[R] Getting Stangle to tangle Sexpr expressions

[Michael Hoffman]

Is there a way to get Stangle to print out Sexpr expressions as well as 
code chunks?

I am using weaver and when trying to debug Sweave files, it is sometimes 
difficult to figure out where the error is. The errors are hardest to 
find when they are in Sexpr expressions because stepping through the 
output produced by Stangle reveals nothing.

That said, any other suggestions on debugging Sweave would be welcome.