Support for two-page entries in table of contents

[jodros]

For example, these books have, for each chapter/section, a page number where the content itself is, and besides it is the page with its corresponding commentaries.

[Omikhleia]

Interesting examples. It's kind of a "niche" use case, and I can think of several ways for doing it, though it requires specific segmenting commands that go beyond a regular "book" class.

[alerque]

I've done something like this already. It isn't hard to stuff extra information in the TOC data entries that get saved in an info file, and then use them when typesetting the TOC.

For example I used it in a commentary on Galatians that kept track of the chapter/verse ranges covered in each chapter, then added that info to the TOC.

Given the plethora of different content could be handled this way I'm not sure what a robust higher level API would look like. SILE already provides the lower level building blocks for the to be possible to implement.

Thoughts?