Remove Pexp_function, which is never produced by the parser.

CHANGELOG.md

@@ -24,6 +24,7 @@
 - Ast cleanup: explicit representation for optional record fields in types. https://github.com/rescript-lang/rescript/pull/7190 https://github.com/rescript-lang/rescript/pull/7191
 - AST cleanup: first-class expression and patterns for records with optional fields. https://github.com/rescript-lang/rescript/pull/7192
 - AST cleanup: Represent the arity of uncurried function definitions directly in the AST. https://github.com/rescript-lang/rescript/pull/7197
+- AST cleanup: Remove Pexp_function from the AST. https://github.com/rescript-lang/rescript/pull/7198
 
 
 # 12.0.0-alpha.5

analysis/reanalyze/src/Arnold.ml

@@ -908,7 +908,7 @@ module Compile = struct
         let open Command in
         c +++ ConstrOption Rnone
       | _ -> c)
-    | Texp_function {cases} -> cases |> List.map (case ~ctx) |> Command.nondet
+    | Texp_function {case = case_} -> case ~ctx case_
     | Texp_match (e, casesOk, casesExn, _partial)
       when not
              (casesExn

analysis/reanalyze/src/DeadValue.ml

@@ -156,18 +156,16 @@ let rec collectExpr super self (e : Typedtree.expression) =
           exp_desc =
             Texp_function
               {
-                cases =
-                  [
-                    {
-                      c_lhs = {pat_desc = Tpat_var (etaArg, _)};
-                      c_rhs =
-                        {
-                          exp_desc =
-                            Texp_apply
-                              ({exp_desc = Texp_ident (idArg2, _, _)}, args);
-                        };
-                    };
-                  ];
+                case =
+                  {
+                    c_lhs = {pat_desc = Tpat_var (etaArg, _)};
+                    c_rhs =
+                      {
+                        exp_desc =
+                          Texp_apply
+                            ({exp_desc = Texp_ident (idArg2, _, _)}, args);
+                      };
+                  };
               };
         } )
     when Ident.name idArg = "arg"

analysis/src/DocumentSymbol.ml

@@ -41,7 +41,6 @@ let command ~path =
   let rec exprKind (exp : Parsetree.expression) =
     match exp.pexp_desc with
     | Pexp_fun _ -> Function
-    | Pexp_function _ -> Function
     | Pexp_constraint (e, _) -> exprKind e
     | Pexp_constant (Pconst_string _) -> String
     | Pexp_constant (Pconst_float _ | Pconst_integer _) -> Number

analysis/src/Utils.ml

@@ -85,7 +85,6 @@ let identifyPexp pexp =
   | Parsetree.Pexp_ident _ -> "Pexp_ident"
   | Pexp_constant _ -> "Pexp_constant"
   | Pexp_let _ -> "Pexp_let"
-  | Pexp_function _ -> "Pexp_function"
   | Pexp_fun _ -> "Pexp_fun"
   | Pexp_apply _ -> "Pexp_apply"
   | Pexp_match _ -> "Pexp_match"

compiler/frontend/bs_ast_mapper.ml

@@ -319,7 +319,6 @@ module E = struct
       fun_ ~loc ~attrs ~arity lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_function pel -> function_ ~loc ~attrs (sub.cases sub pel)
     | Pexp_apply (e, l) ->
       apply ~loc ~attrs (sub.expr sub e) (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->

compiler/frontend/bs_builtin_ppx.ml

@@ -110,9 +110,6 @@ let expr_mapper ~async_context ~in_function_def (self : mapper)
   | Pexp_constant (Pconst_integer (s, Some 'l')) ->
     {e with pexp_desc = Pexp_constant (Pconst_integer (s, None))}
   (* End rewriting *)
-  | Pexp_function _ ->
-    async_context := false;
-    default_expr_mapper self e
   | _
     when Ast_uncurried.expr_is_uncurried_fun e
          &&

compiler/gentype/TranslateStructure.ml

@@ -3,9 +3,8 @@ open GenTypeCommon
 let rec addAnnotationsToTypes_ ~config ~(expr : Typedtree.expression)
     (arg_types : arg_type list) =
   match (expr.exp_desc, expr.exp_type.desc, arg_types) with
-  | ( Texp_function {arg_label; param; cases = [{c_rhs}]},
-      _,
-      {a_type} :: next_types ) ->
+  | Texp_function {arg_label; param; case = {c_rhs}}, _, {a_type} :: next_types
+    ->
     let next_types1 =
       next_types |> addAnnotationsToTypes_ ~config ~expr:c_rhs
     in
@@ -51,7 +50,7 @@ and add_annotations_to_fields ~config (expr : Typedtree.expression)
     (fields : fields) (arg_types : arg_type list) =
   match (expr.exp_desc, fields, arg_types) with
   | _, [], _ -> ([], arg_types |> add_annotations_to_types ~config ~expr)
-  | Texp_function {cases = [{c_rhs}]}, field :: next_fields, _ ->
+  | Texp_function {case = {c_rhs}}, field :: next_fields, _ ->
     let next_fields1, types1 =
       add_annotations_to_fields ~config c_rhs next_fields arg_types
     in

compiler/ml/ast_helper.ml

@@ -152,7 +152,6 @@ module Exp = struct
   let let_ ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_let (a, b, c))
   let fun_ ?loc ?attrs ~arity a b c d =
     mk ?loc ?attrs (Pexp_fun (a, b, c, d, arity))
-  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))

compiler/ml/ast_helper.mli

@@ -138,7 +138,6 @@ module Exp : sig
     pattern ->
     expression ->
     expression
-  val function_ : ?loc:loc -> ?attrs:attrs -> case list -> expression
   val apply :
     ?loc:loc ->
     ?attrs:attrs ->

compiler/ml/ast_iterator.ml

@@ -286,7 +286,6 @@ module E = struct
       iter_opt (sub.expr sub) def;
       sub.pat sub p;
       sub.expr sub e
-    | Pexp_function pel -> sub.cases sub pel
     | Pexp_apply (e, l) ->
       sub.expr sub e;
       List.iter (iter_snd (sub.expr sub)) l

compiler/ml/ast_mapper.ml

@@ -282,7 +282,6 @@ module E = struct
       fun_ ~loc ~attrs ~arity lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_function pel -> function_ ~loc ~attrs (sub.cases sub pel)
     | Pexp_apply (e, l) ->
       apply ~loc ~attrs (sub.expr sub e) (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->

compiler/ml/ast_mapper_from0.ml

@@ -288,7 +288,7 @@ module E = struct
       fun_ ~loc ~attrs ~arity:None lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_function pel -> function_ ~loc ~attrs (sub.cases sub pel)
+    | Pexp_function _ -> assert false
     | Pexp_apply (e, l) ->
       apply ~loc ~attrs (sub.expr sub e) (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->

compiler/ml/ast_mapper_to0.ml

@@ -287,7 +287,6 @@ module E = struct
       fun_ ~loc ~attrs lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_function pel -> function_ ~loc ~attrs (sub.cases sub pel)
     | Pexp_apply (e, l) ->
       apply ~loc ~attrs (sub.expr sub e) (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->

compiler/ml/depend.ml

@@ -221,7 +221,6 @@ let rec add_expr bv exp =
   | Pexp_fun (_, opte, p, e, _) ->
     add_opt add_expr bv opte;
     add_expr (add_pattern bv p) e
-  | Pexp_function pel -> add_cases bv pel
   | Pexp_apply (e, el) ->
     add_expr bv e;
     List.iter (fun (_, e) -> add_expr bv e) el

compiler/ml/parsetree.ml

@@ -224,7 +224,6 @@ and expression_desc =
     (* let P1 = E1 and ... and Pn = EN in E       (flag = Nonrecursive)
        let rec P1 = E1 and ... and Pn = EN in E   (flag = Recursive)
     *)
-  | Pexp_function of case list (* function P1 -> E1 | ... | Pn -> En *)
   | Pexp_fun of
       arg_label * expression option * pattern * expression * int option
     (* fun P -> E1                          (Simple, None)

compiler/ml/pprintast.ml

@@ -535,7 +535,7 @@ and expression ctxt f x =
     pp f "((%a)@,%a)" (expression ctxt) {x with pexp_attributes=[]}
       (attributes ctxt) x.pexp_attributes
   else match x.pexp_desc with
-    | Pexp_function _ | Pexp_fun _ | Pexp_match _ | Pexp_try _ | Pexp_sequence _
+    | Pexp_fun _ | Pexp_match _ | Pexp_try _ | Pexp_sequence _
       when ctxt.pipe || ctxt.semi ->
         paren true (expression reset_ctxt) f x
     | Pexp_ifthenelse _ | Pexp_sequence _ when ctxt.ifthenelse ->
@@ -551,8 +551,6 @@ and expression ctxt f x =
         pp f "@[<2>fun@;%s%a->@;%a@]"
           arity_str (label_exp ctxt) (l, e0, p)
           (expression ctxt) e
-    | Pexp_function l ->
-        pp f "@[<hv>function%a@]" (case_list ctxt) l
     | Pexp_match (e, l) ->
         pp f "@[<hv0>@[<hv0>@[<2>match %a@]@ with@]%a@]"
           (expression reset_ctxt) e (case_list ctxt) l

compiler/ml/printast.ml

@@ -233,9 +233,6 @@ and expression i ppf x =
     line i ppf "Pexp_let %a\n" fmt_rec_flag rf;
     list i value_binding ppf l;
     expression i ppf e
-  | Pexp_function l ->
-    line i ppf "Pexp_function\n";
-    list i case ppf l
   | Pexp_fun (l, eo, p, e, arity) ->
     line i ppf "Pexp_fun\n";
     let () =

compiler/ml/printtyped.ml

@@ -285,11 +285,11 @@ and expression i ppf x =
     line i ppf "Texp_let %a\n" fmt_rec_flag rf;
     list i value_binding ppf l;
     expression i ppf e
-  | Texp_function {arg_label = p; param; cases; partial = _} ->
+  | Texp_function {arg_label = p; param; case = case_; partial = _} ->
     line i ppf "Texp_function\n";
     line i ppf "%a" Ident.print param;
     arg_label i ppf p;
-    list i case ppf cases
+    case i ppf case_
   | Texp_apply (e, l) ->
     line i ppf "Texp_apply\n";
     expression i ppf e;

compiler/ml/rec_check.ml

@@ -292,8 +292,8 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
     let case env {Typedtree.c_rhs} = expression env c_rhs in
     Use.join (expression env e) (list case env cases)
   | Texp_override () -> assert false
-  | Texp_function {cases} ->
-    Use.delay (list (case ~scrutinee:Use.empty) env cases)
+  | Texp_function {case = case_} ->
+    Use.delay (list (case ~scrutinee:Use.empty) env [case_])
   | Texp_lazy e -> (
     match Typeopt.classify_lazy_argument e with
     | `Constant_or_function | `Identifier _ | `Float -> expression env e

compiler/ml/tast_iterator.ml

@@ -155,7 +155,7 @@ let expr sub {exp_extra; exp_desc; exp_env; _} =
   | Texp_let (rec_flag, list, exp) ->
     sub.value_bindings sub (rec_flag, list);
     sub.expr sub exp
-  | Texp_function {cases; _} -> sub.cases sub cases
+  | Texp_function {case; _} -> sub.case sub case
   | Texp_apply (exp, list) ->
     sub.expr sub exp;
     List.iter (fun (_, o) -> Option.iter (sub.expr sub) o) list

compiler/ml/tast_mapper.ml

@@ -199,8 +199,8 @@ let expr sub x =
     | Texp_let (rec_flag, list, exp) ->
       let rec_flag, list = sub.value_bindings sub (rec_flag, list) in
       Texp_let (rec_flag, list, sub.expr sub exp)
-    | Texp_function {arg_label; param; cases; partial} ->
-      Texp_function {arg_label; param; cases = sub.cases sub cases; partial}
+    | Texp_function {arg_label; arity; param; case; partial} ->
+      Texp_function {arg_label; arity; param; case = sub.case sub case; partial}
     | Texp_apply (exp, list) ->
       Texp_apply
         (sub.expr sub exp, List.map (tuple2 id (opt (sub.expr sub))) list)