Schema major 2 Phase A: ratify the v2 data-model wire form (spec only)
Push 2's spec-first phase. core_spec (schema-major-2 revision): defines
the nineteen leaf types Ch5's ratified shapes referenced but never
pinned (SlurKind, CurveDirection, CurvatureOverride, the shared
SpanStyle record consolidating the identical SlurStyle/TieStyle/
SpannerStyle triplet, SubBeam, BeamGeometryOverride, SpannerKind's five
payload types + a leading Generic migration default, Volta,
MetadataValue, Timestamp, SoundConfiguration, TranspositionInterval
(structural, advisory until Ch4 per the P12-K2 discipline),
UnpitchedMember + member-resolution semantics (first-match, no-match
tolerated; StaffPosition vertical convention explicitly deferred),
SpaceUnit, LineStyle, StaffBracketKind); ratifies the visible-slice
clef/key content model into Ch5 (Clef/ClefShape/KeySignature/
ClefChange/KeySignatureChange) and retires the ClefId sketch;
strictly-authored metadata timestamps (req:graph:metadata-timestamps);
metadata `additional` = ordered list, duplicates permitted; Ch8 gains
the major-2 paragraph; Ch6 OperationKind listing gains its seven
missing variants (staleness fix).
binary_format 0.4.0 -> 0.5.0: new "Schema Major 2" section — per-
payload-type major assignment (snapshot-only Instrument/
RepeatStructure; SEVEN canonical embedding payloads incl. CreateRegion
transitively and SetStaffLayout's direct staff_lines_override field);
the MINIMAL-STAMPING rule (a block stamps the lowest major whose
layouts decode its bytes — deterministic, per-payload table given;
extends the major-1 no-restamp principle); append-after-prior-major
wire layouts with field-order divergences called out; new leaf layouts
with framing pinned (SubBeam EventIds = framed leaves; UnpitchedMember
fields = bare primitives; SpaceUnit = framed 12); total default-fill
v1->v2 migration table (complete StaffLineConfiguration defaults at
all four embed sites; RepeatKind default SimpleRepeat{count:2});
accept-set {0,1,2} with per-role staging note; CanonicalValue seam
list corrected 18 -> 22 (staleness fix).
Two review rounds (8 + 9 findings, all fixed pre-commit — the
stamping-rule determinism contradiction, the CreateRegion transitive
embedding, SubBeam leaf framing, and the SetStaffLayout direct-field
site being the load-bearing ones). Both PDFs build clean, zero
undefined references. No code changes; Phase B (snapshot side) next.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd