Source code for orbichord.symbol

"""Map postonal chord names to symbols commonly found on lead sheets."""

from copy import deepcopy
from music21.chord import Chord
from orbichord.identify import chordSymbolIndex
from orbichord.maps import SYMBOL_INDEX_TO_FIGURE


def hasChordSymbolFigure(chord : Chord) -> bool:
    """Return true if the chord has figure.

    This only applies to chords commonly found on lead sheets.

    Parameters
    ----------
        chord : Chord
            Chord to be identified.

    Return
    ------
        bool:
            Return if symbol figure exist (named chord).
    """
    key = chordSymbolIndex(chord)
    return key in SYMBOL_INDEX_TO_FIGURE


def chordSymbolFigure(
        chord : Chord,
        inversion : int = None,
        enharmonic : int = 0
    ) -> str:
    """Identify chords based chord symbol figure.

    This only applies to chords commonly found on lead sheets.

    Parameters
    ----------
        chord : Chord
            Chord to be identified.
        inversion : int, optional
            Inversion index.
        enharmonic : int, optional
            Enharmonic index

    Return
    ------
        str
            A string with with the chord symbol figure.
    """
    key = chordSymbolIndex(chord)
    if key not in SYMBOL_INDEX_TO_FIGURE:
        return chord.pitchClasses
    figure, inversions = SYMBOL_INDEX_TO_FIGURE[key]
    if inversion is None:
        return figure[enharmonic]
    key = inversions[inversion]
    figure, _ = SYMBOL_INDEX_TO_FIGURE[key]
    return figure[enharmonic]