Implement R code highlight

[shun2wang]

Close: https://github.com/jasp-stats/INTERNAL-jasp/issues/2328

Now looks like:

TODO:

• Highlighting in exported HTML (Not now)
• Highlighting in Help Docs
• Style improvement
• Performance Testing (EDIT: about 16ms for a r code syntax of one analysis)

[EJWagenmakers]

awesome

[boutinb]

Really nice!!!
Just one remark.

[JorisGoosen]

Could we also use this to highlight the rcode in textareas in the gui?

Ive done some reading in the https://doc.qt.io/qt-6/qsyntaxhighlighter.html and some related pages.
It seems that we cant reuse the js highlighter.

But if we have a regex that can highlight R we could use that.

And looking in the PR I guess the highlighter itself already has some definition inside. Ill have a look at their docs

Edit: https://github.com/highlightjs/highlight.js/blob/main/src/languages/r.js seems quite useful for implementing this later.
But reading https://doc.qt.io/qt-6/qsyntaxhighlighter.html#highlightBlock indicates it might require a bunch more work.
Better postpone that.

Having R code look awesome in the results-notes will already be very nice.

[shun2wang]

Could we also use this to highlight the rcode in textareas in the gui?

Is there a way to import js directly in QML? However that seems to require using qmake build system? if so sounds terrible🤪

But if we have a regex that can highlight R we could use that.

I recommend here https://prismjs.com/download.html#themes=prism&languages=r

[JorisGoosen]

Is there a way to import js directly in QML? However that seems to require using qmake build system? if so sounds terrible🤪

Well it is possible to include js directly for use in qml it wont then be available to the QSyntaxHighlighter without a bunch of C++ trickery. So it wouldnt make things much easier :p

prism.js

https://github.com/PrismJS/prism/blob/master/components/prism-r.js
It does look slightly cleaner

[shun2wang]

Now in help docs:

\`\`\`r
if (i == 0) {
  y = TRUE
} else {
  y = FALSE
}
\`\`\`

So I think it ready to review.
Legacy :
Implemented code highlighting for exporting HTML, in fact only needed to come with css styles, but I don't want to "add more css styles inline" right now so it's left to next time I clean up all styles. some of them in #5073

[JorisGoosen]

Changes look fine and it works splendidly!

But...Dark theme support is still lacking for the rsyntax box:

[JorisGoosen]

Looks good to me ^^

[JorisGoosen]

@boutinb you think you can also review this?