The first phase of the first-ever binary-format schema-major bump (v0 -> v1),
the machinery-first minimal major. Spec-only: ratifies the contract that
Phases B-F build against; no code changes.
core_spec.tex: defines the two referenced-but-undefined types that were the
P12-I7 / P12-K7 gaps -- CanvasLayoutDefaults (with core geometry primitives
CanvasSize/CanvasMargins in staff spaces via CanonicalF64, A4/8mm default,
since core has no geometry types and must not depend on layout-ir) and
PitchRange (advisory pitch compass used by Instrument.range and
IndeterminacyHints) -- and adds Region.permits_spanning_slurs (default false).
Records schema major 1 as the first data-model expansion major and tightens
the minor-version rule (a field add, even Option, is major; minor = append
discriminants to the companion's append-safe vocabularies only).
binary_format.tex -> 0.3.0: the full "Schema Major 1" section --
- Where the changed fields reach: Canvas.layout_defaults and
Instrument.range are snapshot-only (no CreateCanvas/CreateInstrument op),
but Region.permits_spanning_slurs also reaches the CANONICAL CreateRegion
operation payload (CreateRegion embeds the full Region). The canonical-base
MaterializedState embeds none of these and stays major 0, byte-identical.
- Cross-major reader rules: discard-and-regenerate non-canonical chunks;
parse-or-read-only for canonical ones, so a major-0 reader opens a bundle
carrying v1 CreateRegion ops read-only.
- Accept-set gate [min,max] (rejects majors outside the set); per-payload-
type major assignment; the changed v1 value layouts (the wire form ratifies
the reduced reference-code layout, not the fuller data model); the total
default-filling v0->v1 migration table (including the CreateRegion payload).
- Length-prefix unification NARROWED to the resolved-layout (its own
non-canonical LayoutCache): the barrier/extension blobs stay regime (b) u64
because they ride the canonical manifest, which stays major 0.
Two review passes hardened this checkpoint. The first caught that Region is a
canonical operation payload (not cache-only, as the architecture analysis had
assumed) -- user chose to embrace it and build the canonical op-payload
migration. It also surfaced the barrier-blobs-in-manifest constraint that
narrows the unification. The second refined the minor-version delegation, the
accept-set outside-[min,max] semantics, and stale "no defined type" text in
the reference-suite / quality-metric companions and the engrave DECISIONS.
P12-I7 moved to IN PROGRESS (spec type defined here; code graph home lands in
Phase C). Both companions and the engrave DECISIONS reworded accordingly. All
four affected PDFs rebuild clean (0 undefined references).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd
The chosen Phase-3 attack, run as two parallel waves. 829 workspace
tests pass; clippy -D warnings, fmt, and rustdoc clean; all three
spec documents build with zero undefined references.
Casting-off (epiphany-engrave/src/casting.rs, wired into the
Engraver):
- Greedy first-fit system breaking per region at measure-start
barline columns; a measure that would overflow the content width
starts a new system. Hard SystemBreakAt/PageBreakAt always
honoured; soft breaks honoured unless pathological (skipped with
the spec's warning + IrOverride-recorded decision).
- Vertical stacking from real content extents with the inter-system
gap read from the vertical band model; page overflow starts the
next page. World frame: pages stacked vertically, coordinates
baked into glyphs/strokes, so the SVG renderer, hit-testing, and
the GUI viewport are unchanged.
- Real ResolvedPage/ResolvedSystem trees (1-based page numbers,
content bounding boxes, staves from staff-line segments, measures
from barline columns); every chosen break appends an
EngravingDecision with MUSCLOID EngravedBreak provenance,
UserOverride-attributed via the new ConstrainedLayoutIR
break_origins sidecar; staff lines split per system with
synthesized continuation provenance.
- Break-constraint evaluation flips: satisfied iff the layout breaks
at the slot. The two single-system tests invert deliberately
(a hard break is now honoured; a user break is honoured and
attributed instead of warned). Geometric constraints evaluate in
the pre-casting spaced frame (documented).
- Page geometry is engraver-side PageGeometry (A4 portrait at an
8 mm staff: page 105 x 148.5 staff spaces, margins 7.5, content
90 x 133.5; arithmetic documented) — Canvas.layout_defaults has no
graph home and is a schema-major addition (P12-I7).
ENGRAVER_VERSION = 2. Goldens regenerated: ten_measure_single_staff
engraves as 2 systems (viewBox 84x20.6, was 103x11);
valid_score_rich as 3 systems; stub goldens byte-identical.
K1 schema-fill (Operation Catalog 0.4.0 -> 0.5.0, ratified first;
wire discriminants strictly appended):
- CreateStaff (24 / tag InsertStaff 24): set-union mint of a global
Staff; CreateStaffInstance now preconditions that its referenced
staff is live.
- SetTimeSignature (25): value-carrying meter-change LWW keyed by
(region, resolved position); the carried TimeSignature mints
set-union; StructuralFieldCollision on meter_sequence.
- SetTempoSegment (26): LWW keyed by (scope, resolved start) over
the score or region tempo map; a write that would malform the map
refuses with the appended PreconditionFailureReason 11
(TempoMapMalformed).
- SetStaffLayout (27): LWW advisory over the staff instance's three
inline layout fields.
- Create score/canvas remain deliberately unavailable slots: the
root and canvas are inline singletons with no addressable object
model (P12-K8), not force-designed.
Value-restoring undo (P11-C8 narrowed; catalog §UndoTransaction
rewritten and per-primitive undo notes updated):
- Canonical-order write chains (base-seeded) across all eleven LWW
families. StrictInverse restores each written key to its
chain-predecessor value iff the transaction's write is still the
key's last writer, else refuses the whole undo with a
TransactionConflict naming the superseder; BestEffort restores the
still-last keys. Clean compensations are Applied; only minted-
object tombstone repairs ride AppliedWithRepair (no new repair
vocabulary). Mixed mint+overwrite transactions compose; strand
guards refuse tombstoning mints still referenced by live
non-members.
- Undo-of-undo pinned and tested: restorations are chain writes, so
undoing the undo's transaction restores the undone value, and a
second undo of the same transaction conflicts (absence-restores
repeat idempotently — documented asymmetry, P12-K11).
- Permutation invariance pinned across five delivery orders; the
convergence generators gain the new ops and a tx-then-undo flow.
- Still deferred in normative text: delete resurrection (needs a
system-derived tag outside the ratified closed set), Transpose
inversion (P12-K2), Cascade dependent closure.
Trackers: Binary Format companion 0.1.0 -> 0.2.0 (appended wire/tag
tables, PreconditionFailureReason 11, payload layouts, history row —
a schema-minor evolution under its own rules); nine new Pass-12 rows
(C5, K8-K11, I7-I10); core-spec OperationKind listing gains the four
kinds; revision-history rows in core spec and companion.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd
The audit's fourth push: the biggest outstanding Phase-2 item plus the
performance gate. 793 workspace tests pass; clippy -D warnings, fmt,
and rustdoc (deny-warnings) clean; all three spec documents build with
zero undefined references.
Binary Format companion (spec/binary_format.tex, v0.1.0 — Agent J's
deliverable, 43 pages):
- Twelve chapters transcribed from the golden-locked implementation:
encoding conventions (the three prefix/endianness regimes, a
normative no-varint rule, reject-never-normalize decode discipline),
identifiers imported from the core spec's Canonical Byte-Layout
Reference, primitive value encodings, the whole-Score positional
codec ratified as the schema-major-0 wire form, operation wire
forms (envelope field order with the normative id-leads property,
the OperationPayload 0..=3 and OperationKind 0..=23 tables,
effects/conflict/anomaly/MaterializedState vocabulary), the bundle
physical layout (64-byte header, 256-byte superblock, chunk
preimages and framing, ChunkRef, manifest body order), the
operation-index payload, and the extension-blob/edit-barrier byte
forms.
- Ratifies P12-D1 (req:binfmt:opindex), P12-E1 (req:binfmt:ext-blobs),
P12-E2 (req:binfmt:condition-depth, MAX_CONDITION_DEPTH = 64
normative), and P12-E3 (req:binfmt:object-kind-open) — batch rows
struck through; discharges the provisional-codec notes in core
(P11-4), ops, and bundle (P11-D2/D4/D5) DECISIONS with ratification
cross-references.
- Pins the frozen-layout schema-evolution keystone: within schema
major 0 every positional struct layout is frozen; a field-set change
is a schema-major change with migration — formally grounding the
data-model-expansion staging decision. Open questions kept honest
in-document: SnapshotId derivation, index-refresh threshold, u64/u32
prefix unification at the next major.
- Not yet delivered from J's charter: the cross-implementation decoder
test and the wire-format fuzzer (follow-up harnesses).
F1 benches (crates/epiphany-testkit/benches/, per the F0 decision):
- criterion 0.5.1 (workspace dev-dependency; MSRV 1.77 respected with
documented transitive pins: clap 4.5.53, half 2.4.1).
- reduction bench at 1K/10K/50K envelopes with the Chapter-10 budget
(>10,000 envelopes/second cold) written in the bench as a Pass/Xfail
gate; bundle benches for the typical-edit commit (<=50 ms; measured
~14.7 ms on real disk after catching that tmpfs neuters fsync) and
the open/bootstrap read (<=200 ms; measured ~60 us).
- CI: quick budget gates in the conformance job, full gates nightly.
Subquadratic canonical_reduction_order (the F-surfaces/K-fixes
handshake, closing K's 10K-envelope acceptance gate):
- The bench documented the failure (50K at ~1.7K env/s, a 29 s cold
reduction; two O(n^2) loops); the fix replaces pair enumeration with
threshold/frontier readiness per replica plus explicit-dot dependent
lists and a stamp-tuple binary heap — O((n + sum(context)) log n),
never materializing covered pairs.
- Byte-identical order: same edge relation, same ready predicate, same
total order; the old implementation is retained as a test-only
oracle with element-for-element order-equality property tests over
fuzz sets, adversarial sets, and directed shapes (2,000-envelope
full-coverage chains, dot cycles, duplicate-id stamp ties),
mutation-tested for sensitivity.
- Measured: 1K 155K->674K env/s, 10K 12.5K->257K, 50K 1.7K->87K; all
three scale points now pass and the 50K row is promoted from Xfail.
Also: fixed nine rustdoc private/unresolved intra-doc links that had
accumulated across the pushes (the CI deny-doc-warnings job would have
failed on them).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd
Levi Neuwirth