Typst: symbols in equations are casified

[eltos]

Having math symbols in titles or headings is quite common in scientific writing. Consider the following example:

#import "@preview/decasify:0.11.2": *

#titlecase[Is it $pi$ or $e^x$ in the title]

The equations are incorrectly affected by the titlecasing:

Instead of the expected output:

[alerque]

Well, that's a bit unexpected! And yes, wrong. Frankly I'm surprised we're getting fed Unicode symbols and are even able to iterate those bits of the content.

The fix for this is probably fairly simple and on the Typst side of things in decasify.typ to check the content types before passing anything through to the WASM side of things and just pass through anything that is a math formula, but I'm also not sure off the top of my head what incantation is necessary. If anybody wants to jump in I'm open to a fix!

[alerque]

@eltos I took a stab at this in #56 and did get it to give the expected output — minus the fact that "in" is detected as the first word in a new sequence and hence capitalized. That might actually be a more involved problem, but it should already be covered by #38.

As commented in the PR though the Typst code to fix the rule on how to apply this does not sit well with me. If you happen to know better or what to bring this up on the Typst forum or discord it would be great to have some expertise take a gander at that bit.

[alerque]

I closed this because I merged #56 (my availability for FOSS work is spotty, so taking advantage of the time while I have a moment) but I'm definitely still open to a better implementation for the Typst script side of things. Also note that this doesn't fix the "in" or other minor words after math equations being capitalized, but that's covered in another open issue that affects more than Typst and I'm still looking into.