def parse_kern_octave(note, accs, lineno=1):
"""Calculate the octave of a note in the kern representation.
Since kern uses repetition and case to indicate octave, we need to
parse it. The central octave is 4, these are the most common
octaves: ccc = 6, cc = 5, c = 4, C = 3, CC = 2, CCC = 1, CCCC = 0
This is a basic example of use:
>>> parse_kern_octave('bb', '')
5
And we need to take care of the cases where an accidental will
change the octave:
>>> parse_kern_octave('bb', '#')
6
"""
size = len(note)
if size > 0:
if note[0].islower():
octave = 3 + size
else:
octave = -size + 4
assert size <= 4, "octave can't be lower than 0, the value is " + str(octave)
else:
kern_error("Note can't be empty.", lineno)
n = music.string_to_code(note[0], "", "base12")
a = music.accidental(accs)
return octave + ((n + a) // 12)
def parse_kern_item(item, note_system="base40", lineno=1, itemno=1):
tokens = kern_tokenizer(item, lineno)
if (not tokens['dur']) and ((not tokens['acciac']) or (not tokens['app'])):
kern_error("Duration can't be NULL.", lineno)
if (tokens['note'] and tokens['rest']):
kern_error("A note can't have a pitch and a rest.", lineno)
dur = int("".join(tokens['dur']))
dots = len(tokens['dot'])
duration = music.calculate_duration(dur, dots)
if tokens['note']:
notename = "".join(tokens['note'])
acc = "".join(tokens['acc'])
name = parse_kern_note(notename, acc)
note = Note(name, duration)
note.articulations = tokens['art']
note.beams = tokens['beam']
note.octave = parse_kern_octave(notename, acc, lineno)
note.code = music.string_to_code(notename[0], acc, note_system, note.octave)
note.system = note_system
note.type = "kern"
return note
elif tokens['rest']:
wholeNote = not bool(tokens['rest'] or len(tokens['rest']) >= 1)
return Rest(duration, wholeNote)
else:
kern_error("Kern data must have a note or rest.", lineno)
def test_string_to_code_bf_base12():
assert music.string_to_code("b", "-", "base12") == 10
def test_string_to_code_bs_base12():
assert music.string_to_code("b", "#", "base12") == 0
def test_string_to_code_cs_base40():
assert music.string_to_code("c", "#", "base40") == 4
