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Fix #217 — don't beam notes too long to carry a flag - #219
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A note is beamable when it is shorter than a quarter note, whatever the meter (ABC v2.2 §4.7: "if L:1/8 then ABC2DE is equivalent to AB C2 DE"). BeamResolver used to compare against the meter's beat instead, so in compound meter (and 2/2, 3/2) quarter notes were beamed to their neighbours: `B2A G2d` in 6/8 came out as two beamed pairs. - BeamResolver takes only the unit note length; the meter no longer reaches it, so SemanticPass stops rebuilding it on [M:] and the now-unused BodyContext.openingMeter goes. - The #85 [M:] tests asserted the old rule; they now check the meter lands on the right measure and leaves the beams alone. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Fix #217
Summary
A note is beamable only if it would carry a flag (shorter than a quarter), whatever the meter, per ABC v2.2 §4.7: "if L:1/8 then ABC2DE is equivalent to AB C2 DE".
BeamResolverused to compare against the meter's beat, so in 6/8, 9/8, 2/2 and 3/2 quarter notes were beamed to their neighbours (B2A G2din 6/8 came out as two beamed pairs). abcm2ps 8.14 draws plain quarters and flagged eighths.How
BeamResolvertakes only the unit note length;isBeamableDurationtestsdur × L < 1/4.SemanticPassno longer rebuilds the resolver on[M:], and the now-unusedBodyContext.openingMeteris removed.Tests
NoteRhythmTests:ABC2DEbeams asAB C2 DEin 4/4, 6/8, 2/2, 3/2, 9/8;B2A G2din 6/8 is all single;c>dis still beamed.InlineLengthAndMeterBeamingTests: the two[M:]tests from Inline [L:] and [M:] never reach BeamResolver — beams computed against stale unit length and meter #85 asserted the old rule (quarters beamed in 6/8). They now check that the meter lands on the right measure and leaves the beams alone.🤖 Generated with Claude Code