Changing show rules in multiple levels of headings

[psads-git]

I am trying to change the show rules of levels 2 and 3 of the headings, to remove the numbering. I am using the code below, which works when I uncomment the commented part. However, the compacted way that uses a for loop does not work. Could you please explain why the for loop approach does not work? Thanks!

#set heading(numbering: "1.")

#for i in (2, 3) {
  show heading.where(
    level: i
  ): it => {
    [#strong(it.body)]
  }
}

// #show heading.where(
//     level: 2
//   ): it => {
//     [#strong(it.body)]
//   }

// #show heading.where(
//     level: 3
//   ): it => {
//     [#strong(it.body)]
//   }


= head 1

== head 2

=== head 3

[xkevio]

Because in the first case, the show-rule is scoped to only affect everything inside of the for-loop.
In the second case, their scope is global.

[psads-git]

Thanks, @xkevio, for your clarification!

So, there is no more compact way of setting a show rule for multiple levels than setting a show rule for each level, without avoiding code repetition?

[laurmaedje]

It is possible like this:

#set heading(numbering: "1.")
#show: rest => {
  for i in (2, 3) {
    rest = {
      show heading.where(level: i): it => strong(it.body)
      rest
    }
  }
  rest
}

= head 1
== head 2
=== head 3

There are plans to make programmatic manipulation of show rules like this simpler, along these lines (but it's not yet implemented):

#apply for i in (2, 3) {
  show heading.where(level: i): it => strong(it.body)
}

Here the show rules would join together like content does, but an explicit apply would be necessary to ensure that the show rules "leak" intentionally.

What would also help (but is also unimplemented) is support for "or"-selectors in show rules (these currently only work with query()). Then, you could write something like:

#show heading.where(level: 2).or(heading.where(level: 3)): ..

[Julian-Wassmann]

Another option is to reconstruct the heading in a show rule. Note the parbreak(), which is important if you want the heading in its own line.

#show heading: it => {
  if it.numbering != none and not it.level in (2, 3) {
    counter(heading).display()
    h(0.3em)
  }
  it.body
  parbreak()
}

[psads-git]

Thanks, @laurmaedje, for your solution and explanations! The improvements you are planning appear to be in the right direction!

[psads-git]

Thanks, @Julian-Wassmann, for your solution!