[matt-edmondson]

Requested by Matt · project thread

Fixes #328, #339, #353, #384, #321, #447, #471, #475.

Parsing

• Duration, Velocity, TimeSignature, Interval, Note and Tempo accept whitespace and '+' that ToString never prints: Duration.Parse(" 1 / 4 "), Note.Parse("C4: 1/4 :v 64 ") #471: integer fields in Duration, Velocity, TimeSignature, Interval and Pitch go through one helper (Notation.TryParseInteger) that rejects whitespace and a leading +. A Duration denominator takes no sign at all, since ToString never writes one, so "1/-4" and "-2147483648/-2" are now rejected (the test that accepted the latter is changed). Tempo's BPM takes no whitespace or sign but keeps the exponent that the R format writes.
• Duration accepts zero and negative lengths, so Note, Rest, ChordEvent and Progression.Parse accept "C4:-1/4:v64", "R:0/4", "C@-1/4" #353: I kept Duration as a signed rational and put the rule on the events. Note, Rest and ChordEvent throw ArgumentOutOfRangeException from Create and return false from TryParse for a zero or negative duration, and so does a progression chord@n/d cell. The zero that seeds TotalDuration is unaffected.
• Progression.Parse silently drops beat slashes after a Chord@n/d cell: "4/4 C@1/2 / / | G" parses as C for 2 beats with G on beat 3 #328: a / after a chord@n/d cell is rejected instead of dropped.
• | validation (Progression.Parse silently drops beat slashes after a Chord@n/d cell: "4/4 C@1/2 / / | G" parses as C for 2 beats with G on beat 3 #328 optional, Progression.ToString() puts bar lines in the wrong place: after a sub-beat chord | lands mid-bar, and a chord held across a barline gets none #475 "decide separately"): I chose not to validate bar lines. The "4/4 C | G" shorthand (one-beat chords with bar lines between them) appears in about 25 tests across cadences, key inference and chromatic analysis, and validating would reject all of them. The spec now says Parse ignores |.
• Arrangement.Parse rejects a chart whose sections are separated by two blank lines or by a whitespace-only line #339: Arrangement.Parse treats any run of empty or whitespace-only lines as one section separator.

Writing

• Progression.ToString() puts bar lines in the wrong place: after a sub-beat chord | lands mid-bar, and a chord held across a barline gets none #475: Progression.ToString tracks the bar position as an exact Duration and writes | wherever a bar ends between two tokens, including between the slashes of a held chord (G | /). Both examples from the issue now produce their "correct chart" output. A bar that ends inside an @n/d cell has no token boundary, so it gets no bar line.

Form

• Form names any AABA arrangement ThirtyTwoBarAABA regardless of section length, and NamedForm.VerseChorus can never be produced #384: Form.Of names AABA ThirtyTwoBarAABA only when all four sections are exactly eight bars long. Otherwise the result is Unknown. Form.Parse("AABA") has no bar data, so it still names the 32-bar form, and the XML docs say so.
• NamedForm.VerseChorus is declared but Form never produces it; the spec's own verse–chorus example comes out Unknown #321 / Form names any AABA arrangement ThirtyTwoBarAABA regardless of section length, and NamedForm.VerseChorus can never be produced #384: VerseChorus is now recognized from section types. The rule is at least two verses and two choruses, and every verse is answered by a chorus before the next verse or the end. Intro, pre-chorus, post-chorus, bridge, solo, interlude, outro and coda sections are allowed anywhere; a Refrain or Other section rules it out. Blues is checked first, then verse-chorus, then AABA, then the letter pattern.
• Twelve-bar-blues Form does not round-trip: Form.Parse(form.ToString()) != form #447: option (b). ToString appends (Name) only when the name differs from the one the pattern implies, as in A (TwelveBarBlues), AABA (Unknown) and ABABCB (VerseChorus). Every other form prints exactly as it did before. Parse reads the suffix (only an exact NamedForm member name), so every Form round-trips with equality unchanged.

The README's AABA example now uses eight-bar sections so its comment stays true.

Tests

New StrictParsingTests cover every input from the issues. FormTests adds AABA length, verse-chorus, strophic, blues round-trip and malformed-name cases. The full Semantics.Test suite passes locally: 1813 passed, 12 skipped.

Commit is tagged [minor], because inputs that used to be accepted are now rejected and Form's text can carry a name.

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Generated by Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
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98.9% Coverage on New Code
0.0% Duplication on New Code

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