One grammar, four call sites. `read_block_mappings` moves out of
`consume.read_sources` -- where it was written and measured -- into
`profiles`, the module both the flat readers and `consume` already import,
and the three copies of the line-oriented frontmatter grammar now decode a
block sequence for the keys `STRUCTURED_BLOCK_KEYS` names. Two copies of a
block grammar would be two answers to one question.
The value TYPE was the real choice and it was measured, not argued.
`parse_frontmatter` is public API (`okf.parse_frontmatter`) returning
`dict[str, str]`, and a list of mappings is not a `str`. Widening the return
type to `str | list[dict[str, str]]` costs 15 `mypy --strict` errors across
four of the five modules that touch the reader, plus a signature every
caller outside this repository would have to follow. Rendering the entries
back into the flow form those same readers already round-trip costs 0. The
rendering is a READING projection and says so: it is not a claim that the
value is writable -- `yaml_flow_plain` still refuses a `?` and the guard
still refuses a quote inside a flow mapping, which is why the producer
writes block in the first place.
`STRUCTURED_BLOCK_KEYS` is one key wide. `sources` is the key `read_sources`
already knows how to read; a fixture in this tree carries a block
`verified:` that still reads as an empty value, and a test pins that state
so the next widening is a decision rather than a side effect.
Nothing nested reaches the document's namespace: the entries land inside
their own value, and the K3-20 substitution guarantee is asserted per reader
copy.
Three tests that pinned the old behaviour are rewritten to what is now true,
none weakened on its other half: the block round trip in
`test_multi_source_provenance` (the evidence behind `_render_sources`'
reason 1), the v0.2 characterization (whose key-space assertion is the half
that must never weaken), and K3-22's shipped-file known-positive, where the
one difference is counted and pinned at 1.
Suite 1807 passed / 1 skipped, rc 0, 94 s -- 1782/1 before plus 25 new.
ruff clean, `mypy --strict` clean over 21 files, `uv.lock` untouched.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
K3-22, red first. SPEC SS 11 point 1 requires "a parseable YAML frontmatter
block" in every file. Measured with PyYAML 6.0.3 before any code moved: the
K2 default bundle this repository pins fails safe_load on 41 of 455
frontmatter blocks, all on `title` (a leading `- `, `**` or `*`, or ": "),
and the R761 build on 1 of 2 763 (a title ending in `:`). No `sources` value
okf itself wrote failed; the 4 605 consumer failures come from that
consumer's own writer.
Each case goes through a public path (render_inbox_concept, the profile
emitter, Door A's sources renderer, skill.render) and is held to three
readers: safe_load must not raise, BaseLoader must return the same strings
as parse_frontmatter / read_sources, and the pinned guard must admit it. The
guard is why quoting inside a flow mapping is not the fix: 1.3.0 refuses any
quote in a flow mapping (measured), so a `sources` leaf PyYAML needs quoted
has no form both readers accept, and is refused instead.
57 of 85 red on 0308169; the 28 green are the known-negatives and controls.
The rest of the suite is unchanged: 1695 passed (1667 + 28), 1 skipped.
pyyaml joins [dependency-groups] dev and nothing else; uv.lock moves by
exactly the two lines that dev dependency adds.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
