Levi Neuwirth
6c5e69f19d
CreateStaffGroup (35), CreatePartDefinition (36), CreateAnalysisLayer (37), CreateView (38) -- all schema major 0, all schema-minor epoch 11, on CreateStaff's set-union mint pattern with byte-identical re-carry idempotence. Completes the four remaining root-level Score entity vectors. No epiphany-bundle change of any kind: schema_major() gained NO arm (all four fall through the catch-all _ => 0), so the op-block accept-set stays at 3 where G2b left it. The OperationKind golden lock stays at [(OperationKind, u8); 30] -- kinds 35-38 remain outside it by design, per P13-S15's own rung. Closes the satisfiability half of the from-empty defect: every G3 object kind previously became Live only through base ingest, so CreateStaff's group precondition was unsatisfiable from empty. It does NOT make a consistent group authorable -- §1.1 disposition B rules Staff.group the sole authority and StaffGroup.members a non-authoritative projection G3a stores without maintaining, with both stale forms permitted. That ruling now reaches all four normative sites: both field doc comments (neither field was documented before), core_spec.tex, and both the new CreateStaffGroup and the existing CreateStaff sections of operation_catalog.tex. Carried-value maps for all four families thread through seven sites each, including the base seed that fails silently -- a re-carry test reducing only from empty cannot see a missing seed, which is why t5b reduces onto a populated base. Verified independently, not relayed. Full gate re-run: 1429 tests / 0 failed, clippy 0, fmt clean, git diff --check clean. Two mutations the agent had not observed were run here and observed: reverting COMPANION_VERSION to 0.11.0 kills t11 (the agent had only reasoned this), and skipping the staff_group_values base seed kills t5b. Both reversed by editing back, with the baseline green. Two findings recorded rather than silently absorbed: - valuegen::analysis_layer's name format was accidentally exactly 16 bytes, the same width as AnalysisLayerId's encoding, which made a field-swap mutation on the two-field AnalysisLayer struct byte-invisible. Shortened and documented -- a fixture that makes a mutation undetectable is the same failure class as a guard that cannot fail. - binary_format.tex has NO Revision History row for G2b. G2b's own contract required one (touch row 27: "version, Revision History row"); it changed the payload-layout row, tag row, accept-set text and §2373 history but never bumped the version or added the row. The document went 0.12.0 (G2a) -> 0.13.0 (G-minor) -> 0.14.0 (G3a) with the accept-set raise unrecorded. G3a adds its own row without retroactively backfilling G2b's. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QjsEnYhm1gPpf6ii2iFxFV |
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| Cargo.toml | ||
| DECISIONS.md | ||
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README.md
epiphany-layout-ir
The Epiphany layout intermediate representation and constraint-solver
interface, implementing the normative requirements of Chapter 7 ("Layout
Intermediate Representation") and the interface of Chapter 9
("Constraint-Solver Interface") of the core specification
(spec/core_spec.pdf). This is Agent E's crate per spec/QUICKSTART.md — it
lands last among the implementation crates, building on Agent A's
epiphany-determinism and Agent B's epiphany-core (and on Agent C's
OperationKindTag for the edit-barrier types — see DECISIONS.md).
The IR sits between the score graph and two downstream consumers: the constraint solver, which resolves spacing and positioning, and the renderer, which produces final visual output. — Chapter 7
The score graph is the canonical truth about the music; this crate is a downstream projection of it. The transformation is a pipeline of four stages, each with its own type and a deterministic, provenance-preserving contract for the next.
What's here
| Area | Items | Spec |
|---|---|---|
| Stage 1 — logical | LogicalLayoutIR, LayoutRegion, composite LayoutObject, overrides/cross-region objects, to_logical |
Ch. 7 §"LogicalLayoutIR" |
| Stage 2 — constrained | ConstrainedLayoutIR, SpringSlot, LayoutConstraint, GlyphObject, to_constrained |
Ch. 7 §"ConstrainedLayoutIR" |
| Stage 3 — resolved | ResolvedLayoutIR, pages/systems/staves/measures, ResolvedGlyph |
Ch. 7 §"ResolvedLayoutIR" |
| Stage 4 — render (interface only) | RenderIR, RenderPrimitive, RenderIRProducer, to_render |
Ch. 7 §"RenderIR" |
| Time axis | canonical TimeAxisModel plus dynamic TimeAxis, including registered payload preservation |
Ch. 7 §"Layout Regions" |
| Provenance | Provenance, LayoutObjectId, SynthesisKind, stable_layout_id (a pure function of the source — stable across relayouts) |
Ch. 7 §"Provenance" |
| Engraving decisions | EngravingDecision/EngravingDecisionId/EngravingDecisionKind, DecisionSource |
Ch. 7 §"Engraving Decisions" |
| Vertical bands | VerticalBand/VerticalBandId/VerticalBandKind |
Ch. 7 §"Vertical Bands" |
| Incremental cache | LayoutCache, DependencyIndex, granular stage caches and invalidation |
Ch. 7 §"Incremental Layout and Caching" |
| Glyph catalog | GlyphCatalog (metric-lookup interface) + in-tree BravuraCatalog, GlyphCatalogIdentity, SmuflVersion, FontId, GlyphMetric/GlyphAnchor, BRAVURA_METRICS/BRAVURA_VERSION, metrics_hash_for (MUSCFNTM-tagged) |
Ch. 7 §"Glyph Catalog Interface" / §7.3.2 |
| Edit barriers | EditBarrier, BarrierScope, BarrierCondition, ObjectKind, EditContext (precise scope evaluation), keyed on Agent C's OperationKindTag |
Ch. 8 §"Edit Barriers" |
| Solver interface | ConstraintSolver (solve/solve_incremental, Send + Sync), SolverConfig/SolverBudget, SolverState, InvalidationSet, SolveReport, SolveStatus, SolverTier/SolverVersion, the v0 StubSolver |
Ch. 9 |
| Round-trip | round_trip, RoundTripReport, laid_out_object_ids |
Ch. 7 (v0 acceptance criterion 6) |
The stub solver
Per the QUICKSTART, the v0 constraint solver is a stub: StubSolver returns
SolveStatus::Solved with the input geometry verbatim (each glyph's resolved
position is exactly its constrained baseline), preserves provenance, and reports
all hard constraints satisfied. The real solver — Cassowary or otherwise — comes
later (Chapter 9 specifies the interface, not the algorithm); v0 only needs to
round-trip IR through the solver interface to prove the contracts hold. The one
stub validates the full Chapter 7 §7.3.2 catalog identity and all slot, band,
and geometry cross-references before reporting Solved. Explicit constraints
are rejected because this interface-only solver cannot honestly evaluate them.
The round-trip (v0 acceptance criterion 6)
round_trip runs graph → LogicalLayoutIR → ConstrainedLayoutIR →
stub-solved ResolvedLayoutIR → RenderIR and asserts the contract every stage
must satisfy:
- the stub solver reports
Solvedwith all hard constraints satisfied; - the complete
Provenanceof every object —source,synthesis,dependencies, andstable_id— survives every stage unchanged; - no two objects ever share a
stable_id, so manifestation multiplicity is preserved (a source manifested in two regions stays two layout objects); - the stub solver returns the input geometry verbatim;
- the set of score-graph sources recovered from the
RenderIRis exactly the set laid out — a surjection onto graph identity (one source may back several manifestations, each with its own stable id).
Agent F's testkit drives this same entry point (layout_stub::round_trip) on the
10-measure single-staff hand-off fixture and the rich multi-region generator.
Algorithmic scope
Per the QUICKSTART ("a prototype baseline, not the product"), this crate implements the Chapter 7 IR contracts and interface types, not a production engraving engine. The real spacing and casting-off algorithms, quality-metric computation, constraint solver, and renderer remain later implementations of these interfaces.
Determinism
IR coordinates are single-precision staff spaces (StaffSpace(f32),
Chapter 7 §7.2); the canonical ResolvedLayoutIR output quantizes them to
the 1/1024 grid at serialization time
(ResolvedLayoutIR::canonical_bytes), exactly as Appendix D §"Quantized Layout
Coordinates" prescribes — quantization absorbs all f32 variation below 1/2048
staff space, so the canonical output is independent of the floating-point
environment. The glyph-catalog identity hashes its consulted metrics (advance,
bounding box, named anchors) under the MUSCFNTM domain tag, and the
edit-barrier types carry a canonical encoding with set-valued fields emitted in
canonical byte order (sorted and de-duplicated). See DECISIONS.md.
Tests
cargo test -p epiphany-layout-ir covers each module plus the round-trip on
Agent B's valid_score / valid_score_rich generators. The end-to-end v0
acceptance gate (criterion 6) lives in the testkit.