katex.html

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.18.1/dist/katex.min.css" integrity="sha384-1vdNCNel6Tx/NQa8IR1mGOGKsbGreCkOPfbtPPnUURJ5Tu2PRVfQ/7KLZC+Pi1p1" crossorigin="anonymous">
<script defer src="https://cdn.jsdelivr.net/npm/katex@0.18.1/dist/katex.min.js" integrity="sha384-ycJ6GAwiS15LoUPipwJOrWTvkUHl/YqELValBwI5I4awP1EeEQJYarj+w85ntcz7" crossorigin="anonymous"></script>
<!-- From: https://github.com/rust-lang/rust/pull/95691#issuecomment-1089080597 -->
<script>
document.addEventListener("DOMContentLoaded", function () {
    // Make a list of all replacements to make. Otherwise, the for loops
    // fail to iterate over all elements that need to be replaced.
    let to_do = [];

    // Render
    // ```math
    // equation
    // ```
    // blocks as display mode equations with katex. Markdown translates this to
    // <pre class="language-math"><code>equation</code></pre>
    for (let e of document.getElementsByTagName('pre')) {
        if (e.classList.contains('language-math')) {
            to_do.push(function () {
                let x = document.createElement('p');
                katex.render(e.innerText, x, {displayMode: true, throwOnError: false});
                e.parentNode.parentNode.replaceChild(x, e.parentNode);
            });
        }
    }
    // Render $`equation`$ elements as inline equations with katex. Markdown
    // translates this to <p>...$<code>equation</code>$...</p>. Also remove the
    // extra $ characters.
    // <pre class="language-math"><code>equation</code></pre>
    for (let e of document.getElementsByTagName('code')) {
        let n = e.nextSibling; let p = e.previousSibling;
        if (n && p && /^\$/.test(n.data) && /\$$/.test(p.data)) {
            to_do.push(function () {
                let n = e.nextSibling; let p = e.previousSibling;
                let x = document.createElement('span');
                katex.render(e.innerText, x, {throwOnError: false});
                e.parentNode.replaceChild(x, e);
                n.splitText(1); n.remove();
                p.splitText(p.data.length - 1).remove();
            });
        }
    }
    for (let f of to_do) f();
});
</script>