From 1b5b1dc34b1f92ef4d07da8ef9c194ffe222e5d2 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 16:10:20 +0100
Subject: [PATCH 1/8] Remove Pexp_new

---
 analysis/src/Utils.ml                   | 1 -
 compiler/frontend/bs_ast_invariant.ml   | 2 --
 compiler/frontend/bs_ast_mapper.ml      | 1 -
 compiler/ml/ast_helper.ml               | 1 -
 compiler/ml/ast_helper.mli              | 1 -
 compiler/ml/ast_iterator.ml             | 1 -
 compiler/ml/ast_mapper.ml               | 1 -
 compiler/ml/ast_mapper_from0.ml         | 2 +-
 compiler/ml/ast_mapper_to0.ml           | 1 -
 compiler/ml/depend.ml                   | 1 -
 compiler/ml/parsetree.ml                | 1 -
 compiler/ml/pprintast.ml                | 1 -
 compiler/ml/printast.ml                 | 1 -
 compiler/ml/typecore.ml                 | 4 ++--
 compiler/syntax/src/res_ast_debugger.ml | 1 -
 compiler/syntax/src/res_printer.ml      | 1 -
 16 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/analysis/src/Utils.ml b/analysis/src/Utils.ml
index 127ceef0f3..03e7ec9a1e 100644
--- a/analysis/src/Utils.ml
+++ b/analysis/src/Utils.ml
@@ -103,7 +103,6 @@ let identifyPexp pexp =
   | Pexp_constraint _ -> "Pexp_constraint"
   | Pexp_coerce _ -> "Pexp_coerce"
   | Pexp_send _ -> "Pexp_send"
-  | Pexp_new _ -> "Pexp_new"
   | Pexp_setinstvar _ -> "Pexp_setinstvar"
   | Pexp_override _ -> "Pexp_override"
   | Pexp_letmodule _ -> "Pexp_letmodule"
diff --git a/compiler/frontend/bs_ast_invariant.ml b/compiler/frontend/bs_ast_invariant.ml
index 6870c6d160..7da08fea57 100644
--- a/compiler/frontend/bs_ast_invariant.ml
+++ b/compiler/frontend/bs_ast_invariant.ml
@@ -94,8 +94,6 @@ let emit_external_warnings : iterator =
       (fun self ({pexp_loc = loc} as a) ->
         match a.pexp_desc with
         | Pexp_constant const -> check_constant loc const
-        | Pexp_new _ ->
-          Location.raise_errorf ~loc "OCaml style objects are not supported"
         | Pexp_variant (s, None) when Ext_string.is_valid_hash_number s -> (
           try ignore (Ext_string.hash_number_as_i32_exn s : int32)
           with _ ->
diff --git a/compiler/frontend/bs_ast_mapper.ml b/compiler/frontend/bs_ast_mapper.ml
index 99742c849c..3f5ca1e102 100644
--- a/compiler/frontend/bs_ast_mapper.ml
+++ b/compiler/frontend/bs_ast_mapper.ml
@@ -354,7 +354,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_new lid -> new_ ~loc ~attrs (map_loc sub lid)
     | Pexp_setinstvar (s, e) ->
       setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index e9ddd8630b..e8a333c575 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -171,7 +171,6 @@ module Exp = struct
   let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_constraint (a, b))
   let coerce ?loc ?attrs a c = mk ?loc ?attrs (Pexp_coerce (a, (), c))
   let send ?loc ?attrs a b = mk ?loc ?attrs (Pexp_send (a, b))
-  let new_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_new a)
   let setinstvar ?loc ?attrs a b = mk ?loc ?attrs (Pexp_setinstvar (a, b))
   let override ?loc ?attrs a = mk ?loc ?attrs (Pexp_override a)
   let letmodule ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_letmodule (a, b, c))
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index 99b5018583..8be8753a25 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -192,7 +192,6 @@ module Exp : sig
   val constraint_ :
     ?loc:loc -> ?attrs:attrs -> expression -> core_type -> expression
   val send : ?loc:loc -> ?attrs:attrs -> expression -> str -> expression
-  val new_ : ?loc:loc -> ?attrs:attrs -> lid -> expression
   val setinstvar : ?loc:loc -> ?attrs:attrs -> str -> expression -> expression
   val override :
     ?loc:loc -> ?attrs:attrs -> (str * expression) list -> expression
diff --git a/compiler/ml/ast_iterator.ml b/compiler/ml/ast_iterator.ml
index 4013ba4d29..93a5978732 100644
--- a/compiler/ml/ast_iterator.ml
+++ b/compiler/ml/ast_iterator.ml
@@ -333,7 +333,6 @@ module E = struct
       sub.expr sub e;
       sub.typ sub t
     | Pexp_send (e, _s) -> sub.expr sub e
-    | Pexp_new lid -> iter_loc sub lid
     | Pexp_setinstvar (s, e) ->
       iter_loc sub s;
       sub.expr sub e
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index eb08e516f0..4f6759cd75 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -317,7 +317,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_new lid -> new_ ~loc ~attrs (map_loc sub lid)
     | Pexp_setinstvar (s, e) ->
       setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index 345354d616..23a87d799d 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -376,7 +376,7 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_new lid -> new_ ~loc ~attrs (map_loc sub lid)
+    | Pexp_new _ -> failwith "Pexp_new is no longer present in ReScript"
     | Pexp_setinstvar (s, e) ->
       setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
diff --git a/compiler/ml/ast_mapper_to0.ml b/compiler/ml/ast_mapper_to0.ml
index c23c292b9b..82faf061c7 100644
--- a/compiler/ml/ast_mapper_to0.ml
+++ b/compiler/ml/ast_mapper_to0.ml
@@ -365,7 +365,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_new lid -> new_ ~loc ~attrs (map_loc sub lid)
     | Pexp_setinstvar (s, e) ->
       setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
diff --git a/compiler/ml/depend.ml b/compiler/ml/depend.ml
index d7114db984..4f85c4ebb7 100644
--- a/compiler/ml/depend.ml
+++ b/compiler/ml/depend.ml
@@ -271,7 +271,6 @@ let rec add_expr bv exp =
     add_expr bv e1;
     add_type bv ty2
   | Pexp_send (e, _m) -> add_expr bv e
-  | Pexp_new li -> add bv li
   | Pexp_setinstvar (_v, e) -> add_expr bv e
   | Pexp_override sel -> List.iter (fun (_s, e) -> add_expr bv e) sel
   | Pexp_letmodule (id, m, e) ->
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index d4a75b32e3..c40efb0755 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -291,7 +291,6 @@ and expression_desc =
     (* (E :> T)        (None, T)
          *)
   | Pexp_send of expression * label loc (*  E # m *)
-  | Pexp_new of Longident.t loc (* new M.c *)
   | Pexp_setinstvar of label loc * expression (* x <- 2 *)
   | Pexp_override of (label loc * expression) list
     (* {< x1 = E1; ...; Xn = En >} *)
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index ea826c2689..5548417f8c 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -702,7 +702,6 @@ and expression ctxt f x =
       in
       let lst = sequence_helper [] x in
       pp f "@[<hv>%a@]" (list (expression (under_semi ctxt)) ~sep:";@;") lst
-    | Pexp_new li -> pp f "@[<hov2>new@ %a@]" longident_loc li
     | Pexp_setinstvar (s, e) ->
       pp f "@[<hov2>%s@ <-@ %a@]" s.txt (expression ctxt) e
     | Pexp_override l ->
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index b521072bb8..3041d8bc47 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -317,7 +317,6 @@ and expression i ppf x =
   | Pexp_send (e, s) ->
     line i ppf "Pexp_send \"%s\"\n" s.txt;
     expression i ppf e
-  | Pexp_new li -> line i ppf "Pexp_new %a\n" fmt_longident_loc li
   | Pexp_setinstvar (s, e) ->
     line i ppf "Pexp_setinstvar %a\n" fmt_string_loc s;
     expression i ppf e
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index 43d834a8e2..1becb2b000 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -134,7 +134,7 @@ let iter_expression f e =
     f e;
     match e.pexp_desc with
     | Pexp_extension _ (* we don't iterate under extension point *)
-    | Pexp_ident _ | Pexp_new _ | Pexp_constant _ ->
+    | Pexp_ident _ | Pexp_constant _ ->
       ()
     | Pexp_fun {default = eo; rhs = e} ->
       may expr eo;
@@ -3034,7 +3034,7 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
         (Error
            (e.pexp_loc, env, Undefined_method (obj.exp_type, met, valid_methods)))
     )
-  | Pexp_new _ | Pexp_setinstvar _ | Pexp_override _ -> assert false
+  | Pexp_setinstvar _ | Pexp_override _ -> assert false
   | Pexp_letmodule (name, smodl, sbody) ->
     let ty = newvar () in
     (* remember original level *)
diff --git a/compiler/syntax/src/res_ast_debugger.ml b/compiler/syntax/src/res_ast_debugger.ml
index e72230596a..91ad834334 100644
--- a/compiler/syntax/src/res_ast_debugger.ml
+++ b/compiler/syntax/src/res_ast_debugger.ml
@@ -679,7 +679,6 @@ module SexpAst = struct
       | Pexp_coerce (expr, (), typexpr) ->
         Sexp.list [Sexp.atom "Pexp_coerce"; expression expr; core_type typexpr]
       | Pexp_send _ -> Sexp.list [Sexp.atom "Pexp_send"]
-      | Pexp_new _ -> Sexp.list [Sexp.atom "Pexp_new"]
       | Pexp_setinstvar _ -> Sexp.list [Sexp.atom "Pexp_setinstvar"]
       | Pexp_override _ -> Sexp.list [Sexp.atom "Pexp_override"]
       | Pexp_letmodule (mod_name, mod_expr, expr) ->
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index 15a85b6345..a0723a1839 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -3390,7 +3390,6 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
         Doc.concat [Doc.text "\""; member_doc; Doc.text "\""]
       in
       Doc.group (Doc.concat [parent_doc; Doc.lbracket; member; Doc.rbracket])
-    | Pexp_new _ -> Doc.text "Pexp_new not implemented in printer"
     | Pexp_setinstvar _ -> Doc.text "Pexp_setinstvar not implemented in printer"
     | Pexp_override _ -> Doc.text "Pexp_override not implemented in printer"
     | Pexp_poly _ -> Doc.text "Pexp_poly not implemented in printer"

From 5720ace3f5effd5c78912fa1d7676fec5686bcd3 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 17:14:19 +0100
Subject: [PATCH 2/8] Add changelog entry

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c84d8a9cf8..5c9f01e7a1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 - AST cleanup: Prepare for ast async cleanup: Refactor code for "@res.async" payload handling and clean up handling of type and term parameters, so that now each `=>` in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
 - AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
 - AST cleanup: Remove `@res.async` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
+- AST cleanup: Remove `expression_desc.Pexp_new` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 
 # 12.0.0-alpha.7
 

From 09d0b7b7db5a21415311928a071210ea6be5ec89 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 19:10:20 +0100
Subject: [PATCH 3/8] Remove Pexp_setinstvar

---
 analysis/src/Utils.ml                   |  1 -
 compiler/frontend/bs_ast_mapper.ml      |  2 --
 compiler/frontend/bs_builtin_ppx.ml     | 18 ------------------
 compiler/ml/ast_helper.ml               |  1 -
 compiler/ml/ast_helper.mli              |  1 -
 compiler/ml/ast_iterator.ml             |  3 ---
 compiler/ml/ast_mapper.ml               |  2 --
 compiler/ml/ast_mapper_from0.ml         |  4 ++--
 compiler/ml/ast_mapper_to0.ml           |  2 --
 compiler/ml/depend.ml                   |  1 -
 compiler/ml/parsetree.ml                |  1 -
 compiler/ml/pprintast.ml                |  2 --
 compiler/ml/printast.ml                 |  3 ---
 compiler/ml/typecore.ml                 |  3 +--
 compiler/syntax/src/res_ast_debugger.ml |  1 -
 compiler/syntax/src/res_printer.ml      |  1 -
 16 files changed, 3 insertions(+), 43 deletions(-)

diff --git a/analysis/src/Utils.ml b/analysis/src/Utils.ml
index 03e7ec9a1e..7fcb3f3f0e 100644
--- a/analysis/src/Utils.ml
+++ b/analysis/src/Utils.ml
@@ -103,7 +103,6 @@ let identifyPexp pexp =
   | Pexp_constraint _ -> "Pexp_constraint"
   | Pexp_coerce _ -> "Pexp_coerce"
   | Pexp_send _ -> "Pexp_send"
-  | Pexp_setinstvar _ -> "Pexp_setinstvar"
   | Pexp_override _ -> "Pexp_override"
   | Pexp_letmodule _ -> "Pexp_letmodule"
   | Pexp_letexception _ -> "Pexp_letexception"
diff --git a/compiler/frontend/bs_ast_mapper.ml b/compiler/frontend/bs_ast_mapper.ml
index 3f5ca1e102..83a57a9351 100644
--- a/compiler/frontend/bs_ast_mapper.ml
+++ b/compiler/frontend/bs_ast_mapper.ml
@@ -354,8 +354,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_setinstvar (s, e) ->
-      setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
       override ~loc ~attrs
         (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
diff --git a/compiler/frontend/bs_builtin_ppx.ml b/compiler/frontend/bs_builtin_ppx.ml
index 054a9976a3..b15a683ddd 100644
--- a/compiler/frontend/bs_builtin_ppx.ml
+++ b/compiler/frontend/bs_builtin_ppx.ml
@@ -87,24 +87,6 @@ let expr_mapper ~async_context ~in_function_def (self : mapper)
   (* Its output should not be rewritten anymore *)
   | Pexp_extension extension ->
     Ast_exp_extension.handle_extension e self extension
-  | Pexp_setinstvar ({txt; loc}, expr) ->
-    if Stack.is_empty Js_config.self_stack then
-      Location.raise_errorf ~loc:e.pexp_loc
-        "This assignment can only happen in object context";
-    let name = Stack.top Js_config.self_stack in
-    if name = "" then
-      Location.raise_errorf ~loc:e.pexp_loc
-        "The current object does not assign a name";
-    let open Ast_helper in
-    self.expr self
-      (Exp.apply ~loc:e.pexp_loc
-         (Exp.ident ~loc {loc; txt = Lident "#="})
-         [
-           ( Nolabel,
-             Exp.send ~loc (Exp.ident ~loc {loc; txt = Lident name}) {loc; txt}
-           );
-           (Nolabel, expr);
-         ])
   | Pexp_constant (Pconst_string (s, Some delim)) ->
     Ast_utf8_string_interp.transform_exp e s delim
   | Pexp_constant (Pconst_integer (s, Some 'l')) ->
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index e8a333c575..cf19a669a8 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -171,7 +171,6 @@ module Exp = struct
   let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_constraint (a, b))
   let coerce ?loc ?attrs a c = mk ?loc ?attrs (Pexp_coerce (a, (), c))
   let send ?loc ?attrs a b = mk ?loc ?attrs (Pexp_send (a, b))
-  let setinstvar ?loc ?attrs a b = mk ?loc ?attrs (Pexp_setinstvar (a, b))
   let override ?loc ?attrs a = mk ?loc ?attrs (Pexp_override a)
   let letmodule ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_letmodule (a, b, c))
   let letexception ?loc ?attrs a b = mk ?loc ?attrs (Pexp_letexception (a, b))
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index 8be8753a25..35028fe4ed 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -192,7 +192,6 @@ module Exp : sig
   val constraint_ :
     ?loc:loc -> ?attrs:attrs -> expression -> core_type -> expression
   val send : ?loc:loc -> ?attrs:attrs -> expression -> str -> expression
-  val setinstvar : ?loc:loc -> ?attrs:attrs -> str -> expression -> expression
   val override :
     ?loc:loc -> ?attrs:attrs -> (str * expression) list -> expression
   val letmodule :
diff --git a/compiler/ml/ast_iterator.ml b/compiler/ml/ast_iterator.ml
index 93a5978732..2a11a99d96 100644
--- a/compiler/ml/ast_iterator.ml
+++ b/compiler/ml/ast_iterator.ml
@@ -333,9 +333,6 @@ module E = struct
       sub.expr sub e;
       sub.typ sub t
     | Pexp_send (e, _s) -> sub.expr sub e
-    | Pexp_setinstvar (s, e) ->
-      iter_loc sub s;
-      sub.expr sub e
     | Pexp_override sel ->
       List.iter (iter_tuple (iter_loc sub) (sub.expr sub)) sel
     | Pexp_letmodule (s, me, e) ->
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index 4f6759cd75..fdb42d772d 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -317,8 +317,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_setinstvar (s, e) ->
-      setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
       override ~loc ~attrs
         (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index 23a87d799d..c486e679cd 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -377,8 +377,8 @@ module E = struct
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
     | Pexp_new _ -> failwith "Pexp_new is no longer present in ReScript"
-    | Pexp_setinstvar (s, e) ->
-      setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
+    | Pexp_setinstvar _ ->
+      failwith "Pexp_setinstvar is no longer present in ReScript"
     | Pexp_override sel ->
       override ~loc ~attrs
         (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
diff --git a/compiler/ml/ast_mapper_to0.ml b/compiler/ml/ast_mapper_to0.ml
index 82faf061c7..2adf42693e 100644
--- a/compiler/ml/ast_mapper_to0.ml
+++ b/compiler/ml/ast_mapper_to0.ml
@@ -365,8 +365,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_setinstvar (s, e) ->
-      setinstvar ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_override sel ->
       override ~loc ~attrs
         (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
diff --git a/compiler/ml/depend.ml b/compiler/ml/depend.ml
index 4f85c4ebb7..20d60c1467 100644
--- a/compiler/ml/depend.ml
+++ b/compiler/ml/depend.ml
@@ -271,7 +271,6 @@ let rec add_expr bv exp =
     add_expr bv e1;
     add_type bv ty2
   | Pexp_send (e, _m) -> add_expr bv e
-  | Pexp_setinstvar (_v, e) -> add_expr bv e
   | Pexp_override sel -> List.iter (fun (_s, e) -> add_expr bv e) sel
   | Pexp_letmodule (id, m, e) ->
     let b = add_module_binding bv m in
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index c40efb0755..45edd23132 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -291,7 +291,6 @@ and expression_desc =
     (* (E :> T)        (None, T)
          *)
   | Pexp_send of expression * label loc (*  E # m *)
-  | Pexp_setinstvar of label loc * expression (* x <- 2 *)
   | Pexp_override of (label loc * expression) list
     (* {< x1 = E1; ...; Xn = En >} *)
   | Pexp_letmodule of string loc * module_expr * expression
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index 5548417f8c..d311aae197 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -702,8 +702,6 @@ and expression ctxt f x =
       in
       let lst = sequence_helper [] x in
       pp f "@[<hv>%a@]" (list (expression (under_semi ctxt)) ~sep:";@;") lst
-    | Pexp_setinstvar (s, e) ->
-      pp f "@[<hov2>%s@ <-@ %a@]" s.txt (expression ctxt) e
     | Pexp_override l ->
       (* FIXME *)
       let string_x_expression f (s, e) =
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index 3041d8bc47..ce8498c37d 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -317,9 +317,6 @@ and expression i ppf x =
   | Pexp_send (e, s) ->
     line i ppf "Pexp_send \"%s\"\n" s.txt;
     expression i ppf e
-  | Pexp_setinstvar (s, e) ->
-    line i ppf "Pexp_setinstvar %a\n" fmt_string_loc s;
-    expression i ppf e
   | Pexp_override l ->
     line i ppf "Pexp_override\n";
     list i string_x_expression ppf l
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index 1becb2b000..7f518d4e6e 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -158,7 +158,6 @@ let iter_expression f e =
     | Pexp_poly (e, _)
     | Pexp_lazy e
     | Pexp_assert e
-    | Pexp_setinstvar (_, e)
     | Pexp_send (e, _)
     | Pexp_constraint (e, _)
     | Pexp_coerce (e, _, _)
@@ -3034,7 +3033,7 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
         (Error
            (e.pexp_loc, env, Undefined_method (obj.exp_type, met, valid_methods)))
     )
-  | Pexp_setinstvar _ | Pexp_override _ -> assert false
+  | Pexp_override _ -> assert false
   | Pexp_letmodule (name, smodl, sbody) ->
     let ty = newvar () in
     (* remember original level *)
diff --git a/compiler/syntax/src/res_ast_debugger.ml b/compiler/syntax/src/res_ast_debugger.ml
index 91ad834334..7627968392 100644
--- a/compiler/syntax/src/res_ast_debugger.ml
+++ b/compiler/syntax/src/res_ast_debugger.ml
@@ -679,7 +679,6 @@ module SexpAst = struct
       | Pexp_coerce (expr, (), typexpr) ->
         Sexp.list [Sexp.atom "Pexp_coerce"; expression expr; core_type typexpr]
       | Pexp_send _ -> Sexp.list [Sexp.atom "Pexp_send"]
-      | Pexp_setinstvar _ -> Sexp.list [Sexp.atom "Pexp_setinstvar"]
       | Pexp_override _ -> Sexp.list [Sexp.atom "Pexp_override"]
       | Pexp_letmodule (mod_name, mod_expr, expr) ->
         Sexp.list
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index a0723a1839..950b93c20e 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -3390,7 +3390,6 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
         Doc.concat [Doc.text "\""; member_doc; Doc.text "\""]
       in
       Doc.group (Doc.concat [parent_doc; Doc.lbracket; member; Doc.rbracket])
-    | Pexp_setinstvar _ -> Doc.text "Pexp_setinstvar not implemented in printer"
     | Pexp_override _ -> Doc.text "Pexp_override not implemented in printer"
     | Pexp_poly _ -> Doc.text "Pexp_poly not implemented in printer"
   in

From be8aedde2c054e27200e3daf3a54ae787eca5d8c Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 19:17:26 +0100
Subject: [PATCH 4/8] Remove Pexp_override

---
 CHANGELOG.md                            | 2 +-
 analysis/src/Utils.ml                   | 1 -
 compiler/frontend/bs_ast_mapper.ml      | 3 ---
 compiler/ml/ast_helper.ml               | 1 -
 compiler/ml/ast_helper.mli              | 2 --
 compiler/ml/ast_iterator.ml             | 2 --
 compiler/ml/ast_mapper.ml               | 3 ---
 compiler/ml/ast_mapper_from0.ml         | 5 ++---
 compiler/ml/ast_mapper_to0.ml           | 3 ---
 compiler/ml/depend.ml                   | 1 -
 compiler/ml/parsetree.ml                | 2 --
 compiler/ml/pprintast.ml                | 6 ------
 compiler/ml/printast.ml                 | 7 -------
 compiler/ml/typecore.ml                 | 2 --
 compiler/syntax/src/res_ast_debugger.ml | 1 -
 compiler/syntax/src/res_printer.ml      | 1 -
 16 files changed, 3 insertions(+), 39 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c9f01e7a1..90bc49b9b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,7 +24,7 @@
 - AST cleanup: Prepare for ast async cleanup: Refactor code for "@res.async" payload handling and clean up handling of type and term parameters, so that now each `=>` in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
 - AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
 - AST cleanup: Remove `@res.async` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
-- AST cleanup: Remove `expression_desc.Pexp_new` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
+- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar` & `expression_desc.Pexp_override` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 
 # 12.0.0-alpha.7
 
diff --git a/analysis/src/Utils.ml b/analysis/src/Utils.ml
index 7fcb3f3f0e..ae59178d70 100644
--- a/analysis/src/Utils.ml
+++ b/analysis/src/Utils.ml
@@ -103,7 +103,6 @@ let identifyPexp pexp =
   | Pexp_constraint _ -> "Pexp_constraint"
   | Pexp_coerce _ -> "Pexp_coerce"
   | Pexp_send _ -> "Pexp_send"
-  | Pexp_override _ -> "Pexp_override"
   | Pexp_letmodule _ -> "Pexp_letmodule"
   | Pexp_letexception _ -> "Pexp_letexception"
   | Pexp_assert _ -> "Pexp_assert"
diff --git a/compiler/frontend/bs_ast_mapper.ml b/compiler/frontend/bs_ast_mapper.ml
index 83a57a9351..8788932848 100644
--- a/compiler/frontend/bs_ast_mapper.ml
+++ b/compiler/frontend/bs_ast_mapper.ml
@@ -354,9 +354,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_override sel ->
-      override ~loc ~attrs
-        (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
     | Pexp_letmodule (s, me, e) ->
       letmodule ~loc ~attrs (map_loc sub s) (sub.module_expr sub me)
         (sub.expr sub e)
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index cf19a669a8..c01771ef4f 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -171,7 +171,6 @@ module Exp = struct
   let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_constraint (a, b))
   let coerce ?loc ?attrs a c = mk ?loc ?attrs (Pexp_coerce (a, (), c))
   let send ?loc ?attrs a b = mk ?loc ?attrs (Pexp_send (a, b))
-  let override ?loc ?attrs a = mk ?loc ?attrs (Pexp_override a)
   let letmodule ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_letmodule (a, b, c))
   let letexception ?loc ?attrs a b = mk ?loc ?attrs (Pexp_letexception (a, b))
   let assert_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_assert a)
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index 35028fe4ed..329b1201b4 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -192,8 +192,6 @@ module Exp : sig
   val constraint_ :
     ?loc:loc -> ?attrs:attrs -> expression -> core_type -> expression
   val send : ?loc:loc -> ?attrs:attrs -> expression -> str -> expression
-  val override :
-    ?loc:loc -> ?attrs:attrs -> (str * expression) list -> expression
   val letmodule :
     ?loc:loc -> ?attrs:attrs -> str -> module_expr -> expression -> expression
   val letexception :
diff --git a/compiler/ml/ast_iterator.ml b/compiler/ml/ast_iterator.ml
index 2a11a99d96..e9d206446f 100644
--- a/compiler/ml/ast_iterator.ml
+++ b/compiler/ml/ast_iterator.ml
@@ -333,8 +333,6 @@ module E = struct
       sub.expr sub e;
       sub.typ sub t
     | Pexp_send (e, _s) -> sub.expr sub e
-    | Pexp_override sel ->
-      List.iter (iter_tuple (iter_loc sub) (sub.expr sub)) sel
     | Pexp_letmodule (s, me, e) ->
       iter_loc sub s;
       sub.module_expr sub me;
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index fdb42d772d..4b55df4dec 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -317,9 +317,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_override sel ->
-      override ~loc ~attrs
-        (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
     | Pexp_letmodule (s, me, e) ->
       letmodule ~loc ~attrs (map_loc sub s) (sub.module_expr sub me)
         (sub.expr sub e)
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index c486e679cd..fd370acb43 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -379,9 +379,8 @@ module E = struct
     | Pexp_new _ -> failwith "Pexp_new is no longer present in ReScript"
     | Pexp_setinstvar _ ->
       failwith "Pexp_setinstvar is no longer present in ReScript"
-    | Pexp_override sel ->
-      override ~loc ~attrs
-        (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
+    | Pexp_override _ ->
+      failwith "Pexp_override is no longer present in ReScript"
     | Pexp_letmodule (s, me, e) ->
       letmodule ~loc ~attrs (map_loc sub s) (sub.module_expr sub me)
         (sub.expr sub e)
diff --git a/compiler/ml/ast_mapper_to0.ml b/compiler/ml/ast_mapper_to0.ml
index 2adf42693e..ce899c6ba0 100644
--- a/compiler/ml/ast_mapper_to0.ml
+++ b/compiler/ml/ast_mapper_to0.ml
@@ -365,9 +365,6 @@ module E = struct
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
     | Pexp_send (e, s) -> send ~loc ~attrs (sub.expr sub e) (map_loc sub s)
-    | Pexp_override sel ->
-      override ~loc ~attrs
-        (List.map (map_tuple (map_loc sub) (sub.expr sub)) sel)
     | Pexp_letmodule (s, me, e) ->
       letmodule ~loc ~attrs (map_loc sub s) (sub.module_expr sub me)
         (sub.expr sub e)
diff --git a/compiler/ml/depend.ml b/compiler/ml/depend.ml
index 20d60c1467..557046dba0 100644
--- a/compiler/ml/depend.ml
+++ b/compiler/ml/depend.ml
@@ -271,7 +271,6 @@ let rec add_expr bv exp =
     add_expr bv e1;
     add_type bv ty2
   | Pexp_send (e, _m) -> add_expr bv e
-  | Pexp_override sel -> List.iter (fun (_s, e) -> add_expr bv e) sel
   | Pexp_letmodule (id, m, e) ->
     let b = add_module_binding bv m in
     add_expr (StringMap.add id.txt b bv) e
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index 45edd23132..8750341ddb 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -291,8 +291,6 @@ and expression_desc =
     (* (E :> T)        (None, T)
          *)
   | Pexp_send of expression * label loc (*  E # m *)
-  | Pexp_override of (label loc * expression) list
-    (* {< x1 = E1; ...; Xn = En >} *)
   | Pexp_letmodule of string loc * module_expr * expression
     (* let module M = ME in E *)
   | Pexp_letexception of extension_constructor * expression
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index d311aae197..d2d6b8daa9 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -702,12 +702,6 @@ and expression ctxt f x =
       in
       let lst = sequence_helper [] x in
       pp f "@[<hv>%a@]" (list (expression (under_semi ctxt)) ~sep:";@;") lst
-    | Pexp_override l ->
-      (* FIXME *)
-      let string_x_expression f (s, e) =
-        pp f "@[<hov2>%s@ =@ %a@]" s.txt (expression ctxt) e
-      in
-      pp f "@[<hov2>{<%a>}@]" (list string_x_expression ~sep:";") l
     | Pexp_letmodule (s, me, e) ->
       pp f "@[<hov2>let@ module@ %s@ =@ %a@ in@ %a@]" s.txt
         (module_expr reset_ctxt) me (expression ctxt) e
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index ce8498c37d..afb4331761 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -317,9 +317,6 @@ and expression i ppf x =
   | Pexp_send (e, s) ->
     line i ppf "Pexp_send \"%s\"\n" s.txt;
     expression i ppf e
-  | Pexp_override l ->
-    line i ppf "Pexp_override\n";
-    list i string_x_expression ppf l
   | Pexp_letmodule (s, me, e) ->
     line i ppf "Pexp_letmodule %a\n" fmt_string_loc s;
     module_expr i ppf me;
@@ -661,10 +658,6 @@ and value_binding i ppf x =
   pattern (i + 1) ppf x.pvb_pat;
   expression (i + 1) ppf x.pvb_expr
 
-and string_x_expression i ppf (s, e) =
-  line i ppf "<override> %a\n" fmt_string_loc s;
-  expression (i + 1) ppf e
-
 and longident_x_expression i ppf (li, e, opt) =
   line i ppf "%a%s\n" fmt_longident_loc li (if opt then "?" else "");
   expression (i + 1) ppf e
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index 7f518d4e6e..92adf78f0c 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -176,7 +176,6 @@ let iter_expression f e =
       expr e1;
       expr e2;
       expr e3
-    | Pexp_override sel -> List.iter (fun (_, e) -> expr e) sel
     | Pexp_letmodule (_, me, e) ->
       expr e;
       module_expr me
@@ -3033,7 +3032,6 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
         (Error
            (e.pexp_loc, env, Undefined_method (obj.exp_type, met, valid_methods)))
     )
-  | Pexp_override _ -> assert false
   | Pexp_letmodule (name, smodl, sbody) ->
     let ty = newvar () in
     (* remember original level *)
diff --git a/compiler/syntax/src/res_ast_debugger.ml b/compiler/syntax/src/res_ast_debugger.ml
index 7627968392..2205e55b32 100644
--- a/compiler/syntax/src/res_ast_debugger.ml
+++ b/compiler/syntax/src/res_ast_debugger.ml
@@ -679,7 +679,6 @@ module SexpAst = struct
       | Pexp_coerce (expr, (), typexpr) ->
         Sexp.list [Sexp.atom "Pexp_coerce"; expression expr; core_type typexpr]
       | Pexp_send _ -> Sexp.list [Sexp.atom "Pexp_send"]
-      | Pexp_override _ -> Sexp.list [Sexp.atom "Pexp_override"]
       | Pexp_letmodule (mod_name, mod_expr, expr) ->
         Sexp.list
           [
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index 950b93c20e..e1b5568269 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -3390,7 +3390,6 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
         Doc.concat [Doc.text "\""; member_doc; Doc.text "\""]
       in
       Doc.group (Doc.concat [parent_doc; Doc.lbracket; member; Doc.rbracket])
-    | Pexp_override _ -> Doc.text "Pexp_override not implemented in printer"
     | Pexp_poly _ -> Doc.text "Pexp_poly not implemented in printer"
   in
   let expr_with_await =

From 4f4b88c82d69cebfb90a9c667f96f2bb2c1336d7 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 19:29:18 +0100
Subject: [PATCH 5/8] Try removing Pexp_poly

---
 analysis/src/Utils.ml                   |  1 -
 compiler/frontend/bs_ast_mapper.ml      |  2 --
 compiler/ml/ast_helper.ml               |  1 -
 compiler/ml/ast_helper.mli              |  2 --
 compiler/ml/ast_iterator.ml             |  3 --
 compiler/ml/ast_mapper.ml               |  2 --
 compiler/ml/ast_mapper_from0.ml         |  3 +-
 compiler/ml/ast_mapper_to0.ml           |  2 --
 compiler/ml/depend.ml                   |  3 --
 compiler/ml/parsetree.ml                |  5 ----
 compiler/ml/pprintast.ml                |  6 ----
 compiler/ml/printast.ml                 |  4 ---
 compiler/ml/typecore.ml                 | 37 -------------------------
 compiler/syntax/src/res_ast_debugger.ml |  1 -
 compiler/syntax/src/res_printer.ml      |  1 -
 15 files changed, 1 insertion(+), 72 deletions(-)

diff --git a/analysis/src/Utils.ml b/analysis/src/Utils.ml
index ae59178d70..c274b5a9fb 100644
--- a/analysis/src/Utils.ml
+++ b/analysis/src/Utils.ml
@@ -107,7 +107,6 @@ let identifyPexp pexp =
   | Pexp_letexception _ -> "Pexp_letexception"
   | Pexp_assert _ -> "Pexp_assert"
   | Pexp_lazy _ -> "Pexp_lazy"
-  | Pexp_poly _ -> "Pexp_poly"
   | Pexp_newtype _ -> "Pexp_newtype"
   | Pexp_pack _ -> "Pexp_pack"
   | Pexp_extension _ -> "Pexp_extension"
diff --git a/compiler/frontend/bs_ast_mapper.ml b/compiler/frontend/bs_ast_mapper.ml
index 8788932848..082a0dcf58 100644
--- a/compiler/frontend/bs_ast_mapper.ml
+++ b/compiler/frontend/bs_ast_mapper.ml
@@ -363,8 +363,6 @@ module E = struct
         (sub.expr sub e)
     | Pexp_assert e -> assert_ ~loc ~attrs (sub.expr sub e)
     | Pexp_lazy e -> lazy_ ~loc ~attrs (sub.expr sub e)
-    | Pexp_poly (e, t) ->
-      poly ~loc ~attrs (sub.expr sub e) (map_opt (sub.typ sub) t)
     | Pexp_newtype (s, e) ->
       newtype ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_pack me -> pack ~loc ~attrs (sub.module_expr sub me)
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index c01771ef4f..a1eec7548e 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -175,7 +175,6 @@ module Exp = struct
   let letexception ?loc ?attrs a b = mk ?loc ?attrs (Pexp_letexception (a, b))
   let assert_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_assert a)
   let lazy_ ?loc ?attrs a = mk ?loc ?attrs (Pexp_lazy a)
-  let poly ?loc ?attrs a b = mk ?loc ?attrs (Pexp_poly (a, b))
   let newtype ?loc ?attrs a b = mk ?loc ?attrs (Pexp_newtype (a, b))
   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))
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index 329b1201b4..f11b17a46a 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -202,8 +202,6 @@ module Exp : sig
     expression
   val assert_ : ?loc:loc -> ?attrs:attrs -> expression -> expression
   val lazy_ : ?loc:loc -> ?attrs:attrs -> expression -> expression
-  val poly :
-    ?loc:loc -> ?attrs:attrs -> expression -> core_type option -> expression
   val newtype : ?loc:loc -> ?attrs:attrs -> str -> expression -> expression
   val pack : ?loc:loc -> ?attrs:attrs -> module_expr -> expression
   val open_ :
diff --git a/compiler/ml/ast_iterator.ml b/compiler/ml/ast_iterator.ml
index e9d206446f..950fc7964c 100644
--- a/compiler/ml/ast_iterator.ml
+++ b/compiler/ml/ast_iterator.ml
@@ -342,9 +342,6 @@ module E = struct
       sub.expr sub e
     | Pexp_assert e -> sub.expr sub e
     | Pexp_lazy e -> sub.expr sub e
-    | Pexp_poly (e, t) ->
-      sub.expr sub e;
-      iter_opt (sub.typ sub) t
     | Pexp_newtype (_s, e) -> sub.expr sub e
     | Pexp_pack me -> sub.module_expr sub me
     | Pexp_open (_ovf, lid, e) ->
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index 4b55df4dec..2d93a59fb6 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -326,8 +326,6 @@ module E = struct
         (sub.expr sub e)
     | Pexp_assert e -> assert_ ~loc ~attrs (sub.expr sub e)
     | Pexp_lazy e -> lazy_ ~loc ~attrs (sub.expr sub e)
-    | Pexp_poly (e, t) ->
-      poly ~loc ~attrs (sub.expr sub e) (map_opt (sub.typ sub) t)
     | Pexp_newtype (s, e) ->
       newtype ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_pack me -> pack ~loc ~attrs (sub.module_expr sub me)
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index fd370acb43..398c42bdbe 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -390,8 +390,7 @@ module E = struct
         (sub.expr sub e)
     | Pexp_assert e -> assert_ ~loc ~attrs (sub.expr sub e)
     | Pexp_lazy e -> lazy_ ~loc ~attrs (sub.expr sub e)
-    | Pexp_poly (e, t) ->
-      poly ~loc ~attrs (sub.expr sub e) (map_opt (sub.typ sub) t)
+    | Pexp_poly _ -> failwith "Pexp_poly is no longer present in ReScript"
     | Pexp_object () -> assert false
     | Pexp_newtype (s, e) ->
       newtype ~loc ~attrs (map_loc sub s) (sub.expr sub e)
diff --git a/compiler/ml/ast_mapper_to0.ml b/compiler/ml/ast_mapper_to0.ml
index ce899c6ba0..31ec18fc58 100644
--- a/compiler/ml/ast_mapper_to0.ml
+++ b/compiler/ml/ast_mapper_to0.ml
@@ -374,8 +374,6 @@ module E = struct
         (sub.expr sub e)
     | Pexp_assert e -> assert_ ~loc ~attrs (sub.expr sub e)
     | Pexp_lazy e -> lazy_ ~loc ~attrs (sub.expr sub e)
-    | Pexp_poly (e, t) ->
-      poly ~loc ~attrs (sub.expr sub e) (map_opt (sub.typ sub) t)
     | Pexp_newtype (s, e) ->
       newtype ~loc ~attrs (map_loc sub s) (sub.expr sub e)
     | Pexp_pack me -> pack ~loc ~attrs (sub.module_expr sub me)
diff --git a/compiler/ml/depend.ml b/compiler/ml/depend.ml
index 557046dba0..e762a729d4 100644
--- a/compiler/ml/depend.ml
+++ b/compiler/ml/depend.ml
@@ -277,9 +277,6 @@ let rec add_expr bv exp =
   | Pexp_letexception (_, e) -> add_expr bv e
   | Pexp_assert e -> add_expr bv e
   | Pexp_lazy e -> add_expr bv e
-  | Pexp_poly (e, t) ->
-    add_expr bv e;
-    add_opt add_type bv t
   | Pexp_newtype (_, e) -> add_expr bv e
   | Pexp_pack m -> add_module bv m
   | Pexp_open (_ovf, m, e) ->
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index 8750341ddb..c64e98933a 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -300,11 +300,6 @@ and expression_desc =
        Note: "assert false" is treated in a special way by the
        type-checker. *)
   | Pexp_lazy of expression (* lazy E *)
-  | Pexp_poly of expression * core_type option
-    (* Used for method bodies.
-
-       Can only be used as the expression under Cfk_concrete
-       for methods (not values). *)
   | Pexp_newtype of string loc * expression (* fun (type t) -> E *)
   | Pexp_pack of module_expr
     (* (module ME)
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index d2d6b8daa9..925cf5f318 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -711,12 +711,6 @@ and expression ctxt f x =
         cd (expression ctxt) e
     | Pexp_assert e -> pp f "@[<hov2>assert@ %a@]" (simple_expr ctxt) e
     | Pexp_lazy e -> pp f "@[<hov2>lazy@ %a@]" (simple_expr ctxt) e
-    (* Pexp_poly: impossible but we should print it anyway, rather than
-       assert false *)
-    | Pexp_poly (e, None) -> pp f "@[<hov2>!poly!@ %a@]" (simple_expr ctxt) e
-    | Pexp_poly (e, Some ct) ->
-      pp f "@[<hov2>(!poly!@ %a@ : %a)@]" (simple_expr ctxt) e (core_type ctxt)
-        ct
     | Pexp_open (ovf, lid, e) ->
       pp f "@[<2>let open%s %a in@;%a@]" (override ovf) longident_loc lid
         (expression ctxt) e
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index afb4331761..ef467a79a9 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -331,10 +331,6 @@ and expression i ppf x =
   | Pexp_lazy e ->
     line i ppf "Pexp_lazy\n";
     expression i ppf e
-  | Pexp_poly (e, cto) ->
-    line i ppf "Pexp_poly\n";
-    expression i ppf e;
-    option i core_type ppf cto
   | Pexp_newtype (s, e) ->
     line i ppf "Pexp_newtype \"%s\"\n" s.txt;
     expression i ppf e
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index 92adf78f0c..b2268e9bb0 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -155,7 +155,6 @@ let iter_expression f e =
       List.iter (fun (_, e, _) -> expr e) iel
     | Pexp_open (_, _, e)
     | Pexp_newtype (_, e)
-    | Pexp_poly (e, _)
     | Pexp_lazy e
     | Pexp_assert e
     | Pexp_send (e, _)
@@ -3107,42 +3106,6 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
         exp_attributes = sexp.pexp_attributes;
         exp_env = env;
       }
-  | Pexp_poly (sbody, sty) ->
-    let ty, cty =
-      match sty with
-      | None -> (repr ty_expected, None)
-      | Some sty ->
-        let sty = Ast_helper.Typ.force_poly sty in
-        let cty = Typetexp.transl_simple_type env false sty in
-        (repr cty.ctyp_type, Some cty)
-    in
-    if sty <> None then
-      unify_exp_types loc env (instance env ty) (instance env ty_expected);
-    let exp =
-      match (expand_head env ty).desc with
-      | Tpoly (ty', []) ->
-        let exp = type_expect env sbody ty' in
-        {exp with exp_type = instance env ty}
-      | Tpoly (ty', tl) ->
-        (* One more level to generalize locally *)
-        begin_def ();
-        let vars, ty'' = instance_poly true tl ty' in
-        let exp = type_expect env sbody ty'' in
-        end_def ();
-        check_univars env false "method" exp ty_expected vars;
-        {exp with exp_type = instance env ty}
-      | Tvar _ ->
-        let exp = type_exp env sbody in
-        let exp = {exp with exp_type = newty (Tpoly (exp.exp_type, []))} in
-        unify_exp env exp ty;
-        exp
-      | _ -> assert false
-    in
-    re
-      {
-        exp with
-        exp_extra = (Texp_poly cty, loc, sexp.pexp_attributes) :: exp.exp_extra;
-      }
   | Pexp_newtype ({txt = name}, sbody) ->
     let ty = newvar () in
     (* remember original level *)
diff --git a/compiler/syntax/src/res_ast_debugger.ml b/compiler/syntax/src/res_ast_debugger.ml
index 2205e55b32..fb5c58896f 100644
--- a/compiler/syntax/src/res_ast_debugger.ml
+++ b/compiler/syntax/src/res_ast_debugger.ml
@@ -696,7 +696,6 @@ module SexpAst = struct
           ]
       | Pexp_assert expr -> Sexp.list [Sexp.atom "Pexp_assert"; expression expr]
       | Pexp_lazy expr -> Sexp.list [Sexp.atom "Pexp_lazy"; expression expr]
-      | Pexp_poly _ -> Sexp.list [Sexp.atom "Pexp_poly"]
       | Pexp_newtype (lbl, expr) ->
         Sexp.list
           [Sexp.atom "Pexp_newtype"; string lbl.Asttypes.txt; expression expr]
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index e1b5568269..9ab6c04084 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -3390,7 +3390,6 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
         Doc.concat [Doc.text "\""; member_doc; Doc.text "\""]
       in
       Doc.group (Doc.concat [parent_doc; Doc.lbracket; member; Doc.rbracket])
-    | Pexp_poly _ -> Doc.text "Pexp_poly not implemented in printer"
   in
   let expr_with_await =
     if ParsetreeViewer.has_await_attribute e.pexp_attributes then

From 41bf9aa4b8c73ec1e4c502af2d5c77c648126115 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 19:59:17 +0100
Subject: [PATCH 6/8] Correct changelog

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90bc49b9b7..26d6e4e695 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,7 +24,7 @@
 - AST cleanup: Prepare for ast async cleanup: Refactor code for "@res.async" payload handling and clean up handling of type and term parameters, so that now each `=>` in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
 - AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
 - AST cleanup: Remove `@res.async` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
-- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar` & `expression_desc.Pexp_override` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
+- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override` & `expression_desc.Pexp_poly` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 
 # 12.0.0-alpha.7
 

From 195ae4314b47f58ac0a1aef5643d0ff9a0a68646 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 20:52:39 +0100
Subject: [PATCH 7/8] Remove `exp_extra.Texp_poly`, `expression_desc.Texp_new`,
 `expression_desc.Texp_setinstvar` & `expression_desc.Texp_override`

---
 CHANGELOG.md                          |  2 +-
 analysis/reanalyze/src/Arnold.ml      |  9 ---------
 analysis/reanalyze/src/SideEffects.ml |  3 ---
 compiler/ml/printtyped.ml             |  5 -----
 compiler/ml/rec_check.ml              | 14 +++++---------
 compiler/ml/tast_iterator.ml          |  4 ----
 compiler/ml/tast_mapper.ml            |  4 +---
 compiler/ml/translcore.ml             |  3 +--
 compiler/ml/typecore.ml               |  1 -
 compiler/ml/typedtree.ml              |  4 ----
 compiler/ml/typedtree.mli             |  4 ----
 compiler/ml/typedtreeIter.ml          |  3 +--
 12 files changed, 9 insertions(+), 47 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26d6e4e695..b9256c6092 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,7 +24,7 @@
 - AST cleanup: Prepare for ast async cleanup: Refactor code for "@res.async" payload handling and clean up handling of type and term parameters, so that now each `=>` in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
 - AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
 - AST cleanup: Remove `@res.async` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
-- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override` & `expression_desc.Pexp_poly` from the untyped typed AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
+- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override`, `expression_desc.Pexp_poly`, `exp_extra.Texp_poly`, `expression_desc.Texp_new`, `expression_desc.Texp_setinstvar` & `expression_desc.Texp_override` from AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 
 # 12.0.0-alpha.7
 
diff --git a/analysis/reanalyze/src/Arnold.ml b/analysis/reanalyze/src/Arnold.ml
index e4dd423e2f..eee8753377 100644
--- a/analysis/reanalyze/src/Arnold.ml
+++ b/analysis/reanalyze/src/Arnold.ml
@@ -975,18 +975,9 @@ module Compile = struct
     | Texp_send _ ->
       notImplemented "Texp_send";
       assert false
-    | Texp_new _ ->
-      notImplemented "Texp_new";
-      assert false
     | Texp_instvar _ ->
       notImplemented "Texp_instvar";
       assert false
-    | Texp_setinstvar _ ->
-      notImplemented "Texp_setinstvar";
-      assert false
-    | Texp_override _ ->
-      notImplemented "Texp_override";
-      assert false
     | Texp_letmodule _ ->
       notImplemented "Texp_letmodule";
       assert false
diff --git a/analysis/reanalyze/src/SideEffects.ml b/analysis/reanalyze/src/SideEffects.ml
index d356ac23ae..46c4eab974 100644
--- a/analysis/reanalyze/src/SideEffects.ml
+++ b/analysis/reanalyze/src/SideEffects.ml
@@ -61,10 +61,7 @@ let rec exprNoSideEffects (expr : Typedtree.expression) =
     e1 |> exprNoSideEffects && e2 |> exprNoSideEffects
     && e3 |> exprNoSideEffects
   | Texp_send _ -> false
-  | Texp_new _ -> true
   | Texp_instvar _ -> true
-  | Texp_setinstvar _ -> false
-  | Texp_override _ -> false
   | Texp_letexception (_ec, e) -> e |> exprNoSideEffects
   | Texp_pack _ -> false
   | Texp_extension_constructor _ when true -> true
diff --git a/compiler/ml/printtyped.ml b/compiler/ml/printtyped.ml
index 686caa4083..f356737c81 100644
--- a/compiler/ml/printtyped.ml
+++ b/compiler/ml/printtyped.ml
@@ -259,10 +259,6 @@ and expression_extra i ppf x attrs =
   | Texp_open (ovf, m, _, _) ->
     line i ppf "Texp_open %a \"%a\"\n" fmt_override_flag ovf fmt_path m;
     attributes i ppf attrs
-  | Texp_poly cto ->
-    line i ppf "Texp_poly\n";
-    attributes i ppf attrs;
-    option i core_type ppf cto
   | Texp_newtype s ->
     line i ppf "Texp_newtype \"%s\"\n" s;
     attributes i ppf attrs
@@ -360,7 +356,6 @@ and expression i ppf x =
     line i ppf "Texp_send \"%s\"\n" s;
     expression i ppf e;
     option i expression ppf eo
-  | Texp_new _ | Texp_setinstvar _ | Texp_override _ -> ()
   | Texp_letmodule (s, _, me, e) ->
     line i ppf "Texp_letmodule \"%a\"\n" fmt_ident s;
     module_expr i ppf me;
diff --git a/compiler/ml/rec_check.ml b/compiler/ml/rec_check.ml
index a669915a57..b467f07ff3 100644
--- a/compiler/ml/rec_check.ml
+++ b/compiler/ml/rec_check.ml
@@ -195,15 +195,14 @@ let rec classify_expression : Typedtree.expression -> sd =
   | Texp_sequence (_, e)
   | Texp_letexception (_, e) ->
     classify_expression e
-  | Texp_ident _ | Texp_for _ | Texp_constant _ | Texp_new _ | Texp_instvar _
-  | Texp_tuple _ | Texp_array _ | Texp_construct _ | Texp_variant _
-  | Texp_record _ | Texp_setfield _ | Texp_while _ | Texp_setinstvar _
-  | Texp_pack _ | Texp_function _ | Texp_lazy _ | Texp_extension_constructor _
-    ->
+  | Texp_ident _ | Texp_for _ | Texp_constant _ | Texp_instvar _ | Texp_tuple _
+  | Texp_array _ | Texp_construct _ | Texp_variant _ | Texp_record _
+  | Texp_setfield _ | Texp_while _ | Texp_pack _ | Texp_function _ | Texp_lazy _
+  | Texp_extension_constructor _ ->
     Static
   | Texp_apply ({exp_desc = Texp_ident (_, _, vd)}, _) when is_ref vd -> Static
   | Texp_apply _ | Texp_match _ | Texp_ifthenelse _ | Texp_send _ | Texp_field _
-  | Texp_assert _ | Texp_try _ | Texp_override _ ->
+  | Texp_assert _ | Texp_try _ ->
     Dynamic
 
 let rec expression : Env.env -> Typedtree.expression -> Use.t =
@@ -233,7 +232,6 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
            for inclusion in another value *)
         (discard (expression env e3)))
   | Texp_constant _ -> Use.empty
-  | Texp_new _ -> assert false
   | Texp_instvar _ -> Use.empty
   | Texp_apply ({exp_desc = Texp_ident (_, _, vd)}, [(_, Some arg)])
     when is_ref vd ->
@@ -283,7 +281,6 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
     Use.(
       join (inspect (expression env e1)) (inspect (option expression env eo)))
   | Texp_field (e, _, _) -> Use.(inspect (expression env e))
-  | Texp_setinstvar () -> assert false
   | Texp_letexception (_, e) -> expression env e
   | Texp_assert e -> Use.inspect (expression env e)
   | Texp_pack m -> modexp env m
@@ -291,7 +288,6 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
     (* This is more permissive than the old check. *)
     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 {case = case_} ->
     Use.delay (list (case ~scrutinee:Use.empty) env [case_])
   | Texp_lazy e -> (
diff --git a/compiler/ml/tast_iterator.ml b/compiler/ml/tast_iterator.ml
index 62167ea372..1b591b675d 100644
--- a/compiler/ml/tast_iterator.ml
+++ b/compiler/ml/tast_iterator.ml
@@ -144,7 +144,6 @@ let expr sub {exp_extra; exp_desc; exp_env; _} =
     | Texp_constraint cty -> sub.typ sub cty
     | Texp_coerce ((), cty2) -> sub.typ sub cty2
     | Texp_newtype _ -> ()
-    | Texp_poly cto -> Option.iter (sub.typ sub) cto
     | Texp_open (_, _, _, _) -> ()
   in
   List.iter (fun (e, _, _) -> extra e) exp_extra;
@@ -198,10 +197,7 @@ let expr sub {exp_extra; exp_desc; exp_env; _} =
   | Texp_send (exp, _, expo) ->
     sub.expr sub exp;
     Option.iter (sub.expr sub) expo
-  | Texp_new _ -> ()
   | Texp_instvar _ -> ()
-  | Texp_setinstvar _ -> ()
-  | Texp_override _ -> ()
   | Texp_letmodule (_, _, mexpr, exp) ->
     sub.module_expr sub mexpr;
     sub.expr sub exp
diff --git a/compiler/ml/tast_mapper.ml b/compiler/ml/tast_mapper.ml
index 24541f60e8..b6d17285e0 100644
--- a/compiler/ml/tast_mapper.ml
+++ b/compiler/ml/tast_mapper.ml
@@ -189,7 +189,6 @@ let expr sub x =
     | Texp_open (ovf, path, loc, env) ->
       Texp_open (ovf, path, loc, sub.env sub env)
     | Texp_newtype _ as d -> d
-    | Texp_poly cto -> Texp_poly (opt (sub.typ sub) cto)
   in
   let exp_extra = List.map (tuple3 extra id id) x.exp_extra in
   let exp_env = sub.env sub x.exp_env in
@@ -244,8 +243,7 @@ let expr sub x =
         (id, p, sub.expr sub exp1, sub.expr sub exp2, dir, sub.expr sub exp3)
     | Texp_send (exp, meth, expo) ->
       Texp_send (sub.expr sub exp, meth, opt (sub.expr sub) expo)
-    | (Texp_new _ | Texp_instvar _) as d -> d
-    | Texp_setinstvar _ | Texp_override _ -> assert false
+    | Texp_instvar _ as d -> d
     | Texp_letmodule (id, s, mexpr, exp) ->
       Texp_letmodule (id, s, sub.module_expr sub mexpr, sub.expr sub exp)
     | Texp_letexception (cd, exp) ->
diff --git a/compiler/ml/translcore.ml b/compiler/ml/translcore.ml
index 73986b5d57..c6fb2c398a 100644
--- a/compiler/ml/translcore.ml
+++ b/compiler/ml/translcore.ml
@@ -911,8 +911,7 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
   | Texp_send (expr, Tmeth_name nm, _) ->
     let obj = transl_exp expr in
     Lsend (nm, obj, e.exp_loc)
-  | Texp_new _ | Texp_instvar _ | Texp_setinstvar _ | Texp_override _ ->
-    assert false
+  | Texp_instvar _ -> assert false
   | Texp_letmodule (id, _loc, modl, body) ->
     let defining_expr = !transl_module Tcoerce_none None modl in
     Llet (Strict, Pgenval, id, defining_expr, transl_exp body)
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index b2268e9bb0..193c6da536 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -1820,7 +1820,6 @@ let rec is_nonexpansive exp =
   | Texp_ifthenelse (_cond, ifso, ifnot) ->
     is_nonexpansive ifso && is_nonexpansive_opt ifnot
   | Texp_sequence (_e1, e2) -> is_nonexpansive e2 (* PR#4354 *)
-  | Texp_new _ -> assert false
   (* Note: nonexpansive only means no _observable_ side effects *)
   | Texp_lazy e -> is_nonexpansive e
   | Texp_letmodule (_, _, mexp, e) ->
diff --git a/compiler/ml/typedtree.ml b/compiler/ml/typedtree.ml
index c3af7028fd..c2884b6243 100644
--- a/compiler/ml/typedtree.ml
+++ b/compiler/ml/typedtree.ml
@@ -69,7 +69,6 @@ and exp_extra =
   | Texp_constraint of core_type
   | Texp_coerce of unit * core_type
   | Texp_open of override_flag * Path.t * Longident.t loc * Env.t
-  | Texp_poly of core_type option
   | Texp_newtype of string
 
 and expression_desc =
@@ -115,10 +114,7 @@ and expression_desc =
       * direction_flag
       * expression
   | Texp_send of expression * meth * expression option
-  | Texp_new of unit
   | Texp_instvar of unit
-  | Texp_setinstvar of unit
-  | Texp_override of unit
   | Texp_letmodule of Ident.t * string loc * module_expr * expression
   | Texp_letexception of extension_constructor * expression
   | Texp_assert of expression
diff --git a/compiler/ml/typedtree.mli b/compiler/ml/typedtree.mli
index 2aabedb4aa..6285a7409f 100644
--- a/compiler/ml/typedtree.mli
+++ b/compiler/ml/typedtree.mli
@@ -117,7 +117,6 @@ and exp_extra =
       (** let open[!] M in    [Texp_open (!, P, M, env)]
                                 where [env] is the environment after opening [P]
          *)
-  | Texp_poly of core_type option  (** Used for method bodies. *)
   | Texp_newtype of string  (** fun (type t) ->  *)
 
 and expression_desc =
@@ -217,10 +216,7 @@ and expression_desc =
       * direction_flag
       * expression
   | Texp_send of expression * meth * expression option
-  | Texp_new of unit
   | Texp_instvar of unit
-  | Texp_setinstvar of unit
-  | Texp_override of unit
   | Texp_letmodule of Ident.t * string loc * module_expr * expression
   | Texp_letexception of extension_constructor * expression
   | Texp_assert of expression
diff --git a/compiler/ml/typedtreeIter.ml b/compiler/ml/typedtreeIter.ml
index 74213d65a9..414975715c 100644
--- a/compiler/ml/typedtreeIter.ml
+++ b/compiler/ml/typedtreeIter.ml
@@ -221,7 +221,6 @@ end = struct
           | Texp_constraint ct -> iter_core_type ct
           | Texp_coerce ((), cty2) -> iter_core_type cty2
           | Texp_open _ -> ()
-          | Texp_poly cto -> option iter_core_type cto
           | Texp_newtype _ -> ()))
       exp.exp_extra;
     (match exp.exp_desc with
@@ -287,7 +286,7 @@ end = struct
       match expo with
       | None -> ()
       | Some exp -> iter_expression exp)
-    | Texp_new _ | Texp_instvar _ | Texp_setinstvar _ | Texp_override _ -> ()
+    | Texp_instvar _ -> ()
     | Texp_letmodule (_id, _, mexpr, exp) ->
       iter_module_expr mexpr;
       iter_expression exp

From 09d18bb39ccd6ff31c7970d70e2262102d233f84 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Fri, 10 Jan 2025 22:04:26 +0100
Subject: [PATCH 8/8] Remove expression_desc.Texp_instvar

---
 CHANGELOG.md                          | 2 +-
 analysis/reanalyze/src/Arnold.ml      | 3 ---
 analysis/reanalyze/src/SideEffects.ml | 1 -
 compiler/ml/printtyped.ml             | 1 -
 compiler/ml/rec_check.ml              | 7 +++----
 compiler/ml/tast_iterator.ml          | 1 -
 compiler/ml/tast_mapper.ml            | 1 -
 compiler/ml/translcore.ml             | 1 -
 compiler/ml/typedtree.ml              | 1 -
 compiler/ml/typedtree.mli             | 1 -
 compiler/ml/typedtreeIter.ml          | 1 -
 11 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b9256c6092..f8b2156feb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,7 +24,7 @@
 - AST cleanup: Prepare for ast async cleanup: Refactor code for "@res.async" payload handling and clean up handling of type and term parameters, so that now each `=>` in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
 - AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
 - AST cleanup: Remove `@res.async` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
-- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override`, `expression_desc.Pexp_poly`, `exp_extra.Texp_poly`, `expression_desc.Texp_new`, `expression_desc.Texp_setinstvar` & `expression_desc.Texp_override` from AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
+- AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override`, `expression_desc.Pexp_poly`, `exp_extra.Texp_poly`, `expression_desc.Texp_new`, `expression_desc.Texp_setinstvar`, `expression_desc.Texp_override` & `expression_desc.Texp_instvar` from AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 
 # 12.0.0-alpha.7
 
diff --git a/analysis/reanalyze/src/Arnold.ml b/analysis/reanalyze/src/Arnold.ml
index eee8753377..d6c49357fa 100644
--- a/analysis/reanalyze/src/Arnold.ml
+++ b/analysis/reanalyze/src/Arnold.ml
@@ -975,9 +975,6 @@ module Compile = struct
     | Texp_send _ ->
       notImplemented "Texp_send";
       assert false
-    | Texp_instvar _ ->
-      notImplemented "Texp_instvar";
-      assert false
     | Texp_letmodule _ ->
       notImplemented "Texp_letmodule";
       assert false
diff --git a/analysis/reanalyze/src/SideEffects.ml b/analysis/reanalyze/src/SideEffects.ml
index 46c4eab974..338149d659 100644
--- a/analysis/reanalyze/src/SideEffects.ml
+++ b/analysis/reanalyze/src/SideEffects.ml
@@ -61,7 +61,6 @@ let rec exprNoSideEffects (expr : Typedtree.expression) =
     e1 |> exprNoSideEffects && e2 |> exprNoSideEffects
     && e3 |> exprNoSideEffects
   | Texp_send _ -> false
-  | Texp_instvar _ -> true
   | Texp_letexception (_ec, e) -> e |> exprNoSideEffects
   | Texp_pack _ -> false
   | Texp_extension_constructor _ when true -> true
diff --git a/compiler/ml/printtyped.ml b/compiler/ml/printtyped.ml
index f356737c81..f480554744 100644
--- a/compiler/ml/printtyped.ml
+++ b/compiler/ml/printtyped.ml
@@ -275,7 +275,6 @@ and expression i ppf x =
   in
   match x.exp_desc with
   | Texp_ident (li, _, _) -> line i ppf "Texp_ident %a\n" fmt_path li
-  | Texp_instvar () -> assert false
   | Texp_constant c -> line i ppf "Texp_constant %a\n" fmt_constant c
   | Texp_let (rf, l, e) ->
     line i ppf "Texp_let %a\n" fmt_rec_flag rf;
diff --git a/compiler/ml/rec_check.ml b/compiler/ml/rec_check.ml
index b467f07ff3..292bdeb48d 100644
--- a/compiler/ml/rec_check.ml
+++ b/compiler/ml/rec_check.ml
@@ -195,9 +195,9 @@ let rec classify_expression : Typedtree.expression -> sd =
   | Texp_sequence (_, e)
   | Texp_letexception (_, e) ->
     classify_expression e
-  | Texp_ident _ | Texp_for _ | Texp_constant _ | Texp_instvar _ | Texp_tuple _
-  | Texp_array _ | Texp_construct _ | Texp_variant _ | Texp_record _
-  | Texp_setfield _ | Texp_while _ | Texp_pack _ | Texp_function _ | Texp_lazy _
+  | Texp_ident _ | Texp_for _ | Texp_constant _ | Texp_tuple _ | Texp_array _
+  | Texp_construct _ | Texp_variant _ | Texp_record _ | Texp_setfield _
+  | Texp_while _ | Texp_pack _ | Texp_function _ | Texp_lazy _
   | Texp_extension_constructor _ ->
     Static
   | Texp_apply ({exp_desc = Texp_ident (_, _, vd)}, _) when is_ref vd -> Static
@@ -232,7 +232,6 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
            for inclusion in another value *)
         (discard (expression env e3)))
   | Texp_constant _ -> Use.empty
-  | Texp_instvar _ -> Use.empty
   | Texp_apply ({exp_desc = Texp_ident (_, _, vd)}, [(_, Some arg)])
     when is_ref vd ->
     Use.guard (expression env arg)
diff --git a/compiler/ml/tast_iterator.ml b/compiler/ml/tast_iterator.ml
index 1b591b675d..2f50911a17 100644
--- a/compiler/ml/tast_iterator.ml
+++ b/compiler/ml/tast_iterator.ml
@@ -197,7 +197,6 @@ let expr sub {exp_extra; exp_desc; exp_env; _} =
   | Texp_send (exp, _, expo) ->
     sub.expr sub exp;
     Option.iter (sub.expr sub) expo
-  | Texp_instvar _ -> ()
   | Texp_letmodule (_, _, mexpr, exp) ->
     sub.module_expr sub mexpr;
     sub.expr sub exp
diff --git a/compiler/ml/tast_mapper.ml b/compiler/ml/tast_mapper.ml
index b6d17285e0..f4b8b26eca 100644
--- a/compiler/ml/tast_mapper.ml
+++ b/compiler/ml/tast_mapper.ml
@@ -243,7 +243,6 @@ let expr sub x =
         (id, p, sub.expr sub exp1, sub.expr sub exp2, dir, sub.expr sub exp3)
     | Texp_send (exp, meth, expo) ->
       Texp_send (sub.expr sub exp, meth, opt (sub.expr sub) expo)
-    | Texp_instvar _ as d -> d
     | Texp_letmodule (id, s, mexpr, exp) ->
       Texp_letmodule (id, s, sub.module_expr sub mexpr, sub.expr sub exp)
     | Texp_letexception (cd, exp) ->
diff --git a/compiler/ml/translcore.ml b/compiler/ml/translcore.ml
index c6fb2c398a..02e5ac411a 100644
--- a/compiler/ml/translcore.ml
+++ b/compiler/ml/translcore.ml
@@ -911,7 +911,6 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
   | Texp_send (expr, Tmeth_name nm, _) ->
     let obj = transl_exp expr in
     Lsend (nm, obj, e.exp_loc)
-  | Texp_instvar _ -> assert false
   | Texp_letmodule (id, _loc, modl, body) ->
     let defining_expr = !transl_module Tcoerce_none None modl in
     Llet (Strict, Pgenval, id, defining_expr, transl_exp body)
diff --git a/compiler/ml/typedtree.ml b/compiler/ml/typedtree.ml
index c2884b6243..f43e0e8da8 100644
--- a/compiler/ml/typedtree.ml
+++ b/compiler/ml/typedtree.ml
@@ -114,7 +114,6 @@ and expression_desc =
       * direction_flag
       * expression
   | Texp_send of expression * meth * expression option
-  | Texp_instvar of unit
   | Texp_letmodule of Ident.t * string loc * module_expr * expression
   | Texp_letexception of extension_constructor * expression
   | Texp_assert of expression
diff --git a/compiler/ml/typedtree.mli b/compiler/ml/typedtree.mli
index 6285a7409f..5e2f992860 100644
--- a/compiler/ml/typedtree.mli
+++ b/compiler/ml/typedtree.mli
@@ -216,7 +216,6 @@ and expression_desc =
       * direction_flag
       * expression
   | Texp_send of expression * meth * expression option
-  | Texp_instvar of unit
   | Texp_letmodule of Ident.t * string loc * module_expr * expression
   | Texp_letexception of extension_constructor * expression
   | Texp_assert of expression
diff --git a/compiler/ml/typedtreeIter.ml b/compiler/ml/typedtreeIter.ml
index 414975715c..876206c512 100644
--- a/compiler/ml/typedtreeIter.ml
+++ b/compiler/ml/typedtreeIter.ml
@@ -286,7 +286,6 @@ end = struct
       match expo with
       | None -> ()
       | Some exp -> iter_expression exp)
-    | Texp_instvar _ -> ()
     | Texp_letmodule (_id, _, mexpr, exp) ->
       iter_module_expr mexpr;
       iter_expression exp