Enhancement: Visual support for Pandoc-style ::: Div blocks (matching, folding, navigation)

[fretwurst]

Description

Note on context and origin of this question
This question was originally raised in the Positron discussion board. I was advised there to move the topic here, as it appears to concern the structure and behavior of Quarto extensions rather than Positron itself.

I'm therefore reposting the question here, as recommended. Thank you in advance for your support!

Enhancement: Visual pairing and navigation support for Pandoc ::: Div blocks in Quarto documents

Context

Quarto relies heavily on Pandoc-style Div blocks using the ::: syntax to structure content, style callouts, create columns, collapsibles, etc. These blocks are increasingly used for layout and interactivity, especially in Reveal.js presentations or Quarto books.

However, the ::: syntax has no native editor support for:

• Bracket matching (like {} or ()),
• Folding by nesting level,
• Visual pairing or indentation to show the block structure.

This makes it difficult to maintain clean documents, especially when using modular includes or multiple nested Divs with 4+ colons like ::::::. Mistakes (unclosed blocks) are only caught as Pandoc warnings such as:

[WARNING] Div at line 3629 unclosed at line 17148, closing implicitly.

Problem

As users, we are forced to:

• Manually count colons (::: vs :::::),
• Comment every block open/close manually,
• Search large documents line-by-line for mismatches.

This is error-prone and doesn't scale with complex or reusable content (e.g., via include:).

Proposal

Positron (or VS Code via the Quarto extension) could provide:

• Bracket matching for ::: blocks, similar to {} or [].
• Folding support based on nesting depth or ::: levels.
• Gutter icons or scope highlighting for nested Divs.
• Optional: Linting for unmatched ::: pairs, like unclosed HTML tags.

Even simple support such as scope matching or minimal indentation guides would drastically improve usability for Quarto authors.

Example Use Case

:::::: {.callout-note collapse="true"}
::::: {.columns}
:::: {.column width="60%"}
- Content…
::::
:::: {.column width="40%"}
- Image…
::::
:::::
::::::

Currently, it's hard to track visually whether all blocks are closed correctly, especially across includes.

Closing Thoughts

As Quarto becomes more widely used for complex documents, this is an increasingly pressing issue. A lightweight implementation (even optional) would provide great benefit to the growing base of scientific and technical users.

[cderv]

thanks for your feature request. I moved it to the quarto-dev/quarto repo, which is where Quarto Extension improvement takes place.

• Enhancement: Visual support for Pandoc-style ::: Div blocks (matching, folding, navigation) quarto#720

You may also search this repo for similar or related topic to add your 👍 to.