Katex: Is it possible to config $ as delimiters only when it is not followed immediately by a word of digits?

[jiewuza]

Usually we use $ as dollar sign as $20, it is followed immediately by digits.
So if we can config both the left and the right $ as delimiter only when it is not followed immediately by a word of digits, we are freely to mix Katex math with dollar sign in most cases,
i.e. "Here is the math $2x^3$, .... $30 is enough"

[edemaine]

It would be easy to tweak the autorender contrib plug in to do this, but I don't think most users would want it to work this way.

Personally I'd rather have \$ ignored by autorender.

The simplest thing would be to modify the delimiters supplied to autorender to use something other than a single $.

[ronkok]

Pandoc's tex_math_dollars extension treats $...$ with just a bit more nuance. Reference. If we change the autorender contrib plug in, maybe we should follow its lead.

[jiewuza]

@ronkok I brought up the issue after I read Pandoc's tex_math_dollars.

[jiewuza]

@edemaine I read the code of the autorender contrib plug.
It seems that the delimiters are located by string comparison (not by regexp) when splitting the text.

The point I brought up the issue is that it is obscure for users to input a dollar sign when using $ as delimiters. For instance, instead of
Here is the math $2x^3$, .... $30 is enough
users have to input
Here is the math $2x^3$, .... $\$$30 is enough
or
Here is the math $2x^3$, .... $\$30$ is enough

Using something other than a single $ is a fair option, but I'd rather keep it compatible with LaTex.

[ylemkimon]

Related: #437

[jiewuza]

@ylemkimon That is exactly what I ask for.
Now I came up with a config:

delimiters: [
    {left: '$$\n', right: '\n$$', display: true},
    {left: '$$', right: '$$', display: false}
  ]

The idea behind is that $$ is seldom seen in regular text, and
$$
math stuff
$$
as display math is visually easy to memorize/use.

But it does not work. For example

test $$ax^2$$
and then $$
ax^2
$$

The inline math on the first line is not recognized as math, because the right delimiter which is followed by a \n is treated as the left delimiter of display math.
If you append some text on the first line, it renders perfectly.

I think it may be a bug, for the right delimiter should be paired first before it be recognized as a left one.

[kevinbarabash]

@jiewuza I would try:

delimiters: [
    {left: '$$', right: '$$', display: false},
    {left: '$$\n', right: '\n$$', display: true}
  ]

and see if that helps.

[jiewuza]

@kevinbarabash
I tried. Both are treated as inline math in this case.

test $$ax^2$$
and then $$
ax^2
$$

[kevinbarabash]

I see. Yeah, that's a tough problem. I don't think there's a clean way to solve the problem by simply defining different delimiters. You'll probably want to write your auto-render code. I would probably just use \(/\) and \[/\] or something like that.

[kevinbarabash]

I'm going to close this since it's going to be very difficult to implement something that handles the different behaviors people want. Also, there is a workaround by using different delimiters.