abstract row_field

Changes

@@ -213,6 +213,12 @@ Working version
   (Jacques Garrigue and Takafumi Saikawa,
    review by Thomas Refis and Florian Angeletti)
 
+* #10627: Make row_field abstract
+  Completes #10474 by making row_field abstract too.
+  An immutable view row_field_view is provided, and one converts between it
+  and row_field via inj_row_field and row_field_repr.
+  (Jacques Garrigue and Takafumi Saikawa, review by Florian Angeletti)
+
 - #10433: Remove the distinction between 32-bit aligned and 64-bit aligned
   64-bit floats in Cmm.memory_chunk.
   (Greta Yorsh, review by Xavier Leroy)
@@ -755,6 +761,13 @@ OCaml 4.13.0 (24 September 2021)
 - #10327: Add a subdirectories variable and a copy action to ocamltest
   (Sébastien Hinderer, review by David Allsopp)
 
+* #10337: Normalize type_expr nodes on access
+  One should now use accessors such as get_desc and get_level to access fields
+  of type_expr, rather than calling manually Btype.repr (which is now hidden
+  in Types.Transient_expr).
+  (Jacques Garrigue and Takafumi Saikawa,
+   review by Florian Angeletti and Gabriel Radanne)
+
 - #10358: Use a hash table for the load path.
   (Leo White, review by Gabriel Scherer)
 

lambda/matching.ml

@@ -1807,7 +1807,7 @@ let divide_variant ~scopes row ctx { cases = cl; args; default = def } =
         in
         let head = Simple.head p in
         let variants = divide rem in
-        if row_field lab row = Rabsent then
+        if row_field_repr (get_row_field lab row) = Rabsent then
           variants
         else
           let tag = Btype.hash_variant lab in
@@ -2908,7 +2908,7 @@ let combine_variant loc row arg partial ctx def (tag_lambda_list, total1, _pats)
       (fun (_, f) ->
         match row_field_repr f with
         | Rabsent
-        | Reither (true, _ :: _, _, _) ->
+        | Reither (true, _ :: _, _) ->
             ()
         | _ -> incr num_constr)
       (row_fields row)

toplevel/genprintval.ml

@@ -452,7 +452,7 @@ module Make(O : OBJ)(EVP : EVALPATH with type valu = O.t) = struct
                   | (l, f) :: fields ->
                       if Btype.hash_variant l = tag then
                         match row_field_repr f with
-                        | Rpresent(Some ty) | Reither(_,[ty],_,_) ->
+                        | Rpresent(Some ty) | Reither(_,[ty],_) ->
                             let args =
                               nest tree_of_val (depth - 1) (O.field obj 1) ty
                             in

typing/btype.ml

@@ -240,7 +240,7 @@ let fold_row f init row =
       (fun init (_, fi) ->
          match row_field_repr fi with
          | Rpresent(Some ty) -> f init ty
-         | Reither(_, tl, _, _) -> List.fold_left f init tl
+         | Reither(_, tl, _) -> List.fold_left f init tl
          | _ -> init)
       init
       (row_fields row)
@@ -420,13 +420,13 @@ let copy_row f fixed row keep more =
   let fields = List.map
       (fun (l, fi) -> l,
         match row_field_repr fi with
-        | Rpresent(Some ty) -> Rpresent(Some(f ty))
-        | Reither(c, tl, m, e) ->
-            let e = if keep then e else ref None in
+        | Rpresent oty -> rf_present (Option.map f oty)
+        | Reither(c, tl, m) ->
+            let use_ext_of = if keep then Some fi else None in
             let m = if is_fixed row then fixed else m in
             let tl = List.map f tl in
-            Reither(c, tl, m, e)
-        | _ -> fi)
+            rf_either tl ?use_ext_of ~no_arg:c ~matched:m
+        | Rabsent -> rf_absent)
       orig_fields in
   let name =
     match orig_name with