- the \label command can be used at top-level (Page_marker) or inside
music (LabelEvent);
- for labels inside music: the paper_column_engraver handles
label-events and fills the labels property of the paper column;
- for top-level labels: Paper_book::get_system_specs() fill the labels
property of the previous prob or of the first column of the previous
paper_score;
- when systems are built, the labels of their columns are collected to
set the system labels property;
- in Page_breaking::make_pages(), a label->page-number table is built,
and stored in a variable of the paper_book paper;
- the \page-ref markup command accesses the table though its layout
argument. The actual evaluation of the stencil is postponed to the
layout output phase using a new stencil command:
delayed-stencil-evaluation;
- a MARKUP_HEAD_SCM0_MARKUP1_MARKUP2 token has been added to the
parser for this new markup command.