Find homes for changes in 1.4 to LUA and AST

[cwickham]

The changes in LUA and AST processing don't belong in the Guide, but probably belong somewhere in Extensions > Creating Extensions. (We might also consider moving the changes to AST in 1.3)

[Edit: Expanding these three items out by section to make discussion easier]

AST processing changes in v1.4:

• Finer control over table processing Currently covered in https://quarto.org/docs/authoring/tables.html#disabling-quarto-table-processing
• Include Quarto markdown in LaTeX Raw Blocks Candidate for Advanced Docs?

Lua filter changes:

• Support for crossreferenceable elements in filters
• Custom formats and Custom renderers
• Relative paths in require() calls
• More precise targeting of AST processing phases

AST in 1.3:

• Custom AST Nodes: Callouts, Tabsets, Conditional Blocks

[mcanouil]

I've seen many users using Lua filters without using Quarto extensions mechanism.
I think some users don't know they don't have to write extensions to use a Lua filter (especially all the Lua filters developed initially for Pandoc).

Here the "Extensions" pages should be read as "Extend Quarto with Lua filters, shortcodes formats and possibly distribue as Quarto extensions" but I feel users are reading this as "Use Quarto Extension mechanism", especially since this part starts with a listings of extension followed by how to create extensions.

(my two cents)

FYI, in discussions, there are several simple examples of Lua filters (a lot written by @cscheid):

• exporting all fig-alt together with figure numbers #7526 (comment)
• Create a customised environment #7864 (comment)
• Is there a way to wrap theorems and the linke in tcolorboxes when the output is PDF? #7313 (reply in thread)
• Custom filter for processing Github/Obsidian style callouts stopped working - any tips? #6550 (reply in thread)
• accessing yaml sequence metadta #6111 (comment)

https://github.com/quarto-dev/quarto-cli/discussions?discussions_q=label%3Alua

[cwickham]

Ah, that's a really good point. And there are other things that fall into the "customizing output without actually writing an extension" bucket, like using template partials, that we only talk about in the context of creating extensions.

This might need to part of a larger discussion/redesign of the Extensions section.

[cwickham]

Related issue #4926