I've pushed the version 0.1-5 of highlight to CRAN, it should be available in a couple of days.
This version fixes highlighting of code when one wants to display the prompt and the continue prompt. For example, this code :
rnorm(10, mean = 5) runif(5)
gets highlighted like this:
using this code:
> highlight( "/tmp/test.R", renderer=renderer_html(document=T), showPrompts = TRUE, output = "test.html" )
Under the hood, highlight now depends on Rcpp and uses some of the C++ classes of the new Rcpp API. See the get_highlighted_text function in the code.