lexindex v4.3.1

Fixed

• key_into on a blob in a character code is back at 4.2.0's speed, and id much closer to
  it. 4.3.0 decoded a key a character at a time through the tables the code is stored in — the
  codeword's lead found among the leads, a branch on the mode and on the lead's width,
  char::encode_utf8 — and then checked the finished key as UTF-8 a second time; it spelled a
  query through a two-level index, behind a branch on the mode. A codeword now decodes in two reads
  and one four-byte store, out of a table of the 256 values its first byte can take and one of
  every character's UTF-8. What the decoder writes is whole characters out of a table built from
  chars, so it becomes a String without the second pass; a debug build still checks it, and so
  do the fuzz targets. Code points below U+0800 — ASCII, Cyrillic and every other script UTF-8
  spells in two bytes — are one flat level of the index, and under the eight-bit mode ASCII is in
  the index too, so spelling a query no longer asks which mode it is in. Blobs are unchanged, byte
  for byte. Against 4.2.0 in one process, in two builds of the harness
  (bench/results/charcode-ab-2026-09-23-arz-668a1d3.txt): key_into is 2.5–3.3 % faster on a
  million Russian titles, where 4.3.0 was 19–23 % slower, within 2 % on a million Chinese ones
  (4.3.0: 11–12 % slower) and level on jieba's lexicon (4.3.0: 4–5 % slower); id is 1–2 %
  slower on the Russian titles (4.3.0: 6–7 %), 6–8 % on the Chinese ones (4.3.0: 12–13 %) and 3–4 %
  faster on the lexicon, as in 4.3.0. English titles, whose blob is 4.2's, read within 2 % of
  4.2.0, the band two builds of the harness move by. Most of what id still pays is spelling the
  query: all of it on the Russian titles, where spelling it twice adds 610 instructions and id
  pays 605 over 4.2.0, and two thirds of the 530 instructions it pays on the Chinese ones.

Documentation

• The million-key size table and the README's margin over marisa-trie are re-measured at
  4.3.0 (bench/results/sweep-2026-09-23-arz-4f2a0e9.json), so they show the character code. Of
  the 264 cells the run shares with the 4.0.0 one, 252 are the same to the byte; the twelve that
  moved are DictIndex on the Russian and Chinese titles, 6.7–14.7 % smaller, and their margins
  over marisa's best setting go from 2.2 and 1.6 % to 14 and 9 %, so the README's range now starts
  at English titles' 3.9 %. At ten million keys
  (bench/results/sweep10m-2026-09-23-arz-4f2a0e9.json) all 66 cells are the same to the byte: the
  code takes none of those six corpora. The run's timings are not published, since the machine was
  busy.