(SpanBar . (
(break-align-symbol . Staff_bar)
(bar-size-procedure . ,Span_bar::get_bar_size)
- (molecule-callback . ,Span_bar::brew_molecule)
+ (molecule-callback . ,Bar::brew_molecule)
(visibility-lambda . ,begin-of-line-invisible)
(X-extent-callback . ,Span_bar::width_callback)
(Y-offset-callbacks . (,Span_bar::center_on_spanned_callback))