In-text, note and bibliography citation styles are not supported as per their definition

[Omikhleia]

As of 0.14.17-0.15.0, the bibtex package provides two commands:

• "an inline citation", with \cite -- in our current Chicago-style author-date implementation, (Doe 2023)
• "a full reference", with \reference -- in our Chicago-style implementation... something, but see below....

The crux of the matter is that most bibliography styles define not 2, but 3 ways of formatting entries -- and. Chicago doesn't make an exception here...

• "in-text" citation = how one would format a citation in the text flow. In "true" form: Some text (Doe, 2023; Smith, 2024).
• "note" citation = how one would format a (ex. foot)note. A longer form, e.g. John Doe, "My Article." etc.
• "bibliography" reference = how one format the entry in a bibliography (typically at the end of an article), e.g. Doe, John. "My Article." etc.

Where does CSL stands?

• It usually has 2 different style files, one for "in-text" <citation> and one for "note" <citation>
• This does make sense, because:
  • Normally one does not mix both citation types in a given work.
  • The <bibliography> reference format usually depends on the former citation style, e.g. (I'm simplifying)
    • With "in-text citations (Doe, 2023), the reference in a bibliography would be keyed: Doe, John. 2023. "My Article." etc.
    • With "note" citations, the reference in a bibliography would be keyed: Doe, John. "My Article." etc. (note the use of a period here, not a comma)

Where does SILE stands?

• \cite corresponds to the "in-text" citation but takes one key only, so can't handle (Doe, 2023; Smith 2024)...
• \reference is unclear, but the fact that it uses a comma after the contributors hints toward a "note" citation style, not a bibliography one...

So nothing is right here.

[Omikhleia]

I wonder what's the path here:

• Fix our Lua implementation as a MWE.
• Use a CSL engine such as citeproc-lua - not obvious due to the ties with LuaTeX
• Use another CSL engine, e.g. Rust-based now that 0.15 is surfacing, such as hayagriva (And let's bits of Typst enter SILE. Erm...)

[alerque]

I'm not opposed to leveraging stuff Typst uses or provides. The biggest thing I'd note is that the main distinctive at this point is that we give users free reign with all the internals at run time, and Typst takes the opposite approach of allowing nothing. That doesn't mean we can't wrap some libraries and provide their functions to Lua and have that be a good usable interface for folks, but it does affect the boundary of where tinkering can and can't happen.

[Omikhleia]

On this particular issue, fixing our existing code at least to have a reference implementation for earlier iterations might be the easiest way to go...

But eventually, CSL support would need to be considered, and it's typically a case where a 3rd party library could be neat -- SILE would keep the hands on providing the bib entries and formatting the output, but it should not need tinkering with the internals (CSL XML parsing, implementation of rules etc.)

[Omikhleia]

Vs. CSL = sure, CSL support would make most of this issue moot.

I'm keeping it though: There would be an interested challenge checking (from the CSL style) whether the style is "in-text" or "note", the citation command should output a text content... or directly a \footnote... I'd want to check how feasible this is (and one problem might be whether we need to "gobble" spaces before the \cite to make it generic, but space-gobbling and punctuation-shifting is too Latex-reminiscent for me to be sure, years after remembering it ;)