Change smallcaps into an element function

[Coekjan]

Description

Different from upper and lower, smallcaps is not always supported by selected font (for example, default font in math equation). In my view, smallcaps is more like emph, strong, etc. so I suggest it should be element function (#3977 ).

This pr closes #3977 and maybe can help those who want to use smallcaps in math equations (#3138 ).

Usage

With this feature, users can customize smallcaps behavior with set/show rules:

#set align(center)

$ #smallcaps[SmallCaps] $

#show smallcaps: set text(font: "linux libertine", fill: blue)

$ #smallcaps[SmallCaps] $

#show math.equation: it => {
  show smallcaps: set text(font: "linux libertine", fill: red)
  it
}

$ #smallcaps[SmallCaps inside Math Equation] $

#smallcaps[SmallCaps outside Math Equation]

TODO?

• Should I add some testcases to verify the behavior? If so, how can I add testcases?
• Should documentation on smallcaps be changed? If so, I can add examples about the set/show rules on smallcaps.

[laurmaedje]

Should I add some testcases to verify the behavior? If so, how can I add testcases?

The only existing smallcaps test is in tests/suite/text/smallcaps.typ. You can add a new test there by adding another --- smallcaps-... --- line there and adding your test code below. For instructions on how to run the tests, see the README.md in tests.

Should documentation on smallcaps be changed? If so, I can add examples about the set/show rules on smallcaps.

We could add a second example showing how to use a custom font, i.e. #show smallcaps: set text(font: "..") and adjust the Note in the docs.

[Coekjan]

Hi @laurmaedje , I've made the requested changes to this PR and was hoping you could find time for another review when convenient. Thank you!

[laurmaedje]

Thanks for your contribution!