Pinned down the one slot that still cleared 100x after the record-boundary fix,
and it is the artifact this section was written to guard against.
The discriminator the original version lacked: a slot that really carries moby
class IDs must SPAN the ID space, so some of its values land above a level's moby
count. The artifact does the opposite.
type slot enrichment distinct values ABOVE the moby count
0xd76cc453 6 305x 9 0
0xf2ef4275 34 64x 9 341
0xf2ef4275 7 46x 16 412
0xf2ef4275 14 34x 16 432
0xd76cc453 9 32x 28 702
The 305x slot's nine values are 1, 3, 4, 5, 10, 11, 12, 13, 15 -- all under a
level's ~215 moby classes, so every one scores as a hit and 65536/215 = 305x.
Nine small numbers is not a class-ID array. Every slot that actually spans the ID
space scores 10x to 64x, which is chance.
So the original claim's own numbers gave it away and it was not read that way:
"5 to 42 distinct values at 153x to 289x" is exactly the artifact's shape -- a
handful of small values, none above the count. The record-boundary fix was never
what made this claim wrong. It was wrong when written, and the retraction is
complete rather than the partial one I committed two turns ago.
The test now separates the two quantities: slots clearing 100x (currently 1,
expected to remain the artifact) and slots clearing 100x WHILE ALSO having values
above the moby count (currently 0, must stay empty). That second number is the
one that means something, and a slot appearing in it would be the first genuine
evidence of a class-ID array anywhere in the container.
Worth noting the per-SLOT bookkeeping: the count of values above the moby count
is keyed by (type, slot), not by type. A first attempt keyed it by type and the
artifact type passed the check on the strength of its ordinary slots -- 783 of its
own values sat above the count at other slots. The check has to be about the
individual slot, or one good slot launders a bad one.
245 tests, clippy clean.
ReaperOfVeriod
2d3880b624