Conceal support for more math text style commands

[patnr]

As mentioned after resolution of #1972 I use \mathds to produce (e.g.) the double-struck 1, and would like to see it concealed. Seeing as this is a fairly common use case, I would say adding it to vimtex is reasonable. @lervag agrees that concealment for some more font style commands may be added. However, which ones to add? It's beyond me to firmly judge which ones are pertinent or frivolous, but the following lists those not already in vimtex that appear at the top of this popular stackexchange answer.

To be rendered in bold:

• pmb
• bm

To be rendered as double-struck

• mathds
• mathbbb
• mathbbm
• mathbbmss
• mathbbmtt
• varmathbb

To be rendered as Goth/Frak:

• textfrak
• textswab
• textgoth

@lervag also mentioned that this might be activated upon availability of the corresponding package.

[lervag]

I've pushed an update that should solve at least your issue here. I did not consider pmb, bm, and the text* variants as of now, since I'm not sure if these are really of interest. Perhaps bm is; I can remember using it myself. But the other seems to be fringe commands?

[patnr]

Sorry for the latency. I certainly never used the text* variants, but bm I use a lot. Oh, but I see now that you did also conceal bm! It all looks good to me, except that the use case I mentioned above (double struck 1) is not concealed. However, I personally now have that handled like this anyways:

let g:vimtex_syntax_custom_cmds = [
      \ {'name': 'ones', 'mathmode': 1, 'concealchar': '𝟙'},
      \]

[lervag]

Ah, yes, I've only added the double struck for alphabetic characters. I could add this also for the numbers - it is a trivial change. Will do it later today.

[lervag]

Double struck should work with all letters (a-zA-Z) and numbers (0-9) now.