1 files changed, 109 insertions, 0 deletions
diff --git a/lib/naming/lang.ml b/lib/naming/lang.ml
new file mode 100644
index 0000000..147a49b
--- /dev/null
+++ b/lib/naming/lang.ml
@@ -0,0 +1,109 @@
+module OI = Colitur_kernel.Overlay_ini
+
+module SM = Map.Make (String)
+
+type table = string SM.t
+
+type t = {
+  code : string;
+  fallback_code : string option;
+  celebration : table;
+  weekday : table;
+  month : table;
+  season : table;
+  rank : table;
+  colour : table;
+  term : table;
+  chain : t option;  (** consulted when this table misses *)
+}
+
+let empty_table = SM.empty
+
+let rec lookup t sel key =
+  match SM.find_opt key (sel t) with
+  | Some v -> Some v
+  | None -> ( match t.chain with Some b -> lookup b sel key | None -> None)
+
+(* A miss returns the KEY, never "". See lang.mli for why. *)
+let get t sel key = match lookup t sel key with Some v -> v | None -> key
+
+let celebration t k = get t (fun x -> x.celebration) k
+let season t k = get t (fun x -> x.season) k
+let rank t k = get t (fun x -> x.rank) k
+let colour t k = get t (fun x -> x.colour) k
+let term t k = get t (fun x -> x.term) k
+
+let weekday_key = [| "sunday"; "monday"; "tuesday"; "wednesday"; "thursday"; "friday"; "saturday" |]
+
+(* weekday/month deliberately do NOT go through [get]: their SM key is a
+   presentation detail (an English day-name word for weekday, a numeral for
+   month), not the value a miss should degrade to. [get]'s generic
+   echo-the-search-key fallback would leak that word ("sunday") out of an
+   empty/raw table instead of the documented numeral -- [month] never showed
+   the bug because its key already equals [string_of_int n], but [weekday]
+   did, and it broke [Lang.raw]'s own identity contract (0 = Sunday, not
+   "sunday"). Falling back to [string_of_int n] directly keeps [month]
+   byte-identical and fixes [weekday]. *)
+let weekday t n =
+  if n < 0 || n > 6 then string_of_int n
+  else match lookup t (fun x -> x.weekday) weekday_key.(n) with Some v -> v | None -> string_of_int n
+
+let month t n =
+  if n < 1 || n > 12 then string_of_int n
+  else match lookup t (fun x -> x.month) (string_of_int n) with Some v -> v | None -> string_of_int n
+
+let code t = t.code
+let fallback_code t = t.fallback_code
+
+let raw =
+  { code = "raw"; fallback_code = None; celebration = empty_table; weekday = empty_table;
+    month = empty_table; season = empty_table; rank = empty_table; colour = empty_table;
+    term = empty_table; chain = None }
+
+let with_fallback t base = { t with chain = Some base }
+
+let of_string text =
+  match OI.parse_sections text with
+  | Error e -> Error e
+  | Ok sections ->
+      (* Merge EVERY section sharing [name], not just the first: a hand-edited
+         595-entry language file (Tasks 3/4's la.ini) WILL grow duplicate
+         [section] headers as contributors append entries over time -- a
+         second [celebration] block is the natural way to paste in a new
+         batch of names. Taking only the first match (the original
+         [List.find_opt] here) silently dropped every later block; the
+         failure then surfaces as a coverage report claiming those slugs have
+         "no Latin name", with nothing pointing back at the parser. Folding
+         over all matching sections, in file order, keeps this consistent
+         with the existing within-section behaviour below (last [SM.add]
+         wins): a key repeated across two blocks resolves to the later one,
+         exactly what a reader expects when appending to an INI file. *)
+      let find name =
+        List.fold_left
+          (fun m (s : OI.section) ->
+            if s.OI.name = name then List.fold_left (fun m (k, v) -> SM.add k v m) m s.OI.fields else m)
+          empty_table sections
+      in
+      let meta = find "meta" in
+      (match SM.find_opt "lang" meta with
+       | None -> Error "language file has no [meta] lang = <code>"
+       | Some code ->
+           Ok
+             { code;
+               fallback_code = SM.find_opt "fallback" meta;
+               celebration = find "celebration";
+               weekday = find "weekday";
+               month = find "month";
+               season = find "season";
+               rank = find "rank";
+               colour = find "colour";
+               term = find "term";
+               chain = None })
+
+let keys t =
+  let qualify prefix m = SM.bindings m |> List.map (fun (k, v) -> (prefix ^ "." ^ k, v)) in
+  List.concat
+    [ qualify "celebration" t.celebration; qualify "weekday" t.weekday;
+      qualify "month" t.month; qualify "season" t.season; qualify "rank" t.rank;
+      qualify "colour" t.colour; qualify "term" t.term ]
+  |> List.sort compare