Represent char range patterns with a typed-tree node

analysis/src/process_cmt.ml

@@ -535,7 +535,9 @@ let rec for_structure_item ~(env : Shared_types.Env.t) ~(exported : Exported.t)
         |> List.iter (fun {Typedtree.tdp_pattern} ->
             handle_pattern [] tdp_pattern)
       | Tpat_variant (_, Some p, _) -> handle_pattern [] p
-      | Tpat_variant (_, None, _) | Tpat_any | Tpat_constant _ -> ()
+      | Tpat_variant (_, None, _) | Tpat_any | Tpat_constant _ | Tpat_interval _
+        ->
+        ()
     in
     List.iter
       (fun {Typedtree.vb_pat; vb_attributes} ->

changes/char-range-patterns.polish.md

@@ -0,0 +1 @@
+- Char range patterns such as `'\u{0}' .. '\u{10FFFF}'` compile as fast as a single character, and missing-case warnings show ranges instead of listing every character.

compiler/common/pattern_printer.ml

@@ -66,6 +66,8 @@ let untype typed =
     | Tpat_or (pa, pb, _) -> mkpat (Ppat_or (loop pa, loop pb))
     | Tpat_any | Tpat_var _ -> mkpat Ppat_any
     | Tpat_constant c -> mkpat (Ppat_constant (Untypeast.constant c))
+    | Tpat_interval (c1, c2) ->
+      mkpat (Ppat_interval (Untypeast.constant c1, Untypeast.constant c2))
     | Tpat_alias (p, _, _) -> loop p
     | Tpat_tuple lst -> mkpat (Ppat_tuple (List.map loop lst))
     | Tpat_construct (cstr_lid, cstr, lst) ->
@@ -109,9 +111,9 @@ let untype typed =
         | Tpat_construct (_, cstr, [value]) when cstr.cstr_name = "Some" ->
           Some
             {pdp_key = tdp_key; pdp_pattern = loop value; pdp_optional = false}
-        | Tpat_var _ | Tpat_alias _ | Tpat_constant _ | Tpat_tuple _
-        | Tpat_construct _ | Tpat_variant _ | Tpat_record _ | Tpat_dict _
-        | Tpat_array _ | Tpat_or _ ->
+        | Tpat_var _ | Tpat_alias _ | Tpat_constant _ | Tpat_interval _
+        | Tpat_tuple _ | Tpat_construct _ | Tpat_variant _ | Tpat_record _
+        | Tpat_dict _ | Tpat_array _ | Tpat_or _ ->
           Some
             {
               pdp_key = tdp_key;

compiler/ext/config.ml

@@ -13,7 +13,7 @@ and ast0_impl_magic_number = "Caml1999M022"
 
 and ast0_intf_magic_number = "Caml1999N022"
 
-and cmt_magic_number = "Caml1999T045"
+and cmt_magic_number = "Caml1999T046"
 
 let get_load_path () = (Compiler_request_state.current ()).load_path
 let set_load_path path = (Compiler_request_state.current ()).load_path <- path

compiler/ml/dict_pattern.ml

@@ -9,7 +9,9 @@ open Typedtree
 let rec contains_dict p =
   match p.pat_desc with
   | Tpat_dict _ -> true
-  | Tpat_any | Tpat_var _ | Tpat_constant _ | Tpat_variant (_, None, _) -> false
+  | Tpat_any | Tpat_var _ | Tpat_constant _ | Tpat_interval _
+  | Tpat_variant (_, None, _) ->
+    false
   | Tpat_alias (p, _, _) | Tpat_variant (_, Some p, _) -> contains_dict p
   | Tpat_tuple ps | Tpat_construct (_, _, ps) | Tpat_array ps ->
     List.exists contains_dict ps