[ESS] Formatting long character strings in R source

[Robert Sams]

Hi,

Apologies if this question is too basic ..I did search the archives.

How does one format a very long character string so that it wraps inside the buffer in a sensible way when indent-region is applied? 

By default it wraps like this:
x <- "some very long string some very long string 
long string some very long string"

Whereas it is more readable if the beginning of all subsequent lines indented to the leftmost character of the first line.

Thank you.
Robert