Conceal support for \mathbf and \mathrm

[lervag]

This was raised by @Konfekt in #1883 (comment) and also discussed several years ago in #557. Since VimTeX v2.0, this should be relatively straightforward to implement.

Before I implement anything, I wanted to be sure I "understand" the feature. We want:

• \mathbf{text} to be displayed as simply text but bolded.
• \mathrm{text} to be displayed as text (not bold).

Is there anything more?

[lervag]

For reference, here is how this is implemented in tex-conceal.vim.

[whisperity]

In addition, there is \text which is frequently used in math mode to fall back to text mode, which might have to be handled the same way \mathrm is.

[Konfekt]

These should be all text style modification commands:

\text
\textnormal
\textrm
\textbf
\textit
\textup
\textsl
\textsc
\textsf
\texttt
\mathbb
\mathbf
\mathscr
\mathcal
\mathrm
\mathfrak

For example \mathbb and \mathcal are already implemented in some cases.

[patnr]

Not sure if this is a good idea. But here goes.

It'd be great if it were possible to conceal custom macros/commands. Use case: I have a "master" macro that I use to define my vector and matrix text-styles. Typically this re-directs to mathbf, but depending on journal, it could re-direct to something else. It'd be great if I could use conceal on these with the bold style for example. If not implemented, perhaps it could be documented how to do it?

[Konfekt]

@patricknraanes Are you asking for something like adding a line

syn match texMathSymbol '\\C' contained conceal cchar=ℂ

to ~/.vim/after/syntax/tex/conceal.vim to conceal your custom command \C to ℂ?

[patnr]

Thanks, but I was thinking more something like the following example:

\newcommand{\mat}[1]{{\mathbf{{#1}}}}
\newcommand{\vect}[1]{{\bm{#1}}}

And then in the text I might write $ \mat{A} \vect{x} = \vect{b}$ which would conceal as A x = b somehow (how?)

The advantage of this system is that I can easily change the text styles for vectors and matrices. And I'd be cool if I could get conceal working for it.

[lervag]

These should be all text style modification commands:

\text
\textnormal
...
\mathrm
\mathfrak

For example \mathbb and \mathcal are already implemented in some cases.

Ok, so, this is developing into several related features in one issue. I understand that it might seem "trivial" to know which of the various commands should come under which category, but I don't know this. So, please, can someone please categorize according to my following list and also preferably show explicit examples (especially for the last group). This woul be a very big help for me to properly implement this.

1. Commands that should be fully concealed (e.g. \text).

2. Commands that should be concealed, but whose argument should be simply modified with bold or italics (\textit, \mathbf, etc).

3. Commands that should be concealed, but whose argument should be replaced by different characters (e.g. \mathcal{C} to ℂ). For this category, I would much appreciate a very explicit list of desired replacements.

@patrickraanes It should be simple to allow custom commands for the two categories above. I could see something like the following as an idea:

let g:vimtex_syntax_custom_cmds = {
      \ 'bold': ['mat', 'vect'],
      \ 'italic': ['todo'],
      \ 'hide': ['footnote'],
      \}

This would not differentiate math mode, but since we are concealing, it shouldn't be a problem.

If you want a more dynamic version, then I think I'll pass: parsing the \newcommands will be very challenging and I don't quite see a robust way to make this "just work" (unless I had a lot of spare time, which I don't).

To keep things separated, could you open a new issue for this with a reference here?

[Konfekt]

Commands that should be fully concealed (e.g. \text).

\text
\textnormal
\textrm
\textup
\texttt
\textsf
\textsc

\mathrm

Commands that should be concealed, but whose argument should be simply modified with bold or italics (\textit, \mathbf, etc).

\textbf (bold)
\textit (italic)
\textsl (italic)

\mathbf (bold)

Commands that should be concealed, but whose argument should be replaced by different characters (e.g. \mathcal{C} to ℂ). For this category, I would much appreciate a very explicit list of desired replacements.

\mathfrak

See the \mathfrak list of tex-conceal.vim

\mathcal
\mathscr

See the \mathcal list of tex-conceal.vim

\mathbb

See the \mathbb list of tex-conceal.vim

[Konfekt]

As a sidenote, not all fonts have all the characters used for concealing; for example, Dejavu Sans Mono only the more common blackboard math characters (though, for example, Droid Sans Mono is quite complete and has more of them).

[lervag]

@Konfekt Thanks for clearing things up!

As a sidenote, not all fonts have all the characters used for concealing; for example, Dejavu Sans Mono only the more common blackboard math characters (though, for example, Droid Sans Mono is quite complete and has more of them).

Yes, this is an important note. I guess I should give a comment about this in the docs.

[lervag]

@Konfekt

As a sidenote, not all fonts have all the characters used for concealing; for example, Dejavu Sans Mono only the more common blackboard math characters (though, for example, Droid Sans Mono is quite complete and has more of them).

Do you have an idea of a reference that I could use to guide people on how to install/use fonts with good unicode support?