Allow options.highlight to specify custom classes

[adam-p]

I'm using marked together with highlight.js, but there's a bit of snag: highlight.js (and/or its styles) requires the plain name of the language (like "python") as a class on the <code> tag, but marked uses class names that look like "lang-python". I hacked around this in my copy of marked.js by adding the class name -- you can see the change here -- but it'd be nicer if marked let me specify additional/alternative class names.

I suggest that options.highlight() be allowed (optionally -- use a type check) to return an object that has two properties: the code string (i.e., what is returned now) and an array of class names to be applied. I can certainly code it and submit a pull request, if desired.

(For completeness: I could alternatively ask highlight.js to make the class names it expects be configurable. But it's not clear how to do that in any sane way -- the classes are explicit in the CSS. Making the change in marked feels like the correct approach anyway.)

Thanks for the great tool. It was utterly essential in the development of my Markdown-email browser extension.

[ghost]

+1

[pronebird]

+1

[chjj]

Fixed with: 8332826