perf(Core/SourceLength): swap AsSpan with IsNullOrWhiteSpace#859
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knocte merged 1 commit intoJun 5, 2026
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Recent PR[1] changed this hot-path from `Trim().Length<>0` to `AsSpan().IsWhiteSpace()` and while the latter allocates less, it took actually longer to execute according to the contributor's own benchmark analysis. Using String.IsNullOrWhiteSpace seems better here, because it shouldn't allocate either (vs `Trim()`) while it avoids calling `AsSpan()`, and the poor-man measurement stick I have so far is GitHub's CI runs: 3 jobs with the old codebase were slower than 1 job with this change. [1] fsprojects#854
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Recent PR[1] changed this hot-path from
Trim().Length<>0toAsSpan().IsWhiteSpace()and while the latter allocates less, it took actually longer to execute according to the contributor's own benchmark analysis.Using String.IsNullOrWhiteSpace seems better here, because it shouldn't allocate either (vs
Trim()) while it avoids callingAsSpan(), and the poor-man measurement stick I have so far is GitHub's CI runs: 3 jobs with the old codebase were slower than 1 job with this change.[1] #854