*TODO: chapter overview*

## Misparsing and then cleaning up {#sec-misparsing}

Pandoc offers two ways to implement a syntax extension to Markdown:
either an import extension or a filter for its AST.
This project chose the latter approach,
which may initially seem unusual.

*TODO: About the approach of parsing as Markdown and adjust the fallout,
instead of writing an import extension.*

## Choice of Lua

This project is implemented in the scripting language Lua.

Pandoc filters can be written in any general-purpose language.
Pandoc provides a JSON serialisation and parsing API for its AST,
which some filters make use of.
JSON-based Pandoc filters have been found in active use
that are written in Haskell (same as Pandoc itself), Python, Perl and Rust.

In recent years, Pandoc has embedded a Lua interpreter
and offers the alternative of processing Lua filters
without the need for full serialisation and parsing or for making system calls.
For one simple test, a Lua implementation had an overhead of 2%
compared to 35% for a Haskell-based implementation via the JSON interface
[@MacFarlane2025, section "Introduction"].

While efficiency is desirable,
user convenience is prioritised in this project.
General experience using the Pandoc-based Quarto framework indicates
that non-Lua filters often require additional quirks
like placement in a specific directory, adding a symbolic link
or passing its full path,
whereas Lua filters usually work provided only a relative path.
That issue might be specific to the Quarto framework,
but even that aside, Lua-based filters are quite common
and the documentation for writing them more detailed
than the legacy JSON-based interface.

## Components

*TODO: First parse Namespace blocks, then AnnotationWords*

## Tracking enclosure states

*TODO: Details of parsing AnnotationWords
through correlating Pandoc AST with 4 enclosure states*