Re: Inheritance / fallback for lua writers?

[Albert Krewinkel <albert+pandoc-9EawChwDxG8hFhg+JK9F0w@public.gmane.org>]

Hi Sven,

Sven Lauer writes:
>
> is there a way to "inherit" from another writer when coding a lua writer?
>
> [...]
>
> If this is not possible, is there any chance this could be included in
> the future?

Pandoc's writers expect full AST elements as inputs, which are not
available to the functions in custom writers: the nested elements have
already been turned into strings. There is thus no sane way to write
such a function. We would need to completely refactor custom writers to
make this possible. Using a filter is the best one can do right now.

> (Right now, I am using a lua filter that transforms the spans in question
> to RawInlines (a la
> https://ulyngs.github.io/blog/posts/2019-02-19-how-to-use-pandoc-filters-for-advanced-customisation-of-your-r-markdown-document/ )
> - but this seems hacky, since all I want is to specify how to output those
> spans in a particular output format ... which should be done in a writer,
> shouldn't it?

Lua filters are a good choice; use-cases like this match the intended
usage. If you'd like, you could add a line like this to the top of your
filter

    if not FORMAT:match 'tex$' then return {} end

This will ensure that the filter won't modify anything unless the target
format is LaTeX.

HTH,

Albert