rite(ef): RG 91 Table of Precedence

Precedence_ef.band transcribes RG 91's 28-entry Table of Precedence
(rules-register.md §4) for the EF rite: given a day's context and a
candidate celebration, returns the table's own entry number, 1-28
(I class 1-13, II class 14-21, III class 22-26, IV class 27-28); lower
wins. Every branch carries its entry number and register citation in a
comment, checked in the table's own numeric order.

Two entries are transcribed as the register states them even though
they invert the pattern the rest of the table follows: at III class,
23 (particular calendars) outranks 24 (universal), the reverse of how
11/12 and 14/16/19/20 rank a universal feast ahead of a proper one at
I and II class.

Sanctoral-origin, layer-decided entries (11-13, 14/16/19/20, 23/24)
follow the brief's structural insight: a celebration whose layer is
not the universal base is an overlay -- proper, or indult if its
layer id also carries the indult prefix. Neither the universal-layer
id nor the indult prefix is an RG citation; both are colitur's own
data-modelling convention, exposed from the module so whichever task
loads the real EF sanctoral overlays can align to them.

Vigils (21, 26) are read off the temporal cycle's own -vigil slug
suffix rather than gated on origin, since a II/III-class vigil can be
either temporal-origin (Ascension, already produced by temporal_ef) or
sanctoral-origin (a saint's vigil, no task has loaded yet); Ember days
(part of entry 18) are read off temporal_ef's own ember slug prefixes
rather than re-derived, since the September anchor is independently
flagged there as one of the more contested dates in the calendar.

A candidate shape the table has no row for (e.g. a Class1 vigil that
is not Nativity or Pentecost, or a Class4 candidate marked as a vigil
-- RG 91 has no IV-class vigil either) returns a dedicated unclassified
sentinel (max_int) rather than being folded into a same-rank entry it
does not belong to.

test_precedence_ef.ml is table-driven: one Alcotest.test_case per RG
91 entry (55 rows total, several entries covered by more than one
named day so a single missed offset cannot hide behind a passing
sibling), each date computed from Computus.gregorian_easter rather
than hand-typed, so an arithmetic slip cannot pass by accident.

1 files changed, 35 insertions, 0 deletions

diff --git a/lib/rites/rite_ef/precedence_ef.mli b/lib/rites/rite_ef/precedence_ef.mli
new file mode 100644
index 0000000..e8d4a11
--- /dev/null
+++ b/lib/rites/rite_ef/precedence_ef.mli
@@ -0,0 +1,35 @@
+(** RG 91's Table of Precedence for the EF (1962) rite: ranks any candidate
+    for a given day by its RG 91 entry number. See
+    docs/research/rules-register.md §4, whose 28-entry transcription this
+    module follows line by line. *)
+
+open Colitur_kernel
+
+(** The universal (base) sanctoral layer's {!Celebration.t}.layer id. A
+    Sanctoral-origin candidate whose layer is anything else is an overlay:
+    "proper" (RG 91 entries 12, 19, 23) unless its layer id also carries
+    {!indult_prefix} ("indult", entries 13, 20). This id and the prefix are
+    colitur's own data-modelling convention, not an RG citation -- RG 91
+    prescribes the ranking, not a machine encoding for it. Whichever task
+    loads the real EF sanctoral base layer and its overlays must either
+    reuse these two constants or this classifier will misfile them. *)
+val universal_layer : string
+
+(** See {!universal_layer}. *)
+val indult_prefix : string
+
+(** Returned for a candidate shape RG 91's 28-entry table has no row for --
+    e.g. a [Class1] vigil that is not the Nativity or Pentecost (entries 5,
+    9 are the only I-class vigils the table names), or a [Class4] candidate
+    also marked as a vigil. Deliberately outside 1..28 and larger than any
+    real entry, so an unclassified candidate can never win an occurrence
+    contest by accident; a caller that sees it back knows the shape needs a
+    new rule, not a silently wrong one. *)
+val unclassified : int
+
+(** [band ctx c]: RG 91's Table of Precedence. Returns the table's own entry
+    number -- I class 1-13, II class 14-21, III class 22-26, IV class 27-28;
+    lower wins (see {!Precedence.rules.band}). Total over every candidate
+    {!Precedence.resolve} or {!Calendar} can construct, including shapes the
+    1962 table itself does not describe (see {!unclassified}). *)
+val band : Vocab_ef.season Precedence.context -> Vocab_ef.rank Precedence.candidate -> int