Faster filterDateRange via binary search#31
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SampleValue.swift: add a filterDateRange overload for RandomAccessCollection where Element: TimelineValue, Index == Int. Returns the same result as the existing Sequence-based linear-filter implementation but uses two binary searches instead of a linear scan. Picks up automatically for Array-backed callers (which is every caller in this codebase via Swift protocol dispatch). Significant speedup for hot paths that call filterDateRange repeatedly on long schedules — for example, InsulinMath.glucoseEffectsMidAbsorptionISF and DoseMath.insulinCorrection when the sensitivity schedule has many segments. In a LoopEval 60-day per-step prediction sweep with a per-step ISF schedule, total sim wall-clock went from ~30 min to ~1 min (≈30× faster) with bit-identical output to the linear-filter path. Tests: FilterDateRangeTests.swift with 11 cases covering equivalence with the linear-filter reference: boundary cases (empty, both bounds nil, only start, only end), start-before-all, end-after-all, fully- outside, single-sample collections, exact-match-one-segment, and a 100-iteration randomized fuzz over a 200-element contiguous schedule.
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Summary
Adds a binary-search
filterDateRangeoverload onRandomAccessCollection where Element: TimelineValue, Index == Int. Returns the same result as the existing Sequence-based linear-filter implementation but uses two binary searches instead of a linear scan. Picks up automatically for Array-backed callers (which is every caller in this codebase) via Swift protocol dispatch.Why
In LoopEval workloads that call
filterDateRangerepeatedly on long schedules — e.g.,InsulinMath.glucoseEffectsMidAbsorptionISFandDoseMath.insulinCorrectionwhen the sensitivity schedule has many segments — the linear filter was the dominant cost. A 60-day per-step prediction sweep with a per-step ISF schedule went from ~30 min to ~1 min (≈30× faster) with bit-identical output to the linear-filter path.Test plan
xcrun swift test)FilterDateRangeTests.swift(11 tests):empty input, both bounds nil, only-start, only-end, both-in-middle,
start-before-all, end-after-all, fully-outside, before-all, exact-match-one-segment