Remove uses of "Function$".

Author: cristianoc

compiler/ml/ast_uncurried.ml

@@ -46,6 +46,11 @@ let expr_extract_uncurried_fun (expr : Parsetree.expression) =
     e
   | _ -> assert false
 
+let remove_fun (expr : Parsetree.expression) =
+  match expr.pexp_desc with
+  | Pexp_construct ({txt = Lident "Function$"}, Some e) -> e
+  | _ -> expr
+
 let core_type_is_uncurried_fun (typ : Parsetree.core_type) =
   match typ.ptyp_desc with
   | Ptyp_constr ({txt = Lident "function$"}, [{ptyp_desc = Ptyp_arrow _}; _]) ->

compiler/syntax/src/res_parens.ml

@@ -83,6 +83,7 @@ let unary_expr_operand expr =
   match opt_braces with
   | Some ({Location.loc = braces_loc}, _) -> Braced braces_loc
   | None -> (
+    let expr = Ast_uncurried.remove_fun expr in
     match expr with
     | {Parsetree.pexp_attributes = attrs}
       when match ParsetreeViewer.filter_parsing_attrs attrs with
@@ -111,11 +112,6 @@ let unary_expr_operand expr =
       Parenthesized
     | _ when ParsetreeViewer.has_await_attribute expr.pexp_attributes ->
       Parenthesized
-    | {pexp_desc = Pexp_construct ({txt = Lident "Function$"}, Some expr)}
-      when ParsetreeViewer.is_underscore_apply_sugar expr ->
-      Nothing
-    | {pexp_desc = Pexp_construct ({txt = Lident "Function$"}, Some _)} ->
-      Parenthesized
     | _ -> Nothing)
 
 let binary_expr_operand ~is_lhs expr =

compiler/syntax/src/res_printer.ml

@@ -2793,19 +2793,7 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
           None,
           {ppat_desc = Ppat_var {txt = "__x"}},
           {pexp_desc = Pexp_apply _},
-          _ )
-    | Pexp_construct
-        ( {txt = Lident "Function$"},
-          Some
-            {
-              pexp_desc =
-                Pexp_fun
-                  ( Nolabel,
-                    None,
-                    {ppat_desc = Ppat_var {txt = "__x"}},
-                    {pexp_desc = Pexp_apply _},
-                    _ );
-            } ) ->
+          _ ) ->
       (* (__x) => f(a, __x, c) -----> f(a, _, c)  *)
       print_expression_with_comments ~state
         (ParsetreeViewer.rewrite_underscore_apply e_fun)