Step 9 (convert tests to BAST format) was a no-op: steps 4-8 converted
the tests as they went. The only remaining reference in
src/tests was the intentional rejection test at
src/schema.rs:462 (asserting the old keyword form is rejected). Full
suite passes: 389 tests (312 lib + 77 integration).
Step 10 (sync architecture docs and ADRs):
Descriptive docs rewritten/updated for BAST:
- schema-layer.md: rewritten for the BAST parser (BastDoc/BastDef/
BastType typed tree, AlkTypeKind enum with to_bast_str/from_bast_str,
what was removed). Points at bast-format.md for the normative format.
- validation.md: rewritten for the two-validator model
(bast_validation for validate_bytes, standard jsonschema for
validate_json). Documents the repurposed build_validator, the
AlkTypeError::Validation uniform payload (D-BAST-009), and what is
removed.
- builder.md: updated all output examples to BAST JSON
(struct_() -> { kind: struct, fields: [...] }; object() -> standard
JSON Schema). Documents build_doc, count(), and the field-name union
fields requirement (D-BAST-005).
- overview.md: updated for BAST (what/why, schema-is-the-format table,
dependencies, architecture pointers, design decisions table).
- README.md (architecture index): updated document table, ADR table
(new ADR-BAST + ADR-VAL-SPLIT, superseded ADR-001), OQ table
(OQ-007/OQ-008 resolutions updated for BAST-native validator), and
key design principles (#1, #2, #7, #10 reworded for BAST).
- data-access.md: updated tunion function signatures to BastUnion and
the variant resolution to return BastType (resolve_typeref for refs).
- layout-engine.md: updated construct signatures
(LayoutBuilder::new(bast_doc, root_name), OffsetMap::compute(&doc),
SequentialReader::new(bast_doc, root_name)), the recursive-walk
description (BAST typed tree), and composite-kind headings
(TStruct/TUnion/TArray -> struct/union/array). Added D-BAST-004
note on array count requirement.
New ADRs:
- ADR-BAST (bast-bast-format.md): the BAST format, meta-schema,
//kind vocabulary, design principles, what is removed, the
enum index bounds bug fix. Supersedes ADR-001's format-specific
content; records D-BAST-001..009.
- ADR-VAL-SPLIT (val-split-two-validator-model.md): the two-validator
model (BAST-native for validate_bytes, standard jsonschema for
validate_json), the repurposed build_validator, the uniform
AlkTypeError::Validation payload. Refines ADR-004's validation
strategy and ADR-010's validation step; records D-BAST-006/007/009.
Amended ADRs (supersession/amendment notes added; original decision
text preserved as historical record):
- ADR-001: format-specific content superseded by ADR-BAST;
purpose/scope and schema-is-the-format principle retained.
- ADR-002: unchanged under the pivot; one-line note that the input
format changed but the modes didn't.
- ADR-003: annotation semantics retained; annotation location moved
to BAST type-level properties (amended by ADR-BAST).
- ADR-004: AlkTypeError enum retained (D-BAST-009); validation
strategy section refined by ADR-VAL-SPLIT.
- ADR-009: builder API surface retained; build() output format
amended to BAST / standard JSON Schema by ADR-BAST (D-BAST-008).
- ADR-010: validate_bytes two-step concept retained; validation step
amended to the BAST-native validator by ADR-VAL-SPLIT.
Other:
- Cargo.toml description: JSON Schema with AlkType:* custom keywords
-> BAST document.
- bast-pivot.md research record: status draft -> implemented, with a
pointer to the ADRs that superseded its decisions.
- bast-implementation.md plan: status draft -> complete, with a note
that step 9 was a no-op and step 10 is this commit.
- open-questions.md: OQ-006/OQ-007/OQ-008 resolutions updated for the
BAST-native validator.
- questions/008-unionvalidator-variant-dispatch.md: added a
post-BAST-pivot note pointing to the current bast_validation
implementation; v0.1.0 resolution text preserved as historical
record.
Verification:
- cargo test --release: 389 pass (312 lib + 77 integration)
- cargo clippy --all-targets -- -D warnings: clean
- cargo doc --no-deps: clean
- cross-reference check: every relative link in the new/updated docs
resolves (verified by script).
The bast-pivot.md research doc had grown to 1477 lines (~58KB) through
iterative editing, pushing its most actionable content (D-BAST
decisions, POC result, migration steps) past the 50KB Read tool cap.
Agents peeking at the truncated file landed in duplicated/out-of-order
sections. Decompose into three readable-sized files with distinct roles:
- docs/architecture/bast-format.md (28KB, new): the normative BAST
format spec -- meta-schema, TypeRef, examples, validation model.
Grounded in the POC and D-BAST-001..009. Stable and safe to write
now; schema-layer.md/validation.md stay describing current code and
are rewritten post-implementation (per AGENTS.md ADR-grounding rule).
- docs/plans/bast-implementation.md (31KB, new): the execution entry
point -- ordered 10-step plan with per-step goal/files/spec-ref/
verification, the public-API semver contract table up front as a
scope-creep guardrail, and the ADR-sync checklist at the end. Each
step links to the specific bast-format.md section and D-BAST anchor.
- docs/research/bast-pivot.md (28KB, trimmed): now the research record
only -- Summary, Motivation, POC scope/result, Decisions, Risks,
References. The normative format spec, what-changes tables,
validator-split details, and migration steps moved to the two new
docs; pointers added. 1155 lines removed, 216 added.
- docs/architecture/README.md: index updated to list bast-format.md
and the two in-progress pivot docs, with notes on schema-layer.md
and validation.md being rewritten when the pivot lands.
All three files are under the 50KB Read cap, so an implementing agent
gets the whole document in one call. Cross-reference anchors verified
to resolve. No code changes; cargo test --release (396 tests) green.
Verification: cargo test --release (310 crate + 86 integration, all pass).
Scope-creep guardrail for the public API during implementation. Maps
every item re-exported from src/lib.rs to a class (breaking / additive /
unchanged) with the specific change, and every ADR (001-010) to an
action (supersede / amend / unchanged) with the reason.
Net breaking: compile (signature), validate_json/is_valid_json
(contract), Schema::build/Definitions::build (output format),
build_validator (signature or removal), and the ~13 schema::* helper
re-exports. Net additive: BAST parser, BAST-native validator,
AlkTypeKind::from_str/to_str. Net unchanged: the entire layout +
data-access + materialize + tunion layer, AlkTypeError (D-BAST-009),
the Discriminator builder, AlkTypeKind variants.
Flags three small decisions deferred to their implementation steps
(validate_json JSON Schema source, build_validator fate, schema::*
re-export retention) so they don't become drive-by semver changes.
This is a living guide — it may shift slightly during implementation,
but capturing the contract now prevents public-surface drift. Doc-only.
Converts the open question into a closed decision. Rationale: consumer
ergonomics on the combined validate_json + validate_bytes path — one
uniform payload type means one match arm downstream. Option 2
(Validation(String)) would force validate_json to flatten its
structured errors to a String, losing information on the richer path to
accommodate the less rich one. The no_std/minimal-build angle that
option 2 was meant to enable is moot: validate_json requires jsonschema
regardless, so a bytes-only no_std build already has to give up
validate_json as a separate larger decision; dropping the type from one
error variant doesn't unlock it.
Updates Phase 1 step 5 to reference D-BAST-009 for the error
construction pattern, and rewrites POC Result observation 4 from
'deferred decision' to 'decided — see D-BAST-009'.
No semver-relevant change to the Validation variant. Doc-only.
Adds the POC Result section (POC on branch bast-validator-poc, commit
f371fe4 — 20/20 tests, full 416-test suite green, clippy/wasm/doc clean).
Hypothesis confirmed: a recursive walker over the BAST type tree fully
replaces the 19 custom keyword validators on the validate_bytes path,
recovers OQ-008 union variant dispatch, and fixes the enum-membership
dead constraint. The POC code is reference scaffolding on the branch
and is not merged to main — it is superseded by Phase 1 step 5.
Marks Phase 1 step 2 and the POC Scope section as done with pointers to
the result section.
Elevates the deferred AlkTypeError::Validation payload-shape question
to OQ-BAST-001: keep jsonschema::ValidationError<'static> (POC choice,
simplest, dependency stays) vs introduce Validation(String) (drops
jsonschema from the error type; semver-relevant public-API change).
Decision belongs to the production refactor.
Verification: doc-only change, no code touched.
- Rewrite Validator Split around BAST-native validator for
validate_bytes (walks BAST, checks value-domain constraints, no
external JSON Schema needed); validate_json uses standard
jsonschema::Validator from consumer-provided JSON Schema
- Add targeted POC: BAST-native validator replacing 19 custom keyword
validators on the bytes path, verified via existing test suite
- Fix meta-schema: require count on arrays (variable-element arrays
deferred per OQ-001), add optional fields array to UnionDef for
field-name discriminators
- Remove lying no-count array example, replace with deferred note
- Document dead enum constraint (materialized index never matches
string-membered enum); BAST-native validator fixes it via index
bounds check
- Resolve all 7 OQs + 3 spec gaps as D-BAST-001 through D-BAST-008
- Update Migration Path, Risks table, Engine internals to reflect
BAST-native validator
- Clarify 'no pocs needed' was an overcorrection: layout swap needs
no POC, but the validation model does
Verification: docs-only change, no code affected
- 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.
POC: /workspace/alktype-builder-poc/ (18/18 tests pass, findings in
docs/research/alktype-builder-poc/findings.md). Round 2 adds the SFTP
Packet validate_bytes tests (7 new: valid Init/Read/Write/Status,
short buffer, unknown discriminator, over-maxLength Bytes).
Open questions resolved (OQ-004 through OQ-008):
- OQ-004: Discriminator::Field name is String (already implemented;
docs updated to mark resolved)
- OQ-005: Both union discriminator kinds return the same shape:
{__discriminator, ...variant-fields}. Field-name path also had a
real offset bug (returned start, not end) - fixed.
- OQ-006: builder.md Example 3 now wraps the Union in a
Schema::struct_().field("payload", ...) and merges $defs via
Definitions::merge_into (matches the engine's AlkType:Struct-at-root
constraint and the SFTP wire shape)
- OQ-007: Bytes materialization is array-of-u8 (Value::Array of
Value::Number, one entry per byte 0..=255). BytesValidator accepts
both Value::String (validate_json) and Value::Array (validate_bytes).
maxLength = max byte count. Replaces the lossy from_utf8_lossy path
that corrupted non-UTF-8 bytes and broke maxLength semantics.
- OQ-008 (new): UnionValidator now dispatches to variant schemas via
sub-validators built at factory time. AlkTypeEngine::compile calls
schema::inline_union_variant_refs before build_validator to inline
$refs in union mapping entries (necessary because union_factory
receives the union node, but $defs live at the schema root).
Production-readiness fixes in src/ (no stubs/hedges in a published crate):
- materialize.rs: Record stub -> full count-prefixed key/value pair
implementation per schema-layer.md TRecord
- materialize.rs: root_of() was broken (returned the current node, not
the schema root) -> root schema threaded through every recursive call
so resolve_ref_or_inline can resolve $refs for nested composites
- builder.rs: LengthPrefixed encoding setter was a no-op when the
keyword was already in object form -> complete the branch (updates
the encoding entry in place for both LengthPrefixed and OffsetIndirect)
- builder.rs, engine.rs: POC-referencing comments cleaned up; the
round-trip test's or_else fallback (papering over write_field being
aligned-only) replaced with direct byte writes
Documentation:
- builder.md: Example 3 updated; Discriminator::Field spec shows String;
Open Questions section updated (OQ-004 resolved)
- validation.md: AlkType:Bytes and AlkType:Union validator descriptions
updated for array-of-u8 form and variant dispatch
- open-questions.md: OQ-004/005/006/007/008 marked resolved; new
Validation theme entries
- questions/004-008: individual OQ files updated with resolutions
- findings.md: round 2 results documented
Verification:
- cargo test: 369 -> 391 tests pass (22 new: 14 materialize, 5
inline_union_variant_refs, 3 validation/builder)
- cargo clippy --all-targets: clean
- POC: 11 -> 18 tests (7 new SFTP Packet tests); all pass
Four open questions were scattered inline in builder.md and the POC
findings doc. Moved them into the central OQ tracker under
docs/architecture/questions/ and updated the index:
- OQ-004: Discriminator::Field name type (&str vs String) — raised in
builder.md during ADR-009 spec drafting
- OQ-005: Union materialization shape (byte-offset vs field-name
consistency) — raised in the POC findings
- OQ-006: Builder spec Example 3 wrap Union in Struct — raised in the
POC findings (doc fix; engine requires AlkType:Struct at top level)
- OQ-007: Bytes materialization lossy UTF-8 — raised in the POC
findings (blocks SFTP use case for validate_bytes)
Index updates:
- open-questions.md: new 'Schema Construction' and 'Validation' theme
groups; new 'Open' section for active investigation targets (distinct
from 'Deferred / Blocked' which holds scope-parked OQs)
- README.md: OQ table extended with OQ-004 through OQ-007
- builder.md: inline OQ-004 replaced with a tracker reference
- findings.md: inline OQ-005/006/007 replaced with tracker references
Doc-only change; 369 tests pass.
POC: /workspace/alktype-builder-poc/ (11/11 tests pass, findings in
docs/research/alktype-builder-poc/findings.md). The POC code lives outside
the repo per the internal dev convention.
Implementation:
- src/builder.rs: Schema, Definitions, Discriminator types. Constructors
for all 19 AlkType kinds + standard JSON Schema types (object/array/
string/integer/number/boolean/null/any). Setters for ADR-003 annotations
(endian/align/encoding/max_length), composite builders (field/required/
items/mapping), and standard JSON Schema constraints (minimum/maximum/
minLength/minItems/maxItems/format/title/description). 16 unit tests.
- src/materialize.rs: materialize_packed and materialize_aligned functions
that walk a schema + buffer to produce a serde_json::Value tree. Recurses
into Struct, Array, Union (byte-offset discriminator). Record is stubbed
(deferred for the POC scope).
- src/engine.rs: AlkTypeEngine::validate_bytes(&[u8]) added (ADR-010).
Dispatches on layout mode, materializes Value, then validates against
the existing jsonschema validator. 7 unit tests.
- src/lib.rs: pub mod builder, pub mod materialize; re-exports Schema,
Definitions, Discriminator.
Verification:
- cargo test: 346 -> 369 tests pass (23 new: 16 builder, 7 validate_bytes)
- cargo clippy --all-targets -- -D warnings: clean
- POC (11 tests): builder round-trip + validate_bytes (packed + aligned) +
validate_json for call payloads; all pass
Findings:
- Top-level schema must be AlkType:Struct (existing constraint); unions are
field types within a struct. Builder spec Example 3 needs a doc fix.
- Builder field order preserved (preserve_order feature, load-bearing for
packed mode).
- validate_bytes correctly distinguishes Access (read phase) from
Validation (validate phase) errors, with field paths.
- validate_json path unchanged for call payloads.
Open questions surfaced (OQ-005, OQ-006, OQ-007) tracked in findings.md;
to resolve before the SFTP Packet POC round.