Can I reply to a call message (..., appendLF = FALSE)?

Is there any way to get correspondence compliance messages that don't end with line breaks? I haven't found a hook that regulates this behavior, I may have just missed it.

\documentclass{article}

\begin{document}

<<>>=
do_stuff <- function() {
  message("Doing some stuff...", appendLF = FALSE)
  message("done.")  
}
do_stuff()
@

\end{document}

      

        
        
        
      

    

The result includes a line break between the first and second messages, but if you run it in R, there is no such break.