scr typefaces function to script letters

[SnO2WMaN]

Typst currently has cal as a calligraphic font (https://typst.app/docs/reference/math/variants/#cal), but it would be helpful to add the function scr as a script font. (See, for example, \mathscr at https://katex.org/docs/supported#style-color-size-and-font.) I need some of these alphabets in mathematical logic (when porting some my documents from written in TeX), but another example is the style used in the Hamiltonian of physics.

current cal in Typst

mathscr in KaTeX

My concern is that at least source code, cal is assigned in Unicode to the "Mathematical Script" series, so I think the only way to add scr would be "Mathmetical Bold Script", but have some doubts about whether that is reasonable or the point that there is also the issue of fonts.

[bluebear94]

Libertinus Math has the Mathematical Bold Script series as a bold version of Mathematical Script.

FreeSerif has the Mathematical Script series looking like scr and the Mathematical Bold Script series looking like cal.

[Enivex]

Unicode simply only has one range of calligraphic characters, and it's up to the font whether they should look like what LaTeX calls \mathcal or \mathscr.

It's therefore not possible for typst to provide a reliable scr command. Though you can make your own. Either by assigning scr to a different font with the look you want, or to the same font with different feature flags. Some fonts, like New Computer Modern Math and Stix Two Math use such flags to let the user pick a style for those codepoints.

[Trebor-Huang]

There seems to be a unicode variant selector for Chancery hand (mathcal) and Round hand (mathscr) on these characters.

[Enivex]

There seems to be a unicode variant selector for Chancery hand (mathcal) and Round hand (mathscr) on these characters.

Yes, that is a brand new thing. There's an open PR regarding this at this very moment.