Module music_df.humdrum_export.merge_spines

Functions

def merge_spines(humdrum_contents: str) ‑> List[str]

Expand source code

def merge_spines(humdrum_contents: str) -> t.List[str]:
    """
    Args:
        humdrum_contents: should consist of humdrum-formatted spines,
            where each spine begins with a **kern token. E.g.,
        TODO example
    """

    def _init_measure():
        nonlocal measure
        nonlocal not_rests
        out = []
        if not any(not_rests):
            not_rests[0] = True
        if measure:
            for i, not_rest in enumerate(not_rests):
                if not_rest:
                    out.append(measure[i])
        if out:
            measures.append(out)
        measure = defaultdict(list)
        not_rests = [False for _ in range(n_spines)]

    lines = humdrum_contents.splitlines()
    n_spines = lines[0].count("\t") + 1
    measures = []
    measure = defaultdict(list)

    # not_rests indicates whether each spine contains notes (i.e., not only
    #   rests) within each measure. It is re-initialized by _init_measure().
    not_rests = [False for _ in range(n_spines)]

    for line_i, line in enumerate(lines):
        if line.startswith("="):
            _init_measure()
            continue
        for i, token in enumerate(line.split("\t")):
            assert token != "="
            if _is_note_token(token):
                not_rests[i] = True
            measure[i].append(token)

    # (Malcolm 2023-10-20) calling _init_measure appends the final measure to the
    # output
    _init_measure()

    out = []
    n_spines = len(measures[0])
    for measure in measures:
        _sort_measure_spines(measure)
        delta = len(measure) - n_spines
        if delta > 0:
            for d in range(delta):
                out.append("\t".join(["*"] * (n_spines - 1 + d) + ["*^"]))
        elif delta < 0:
            # 3 -> 2
            # delta = -1
            # n_spines = 3
            #
            for d in range(-delta):
                out.append("\t".join(["*"] * (n_spines - 2 - d) + ["*v", "*v"]))
        n_spines = len(measure)
        out.append("\t".join(["="] * n_spines))
        for row in list(map(list, zip(*measure))):
            out.append("\t".join(row))
    # The first row is a spurious barline that we don't in fact want
    return out[1:]

Args

humdrum_contents

should consist of humdrum-formatted spines, where each spine begins with a **kern token. E.g.,

TODO example