interval method

@override Interval interval(Pitch other)

The interval between this Pitch and other.

Example:

Note.g.inOctave(4).interval(Note.d.inOctave(5)) == .P5
Note.a.flat.inOctave(3).interval(Note.d.inOctave(4)) == .A4
Note.c.inOctave(5).interval(Note.b.inOctave(4)) == -Interval.m2

Implementation

@override
Interval interval(Pitch other) {
  final ordinalDelta = other.note.noteName.ordinal - note.noteName.ordinal;
  final sizeDelta = ordinalDelta + 7 * (other.octave - octave);

  return .fromSizeAndSemitones(
    Size(sizeDelta.abs() + 1),
    difference(other).abs(),
  ).withDescending(sizeDelta.isNegative);
}