New in version 1.1.
Label leaves in expr with leaf numbers:
abjad> staff = Staff("c'8 d'8 e'8 f'8")
abjad> leaftools.label_leaves_in_expr_with_leaf_numbers(staff)
abjad> f(staff)
\new Staff {
c'8 _ \markup { \small 1 }
d'8 _ \markup { \small 2 }
e'8 _ \markup { \small 3 }
f'8 _ \markup { \small 4 }
}
Number leaves starting from 1.
Changed in version 2.0: renamed label.leaf_numbers() to leaftools.label_leaves_in_expr_with_leaf_numbers().
Return none.