[R] line numbers and file names in error messages

[Vivek Rao]

Many of my R scripts call other R scripts using the
source function. If there is a syntax error in one of
the scripts, I get an error message such as

Error in parse(file, n, text, prompt) : syntax error
on line 1

but the name of the file where the error occurs is not
given. Other error messages such as

Error in print(xxx) : Object "xxx" not found

show neither the file name or the line number. Is
there a way to get this information in error messages?
I have found it helpful in other programming
languages.