chore: use Fun.id instead literal lambdas

src/ir_def/rename.ml

@@ -26,7 +26,7 @@ let arg_bind rho a =
   ({a with it = i'}, Renaming.add a.it i' rho)
 
 let rec prim rho p =
-  Ir.map_prim (fun t -> t) (id rho) p (* rename BreakPrim id etc *)
+  Ir.map_prim Fun.id (id rho) p (* rename BreakPrim id etc *)
 
 and exp rho e  =  {e with it = exp' rho e.it}
 and exp' rho = function

src/languageServer/declaration_index.ml

@@ -109,7 +109,7 @@ let lookup_module (project_root : string) (path : string) (index : t) :
       let mic_id = Flags.M.find_opt alias index.ic_aliases in
       let _ =
         Debug.log "lookup_module.ic_alias.ic_id"
-          (string_of_option (fun x -> x) mic_id)
+          (string_of_option Fun.id mic_id)
       in
       let* id = mic_id in
       let lookup_path = ic_id_to_lookup index.actor_idl_path project_root id in
@@ -366,7 +366,7 @@ let make_index_inner project_root vfs entry_points : t Diag.result =
         index_from_scope project_root (empty project_root) libs scope
   in
   let actor_paths = scan_actors () in
-  let _ = Debug.log "Actor paths" (string_of_list (fun x -> x) actor_paths) in
+  let _ = Debug.log "Actor paths" (string_of_list Fun.id actor_paths) in
   let actor_env =
     List.fold_left
       (fun acc f ->

src/lowering/desugar.ml

@@ -580,7 +580,7 @@ and build_actor at ts self_id es obj_typ =
                    note = f.T.typ }
                ) fields vs)
             ty)) in
-  let footprint_d, footprint_f = export_footprint self_id (with_stable_vars (fun e -> e)) in
+  let footprint_d, footprint_f = export_footprint self_id (with_stable_vars Fun.id) in
   let runtime_info_d, runtime_info_f = export_runtime_information self_id in
   I.(ActorE (footprint_d @ runtime_info_d @ ds', footprint_f @ runtime_info_f @ fs,
      { meta;
@@ -845,7 +845,7 @@ and dec' at n = function
     } in
     I.LetD (varPat, fn)
 
-and cases cs = List.map (case (fun x -> x)) cs
+and cases cs = List.map (case Fun.id) cs
 
 and case f c = phrase (case' f) c
 
@@ -932,11 +932,11 @@ and to_args typ po p : Ir.arg list * (Ir.exp -> Ir.exp) * T.control * T.typ list
     | S.AnnotP _ | S.ParP _ -> assert false
     | S.VarP i when not must_wrap ->
       { i with note = p.note },
-      (fun e -> e)
+      Fun.id
     | S.WildP ->
       let v = fresh_var "param" p.note in
       arg_of_var v,
-      (fun e -> e)
+      Fun.id
     |  _ ->
       let v = fresh_var "param" p.note in
       arg_of_var v,
@@ -949,18 +949,18 @@ and to_args typ po p : Ir.arg list * (Ir.exp -> Ir.exp) * T.control * T.typ list
     | _, S.WildP ->
       let vs = fresh_vars "ignored" tys in
       List.map arg_of_var vs,
-      (fun e -> e)
+      Fun.id
     | 1, _ ->
       let a, wrap = to_arg p in
       [a], wrap
     | 0, S.TupP [] ->
-      [] , (fun e -> e)
+      [], Fun.id
     | _, S.TupP ps ->
       assert (List.length ps = n_args);
       List.fold_right (fun p (args, wrap) ->
         let (a, wrap1) = to_arg p in
         (a::args, fun e -> wrap1 (wrap e))
-      ) ps ([], fun e -> e)
+      ) ps ([], Fun.id)
     | _, _ ->
       let vs = fresh_vars "param" tys in
       List.map arg_of_var vs,

src/mo_frontend/typing.ml

@@ -311,7 +311,7 @@ let check_ids env kind member ids = Lib.List.iter_pairs
 
 let infer_mut mut : T.typ -> T.typ =
   match mut.it with
-  | Const -> fun t -> t
+  | Const -> Fun.id
   | Var -> fun t -> T.Mut t
 
 

src/mo_interpreter/interpret.ml

@@ -1075,7 +1075,7 @@ let import_lib env lib =
   let { body = cub; _ } = lib.it in
   match cub.it with
   | Syntax.ModuleU _ ->
-    fun v -> v
+    Fun.id
   | Syntax.ActorClassU (_sp, id, _tbs, _p, _typ, _self_id, _dec_fields) ->
     fun v -> V.Obj (V.Env.from_list
       [ (id.it, v);

src/viper/prep.ml

@@ -38,10 +38,10 @@ let mono_calls_visitor (stk : mono_goal Stack.t) : visitor =
         {it = CallE({it = VarE (s @~ v_at); at=v_at; note=v_note},
                     {it = None; at=inst.at; note = []}, e); at; note}
     | e -> e);
-    visit_typ = (fun t -> t);
-    visit_pat = (fun p -> p);
-    visit_dec = (fun d -> d);
-    visit_inst = (fun i -> i);
+    visit_typ = Fun.id;
+    visit_pat = Fun.id;
+    visit_dec = Fun.id;
+    visit_inst = Fun.id;
   }
 
 let mono_calls_dec_field (df : dec_field) : (mono_goal list * dec_field) =

src/wasm-exts/customModuleEncode.ml

@@ -883,7 +883,7 @@ let encode (em : extended_module) =
       patch s (p + 1) (lsb (n lsr 8));
       patch s (p + 2) (lsb (n lsr 16));
       patch s (p + 3) (lsb (n lsr 24))
-    let dw_patches = ref (fun i -> i)
+    let dw_patches = ref Fun.id
 
     let debug_abbrev_section () =
       let tag (t, ch, kvs) =