Pandoc: Convert links to footnotes (the easy way)

#guide#note#writing#til#tech#programming#pandoc

Pandoc has a feature to covert links to footnotes. Unfortunately, this only applies to LaTeX documents. Since I want to stay away from LaTeX for reasons of bloat, I was looking for a more universal approach.

First, I encountered this thread suggesting to use a regular Pandoc filter. This has one downside though: you need a Haskell toolchain on your system. So I moved on ...

I eventually stumbled across this thread, explaining how to do the same thing but with a Lua filter instead of Haskell. Since Lua is embedded into Pandoc, you don't need to install anything. Hooray for embeddable languages!

Simply place the following snippet into file (/filters/link-to-footnote.lua for example):

function Link(link)
    link.content:insert(pandoc.Note(link.target))
    return link.content
end

Note: If you want to keep the original hyperlink in tact, replace the return link.content with return link.

And add the following flag to your Pandoc build command:

#!/bin/sh
pandoc text.md
    -o book.epub \
    --lua-filter=filters/link-to-footnote.lua \ # <-- This one
    --metadata-file metadata.yaml \
    --standalone \
    # ...

After compiling the document, you should now see that each link has a footnote with the link text.

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