zp-open-file-hot — measured, still hint
Status
hint. Wall-clock JSONL: zp-open-file-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug.
Measurement
Io.Dir.openFileAbsolute of one one-byte file, 2000 times, versus opening once. The result is kept so the after loop is not deleted.
| role | case | median_ms | ops | ratio |
|---|---|---|---|---|
| after | open_once | 0.006 | 2000 | 1 |
| before | open_each_iter | 13.072 | 2000 | 2134.204 |
A path that changes every iteration cannot be hoisted. A loop that needs a fresh timestamp has nothing to hoist. Default stays hint. This ratio is not a general speedup.
Unblock
Do not set the default to error from this file alone. A changing input, a cold path, or another ABI can erase the difference. Corpus triage is still required before any default change.