From this documentation page. After the following line is executed, some call stack info will print upon reaching an error (or upon clicking the Stop sign during computations)
I tried hilite.me but it didn't really support R code. The best is to use gist.github.com because it keeps all your code snippets around and is just super easy to use:
Here's a Github "gist" of the a piece of C++ code:
And here's a bit of .R code. Easy.
This blog is mainly for statistics, R, or Duke-related stuff that is not directly relating to research activity.