| name | sequence-state-bead-closure |
| description | Use when implementing, reviewing, or closing gbllm sequence-state beads, including LinearState, BoundedKv, SequenceBlock traits, exported sequence facts, byte-backed state, and recurrent state tests. |
Sequence-State Bead Closure
Use this for sequence semantics, sequence blocks, state layout, exported state facts, and byte-backed recurrent/cache behavior.
Contract Ownership
- Keep one authoritative sequence semantics contract. If crate dependencies require durable schema in
gbf-artifact, re-export it from gbf-model and state that ownership movement explicitly in bead closure.
- Export paths must consume
SequenceExportFacts derived from model topology or a sequence block, not a free-standing enum supplied at finish time.
- Add a test that
ExportVisitor carries sequence facts into both ArtifactCore and ExportFacts when that path is owned.
- A sequence dispatch trait must use project-native activation/state types with shape and finiteness validation. Do not satisfy acceptance with unconstrained associated
Input/Output/State types.
- Policy/profile selector enums such as
SequenceSemanticsRef are configuration references only until compile profiles consume them. Avoid derived ordering unless ordering has executable policy meaning.
Executable State Rules
- Define batch/state semantics before closure. If
SequenceState is one shared buffer, reject batch > 1 and test the rejection.
- Do not put artifact path naming or fabricated tensor handles in runtime block config. Sequence parameter handles must come from an
ExportVisitor path that emits matching ArtifactCore tensors.
- Fixed recurrence/update behavior needs a literal value-level oracle test over at least two tokens.
- If the update law is a placeholder or research variant, narrow the closure and avoid claiming numeric semantics beyond scaffolding.
- Keep scalar sequence kernels, Burn/autodiff gradient paths,
TrainPhaseSpec hardness scheduling, and shadow-compile A/B fixture adoption as separate claims with separate gates or moved-to beads.
Byte-Backed State
- When a sequence block imposes an executable byte-record layout, align model topology validation and tiny fixtures with that layout.
- Durable artifact schema may stay broader, but model config must reject layouts the executable block cannot instantiate.
- Byte-backed sequence state must validate canonical persisted form before mutation.
- For cache-like records, test validity flags, contiguous live records, empty-record zeroing, sliding/truncation behavior, and failed-forward atomicity.
- If a v1 sequence block uses a simplified mechanism such as tied key/value payloads or record metadata inside
*_bytes_per_token, name that explicitly in docs, tests, and closure.
