(** A language table: strings to strings, nothing more.

    Knows nothing about calendars, dates or rites, and never touches the
    filesystem -- callers hand it text. That is what lets every command use it
    without the kernel learning about presentation.

    Every lookup is TOTAL. A key with no entry returns THE KEY ITSELF, never the
    empty string: a partial translation must be usable from its first line, and
    an untranslated day must still print something a reader can act on. This is
    also why the pre-naming output (bare slugs) is exactly what an empty table
    produces -- the degraded case is the old behaviour, not a blank page. *)

type t

(** Parse INI text. Never raises. [Error] on a malformed file or a missing
    [\[meta\] lang].

    Two duplicate policies, both LAST-WINS:
    - A section name repeated in the file (e.g. two [\[celebration\]]
      blocks) has ALL of its blocks merged, not only the first -- a
      595-entry hand-edited language file WILL grow duplicate section
      headers as contributors append entries over time, and dropping a
      later block would silently lose real translations.
    - Where the same key appears more than once -- within one block or
      across two of them -- the value from further down the file wins.

    Both read the same order a reader would: later in the file overrides
    earlier. This is the OPPOSITE direction from
    {!Colitur_kernel.Overlay_ini.get} ([List.assoc_opt], first match) over
    the very same [section.fields] shape -- the two modules resolve a
    duplicate key in opposite directions, so do not assume one's behaviour
    from the other's. *)
val of_string : string -> (t, string) result

val code : t -> string
val fallback_code : t -> string option

(** [with_fallback t base] resolves through [t] first, then [base], then the key. *)
val with_fallback : t -> t -> t

(** The identity table: every lookup returns its key. This is what [--raw] uses,
    so raw output is one table passed around rather than a special case threaded
    through every call site. *)
val raw : t

val celebration : t -> string -> string
val season : t -> string -> string
val rank : t -> string -> string
val colour : t -> string -> string
val term : t -> string -> string

(** [weekday t n], 0 = Sunday. Out-of-range [n] returns [string_of_int n]. *)
val weekday : t -> int -> string

(** [month t n], 1 = January. Out-of-range [n] returns [string_of_int n]. *)
val month : t -> int -> string

(** Every (section-qualified key, value) pair, sorted. Used by [lang --dump] and
    [lang --check]. Keys are qualified as e.g. ["celebration.ef-epiphany"]. *)
val keys : t -> (string * string) list