After colon, dot and comma a whitespace is added.

Describe the bug:

Katex renders a division colon :, a dot · and a comma , by adding a space after the sign:

= \frac{24\color{blue}{:6}}{30\color{blue}{:6}}

Expected was:

This can only be achieved by using {:} instead of :. But we cannot start to edit 100,000s of posts of our users that have used : and comma (German decimal!) in their latex.

Same situation is when using · instead of {·}:

Same for comma:

Q: How can we set up Katex to render accordingly so that no whitespace is added?

To Reproduce:

1. Go to https://katex.org/

2. Enter latex:

\frac{12}{100} = 0,12
\\
\frac{12}{100} = 0{,}12

1. See different output:

Environment (please complete the following information):

• KaTeX Version: 0.12.0
• Device: Deskto
• OS: Windows 10
• Browser: Chrome
• Version: 85.0.4

[q2apro]

Thanks. I could fix the issue by calling the autorender extension with:

renderMathInElement(document.body, {
    delimiters: [
        {left: "$$", right: "$$", display: true},
        {left: "\\(", right: "\\)", display: false},
    ],
    macros: {
        ":": "{\\char`:}",
        ",": "{\\char`,}",
        "·": "{\\char`·}",
    },
    fleqn: true
});

[edemaine]

Hmm, we must be running it differently? Here’s what I got with the same input (after adding \usepackage{color}):

I just confirmed on my local PDFLaTeX installation: