Implements a total, reversible canonical byte form for the entire
epiphany_core::Score graph, unblocking the byte-level full-Score serialization
gate that M3 had to defer.
epiphany-core/src/codec.rs:
- Score::canonical_bytes() / Score::decode_canonical() with a validating
ScoreDecodeError and a forward-only Reader cursor.
- A local Codec trait with generic combinators (Option/Vec/BTreeSet/BTreeMap/
tuple) and macros (struct_codec!/cstyle_enum_codec!/unit_codec!/
catalog_id_codec!) so encode and decode stay symmetric across ~110 types
spanning graph.rs, event.rs, pitch.rs, time.rs, tempo.rs.
- Uniform form: LE integers, one discriminant byte per tagged union, u32
counts/length-prefixes, every variable-width leaf length-prefixed, raw UTF-8
for free text (so decode(encode(x)) == x for any valid score; catalog ids are
already NFC). EventArena round-trips via iter_canonical + insert.
- Two pub(crate) accessors added for the codec: EventOrderingDAG::edges_ref,
SpellingPrecedence::order_ref.
- Tests: generator-score corpus (valid_score + valid_score_rich), exotic
event/pitch variants the generators omit, distinctness, and decoder
rejection of trailing/truncated/empty bytes.
epiphany-testkit:
- roundtrip::assert_score_serialization_stable: encode the real Score, store it
as a bundle Snapshot, reopen + hash-verify, decode to an equal Score, and
assert a byte-identical re-encode.
- convergence::materialized_score builds a real ~50-bar reduce_onto
materialization for the gate.
- criterion_4_full_score_byte_roundtrip flips from #[ignore] to a live gate;
wired into the conformance suite. Docs (lib.rs, README, core DECISIONS P11-4)
updated to reflect the landed codec.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The audit flagged Agent F's criterion 1 (convergence) and criterion 4
(serialization) as testing the reducer-bookkeeping projection
(MaterializedState) while claiming to be full-Score gates. This makes them
honest, per item 4 of the v0 follow-up plan.
Criterion 1 — real-Score convergence:
- generators::graph_edit_session builds a real ~50-bar, two-voice edit
session targeting a base Score's actual voices (so it survives reduce_onto,
which rejects unknown voices).
- convergence::{assert_graph_convergence, run_graph_convergence} reduce that
session onto a real epiphany_core::Score via OperationSet::reduce_onto and
assert the entire GraphMaterialization (graph + bookkeeping) is identical
across delivery orders, passes check_invariants, and genuinely grows both
voices (non-vacuity).
- acceptance criterion_1_convergence now drives this; the former bookkeeping
convergence is retained and renamed reducer_bookkeeping_convergence.
Criterion 4 — honest serialization tiers:
- criterion_4_canonical_serialization_stability keeps the real typed/manifest
round-trips; the MaterializedState round-trip is split out as
reducer_bookkeeping_serialization.
- full_score_materialization_is_reproducible asserts the materialized Score is
reproducible across orders (the determinism precondition for a byte codec),
achievable without the codec.
- criterion_4_full_score_byte_roundtrip is #[ignore]'d pending item 5's
whole-score codec (visible as ignored, never falsely green).
Negative regression guards (src/negative.rs): one guard per audited M1 defect
(inverted causal/HLC order, missing predecessor via vector, HLC 100/200/50
quarantine-from-0, tx rollback of member conflicts, causally-ordered
same-position non-promotion, partial-duration overlap), driven through the real
epiphany_ops API with explicit negative controls. Wired into acceptance and the
conformance suite. Crate/README docs updated to match.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Levi Neuwirth