Typst: vectors in bold? (\renewcommand equivalent for typst?)

[TS-CUBED]

Description

Hi,

I use Quarto for my lecture material and sometimes I need vectors to have arrows over the letter and sometimes vectors need to be bold font.

Usually I just use \vec{V}, which defaults to the arrow in both HTML, LaTeX, and Typst.

But sometimes I need the same slideset with the alternative vector notation of \mathbf{V} and with HTML and LaTeX it's simply a

$$
\renewcommand{\vec}[1]{\mathbf{#1}}
$$

somewhere in a header file, and the whole lecture series is converted.

I have recently tested Typst and would like to convert to it. But the translation from LaTeX math format in the Markdown to the Typst math syntax does not honour the \renewcommands I use.

So the question is two-fold:

1. immediately I need to switch Typst from arrow to bold for vectors.
2. in the longer term I need a way to redefine math conventions in Typst.

Since Quarto does the translation from LaTeX syntax to Typst (or rather Pandoc, I assume), I think it's more a question for here, than for the typst community?

[mcanouil]

You can try raw Typst to see what is happening (keep-typ: true).

Typst supports the dollar notation (see Typst documentation: https://typst.app/docs/reference/math/).

It is possible that Pandoc does not do well for all symbols.
Quarto does nothing in that area.

The translation issue (if there is indeed one) is Pandoc, redefining math in Typst, is a pure Typst question.

[cderv]

Pandoc will do some translation for known function I think

pandoc -t typst -f markdown
$\vec{AB} = 0_E$
^Z
$accent(A B, ⃗) = 0_E$

❯ pandoc -t typst -f markdown
$$
\mathbf{1 + 1}
$$
^Z
$ upright(bold(1 + 1)) $

And it will try to handle \renewcommand too

❯ pandoc -t typst -f markdown
$$
\renewcommand{\vec}[1]{\mathbf{#1}}
\vec{AB} = 0_E
$$
^Z
$ upright(bold(A B)) = 0_E $

But only in a single math block, not several

❯ pandoc -t typst -f markdown
$$
\renewcommand{\vec}[1]{\mathbf{#1}}
$$

$$
\vec{AB} = 0_E
$$
^Z
$  $

$ accent(A B, ⃗) = 0_E $

Not sure why this pandoc limitation 🤔

I think for that, you'll need to use raw typst blog to redefine some command using typst syntax
Though beware that Typst has it own vec() which is different than \vec https://typst.app/docs/reference/math/vec/

And why Pandoc does translate.

Hope this helps.

[cderv]

Not sure why this pandoc limitation 🤔

I remember now that this parsing and conversion happens at reader time trhough this pandoc extension: https://pandoc.org/MANUAL.html#extension-latex_macros

Which means that this works in pandoc 😅

❯ pandoc -t typst -f markdown
\renewcommand{\vec}[1]{\mathbf{#1}}

$$
\vec{AB} = 0_E
$$
^Z
$ upright(bold(A B)) = 0_E $

Yes when you use the \renewcommand outside of the math block. In this case, Pandoc will read it is a Raw LaTeX with special processing when converting through the LaTeX macros extension.

❯ pandoc -t native -f markdown
\renewcommand{\vec}[1]{\mathbf{#1}}

$$
\vec{AB} = 0_E
$$  
^Z
[ RawBlock
    (Format "tex") "\\renewcommand{\\vec}[1]{\\mathbf{#1}}"
, Para [ Math DisplayMath "\n\\mathbf{AB} = 0_E\n" ]
]

Very stange behavior from Pandoc that currently Pandoc can leverage.

---
title: Demo
format: typst
---

\renewcommand{\vec}[1]{\mathbf{#1}}

$$
\vec{AB} = 0_E
$$  

Leads to this in .typ

$ upright(bold(A B)) = 0_E $

Kind of crazy as a lot of implicit in this. 🤔