Plain-text reference to footnote

[msiniscalchi]

Description

Typst allows attaching labels to footnotes, as in #footnote[This is a test]<myfn>, and then referencing: See footnote @myfn. However, this results in the footnote being typeset as a superscript. It would be useful to have the option to show the reference as regular text. This is the default behavior in LaTeX, and may be a stumbling block for people moving over (it is for me).

Use Case

While footnotes should be used sparingly, they are useful to, for instance, elaborate on possible extensions of a result. In this case, sequences of footnotes arise quite naturally. Example:

Main text says: if X, then Y. Footnote 1 says: if X' instead of X, then we still get Y, provided we also assume Z.

Later, main text says: if X and W, then Q. Footnote 2 says: as in Footnote 1, if X' and W instead of X and W, we can still get Q provided we also assume Z.

The point is that it is useful to refer back to an earlier footnote, and it does not make sense for the label to appear as a superscript.

[freundTech]

You can use a custom function with a show rule for footnotes:

#let big-footnote(reference) = {
  show footnote: it => [
    footnote #numbering(it.numbering, ..counter(footnote).at(it.location()))
  ]
  reference
}

Hello World #footnote[This is a test]<myfn>

See #big-footnote[@myfn].

[msiniscalchi]

Thanks @freundTech. This works, though there is a space right after the footnote number.

In any event, for someone coming from LaTeX, the default typst behavior will come as a surprise. Perhaps a path-of-least-resistance solution is to explicitly mention this difference in the documentation, and offer this workaround for those who need it.

[freundTech]

Oh. I didn't notice that space. You can get rid of it by removing the newline after the number:

#let big-footnote(reference) = {
  show footnote: it => [footnote #numbering(it.numbering, ..counter(footnote).at(it.location()))]
  reference
}

[Enivex]

In any event, for someone coming from LaTeX, the default typst behavior will come as a surprise.

The motivation behind the behavior isn't so much references to footnotes, but reusing footnotes. This is the same thing you can do in LaTeX by using \footnotemark.

(As an aside, I feel that you may be misusing footnotes if you feel the need to reference them.)

[msiniscalchi]

The motivation behind the behavior isn't so much references to footnotes, but reusing footnotes. This is the same thing you can do in LaTeX by using \footnotemark.

Yes, I followed the convos on this on Discord. It's a design decision and I respect it -- just pointing out that LaTeX made a different design decision. And in any case, LaTeX provides both options out of the box, whereas typst requires you to roll your own if you want plain-text references.

(As an aside, I feel that you may be misusing footnotes if you feel the need to reference them.)

My example was admittedly contrived, but different fields, different conventions.

Overall, I think it may be enough to highlight this difference in the documentation, with @freundTech's workaround (which now works beautifully -- and it's wonderful to change code and see its effects on the fly!)

[Enivex]

Here's another solution with a show rule, making you able to reference footnotes like anything else.

#show ref: it => {
  let el = it.element
  if el != none and el.func() == footnote [
    Footnote~#numbering(el.numbering,..counter(footnote).at(el.location()))
  ] else {it}
}

Hello#footnote[world]<first>, and another#footnote[footnote]<second>

See @first or @second

[robamler]

Here's a variation of @Enivex's solution that displays:

• "Footnote X" if the footnote is on the same page as the reference; and
• "Footnote X on page Y" if the footnote is on a different page.

It also turns the references into links.

#show ref: it => {
  let el = it.element
  if el != none and el.func() == footnote {
    let loc = el.location()
    let f_number = numbering(el.numbering, ..counter(footnote).at(loc))
    let p_counter = counter(page).at(loc)
    if p_counter == counter(page).at(it.location()) {
      link(loc, [Footnote~#f_number])
    } else {
      let p_number = numbering(loc.page-numbering(), ..p_counter)
      link(loc, [Footnote~#f_number on page~#p_number])
    }
  } else {
    it
  }
}

(It capitalizes "Footnote" but not "page", which seems like the right thing to me but I can't tell why.)

[curioustolearn]

I think it would be good to be able to reference footnote numbers as regular text as LaTeX allows.

[TheBlckbird]

I agree with this, especially because there still seems to be a difference between the two versions:

My text#footnote[yay]<a> is awesome.

This one@a too.

And this one#footnote(<a>)

This produces the same result with default styling, but when styling refs, it looks different:

#show ref: underline
#show ref: set text(fill: blue)

Even though a comment on the original PR suggests something different: https://github.com/typst/typst/pull/1546#issuecomment-1603318719