cst
| <:class_str_item< inherit $ce$ as $s$ >> ->
(o#class_expr ce)#add_atom s
| <:class_str_item< value $mutable:_$ $s$ = $e$ >> ->
(o#expr e)#add_atom s
| <:class_str_item< value virtual $mutable:_$ $s$ : $t$ >> ->
(o#ctyp t)#add_atom s
| cst -> super#class_str_item cst ];
method module_expr = fun
[ <:module_expr< struct $st$ end >> ->
(o#str_item st)#set_env env
| me -> super#module_expr me ];
end;
value free_vars env_init e =
let fold = new fold_free_vars S.add ~env_init S.empty in (fold#expr e)#free;
end;