Trace types that share the bar extraction: one category and one value per
mark, read the same way whichever mark is drawn.
A dot plot draws a point where a bar chart draws a bar, a lollipop adds a
stem to the baseline, and a funnel draws its stages as trapezoids — none of
which changes what a reader navigates, so all four are built by
buildBarLayer and differ only in the type the layer announces.
Trace types that share the bar extraction: one category and one value per mark, read the same way whichever mark is drawn.
A dot plot draws a point where a bar chart draws a bar, a lollipop adds a stem to the baseline, and a funnel draws its stages as trapezoids — none of which changes what a reader navigates, so all four are built by buildBarLayer and differ only in the type the layer announces.