FiguredBass object (#1614)

* introduces FiguredBass object and makes some changes to Notation and Figures objects

* indentation update

* corrections to notation PR #1614

* added requested changes to figuredbass and notation object

* first commit for fixing issues in place.

* move FiguredBass object to figuredBass.FiguredBass

* lint and mypy

* Cover uncovered test lines. https://coveralls.io/builds/60910555

Check for what is not being covered by tests when adding new features please.

* reuse your setters, Myke!

---------

Co-authored-by: Moritz Heffter <[email protected]>
Co-authored-by: Michael Scott Asato Cuthbert <[email protected]>

music21/figuredBass/__init__.py

@@ -4,17 +4,22 @@
 __all__ = [
     'checker',
     'examples',
+    'harmony',
     'notation',
     'possibility',
     'realizer',
     'realizerScale',
     'resolution',
     'rules',
     'segment',
+
+    'FiguredBass',
 ]
 
 from music21.figuredBass import checker
 from music21.figuredBass import examples
+from music21.figuredBass import harmony
+from music21.figuredBass.harmony import FiguredBass
 from music21.figuredBass import notation
 from music21.figuredBass import possibility
 from music21.figuredBass import realizer

music21/figuredBass/harmony.py

@@ -0,0 +1,164 @@
+# ------------------------------------------------------------------------------
+# Name:         figuredBass.harmony.py
+# Purpose:      Music21Object for FiguredBass as a Harmony subclass
+#
+# Authors:      Moritz Heffter
+#               Michael Scott Asato Cuthbert
+#
+# Copyright:    Copyright © 2011-2023 Michael Scott Asato Cuthbert
+# License:      BSD, see license.txt
+# ------------------------------------------------------------------------------
+'''
+The FiguredBass object is a subclass of Harmony that will (eventually) be able
+to represent figured bass symbols in music notation and also realize it.
+
+BETA at this point.
+
+Based on work by Jose Cabal-Ugaz.
+'''
+from __future__ import annotations
+
+from collections.abc import Iterable
+
+from music21.harmony import Harmony
+
+from music21.figuredBass import notation
+
+
+class FiguredBass(Harmony):
+    '''
+    *BETA*: FiguredBass objects are currently in beta and may change without warning.
+
+    The FiguredBass objects store information about thorough bass figures.
+    It is created as a representation for <fb> tags in MEI and <figured-bass> tags in MusicXML.
+    The FiguredBass object derives from the Harmony object and can be used
+    in the following way:
+
+    >>> fb = figuredBass.FiguredBass('#,6#')
+    >>> fb
+    <music21.figuredBass.harmony.FiguredBass #,6#>
+
+    (note that the FiguredBass object can be found in either music21.figuredBass.FiguredBass
+    or music21.figuredBass.harmony.FiguredBass.  It is the same class)
+
+    The single figures are stored as figuredBass.notation.Figure objects:
+
+    >>> fb.notation.figures[0]
+    <music21.figuredBass.notation.Figure 3 <Modifier # sharp>>
+
+    The figures can be accessed and manipulated individually by passing in `figureStrings`
+    (plural), and extenders are allowed as with `_`:
+
+    >>> fb2 = figuredBass.FiguredBass(figureStrings=['#_', '6#'])
+    >>> fb2
+    <music21.figuredBass.harmony.FiguredBass #_,6#>
+    >>> fb2.notation.hasExtenders
+    True
+
+    Currently, figured bass objects do not have associated pitches.  This will change.
+
+    >>> fb.pitches
+    ()
+
+    * new in v9.3
+    '''
+    def __init__(self,
+                 figureString: str = '',
+                 *,
+                 figureStrings: Iterable[str] = (),
+                 **keywords):
+        super().__init__(**keywords)
+
+        self._figs: str = ''
+
+        if figureString != '':
+            self.figureString = figureString
+        elif figureStrings:
+            self.figureString = ','.join(figureStrings)
+
+        self._figNotation: notation.Notation = notation.Notation(self._figs)
+
+    @property
+    def notation(self) -> notation.Notation:
+        '''
+        Gets or sets the notation property of the FiguresBass object
+
+        >>> fb = figuredBass.FiguredBass('6,#')
+        >>> fb.figureString
+        '6,#'
+        >>> fb.notation
+        <music21.figuredBass.notation.Notation 6,#>
+
+        When setting, this updates the figureString property as well.
+
+        >>> fb.notation = figuredBass.notation.Notation('7b,b')
+        >>> fb.notation
+        <music21.figuredBass.notation.Notation 7b,b>
+        >>> fb.figureString
+        '7b,b'
+        '''
+        return self._figNotation
+
+    @notation.setter
+    def notation(self, figureNotation: notation.Notation):
+        self._figNotation = figureNotation
+        self._figs = figureNotation.notationColumn
+
+    @property
+    def figureString(self) -> str:
+        '''
+        Get the figures as strings of the FiguresBass object.
+
+        >>> fb = figuredBass.FiguredBass('6,#')
+        >>> fb.figureString
+        '6,#'
+        >>> fb.notation
+        <music21.figuredBass.notation.Notation 6,#>
+
+        When setting the figureString the notation property is updated as well:
+
+        >>> fb.figureString = '5,b'
+        >>> fb.figureString
+        '5,b'
+        >>> fb.notation
+        <music21.figuredBass.notation.Notation 5,b>
+        '''
+        return self._figs
+
+    @figureString.setter
+    def figureString(self, figureString: str):
+        self._figs = figureString
+        self.notation = notation.Notation(self._figs)
+
+    @property
+    def figureStrings(self) -> list[str]:
+        '''
+        Does the same as figureStrings but returns a list:
+
+        >>> fb = figuredBass.FiguredBass('6,#')
+        >>> fb.figureStrings
+        ['6', '#']
+
+        Like figureString, figureStrings can be set as well and updates the notation property:
+
+        >>> fb.figureStrings = ['5', 'b']
+        >>> fb.figureStrings
+        ['5', 'b']
+        >>> fb.notation
+        <music21.figuredBass.notation.Notation 5,b>
+        '''
+        return self.figureString.split(',')
+
+    @figureStrings.setter
+    def figureStrings(self, figureStrings: Iterable[str]) -> None:
+        self.figureString = ','.join(figureStrings)
+
+    def _reprInternal(self):
+        return self.notation.notationColumn
+
+
+# ------------------------------------------------------------------------------
+if __name__ == '__main__':
+    import music21
+    music21.mainTest()
+