ConTeXt writer: new section syntax and --section-divs

[hmenke]

Fixes #2609.

This PR introduces the new-style section headings.

\section[my-header]{My Header} -> \section[title={My Header},reference={my-header}]

On top of this, the ConTeXt writer now supports the --section-divs option to write sections in the fenced style

\startsection[title={My Header},reference={my-header}]

contents...

\stopsection

@pmazaitis @ousia @DaveJarvis

[hmenke]

This is not yet ideal. This piece of markdown

# Section
## Subsection
### Subsubsection
#### Subsubsubsection
##### Subsubsubsubsection
###### Subsubsubsubsubsection
####### Subsubsubsubsubsubssection

translates to

\section[title={Section},reference={section}]

\subsection[title={Subsection},reference={subsection}]

\subsubsection[title={Subsubsection},reference={subsubsection}]

\subsubsubsection[title={Subsubsubsection},reference={subsubsubsection}]

\subsubsubsubsection[title={Subsubsubsubsection},reference={subsubsubsubsection}]

\

\

The problem is not so much in the spurious backslashes but rather in the fact that even with the original behaviour section levels beyond 5 were silently discarded.

What should be the desired behaviour here? I would go for simply generating all those lower levels even if they are not predefined in ConTeXt. If the user wants to use such deep nesting they should just adapt their preamble.

[ghost]

What should be the desired behaviour here? I would go for simply generating all those lower levels even if they are not predefined in ConTeXt. If the user wants to use such deep nesting they should just adapt their preamble.

There are a number of possibilities:

• Define \stop and \start environments in the standalone preamble for the number of subsections encountered in the document that go beyond ConTeXt's default depth.
• Create custom title levels so ######### Title generates a preamble with \definehead[section9][section], where 9 indicates the title level depth, so the output becomes \section9 ....
• Introduce a \startsubject section, though this leaves a few issues: the subject sections are unnumbered and they wouldn't appear in the table of contents by default.
• Exit with an error code and message that indicate the number of nested levels is not yet supported.

In any case, it's probably most convenient (and least astonishing) to update the standalone preamble with the environments that allow the output to generate a document with the titles that reflect the author's intent.

Also, nice work on the --section-divs!

[hmenke]

@DaveJarvis

1. Writing defintions for the deeply nested sections to the preamble is certainly possible but only works for standalone documents which include the preamble. Also it is not the prettiest solution.
2. Definitely no.
3. You can use pandoc also with unnumbered sections so this would clash.
4. Isn't this the same as 1.?

I would just generate subsub...subsub and let the user worry about that. As you already mentioned, it's a weird edge case. There is also the subsub module to handle such deep nesting but it has some hick-ups.

[ghost]

I would just generate subsub...subsub and let the user worry about that. There is also the subsub module...

That's a good idea. Perhaps output a warning, then, directing the user to see the subsub module in the event they have nested too deeply?

[jgm]

+++ Henri Menke [Jan 23 18 15:20 ]:

What should be the desired behaviour here? I would go for simply generating all those lower levels even if they are not predefined in ConTeXt. If the user wants to use such deep nesting they should just adapt their preamble.

That sounds okay to me.

[hmenke]

@jgm Done. I have also added a test for --section-divs.

[jgm]

Thanks, merged!