Better check for async rewrite

Resolve the types Async.Std.Deferred.t instead of hard-coding a list
of aliases.

Fix #137
This commit is contained in:
Jeremie Dimino 2016-01-07 10:30:06 +00:00
parent e608977856
commit 9e41bf85da
1 changed files with 62 additions and 63 deletions

View File

@ -399,6 +399,8 @@ let with_loc loc str = {
(* A rule for rewriting a toplevel expression. *)
type rewrite_rule = {
type_to_rewrite : Longident.t;
mutable path_to_rewrite : Path.t option;
required_values : Longident.t list;
(* Values that must exist and be persistent for the rule to apply. *)
rewrite : Location.t -> Parsetree.expression -> Parsetree.expression;
@ -407,10 +409,6 @@ type rewrite_rule = {
(* Whether the rule is enabled or not. *)
}
(* Rewrite rules, indexed by the identifier of the type
constructor. *)
let rewrite_rules : (Longident.t, rewrite_rule) Hashtbl.t = Hashtbl.create 42
let longident_lwt_main_run = Longident.Ldot (Longident.Lident "Lwt_main", "run")
let longident_async_thread_safe_block_on_async_exn =
Longident.parse "Async.Std.Thread_safe.block_on_async_exn"
@ -436,9 +434,11 @@ let nolabel = Asttypes.Nolabel
let nolabel = ""
#endif
let () =
let rewrite_rules = [
(* Rewrite Lwt.t expressions to Lwt_main.run <expr> *)
Hashtbl.add rewrite_rules (Longident.Ldot (Longident.Lident "Lwt", "t")) {
{
type_to_rewrite = Longident.parse "Lwt.t";
path_to_rewrite = None;
required_values = [longident_lwt_main_run];
rewrite = (fun loc e ->
#if OCAML_VERSION < (4, 02, 0)
@ -460,7 +460,9 @@ let () =
(* Rewrite Async.Std.Defered.t expressions to
Async.Std.Thread_safe.block_on_async_exn (fun () -> <expr>). *)
let rule = {
{
type_to_rewrite = Longident.parse "Async.Std.Deferred.t";
path_to_rewrite = None;
required_values = [longident_async_thread_safe_block_on_async_exn];
rewrite = (fun loc e ->
#if OCAML_VERSION < (4, 02, 0)
@ -482,21 +484,32 @@ let () =
#endif
);
enabled = UTop.auto_run_async;
} in
let deferred_aliases =
[ "Async_core.Ivar.Deferred.t"
; "Async_kernel.Ivar.Deferred.t"
; "Async_kernel.Deferred0.t"
]
in
List.iter (fun s ->
Hashtbl.add rewrite_rules (Longident.parse s) rule)
deferred_aliases
}
]
(* Returns whether the argument is a toplevel expression. *)
let is_eval = function
| { Parsetree.pstr_desc = Parsetree.Pstr_eval _ } -> true
| _ -> false
let rule_path rule =
match rule.path_to_rewrite with
| Some _ as x -> x
| None ->
try
let env = !Toploop.toplevel_env in
let path =
match Env.lookup_type rule.type_to_rewrite env with
| path, { Types.type_kind = Types.Type_abstract
; Types.type_private = Asttypes.Public
; Types.type_manifest = Some ty
} -> begin
match Ctype.expand_head env ty with
| { Types.desc = Types.Tconstr (path, _, _) } -> path
| _ -> path
end
| path, _ -> path
in
let opt = Some path in
rule.path_to_rewrite <- opt;
opt
with _ ->
None
(* Returns whether the given path is persistent. *)
let rec is_persistent_path = function
@ -504,38 +517,6 @@ let rec is_persistent_path = function
| Path.Pdot (p, _, _) -> is_persistent_path p
| Path.Papply (_, p) -> is_persistent_path p
(* Convert a path to a long identifier. *)
let rec longident_of_path path =
match path with
| Path.Pident id ->
Longident.Lident (Ident.name id)
| Path.Pdot (path, s, _) ->
Longident.Ldot (longident_of_path path, s)
| Path.Papply (p1, p2) ->
Longident.Lapply (longident_of_path p1, longident_of_path p2)
(* Returns the rewrite rule associated to a type, if any. *)
let rec rule_of_type typ =
match typ.Types.desc with
| Types.Tlink typ ->
rule_of_type typ
| Types.Tconstr (path, _, _) -> begin
match try Some (Env.find_type path !Toploop.toplevel_env) with Not_found -> None with
| Some {
Types.type_kind = Types.Type_abstract;
Types.type_private = Asttypes.Public;
Types.type_manifest = Some typ;
} ->
rule_of_type typ
| _ ->
try
Some (Hashtbl.find rewrite_rules (longident_of_path path))
with Not_found ->
None
end
| _ ->
None
(* Check that the given long identifier is present in the environment
and is persistent. *)
let is_persistent_in_env longident =
@ -544,6 +525,30 @@ let is_persistent_in_env longident =
with Not_found ->
false
let rule_matches rule path =
React.S.value rule.enabled &&
(match rule_path rule with
| None -> false
| Some path' -> Path.same path path') &&
List.for_all is_persistent_in_env rule.required_values
(* Returns whether the argument is a toplevel expression. *)
let is_eval = function
| { Parsetree.pstr_desc = Parsetree.Pstr_eval _ } -> true
| _ -> false
(* Returns the rewrite rule associated to a type, if any. *)
let rec rule_of_type typ =
match (Ctype.expand_head !Toploop.toplevel_env typ).Types.desc with
| Types.Tconstr (path, _, _) -> begin
try
Some (List.find (fun rule -> rule_matches rule path) rewrite_rules)
with _ ->
None
end
| _ ->
None
#if OCAML_VERSION < (4, 02, 0)
let rewrite_str_item pstr_item tstr_item =
match pstr_item, tstr_item.Typedtree.str_desc with
@ -552,11 +557,8 @@ let rewrite_str_item pstr_item tstr_item =
Typedtree.Tstr_eval { Typedtree.exp_type = typ }) -> begin
match rule_of_type typ with
| Some rule ->
if React.S.value rule.enabled && List.for_all is_persistent_in_env rule.required_values then
{ Parsetree.pstr_desc = Parsetree.Pstr_eval (rule.rewrite loc e);
Parsetree.pstr_loc = loc }
else
pstr_item
| None ->
pstr_item
end
@ -570,11 +572,8 @@ let rewrite_str_item pstr_item tstr_item =
Typedtree.Tstr_eval ({ Typedtree.exp_type = typ }, _)) -> begin
match rule_of_type typ with
| Some rule ->
if React.S.value rule.enabled && List.for_all is_persistent_in_env rule.required_values then
{ Parsetree.pstr_desc = Parsetree.Pstr_eval (rule.rewrite loc e, []);
Parsetree.pstr_loc = loc }
else
pstr_item
| None ->
pstr_item
end