From e444ae5b03a9113fc6b2fc3fa3e2fd6b71bf8d4b Mon Sep 17 00:00:00 2001
From: Lukasz Kasprzak <lukas@labunix.xyz>
Date: Tue, 11 Aug 2026 11:21:50 +0200
Subject: kernel: Colour and Subject shared vocabulary

The six liturgical colours and the Lord/BVM/saint/temporal distinction are
common to both Roman forms, so they are shared closed variants rather than
rite-parametric. Subject is so named because class is an OCaml keyword.
---
 lib/kernel/colour.ml   | 14 ++++++++++++++
 lib/kernel/colour.mli  |  6 ++++++
 lib/kernel/subject.ml  | 13 +++++++++++++
 lib/kernel/subject.mli |  6 ++++++
 4 files changed, 39 insertions(+)
 create mode 100644 lib/kernel/colour.ml
 create mode 100644 lib/kernel/colour.mli
 create mode 100644 lib/kernel/subject.ml
 create mode 100644 lib/kernel/subject.mli

(limited to 'lib')

diff --git a/lib/kernel/colour.ml b/lib/kernel/colour.ml
new file mode 100644
index 0000000..c7f81c2
--- /dev/null
+++ b/lib/kernel/colour.ml
@@ -0,0 +1,14 @@
+(* Liturgical colours. Shared across Roman rites (spec §2.1): not
+   rite-parametric, because EF and OF use the same six. *)
+type t = White | Red | Green | Violet | Rose | Black [@@deriving sexp]
+
+let all = [ White; Red; Green; Violet; Rose; Black ]
+
+let to_string = function
+  | White -> "white" | Red -> "red" | Green -> "green"
+  | Violet -> "violet" | Rose -> "rose" | Black -> "black"
+
+let of_string = function
+  | "white" -> Some White | "red" -> Some Red | "green" -> Some Green
+  | "violet" -> Some Violet | "rose" -> Some Rose | "black" -> Some Black
+  | _ -> None
diff --git a/lib/kernel/colour.mli b/lib/kernel/colour.mli
new file mode 100644
index 0000000..f419ecb
--- /dev/null
+++ b/lib/kernel/colour.mli
@@ -0,0 +1,6 @@
+(** Liturgical colours, shared by all Roman rites. *)
+type t = White | Red | Green | Violet | Rose | Black [@@deriving sexp]
+
+val all : t list
+val to_string : t -> string
+val of_string : string -> t option
diff --git a/lib/kernel/subject.ml b/lib/kernel/subject.ml
new file mode 100644
index 0000000..000aaff
--- /dev/null
+++ b/lib/kernel/subject.ml
@@ -0,0 +1,13 @@
+(* Whom the celebration is of. Named [Subject] rather than [Class] because
+   [class] is an OCaml keyword. Used by precedence in Plan 3 (RG 91). *)
+type t = Temporal | Saint | Bvm | Lord [@@deriving sexp]
+
+let all = [ Temporal; Saint; Bvm; Lord ]
+
+let to_string = function
+  | Temporal -> "temporal" | Saint -> "saint" | Bvm -> "bvm" | Lord -> "lord"
+
+let of_string = function
+  | "temporal" -> Some Temporal | "saint" -> Some Saint
+  | "bvm" -> Some Bvm | "lord" -> Some Lord
+  | _ -> None
diff --git a/lib/kernel/subject.mli b/lib/kernel/subject.mli
new file mode 100644
index 0000000..443364d
--- /dev/null
+++ b/lib/kernel/subject.mli
@@ -0,0 +1,6 @@
+(** Whom a celebration is of. [Temporal] is the temporal cycle's own office. *)
+type t = Temporal | Saint | Bvm | Lord [@@deriving sexp]
+
+val all : t list
+val to_string : t -> string
+val of_string : string -> t option
-- 
cgit v1.3