Possible solution to running javascript inside R/knitr

[yixuan]

Just found the V8 package that could run javascript code inside R.

[yihui]

Pull requests welcome :)

Here is what I'd do if I were to add this feature:

1. Use ct$validate() to group lines of JS code into minimal complete blocks (similar idea to https://github.com/yihui/highr/blob/master/R/utils.R#L8-L23);
2. ct$eval() code blocks one by one, and collect output;
3. knitr:::wrap() the list of source code and output created from the previous step.