Description

Feature

(Split off from #3001)

Depends on #5375

Have the ability to specify "levels" of headers and footers, such that a table can be split into multiple sections (each section has a top-level header), and each section may have its own "internal" headers and footers (subsections) which repeat together with the top-level header / are also "sticky". They'd be repeated until the next top-level header, or the next subheader under the same top-level header.

This could be made flexible enough to accept any amount of nesting levels / subsub...subsections (probably rare for actual tables, but could be more useful for layout abstractions using grids).

For example, you'd have something like

#table(
  columns: 2,
  // First section
  table.header(table.cell(colspan: 2)[*Europe*]),
  table.subheader([*Name*], [*Age*]),
  [Peter], [55],
  [Mary], [48],
  table.subheader([*Name*], [*Preference*]),
  [Joseph], [Banana],
  [Jane], [Apple],

  // Second section
  table.header(table.cell(colspan: 2)[*South America*]),
  table.subheader([*Name*], [*Age*]),
  [Pedro], [55],
  [María], [48],
  table.subheader([*Name*], [*Preference*]),
  [José], [Grape juice],
  [Robert], [Strawberry],
)

Which, if broken apart, would generate the following output:

Use Case

Have the flexibility to create table subsections. (The proposed syntax could also be changed to reflect that.)

See ConTeXt's table sections for some inspiration: https://wiki.contextgarden.net/TABLE#Multipage_TABLEs