Here is how I added code styling to this blog. Unfortunately, the code is only styled when you visit the site; the RSS feeds will have unstyled code blocks.

I decided to use highlight.js after struggling with Jekyll configuration/extensions. In particular, I either couldn’t get the highlighting to work at all, or didn’t find support for one or more languages I’ve been touching.

The highlight.js package contains a number of default languages and many more that can be added in. If you use the default set, you can use a CDN-hosted copy. I wanted R, Go, and Lisp which demanded a custom build.

The downloaded bundle contains a highlight.pack.js which I copied into a js/ directory within my Jekyll blog. I am using the sunburst theme, which I copied into css/highlight.css.

In _includes/head.html, add the following:

<link rel="stylesheet" href="/css/highlight.css">
<script src="/js/highlight.pack.js"></script>
<script>hljs.initHighlightingOnLoad();</script>

That’s it! Your code blocks now have syntax highlighting.

If you want to force language-specific code highlighting of a block, say what language you are using:

```lisp
(defun aron/git-grep () ...)
```

which is rendered like:

(defun aron/git-grep () ...)

If you don’t specify a lanuage identifier, highlight.js will still apply some formatting to your block. If you don’t want that, use the nohighlight tag:

```nohighlight
this shall not be formatted
```

which is rendered like:

this shall not be formatted