Refactor scoping / selection

[trevorbaca]

• [ ] item 0: add abjad.leaves().trim() and then replace baca.tleaves() for legibility.

• [ ] item 1: change all selectors to either baca.leaf() or else baca.leaves(). Two reasons. First, it's proven too difficult to remember the selector defaults provided to functions throughout the API. Second, selector defaults have turned out to be less likely than initially thought: too many cases where a function defaulting to baca.phead(0) makes sense with baca.leaf(0) instead, for example. This will also mean changing rmakers defaults to abjad.leaf() or else abjad.leaves(), too.

• [ ] item 2: integrate measure-distributive scoping.

Now:

maker(
    ('v1', [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)]),
    stirrings_still.trajectories('C', 0, -3),
    )

maker(
    ('v2', [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)]),
    stirrings_still.trajectories('C', -1, -2),
    )

maker(
    ('va', [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)]),
    stirrings_still.trajectories('C', -2, -1),
    )

maker(
    ('vc', [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)]),
    stirrings_still.trajectories('C', -3, 0),
    )

Better:

maker(
    [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)],
    baca.new(
        stirrings_still.trajectories('C', 0, -3),
        voice='v1',
        ),
    baca.new(
        stirrings_still.trajectories('C', -1, -2),
        voice='v2',
        ),
    baca.new(
        stirrings_still.trajectories('C', -2, -1),
        voice='va',
        ),
    baca.new(
        stirrings_still.trajectories('C', -3, 0),
        voice='vc',
        ),
    )

Best:

maker(
    [(29, 30), (34, 35), (37, 38), (40, 41), 44, 46, (50, 57)],
    baca.new(
        stirrings_still.trajectories('C', 0, -3),
        stirrings_still.trajectories('C', -1, -2),
        stirrings_still.trajectories('C', -2, -1),
        stirrings_still.trajectories('C', -3, 0),
        voice=baca.thread(['v1', 'v2', 'va', 'vc']),
        ),
    )

Integrate to Stirrings Still [B].

• [ ] item 3: integrate mapped partition selectors.

Now:

    baca.staff_position(
        0,
        selector=baca.leaves()[:3],
        ),
    baca.staff_position(
        1,
        selector=baca.leaves()[3:],
        ),

Better:

    baca.staff_position(
        [0, 1],
        selector=baca.leaves().partition_by_counts([3], overhang=True),
        ),

Integrate into Fabergé J.

[trevorbaca]

Still valid in October 2018.