Why does a display equation break a paragraph?

Questions
,
14

We discussed this on discord a while back and @Eric posted this way of controlling paragraph indent after an equation. This doesn’t change what the paragraphs are (the paragraphs are still separate), it just changes the indent.

equation without parindent
equation without parindent1500×660 175 KB

(Discord link)

#set par(first-line-indent: (amount: 2em, all: true))

#show math.equation: it => it + [#[ #[]<eq-end>]]
#show par: it => {
  if it.first-line-indent.amount == 0pt {
    // Prevent recursion.
    return it
  }
  
  context {
    let eq-end = query(selector(<eq-end>).before(here())).at(-1, default: none)
    if eq-end == none { return it }
    if eq-end.location().position() != here().position() { return it }
    
    // Paragraph start aligns with end of last equation, so recreate
    // the paragraph, but without indent.
    let fields = it.fields()
    let body = fields.remove("body")
    return par(
      ..fields,
      first-line-indent: 0pt,
      body
    )
  }
}

#lorem(15)

$ x = 10 $

#lorem(15)

#lorem(15)

I also experimented with a state based solution to add directives parindent and noparindent. While those look good on the surface, some shortcomings quickly become apparent. Typst Discord link, only

3 Likes