kernel: Names, Citation and Date_spec

Names is an open language-keyed assoc kept in canonical order so equal name
sets serialise identically. Citation carries references only, never text.
Date_spec ships the one form the EF sanctoral needs; 29 February is
constructible and resolves to None in common years.

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/kernel/names.ml b/lib/kernel/names.ml
new file mode 100644
index 0000000..5f433ce
--- /dev/null
+++ b/lib/kernel/names.ml
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+(* Celebration names by language. An open assoc list rather than a fixed record,
+   so an overlay can add a language purely as data (spec §2.1). Kept sorted by
+   language code so sexp output is byte-stable. *)
+type t = (Lang.t * string) list
+
+let empty = []
+let canonical t = List.sort (fun (a, _) (b, _) -> Lang.compare a b) t
+let remove t lang = List.filter (fun (l, _) -> not (Lang.equal l lang)) t
+let set t lang name = canonical ((lang, name) :: remove t lang)
+let of_list l = List.fold_left (fun acc (lang, name) -> set acc lang name) empty l
+let find t lang = List.find_map (fun (l, n) -> if Lang.equal l lang then Some n else None) t
+let rec find_first t = function
+  | [] -> None
+  | lang :: rest -> ( match find t lang with Some n -> Some n | None -> find_first t rest)
+let to_list t = t
+
+let sexp_of_t t =
+  Sexplib0.Sexp_conv.sexp_of_list (fun (lang, name) ->
+    Sexplib0.Sexp.List [ Lang.sexp_of_t lang; Sexplib0.Sexp_conv.sexp_of_string name ])
+    t
+
+let t_of_sexp sexp =
+  let list = Sexplib0.Sexp_conv.list_of_sexp (fun sexp ->
+    match sexp with
+    | Sexplib0.Sexp.List [ lang_sexp; name_sexp ] ->
+        let lang = Lang.t_of_sexp lang_sexp in
+        let name = Sexplib0.Sexp_conv.string_of_sexp name_sexp in
+        (lang, name)
+    | _ -> Sexplib0.Sexp_conv.of_sexp_error "Names.t_of_sexp: expected [lang_sexp name_sexp]" sexp)
+    sexp in
+  canonical list