await AST node for expressions

CHANGELOG.md

@@ -25,6 +25,7 @@
 - Remove `Stdlib_Char` module for now. https://github.com/rescript-lang/rescript/pull/7367
 - Convert internal JavaScript codebase into ESM, ReScript package itself is now ESM (`"type": "module"`). https://github.com/rescript-lang/rescript/pull/6899
 - Add built-in support for the JavaScript `in` operator. https://github.com/rescript-lang/rescript/pull/7342
+- AST cleanup: add `Pexp_await` ast node instead of `res.await` attribute. (The attribute is still used for await on modules currently).
 
 #### :nail_care: Polish
 

analysis/src/CompletionFrontEnd.ml

@@ -312,11 +312,12 @@ let rec exprToContextPathInner ~(inJsxContext : bool) (e : Parsetree.expression)
  if List.length exprs = List.length exprsAsContextPaths then
  Some (CTuple exprsAsContextPaths)
  else None
+ | Pexp_await e -> exprToContextPathInner ~inJsxContext e
  | _ -> None
 
 and exprToContextPath ~(inJsxContext : bool) (e : Parsetree.expression) =
  match
- ( Res_parsetree_viewer.has_await_attribute e.pexp_attributes,
+ ( Res_parsetree_viewer.expr_is_await e,
  exprToContextPathInner ~inJsxContext e )
  with
  | true, Some ctxPath -> Some (CPAwait ctxPath)

analysis/src/Utils.ml

@@ -111,6 +111,7 @@ let identifyPexp pexp =
  | Pexp_pack _ -> "Pexp_pack"
  | Pexp_extension _ -> "Pexp_extension"
  | Pexp_open _ -> "Pexp_open"
+ | Pexp_await _ -> "Pexp_await"
 
 let identifyPpat pat =
  match pat with

compiler/frontend/bs_ast_mapper.ml

@@ -366,6 +366,7 @@ module E = struct
  | Pexp_open (ovf, lid, e) ->
  open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
  | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+ | Pexp_await e -> await ~loc ~attrs (sub.expr sub e)
 end
 
 module P = struct

compiler/frontend/bs_builtin_ppx.ml

@@ -242,10 +242,12 @@ let expr_mapper ~async_context ~in_function_def (self : mapper)
  || Ast_attributes.has_await_payload attrs2 ->
  check_await ();
  result
- | _ when Ast_attributes.has_await_payload e.pexp_attributes ->
- check_await ();
- Ast_await.create_await_expression result
- | _ -> result
+ | _ -> (
+ match result.pexp_desc with
+ | Pexp_await e ->
+ check_await ();
+ Ast_await.create_await_expression e
+ | _ -> result)
 
 let typ_mapper (self : mapper) (typ : Parsetree.core_type) =
  Ast_core_type_class_type.typ_mapper self typ

compiler/ml/ast_helper.ml

@@ -180,7 +180,7 @@ module Exp = struct
  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 await ?loc ?attrs a = mk ?loc ?attrs (Pexp_await a)
  let case lhs ?guard rhs = {pc_lhs = lhs; pc_guard = guard; pc_rhs = rhs}
 end
 

compiler/ml/ast_helper.mli

@@ -210,6 +210,7 @@ module Exp : sig
  val extension : ?loc:loc -> ?attrs:attrs -> extension -> expression
 
  val case : pattern -> ?guard:expression -> expression -> case
+ val await : ?loc:loc -> ?attrs:attrs -> expression -> expression
 end
 
 (** Value declarations *)

compiler/ml/ast_iterator.ml

@@ -344,6 +344,7 @@ module E = struct
  iter_loc sub lid;
  sub.expr sub e
  | Pexp_extension x -> sub.extension sub x
+ | Pexp_await e -> sub.expr sub e
 end
 
 module P = struct

compiler/ml/ast_mapper.ml

@@ -329,6 +329,7 @@ module E = struct
  | Pexp_open (ovf, lid, e) ->
  open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
  | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+ | Pexp_await e -> await ~loc ~attrs (sub.expr sub e)
 end
 
 module P = struct

compiler/ml/ast_mapper_from0.ml

@@ -295,11 +295,30 @@ end
 module E = struct
  (* Value expressions for the core language *)
 
- let map sub {pexp_loc = loc; pexp_desc = desc; pexp_attributes = attrs} =
+ let has_await_attribute attrs =
+ List.exists
+ (function
+ | {Location.txt = "res.await"}, _ -> true
+ | _ -> false)
+ attrs
+
+ let remove_await_attribute attrs =
+ List.filter
+ (function
+ | {Location.txt = "res.await"}, _ -> false
+ | _ -> true)
+ attrs
+
+ let map sub ({pexp_loc = loc; pexp_desc = desc; pexp_attributes = attrs} as e)
+ =
  let open Exp in
  let loc = sub.location sub loc in
  let attrs = sub.attributes sub attrs in
  match desc with
+ | _ when has_await_attribute attrs ->
+ let attrs = remove_await_attribute e.pexp_attributes in
+ let e = sub.expr sub {e with pexp_attributes = attrs} in
+ await ~loc e
  | Pexp_ident x -> ident ~loc ~attrs (map_loc sub x)
  | Pexp_constant x -> constant ~loc ~attrs (map_constant x)
  | Pexp_let (r, vbs, e) ->

compiler/ml/ast_mapper_to0.ml

@@ -407,6 +407,13 @@ module E = struct
  | Pexp_open (ovf, lid, e) ->
  open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
  | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+ | Pexp_await e ->
+ let e = sub.expr sub e in
+ {
+ e with
+ pexp_attributes =
+ (Location.mknoloc "res.await", Pt.PStr []) :: e.pexp_attributes;
+ }
 end
 
 module P = struct

compiler/ml/ast_uncurried.ml

@@ -19,8 +19,3 @@ let expr_is_uncurried_fun (expr : Parsetree.expression) =
  match expr.pexp_desc with
  | Pexp_fun {arity = Some _} -> true
  | _ -> false
-
-let expr_extract_uncurried_fun (expr : Parsetree.expression) =
- match expr.pexp_desc with
- | Pexp_fun {arity = Some _} -> expr
- | _ -> assert false

compiler/ml/depend.ml

@@ -289,6 +289,7 @@ let rec add_expr bv exp =
  | Pstr_eval ({pexp_desc = Pexp_construct (c, None)}, _) -> add bv c
  | _ -> handle_extension e)
  | Pexp_extension e -> handle_extension e
+ | Pexp_await e -> add_expr bv e
 
 and add_cases bv cases = List.iter (add_case bv) cases
 

compiler/ml/parsetree.ml

@@ -313,8 +313,9 @@ and expression_desc =
  let open M in E
  let! open M in E *)
  | Pexp_extension of extension
-(* [%id] *)
-(* . *)
+ (* [%id] *)
+ (* . *)
+ | Pexp_await of expression
 
 and case = {
  (* (P -> E) or (P when E0 -> E) *)

compiler/ml/pprintast.ml

@@ -722,6 +722,7 @@ and expression ctxt f x =
  (expression ctxt) e
  | Pexp_variant (l, Some eo) -> pp f "@[<2>`%s@;%a@]" l (simple_expr ctxt) eo
  | Pexp_extension e -> extension ctxt f e
+ | Pexp_await e -> pp f "@[<hov2>await@ %a@]" (simple_expr ctxt) e
  | _ -> expression1 ctxt f x
 
 and expression1 ctxt f x =

compiler/ml/printast.ml

@@ -345,6 +345,9 @@ and expression i ppf x =
  | Pexp_extension (s, arg) ->
  line i ppf "Pexp_extension \"%s\"\n" s.txt;
  payload i ppf arg
+ | Pexp_await e ->
+ line i ppf "Pexp_await\n";
+ expression i ppf e
 
 and value_description i ppf x =
  line i ppf "value_description %a %a\n" fmt_string_loc x.pval_name fmt_location

compiler/ml/typecore.ml

@@ -178,6 +178,7 @@ let iter_expression f e =
  expr e;
  module_expr me
  | Pexp_pack me -> module_expr me
+ | Pexp_await _ -> assert false (* should be handled earlier *)
  and case {pc_lhs = _; pc_guard; pc_rhs} =
  may expr pc_guard;
  expr pc_rhs
@@ -3195,6 +3196,7 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
  | _ -> raise (Error (loc, env, Invalid_extension_constructor_payload)))
  | Pexp_extension ext ->
  raise (Error_forward (Builtin_attributes.error_of_extension ext))
+ | Pexp_await _ -> (* should be handled earlier *) assert false
 
 and type_function ?in_function ~arity ~async loc attrs env ty_expected_ l
  caselist =

compiler/syntax/src/res_ast_debugger.ml

@@ -707,6 +707,7 @@ module SexpAst = struct
  ]
  | Pexp_extension ext ->
  Sexp.list [Sexp.atom "Pexp_extension"; extension ext]
+ | Pexp_await e -> Sexp.list [Sexp.atom "Pexp_await"; expression e]
  in
  Sexp.list [Sexp.atom "expression"; desc]
 

compiler/syntax/src/res_core.ml

@@ -3307,15 +3307,12 @@ and parse_async_arrow_expression ?(arrow_attrs = []) p =
 
 and parse_await_expression p =
  let await_loc = mk_loc p.Parser.start_pos p.end_pos in
- let await_attr = make_await_attr await_loc in
  Parser.expect Await p;
  let token_prec = Token.precedence MinusGreater in
  let expr = parse_binary_expr ~context:OrdinaryExpr p token_prec in
- {
- expr with
- pexp_attributes = await_attr :: expr.pexp_attributes;
- pexp_loc = {expr.pexp_loc with loc_start = await_loc.loc_start};
- }
+ Ast_helper.Exp.await
+ ~loc:{expr.pexp_loc with loc_start = await_loc.loc_start}
+ ~attrs:[] expr
 
 and parse_try_expression p =
  let start_pos = p.Parser.start_pos in

compiler/syntax/src/res_parens.ml

@@ -56,8 +56,7 @@ let call_expr expr =
  } ->
  Parenthesized
  | _ when Ast_uncurried.expr_is_uncurried_fun expr -> Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | _ -> Nothing)
 
 let structure_expr expr =
@@ -109,8 +108,7 @@ let unary_expr_operand expr =
  | Pexp_try _ | Pexp_while _ | Pexp_for _ | Pexp_ifthenelse _ );
  } ->
  Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | _ -> Nothing)
 
 let binary_expr_operand ~is_lhs expr =
@@ -133,8 +131,7 @@ let binary_expr_operand ~is_lhs expr =
  | expr when ParsetreeViewer.is_binary_expression expr -> Parenthesized
  | expr when ParsetreeViewer.is_ternary_expr expr -> Parenthesized
  | {pexp_desc = Pexp_lazy _ | Pexp_assert _} when is_lhs -> Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | {Parsetree.pexp_attributes = attrs} ->
  if ParsetreeViewer.has_printable_attributes attrs then Parenthesized
  else Nothing)
@@ -229,9 +226,7 @@ let lazy_or_assert_or_await_expr_rhs ?(in_await = false) expr =
  | Pexp_while _ | Pexp_for _ | Pexp_ifthenelse _ );
  } ->
  Parenthesized
- | _
- when (not in_await)
- && ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
+ | _ when (not in_await) && ParsetreeViewer.expr_is_await expr ->
  Parenthesized
  | _ -> Nothing)
 
@@ -277,8 +272,7 @@ let field_expr expr =
  | Pexp_try _ | Pexp_while _ | Pexp_for _ | Pexp_ifthenelse _ );
  } ->
  Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | _ -> Nothing)
 
 let set_field_expr_rhs expr =
@@ -339,8 +333,7 @@ let jsx_prop_expr expr =
  }
  when starts_with_minus x ->
  Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | {
  Parsetree.pexp_desc =
  ( Pexp_ident _ | Pexp_constant _ | Pexp_field _ | Pexp_construct _
@@ -377,8 +370,7 @@ let jsx_child_expr expr =
  }
  when starts_with_minus x ->
  Parenthesized
- | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
- Parenthesized
+ | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
  | {
  Parsetree.pexp_desc =
  ( Pexp_ident _ | Pexp_constant _ | Pexp_field _ | Pexp_construct _

compiler/syntax/src/res_parsetree_viewer.ml

@@ -72,6 +72,11 @@ let has_await_attribute attrs =
  | _ -> false)
  attrs
 
+let expr_is_await e =
+ match e.pexp_desc with
+ | Pexp_await _ -> true
+ | _ -> false
+
 let has_inline_record_definition_attribute attrs =
  List.exists
  (function
@@ -111,12 +116,7 @@ let collect_list_expressions expr =
 
 (* (__x) => f(a, __x, c) -----> f(a, _, c) *)
 let rewrite_underscore_apply expr =
- let expr_fun =
- if Ast_uncurried.expr_is_uncurried_fun expr then
- Ast_uncurried.expr_extract_uncurried_fun expr
- else expr
- in
- match expr_fun.pexp_desc with
+ match expr.pexp_desc with
  | Pexp_fun
  {
  arg_label = Nolabel;

compiler/syntax/src/res_parsetree_viewer.mli

@@ -14,6 +14,7 @@ val functor_type :
  list
  * Parsetree.module_type
 
+val expr_is_await : Parsetree.expression -> bool
 val has_await_attribute : Parsetree.attributes -> bool
 val has_inline_record_definition_attribute : Parsetree.attributes -> bool
 val has_res_pat_variant_spread_attribute : Parsetree.attributes -> bool