jp-intl-datetimeformat-hot — measured, still hint
Status
hint. Wall-clock JSONL: jp-intl-datetimeformat-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug. Sibling of the Swift and Objective-C date-formatter rules. Both sides still format one Date.
Measurement
Node v26.12.1 on linux x64, load 0.74. Harness: examples/bench/evidence_jp_intl.js. 2000 dates, locale en-US. The earlier Node 24 pair was about 53×.
| role | case | median_ms | ops | ratio |
|---|---|---|---|---|
| after | one Intl.DateTimeFormat | 1.999 | 2000 | 1 |
| before | constructed every iteration | 72.002 | 2000 | 36.013 |
new Date is not this rule. Default stays hint.
Matcher
The bench built one unchanged formatter. A locale or options argument that names the loop binding is not reported. Default --scope all reports stable formatters outside loops too; --scope loop keeps the former in-loop-only match. The hint invites reusing one formatter when locale and options are stable.
Unblock
Do not set the default to error from this file alone. Another input or a cold path can erase the difference. Corpus triage is still required before any default change.