The record-length retraction had been applied to the tests and to the section
that discovered the problem, but the same claim was still standing in four other
places -- including the rustdoc for has_uniform_record_length(), which is what a
caller would actually read:
crates/gc-formats/src/chunks.rs:206 "Measured: true for 1,509 of 1,509 chunks"
docs/roadmap.md:448 "uniform record length (1,509 of 1,509)"
docs/formats/core-data-regions.md a whole section titled
"Every chunk has a uniform record length"
All three now say 257 of 1,509, and the method's rustdoc explains WHY the old
number was an artefact -- that resolve sliced at the first offset delta, so every
record came out the same length by construction and the predicate was confirming
the parser back to itself.
That section also contained a withdrawal, and the withdrawal was wrong:
"This withdraws the previous commit's variable-length type. That came from
taking minlen/maxlen over all of a type's records at once, pooling across
chunks; rule 3a's pooled claim, third time this session."
The pooling rule fired correctly and was overruled by a measurement with no
independent content. The per-chunk check that should have caught the pooled
signal was itself reporting the parser's own slicing, so it agreed with the wrong
answer for the same reason the original claim did. Two errors stacked: a real
signal dismissed by a rule that had been right twice already, and a predicate
that could not have told the difference.
This is the third time this session that a test was asserting the parser's
behaviour rather than the disc's, and the third time it was the only thing
standing between a claim and a retraction. has_uniform_record_length is the
clearest instance: a predicate named after a property of the data, returning a
confident answer about the code.
245 tests, clippy clean.
ReaperOfVeriod
8ccc3ddda4