Allow highlighting important parts of code examples.
Specifications
``` html +highlight="important-class"
<div class="important-class other-class">
Lorem ipsum.
</div>
Result:
### The following syntax should be valid:
* `+highlight="xxx"` – hightlight string
* `+highlight="xxx","yyy"` – hightlight multiple strings
* `+highlight=/xxx/` – search for RegExp
* `+highlight=/xxx/g` – allow modifiers
* `+highlight=/xxx/,/yyy/` – allow multiple RegExp
* `+highlight="xxx",/yyy/,/zzz/gi` – mix everything up
### Multiple highlights
When multiple highlights are given (separated by `;`), the highlights should get a different CSS class and different background color. To avoid this, the `|` operator can be used:
* `+highlight=/xxx|yyy/` – highlight `xxx` and `yyy` in yellow
* `+highlight=/xxx/,/yyy/` – highlight `xxx` in yellow, `yyy` in second color (tbd.)
## Open questions
* How to escape `"` and `/`? → Use JavaScript syntax
* Should `"` and `'` be allowed? → No, use JSON syntax (double quotes)
* Maybe `/class=".*(my-class).*"/` could highlight `my-class` only (as in the group). This could be useful for highlighting the tag name of `li` in `<li class="list-item">` but not within `list-item`. Background: Look ahead/behind in JavaScript’s RegExp are not supported well and hard to read/write. Using a group could be much more easy.
violetadev
commented
6 years ago 
New feature
Allow highlighting important parts of code examples.
Specifications