Support for \text and \(short)intertext

[cionx]

The current grammar doesn’t seem to know the command \text, \intertext, and \shortintertext provided by amsmath and mathtools.

• \text{} can be used in math mode (both inline and display) to temporarily enter text mode. A typical application may look as follows:

  Let $C = \{ f \colon M \to \mathbb{R} \mid \text{$f$ is smooth} \}$.

• \intertext{} functions similarly, but can only be used in multi-line display environments (e.g. align*). This command will exit math mode, insert the given text, and then reenter math mode.

  Let
  \begin{align*}
  F &= x^2 + y^2
  \intertext{and similarly}
  G &= x^2 - y^2.
  \end{align*}

• \shortintertex{} is a variant of \intertext{} with different spacing. There should be no difference in terms of function/parsing.

I’m not sure how \(short)intertext ought to be parsed: In terms of code it is a child of the surrounding math environment (e.g. align*). But it can actually contains content that (I think) would not fit in the resulting tree structure.

For example: the following is a valid (and useful) use of \intertext:

\begin{enumerate}
    \item
        Let
        \begin{align*}
            x &= 2.
    \intertext{
    \item
        Let also
    }
            y &= 3.
        \end{align*}
\end{enumerate}

[pfoerster]

Sorry for the long response time. Adding \text is straightforward but parsing \intertext correctly with all its quirks can be quite challenging if not almost impossible without some severe modifications to the grammar. Honestly, I am not sure how to parse the last example correctly, as this does not really fit into a tree.

[clason]

I think having just the "standard" use parsed correctly would be great already. The last example should be very rare and would be acceptable not to support (for the foreseeable future). Especially \text{} is something that is frequently used.

[pfoerster]

I think having just the "standard" use parsed correctly would be great already. The last example should be very rare and would be acceptable not to support (for the foreseeable future). Especially \text{} is something that is frequently used.

5686c9c adds a new rule with support for the simple cases. The hard case is probably a "wont' fix" for now.

[XVilka]

From the issue https://github.com/nvim-treesitter/nvim-treesitter/issues/2214 both \text and \intertext are supported, only missing one is \shortintertext

I don't understand why, though, the grammar looks fine:

    text_mode: $ =>
      seq(
        field('command', choice('\\text', '\\intertext', '\\shortintertext')),
        field('content', $.curly_group),
      ),