sp-dateformatter-hot — measured, still hint
Status
hint. Wall-clock JSONL: sp-dateformatter-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug.
Measurement
2000 formats of one date. Before constructs DateFormatter each iteration; after reuses one.
| role | case | median_ms | ops | ratio |
|---|---|---|---|---|
| after | formatter_once | 1.482010 | 2000 | 1 |
| before | formatter_each_iter | 44.153929 | 2000 | 29.793 |
The microbench shows a cost for this one shape. Default stays hint until the shape is corpus-triaged. 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.