The posted version of the script replaces single-quotes with double-quotes, which is problematic when the quotes are nested.
Below I adapted the relevant portion of the script to allow for single-quotes. To interpret the alternative code (which uses a '$' in the system call), note that it seems that four backslashes are required to produce one blackslash that gets passed to Applescript.
[Note: I had trouble with escaped backslashes (`\\`). So I modified the code below. I don't really entirely understand what's going on with the backslashes between Vim and R--why do I need 16 backslashes for two to make it to R?--but this seems to work. Date: 2011-02-11]
Original code snippet:
if a:mode == "selectedlines"
" sending selected lines to interactive R application
let command = join(getline(a:firstline,a:lastline),"\\n")
let command = substitute(command,"\"","\\\\\"","g")
let command = substitute(command,"\'","\\\\\"","g")
call system("osascript -e 'tell application \"R\" to cmd \"" .command. "\"'")
Modified code snippet:
if a:mode == "selectedlines"
" sending selected lines to interactive R application
let command = join(getline(a:firstline,a:lastline),"\n")
let command = substitute(command,"\\","\\\\\\\\\\\\\\\\","g")
let command = substitute(command,"'","\\\\'","g")
let command = substitute(command,"\"","\\\\\\\\\"","g")
call system("osascript -e $'tell application \"R64\" to cmd \"" .command. "\"'")