- Remove the four proposed POCs: they were implementation smoke tests,
not de-risking probes. The pivot is a backend swap on a proven layout
engine; byte-identity is already proven and the layout code is
unchanged, so there is nothing empirical left to de-risk.
- Remove the recursive TreeNode example and the recursion mention in
design principle 2: recursion is not a binary-layout concern and the
engine has no cycle detection.
- Add a Spec Gaps section: validate_bytes semantics after keyword
validator removal (UnionValidator variant dispatch regression),
arrays of variable-length elements (engine rejects them), and
field-name discriminator unions (meta-schema cannot express them).
- Reframe the engine change as an accessor-layer refactor: the
walkers' (kind, field list, annotations) reads change; everything
beneath them carries over unchanged.
Correct the validator split section to clarify that jsonschema is
not removed — it remains the JSON Schema validator for both paths
(BAST meta-schema validation and standard JSON payload validation).
Only the custom keyword registration path is removed. Also fix the
build_validator and validate_json entries in the engine changes
table to reflect that they are repurposed, not removed.
Proposes replacing custom JSON Schema keywords with a standalone
kind-based JSON format (BAST) using / for composition.
Covers format design, meta-schema, engine changes, validator split,
codegen future, ABI adapter potential, migration path, 7 open
questions, and 4 proposed POCs.
deepseek-v4-pro